JP7231166B1 - Shield manufacturing method - Google Patents

Abstract

A shield manufacturing method capable of manufacturing an inexpensive shield is provided. A method for manufacturing a shield is a method for manufacturing a shield for shielding neutrons. The method for manufacturing the shield is an electric wire or cable containing cross-linked polyethylene as an insulator, and is obtained by an obtaining step (S1, S2) of obtaining chips of cross-linked polyethylene from the waste electric wire or cable, and an obtaining step. and a molding step (S3, S4, S5) of filling a mold with a filling material made from the chips obtained as a molding material and molding the mold. [Selection drawing] Fig. 4

Description

The present invention relates to a method for manufacturing a shield.

Conventionally, shields for shielding neutrons are known. For example, in the method for manufacturing a shield described in Patent Document 1, the shield is formed by stripping a thick-walled pipe of high-molecular-weight polyethylene from its outer circumference.

JP-A-2001-51093

In the method of manufacturing the shield, for example, if the thick-walled pipe is made of virgin material of high-molecular-weight polyethylene, the cost of materials increases, so the shield may be expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a shield that can manufacture an inexpensive shield.

A method for manufacturing a shield according to an aspect of the present invention is a method for manufacturing a shield for shielding neutrons, which is an electric wire or cable containing crosslinked polyethylene as an insulator, and which is a waste electric wire or cable. an acquiring step of acquiring the crosslinked polyethylene chips from the cable; and a molding step of filling a mold with a filling material using the chips acquired in the acquiring step as a molding material and molding the mold. The mold forms the shield into a substantially rectangular parallelepiped shape having a first surface and a second surface opposite to the first surface, and the first surface and the second surface extend in the transverse direction of each of the first surface and the second surface. and a longitudinal dimension ratio of 1:2, and a pair of dividing lines that do not coincide with the longitudinal center line among the three dividing lines that divide into four equal parts in the longitudinal direction, and the transverse center line A pair of concave portions are formed on the first surface at the positions of intersections with each other, and a pair of convex portions are formed on the second surface at the positions of the respective intersections. The pair of projections of the shield can be fitted into the pair of recesses of the second shield .

According to the above aspect, waste materials are used to manufacture the shield. Therefore, the method for manufacturing a shield can manufacture an inexpensive shield. In addition, the method of manufacturing the shields can employ a stacking method that increases the stability of the horizontal and vertical stacking of the plurality of shields.

In the method for manufacturing a shield according to an aspect of the present invention, in the molding step, the chips obtained in the obtaining step are filled in the mold as the filling material, and the mold is heated to mold. may

In this case, since the chips are solid, the shield manufacturing method is easier to handle the filler material than, for example, melting the chips and then filling the mold as filler material.

In the method for manufacturing a shield according to an aspect of the present invention, in the molding step, the mold may be heated while the filling material filled in the mold is pressurized.

In this case, the method for manufacturing the shields facilitates forming each of the plurality of shields in a uniform shape.

Fig. 2 is a perspective view of the shield 1 as seen from the left front upper side; It is the perspective view which looked at the shield 1 from the lower right back. It is a figure which shows the stacking method of the shield 1. FIG. 4 is a flow chart showing a method for manufacturing the shield 1; FIG. 9 is an explanatory diagram of electric wires 9 and pulverized chips 900; It is the perspective view which looked at the metal mold|die 2 from left front upper part. 4 is a front view of the mold 2 with the front plate 31 shown in FIG. 3 removed; FIG. It is the perspective view which looked at the shield 1 of a modification from left front upper direction. FIG. 9 is a sectional view taken along line IV-IV shown in FIG. 8;

An embodiment of the present invention will be described below with reference to the drawings. The referenced drawings are used to explain technical features that the present invention can employ. The configuration of the apparatus, the configuration of the members, and the flow charts described in the drawings are merely illustrative examples and are not intended to be limiting. In addition, in this embodiment, the terms "same", "equal", "match", and "parallel" do not mean exactly the same, completely equal, completely matched, or completely parallel, and are actively made different. It is a concept that excludes cases. In other words, the difference in degree of error is substantially included in "same", "equal", "match", and "parallel".

First, the shield 1 will be described with reference to FIGS. 1 and 2. FIG. Below, the lower left, upper right, lower right, upper left, lower, and upper parts of FIG. The shield 1 is made of crosslinked polyethylene, has higher heat resistance and fire resistance than, for example, polyethylene, and has a function of shielding neutrons.

As shown in FIGS. 1 and 2, the shield 1 is a block and has a substantially rectangular parallelepiped shape. Shield 1 includes front surface 11 , rear surface 12 , left surface 13 , right surface 14 , lower surface 15 and upper surface 16 . The front surface 11 extends vertically and horizontally and faces forward. The rear surface 12 extends parallel to the front surface 11 and faces rearwards. The left surface 13 extends in the front-rear and up-and-down directions and faces left. The right face 14 extends parallel to the left face 13 and faces rightward. The lower surface 15 extends in the front, rear, left, and right directions and faces downward. The upper surface 16 extends parallel to the lower surface 15 and faces upwards.

As shown in FIG. 1, in the shield 1, the dimensional ratio of the length D1 in the front-back direction, the length D2 in the left-right direction, and the length D3 in the up-down direction, that is, length D1:length D2:length D3 is 1 :2:1. Although the length D1 and the length D3 are not limited to specific lengths, they are approximately 10 cm in this embodiment. Although the length D2 is not limited to a specific length, it is about 20 cm in this embodiment. Hereinafter, the left-right direction of the shield 1 is also referred to as the "longitudinal direction", and the front-rear direction of the shield 1 is also referred to as the "short direction".

The center line C1 passes through the center of the shield 1 in the lateral direction (front-rear direction) and extends in the longitudinal direction (left-right direction). The center line C2 passes through the center of the shield 1 in the longitudinal direction (horizontal direction) and extends in the lateral direction (front-rear direction). The dividing lines V1, V2, and V3 each extend in the lateral direction (front-rear direction) and divide the shield 1 into four equal parts in the longitudinal direction (left-right direction). The division lines V1, V2, and V3 are arranged in the order of division lines V1, V2, and V3 from left to right. In this case, the dividing line V2 coincides with the centerline C2.

As shown in FIG. 2, the shield 1 is formed with recesses 151 and 152 . The concave portions 151 and 152 are arranged side by side with each other. Each of the recesses 151 and 152 is recessed upward from the lower surface 15 in a columnar shape. The concave portion 151 is positioned at the intersection point P1 between the center line C1 and the dividing line V1 when viewed from below. The recess 152 is positioned at the intersection P2 between the center line C1 and the dividing line V2 when viewed from below. The concave portions 151 and 152 respectively have circular shapes centered on the intersection points P1 and P2 when viewed from below. The inner diameter of the recess 151 and the inner diameter of the recess 152 are the same size.

As shown in FIG. 1, the shield 1 is formed with projections 161 and 162 . The protrusions 161 and 162 are arranged side by side with each other. Each projection 161 has a cylindrical shape and protrudes upward from the upper surface 16 . The convex portion 161 is located at the intersection point P1 between the center line C1 and the dividing line V1 when viewed from above. The convex portion 162 is located at the intersection point P2 between the center line C1 and the dividing line V2 when viewed from above. In other words, the projections 161 and 162 are located at the same positions as the recesses 151 and 152 (see FIG. 2) on the front, rear, left, and right, respectively.

The protrusions 161 and 162 have circular shapes centered on the intersections P1 and P2, respectively, when viewed from above. The outer diameter of the protrusion 161 and the outer diameter of the protrusion 162 are the same size. Each outer diameter of the protrusions 161, 162 is slightly smaller than the inner diameter of the recesses 151, 152 (see FIG. 2). Therefore, when the second shield 1 is stacked on top of the first shield 1, each of the protrusions 161 and 162 of the first shield 1 becomes the recess 151 of the second shield 1 or It can fit in the recess 152 .

An example of a method of stacking the shields 1 will be described with reference to FIG. An operator forms a wall by, for example, stacking a plurality of shields 1, and surrounds a device (not shown) that generates neutrons with the wall of the plurality of shields 1. FIG. As a result, the walls made up of the plurality of shields 1 shield neutrons generated from the apparatus.

Hereinafter, a line in which a plurality of shields 1 are arranged in a horizontal direction is referred to as a "shield line". The worker forms a wall with a plurality of shields 1 by, for example, stacking the second shield row L2 on top of the first shield row L1. In this case, the operator attaches one or both of the recesses 151 and 152 of the shields 1 in the second shield row L2 to one or both of the protrusions 161 and 162 of the shields 1 in the first shield row L1. By fitting, the second shield row L2 is stacked on the first shield row L1.

More specifically, the operator should make sure that the longitudinal direction of the shield 1A and the longitudinal direction of the shield 1B are perpendicular to each other, and that the convex portion 161 of the shield 1A and the convex portions 161 and 162 of the shield 1B are aligned with the longitudinal direction of the shield 1B. The shields 1A and 1B are arranged so as to be aligned in the direction. In this state, the worker stacks the shield 1C on top of the shield 1A and the shield 1B. In this case, the operator fits the recess 151 of the shield 1C into the protrusion 161 of the shield 1A, and fits the recess 152 of the shield 1C into the protrusion 161 of the shield 1B. Thereby, the shield 1C is horizontally positioned with respect to both the shields 1A and 1B. Therefore, according to the stacking method described above, the stability of the wall due to the plurality of shields 1 is increased.

Next, with reference to FIG. 4, a method for manufacturing the above-described shield 1 will be described. The method for manufacturing the shield 1 includes a crushing step (S1), a sorting step (S2), a filling step (S3), a compressing step (S4), a heating step (S5), and a post-treatment step (S6). By executing, the shield 1 is manufactured.

First, the pulverization step (S1) will be described. In the pulverization step (S1), the waste electric wire 9 (see FIG. 5A) is pulverized manually by an operator or by a pulverizer (not shown). As a result, the wire 9 becomes a chip (see FIG. 5(B)). Hereinafter, the wire 9 crushed into chips in the crushing step (S1) is referred to as "crushed chip 900" (see FIG. 5B).

Here, the electric wire 9 and the pulverized chip 900 will be described with reference to FIG. 5A is a cross-sectional perspective view schematically showing the electric wire 9, and FIG. 5B is a plan view schematically showing the crushing tip 900. As shown in FIG.

As shown in FIG. 5A, the electric wire 9 includes a conductor 91, an insulator 92, and a covering material 93. As shown in FIG. The conductor 91 is composed of copper wire, for example. The insulator 92 is made of crosslinked polyethylene and covers the outer periphery of the conductor 91 . The covering material 93 is made of vinyl chloride, for example, and covers the outer circumference of the insulator 92 .

Therefore, as shown in FIG. 5B, the crushing tip 900 includes a chip-shaped conductor 91 (hereinafter referred to as "conductor chip 911") and a chip-shaped insulator 92 (hereinafter referred to as "crosslinked polyethylene chip 921"). ) and a chip-like covering material 93 (hereinafter referred to as a "covering material chip 931") are mixed. The crushing tip 900 is not limited to a specific size, but has a size of about 2 mm square, for example.

The electric wire 9 may include crosslinked polyethylene as the insulator 92 as described above, and the configurations of the conductor 91 and the covering material 93 are not limited to those of the present embodiment. Also, a cable (not shown) for transmitting light or the like may be employed instead of the electric wire 9 . Again, the cable may contain crosslinked polyethylene as an insulator.

Next, the sorting step (S2) will be described. The sorting step (S2) is performed after the crushing step (S1). In the sorting step (S2), crosslinked polyethylene chips 921 are sorted out of the pulverized chips 900 obtained in the pulverizing step (S1). The sorting method is not limited to a specific method, but in this embodiment, the crosslinked polyethylene chips 921 are sorted out of the pulverized chips 900 as follows. For example, the conductor 91, the insulator 92, and the covering material 93 have different specific gravities. Therefore, the crosslinked polyethylene chips 921 are selected from the pulverized chips 900 by utilizing the difference in specific gravity.

Although it is preferable that only the crosslinked polyethylene chips 921 are completely sorted out of the pulverized chips 900, even if one or both of the conductor chips 911 and the covering material chips 931 are mixed with the sorted crosslinked polyethylene chips 921, good.

Next, the filling step (S3) will be described. The filling step (S3) is performed after the sorting step (S2). In the filling step (S3), a predetermined amount of filling material 300 (see FIG. 7) is filled into the mold 2 (see FIGS. 6 and 7). The filling material 300 uses the crosslinked polyethylene chips 921 (see FIG. 5B) obtained in the sorting step (S2) as a molding material, and in this embodiment, the crosslinked polyethylene chips 921 themselves.

Here, the mold 2 will be described with reference to FIGS. 6 and 7. FIG. Below, the lower left, upper right, lower right, upper left, lower, and upper parts of FIG.

As shown in FIG. 6 , the mold 2 has a lower mold 3 and an upper mold 4 . The upper mold 4 is positioned above the lower mold 3 and can be attached to or detached from the lower mold 3 . Lower mold 3 includes front plate 31 , rear plate 32 , left plate 33 , right plate 34 and lower plate 35 . The front plate 31 is positioned in front of the lower mold 3 . The front plate 31 has a rectangular shape when viewed from the rear and extends vertically and horizontally. The front plate 31 forms the front surface 11 (see FIG. 1) of the shield 1 . The rear plate 32 is positioned behind the front plate 31 . The rear plate 32 has a rectangular shape when viewed from the front and extends parallel to the front plate 31 . A rear plate 32 forms the rear surface 12 (see FIG. 2) of the shield 1 .

The left plate 33 is positioned at the left end of each of the front plate 31 and the rear plate 32 . The left plate 33 has a rectangular shape when viewed from the right, and extends in the front-rear and up-down directions. A left plate 33 forms the left side 13 (see FIG. 1) of the shield 1 . The right plate 34 is positioned at the right end of each of the front plate 31 and the rear plate 32 . The right plate 34 has a rectangular shape when viewed from the left and extends parallel to the left plate 33 . A right plate 34 forms the right face 14 (see FIG. 2) of the shield 1 .

The lower plate 35 is positioned at the lower end of each of the front plate 31 and the rear plate 32 . The lower plate 35 has a rectangular shape when viewed from above, and extends in the front, rear, left, and right directions. A lower plate 35 forms the lower surface 15 (see FIG. 2) of the shield 1 . The lower plate 35 extends forward from the front plate 31 and extends rearward from the rear plate 32 . The front plate 31 is fixed to each of the left plate 33, the right plate 34 and the lower plate 35 by bolts and nuts (not shown) directly or via another plate. The rear plate 32 is also fixed to each of the left plate 33, right plate 34, and lower plate 35 by bolts and nuts (not shown) directly or via another plate.

A space surrounded by the front plate 31, the rear plate 32, the left plate 33, the right plate 34, and the lower plate 35 is hereinafter referred to as a "cavity 30". The length of the cavity 30 in the front-rear direction, that is, the distance between the front plate 31 and the rear plate 32 is equal to the length D1. The length of the cavity 30 in the horizontal direction, that is, the distance between the left plate 33 and the right plate 34 is equal to the length D2.

The cavity 30 is filled with a filling material 300 (see FIG. 7). In the filling step ( S<b>3 ) shown in FIG. 4 , the cavity 30 is filled with crosslinked polyethylene chips 921 as the filling material 300 .

Inside the cavity 30 , the lower plate 35 is provided with projections 351 and 352 . The protrusions 351 and 352 are shaped to form the recesses 151 and 152 (see FIG. 2) in the shield 1, respectively, and protrude upward from positions corresponding to the recesses 151 and 152 in the lower plate 35. As shown in FIG.

The lower mold 3 has four shafts 371, 372, 373, 374. The shaft 371 vertically penetrates a portion of the left end of the lower plate 35 that is forward of the front plate 31 . The shaft 372 vertically penetrates a portion of the right end portion of the lower plate 35 that is forward of the front plate 31 . The shaft 373 vertically penetrates a portion of the left end portion of the lower plate 35 behind the rear plate 32 . The shaft 374 vertically penetrates a portion of the right end portion of the lower plate 35 behind the rear plate 32 . The shafts 371 , 372 , 373 , 374 each extend from below the lower plate 35 to above the upper ends of the front plate 31 , the rear plate 32 , the left plate 33 , and the right plate 34 .

The outer circumference of each of the shafts 371, 372, 373, 374 is threaded. The shaft 371 is fixed to the lower plate 35 by a pair of nuts 381 such that the pair of nuts 381 sandwich the lower plate 35 from above and below. Shafts 372 , 373 and 374 are also fixed to lower plate 35 by a pair of nuts 382 , 383 and 384 in the same manner as shaft 371 is fixed by a pair of nuts 381 .

Upper mold 4 includes upper plate 41 . The upper plate 41 is positioned at the lower end of the upper mold 4 . The upper plate 41 has a rectangular shape when viewed from below, and extends in the front, rear, left, and right directions. A top plate 41 forms the top surface 16 (see FIG. 1) of the shield 1 . The size of the upper plate 41 viewed from below is the same as or slightly smaller than the size of the cavity 30 viewed from above. Therefore, the upper plate 41 can be placed in the cavity 30 parallel to the lower plate 35 .

The upper plate 41 is provided with recesses 411 and 412 . The recesses 411 and 412 are shaped to form the projections 161 and 162 (see FIG. 1) on the shield 1, respectively, and are recessed upward from positions corresponding to the projections 161 and 162 on the upper plate 41. As shown in FIG.

The upper die 4 has extension support portions 42 , 43 , 44 , 45 . The extension support portions 42, 43, 44, and 45 are respectively provided at four corners of the upper mold 4 when viewed from above. The extension support part 42 includes an extension plate 421 and a support plate 422 . The extension plate 421 extends upward from the front left corner of the top plate 41 . The support plate 422 extends forward from the upper end of the extension plate 421 . A hole 423 is provided in the extension plate 421 . The hole 423 vertically penetrates the extension plate 421 .

The extension support portion 43 has a symmetrical structure with the extension support portion 42 in the left-right direction. The extension support portion 44 has a symmetrical structure with respect to the extension support portion 42 in the front-rear direction. The extension support portion 45 has a symmetrical structure with the extension support portion 44 in the left-right direction. Therefore, the description of the extension support portions 43, 44, 45 is simplified.

The extension supports 43 , 44 , 45 respectively include extension plates 431 , 441 , 451 and support plates 432 , 442 , 452 similar to the extension support 42 . The extending plates 431, 441 and 451 are provided with holes 433, 443 and 453, respectively.

As shown in FIG. 7, when the upper plate 41 is placed parallel to the lower plate 35 into the cavity 30 from above, holes 423, 433, 443, 453 (see FIG. 6 for holes 443, 453) , respectively, shafts 371, 372, 373, 374 (see FIG. 6 for the shafts 373, 374) penetrate from below. In this state, compression coil springs 461, 462, 463 and 464 (see FIG. 6 for compression coil springs 461 and 462) are attached to shafts 371, 372, 373 and 374 from above, respectively.

In this case, the compression coil springs 461, 462, 463, 464 are supported by the upper surfaces of the support plates 422, 432, 442, 452 (see FIG. 6 for the support plates 442, 452). In this state, nuts 471, 472, 473 and 474 (see FIG. 6 for nuts 473 and 474) are tightened from above onto shafts 371, 372, 373 and 374, respectively.

Next, the compression step (S4) will be described. The compression step (S4) is performed after the filling step (S3). In the compression step (S4), the filling material 300 filled in the mold 2 in the filling step (S3) is compressed.

As shown in FIG. 7, in the compression step (S4), for example, in the mold 2, with the filling material 300 filled in the cavity 30 in the filling step (S3), the operator moves the upper plate 41 downward. It is placed in the cavity 30 from above in parallel with the plate 35 . In this state, a pressure device (not shown) presses the upper plate 36 downward. The pressure load applied by the pressurizing device is not limited to a specific size, but is, for example, a size that makes the volume of the filling material 300 about 50% of the volume of the filling material 300 before pressurization.

In this state, the operator mounts the compression coil springs 461, 462, 463, and 464 on the shafts 371, 372, 373, and 374 from above, respectively, and attaches the nuts 471, 472, 473, and 474 to the shafts 371, 372. , 373, 374 from above. In this case, the compression coil springs 461, 462, 463, 464 are in a state of being compressed and deformed. Therefore, the compression coil springs 461, 462, 463, 464 urge the upper plate 41 downward. The urging load applied by the compression coil springs 461, 462, 463, 464 is large enough to prevent the compression deformation of the compression coil springs 461, 462, 463, 464 from being released.

Next, the heating step (S5) will be described. The heating step (S5) is performed after the compressing step (S4). In this embodiment, the compression coil springs 461, 462, 463, and 464 urge the top plate 41 downward, and the shafts 371, 372, 373, and 374 are engaged by the nuts 471, 472, 473, and 474. A plate 41 is fixed to the lower plate 35 . Therefore, in the heating step (S5), in the mold 2, the filling material 300 filled in the cavity 30 in the compressing step (S4) is maintained under pressure. In this state, in the heating step (S5), the mold 2 is heated at a predetermined temperature for a predetermined period of time.

In the heating step (S5), for example, the mold 2 is placed on a conveyor (not shown), and the conveyor transports the mold 2 into a kiln (not shown). After a predetermined time has passed, the conveyor discharges the mold 2 from the kiln to the outside. Although the predetermined time is not limited to a specific time, it is, for example, about 10 to 20 minutes. Although the predetermined temperature is not limited to a specific temperature, it is, for example, approximately 300° C., which is higher than the melting point (approximately 110° C.) of crosslinked polyethylene. When the mold 2 is heated at a predetermined temperature for a predetermined period of time, the filling material 300 (crosslinked polyethylene chip 921) inside the cavity 30 melts to its inner center.

In this case, the volume of filling material 300 in cavity 30 is reduced. Compression coil springs 461 , 462 , 463 , 464 urge upper plate 41 downward so that upper plate 41 moves downward along shafts 371 , 372 , 373 , 374 . This further compresses the filler material 300 within the cavity 30 . In this case, the distance between the lower plate 35 and the upper plate 41 is equal to the length D3. Thus, in this embodiment, the filling material 300 in the cavity 30 is compressed in two stages, compression in the compression step (S4) and compression in the heating step (S5).

Next, the post-processing step (S6) will be described. The post-treatment step (S6) is performed after the heating step (S5). In the post-treatment step (S6), the mold 2 is naturally cooled. The mold 2 may be air-cooled or water-cooled. The cooling time is not limited to any particular length.

Furthermore, in the post-treatment step (S6), the shield 1 is removed from the mold 2 after the mold 2 is cooled. For example, the operator removes the top plate 36 from the mold 2 and further removes part or all of the front plate 31 , rear plate 32 , left plate 33 and right plate 34 from the mold 2 . In this state, the operator removes the shield 1 from the mold 2. As shown in FIG. Thereby, the shield 1 is molded.

As described above, in the method for manufacturing the shield 1, the crosslinked polyethylene chip 921 is obtained from the waste electric wire 9 (S1, S2). Next, in the method for manufacturing the shield 1, the mold 2 is filled with the filling material 300 using the obtained crosslinked polyethylene chip 921 as a molding material and molded (S3, S4, S5). According to this, the shield 1 is manufactured using waste materials. Therefore, the method for manufacturing the shield 1 can manufacture the inexpensive shield 1 . In addition, since the method of manufacturing the shield 1 forms the shape of the shield 1 with the mold 2, the surface shape and size of the shield 1 can be easily designed compared to the conventional molding of the shield 1 by cutting. . Furthermore, in the method of manufacturing the shield 1, the shape of the shield 1 is formed by the mold 2, so that the generation of waste such as chips can be suppressed compared to the formation of the shield 1 by conventional cutting.

The shield 1 is manufactured by filling the mold 2 with the obtained crosslinked polyethylene chip 921 as the filling material 300 and heating the mold 2 (S3, S4, S5). According to this, since the cross-linked polyethylene chip 921 is a solid material, the method of manufacturing the shield 1 is easier to handle the filling material 300 than, for example, melting the cross-linked polyethylene chip 921 and then filling it into the mold 2 as the filling material 300. .

In the method for manufacturing the shield 1, the mold 2 is heated while the filling material 300 filled in the mold 2 is pressed (S5). According to this, the method for manufacturing the shield 1 facilitates forming each of the plurality of shields 1 in a uniform shape.

The mold 2 has an uneven shape that forms the shield 1 with a lower surface 15 having concave portions 151 and 152 and an upper surface 16 having convex portions 161 and 162 formed therein. The protrusions 161 , 162 of the first shield 1 can fit into the recesses 151 , 152 of the second shield 1 . According to this, the manufacturing method of the shield 1 can increase the stacking stability of the first shield 1 and the second shield 1 .

The mold 2 molds the shield 1 into a substantially rectangular parallelepiped shape, and molds the lower surface 15 and the upper surface 16 so that the dimension ratio between the lateral direction and the longitudinal direction is 1:2. The mold 2 has a lower surface 15 in which a pair of concave portions 151 and 152 are formed at the positions of intersections P1 and P2 of the pair of dividing lines V1 and V3 and the center line C1, and a pair of molds at the positions of the intersections P1 and P2. The upper surface 16 on which the projections 161 and 162 are formed and the uneven shape formed on the shield 1 . According to this, the manufacturing method of the shield 1 can employ a stacking method that increases the stability of stacking the plurality of shields 1 in the horizontal direction and the vertical direction.

Moreover, in the above embodiment, the electric wire 9 corresponds to the "electric wire" of the present invention. The crosslinked polyethylene chip 921 corresponds to the "crosslinked polyethylene chip" of the present invention. The step of S1 in FIG. 4 corresponds to the "acquisition step" of the present invention. The filling material 300 corresponds to the "filling material" of the present invention. S3, S4, and S5 in FIG. 4 correspond to the "forming step" of the present invention.

The recesses 151 and 152 correspond to "at least one recess" of the present invention. The lower surface 15 corresponds to the "first surface" of the present invention. The convex portions 161 and 162 correspond to "at least one convex portion" of the present invention. The upper surface 16 corresponds to the "second surface" of the present invention. The dividing lines V1, V2, and V3 correspond to "three dividing lines that divide the area into quarters in the longitudinal direction" of the present invention. The centerline C2 corresponds to the "longitudinal centerline" of the present invention. The dividing lines V1 and V3 correspond to "a pair of dividing lines that do not coincide with the longitudinal center line" of the present invention. The centerline C1 corresponds to the "transverse centerline" of the present invention. The intersection points P1 and P2 correspond to "each intersection point" of the present invention.

It should be noted that the present invention is not limited to the above embodiments, and various modifications are possible without departing from the scope of the present invention. Moreover, the modified examples described below can be combined with each other as long as there is no contradiction. For example, in the above-described embodiment, in the method for manufacturing the shield 1, the compressed state may not be maintained in the heating step (S5), or the compressing step (S4) may be omitted.

Moreover, the manufacturing method of the shield 1 may shape|mold the shield 1 by injection molding. In this case, in the method of manufacturing the shield 1, after the sorting step (S2), in the filling step (S3), instead of using the crosslinked polyethylene chip 921 itself as the filling material 300, the crosslinked polyethylene chip 921 is used as the molding material, The mold 2 is filled with a filling material 300 obtained by heating and melting a molding material. In this case, the method for manufacturing the shield 1 omits the compression step (S4) and the heating step (S5).

In the above-described embodiment, the method for manufacturing the shield 1 is such that in the heating step (S5), the filling material 300 (crosslinked polyethylene chip 921) in the cavity 30 does not melt to the center of the interior, and the outer surface (the front plate 31, rear plate 32, left plate 33, right plate 34, lower plate 35, and upper plate 41) may be heated at a predetermined temperature for a predetermined time. In this case, the method for manufacturing the shield 1 can reduce power consumption associated with heating in the heating step (S5).

Moreover, in the above embodiment, the heating method in the heating step (S5) is not limited to heating by a conveyor and a kiln. For example, the method for manufacturing the shield 1 may heat the mold 2 in a heating device (not shown) without transporting the mold 2 .

Further, the respective shapes of the projections 161, 162 and the recesses 151, 152 are not limited to the above embodiment. The shapes of the projections 161 and 162 and the recesses 151 and 152 may be any shape that allows the projections 161 and 162 to fit in the recesses 151 and 152. For example, the shape may be a polygonal columnar shape, a conical shape, or a polygonal pyramidal shape. good. Also, for example, the recesses 151 and 152 may be connected to each other.

A modified shield 1 will be described with reference to FIGS. 8 and 9. FIG. In the shield 1 of the modified example, the shapes of the concave portions 151 and 152 and the convex portions 161 and 162 are different from those of the above embodiment. That is, in the shield 1 of the modified example, the recesses 151 and 152 are recessed upward from the lower surface 15 in the shape of a regular quadrangular pyramid. The left end of the bottom surface 15 of the recess 151 is one side of the bottom surface. The right end of the bottom surface 15 of the concave portion 152 is one side of the bottom surface. In this case, since the length D1:length D2 is 1:2, the side of the bottom surface of the recess 151 opposite to the left end of the bottom surface 15 in the left-right direction and the right end of the bottom surface 15 in the left-right direction of the bottom surface of the recess 152. opposite sides coincide with each other.

Each of the projections 161 and 162 has a regular quadrangular pyramid shape and protrudes upward from the upper surface 16 . The convex portion 161 has the left end of the upper surface 16 as one side of the bottom surface. The convex portion 162 has the right end of the upper surface 16 as one side of the bottom surface. In this case, since the length D1:length D2 is 1:2, the side of the bottom surface of the protrusion 161 opposite to the left end of the top surface 16 in the left-right direction and the top surface 16 of the bottom surface of the protrusion 162 in the left-right direction. The sides opposite the right edge coincide with each other. The vertex Q1 of the concave portion 151, the vertex Q2 of the convex portion 161, and the intersection point P1 are positioned on a straight line. The vertex Q2 of the concave portion 152, the vertex Q4 of the convex portion 162, and the intersection point P2 are positioned on a straight line.

According to the above configuration, for example, when the convex portion 161 of the second shield 1 is fitted into the concave portion 151 of the first shield 1, the contact area between the concave portion 151 and the convex portion 161 is larger than that in the above embodiment. growing. Therefore, the shield 1 of the modified example can suppress the formation of gaps between the shields 1 when a plurality of the shields 1 are stacked.

Further, in the above embodiment, the number of protrusions 161 and 162 may be one, three or more, or zero. The number of recesses 151 and 152 may be one, three or more, or zero. For example, the number of recesses 151 and 152 may not be the same as the number of protrusions 161 and 162 and may be greater than the number of protrusions 161 and 162 .

Further, the positions where the projections 161 and 162 are respectively provided are not limited to those in the above embodiment. For example, one protrusion may be provided on the upper surface 16 at the intersection of the center line C1 and the center line C2 when viewed from above, or four protrusions may be provided on the upper surface 16 at each of the four corners when viewed from above. may be provided in The positions at which the recesses 151 and 152 are respectively provided are not limited to those in the above embodiment, similarly to the projections 161 and 162 .

Further, in the above embodiment, the concave portions 151 and 152 and the convex portions 161 and 162 are respectively provided on the surfaces (lower surface 15 and upper surface 16) facing opposite to each other. Alternatively, the concave portions 151 and 152 and the convex portions 161 and 162 may be provided on surfaces that intersect with each other. That is, for example, the concave portions 151 and 152 may be provided on the lower surface 15 and the convex portions 161 and 162 may be provided on the left surface 13 .

Further, in the above embodiment, the recesses 151 and 152 may be provided on a plurality of surfaces different from each other. That is, for example, recess 151 may be provided in lower surface 15 and recess 152 may be provided in upper surface 16 or left surface 13 . Like the recesses 151 and 152, the protrusions 161 and 162 may also be provided on different surfaces.

Also, the shape of the shield 1 is not limited to the above embodiment. For example, the shield 1 may be cylindrical, conical, polygonal prismatic, or polygonal pyramidal. The lower surface 15 and upper surface 16 may be fan-shaped. Length D1: Length D2: Length D3 may not be 1:2:1. That is, the length D1 may be the same as the length D2, or may be larger or smaller than the length D2. Length D2 may be the same as length D3, or may be larger or smaller than length D3. The length D3 may be the same as the length D1, or may be larger or smaller than the length D1. The shield 1 may be plate-like instead of block-like. In these cases, the mold 2 may have the shape of the cavity 30 corresponding to the shape of the shield 1 described above. Moreover, the manufacturing method of the shield 1 may mold the shields 1 with mutually different shapes using a plurality of molds 2 having cavities 30 with mutually different shapes. Also, the configuration of the mold 2 is not limited to the above embodiment. For example, instead of the compression coil springs 461, 462, 463, and 464, the mold 2 may press the upper plate 41 downward using other springs, cylinders, or the like. Also, the mold 2 may not have a mechanism (for example, compression coil springs 461, 462, 463, 464) for pressing the upper plate 41 downward.

1 Shield 2 Mold 9 Wire 15 Lower surface 16 Upper surface 92 Insulator 151, 152 Concave portions 161, 162 Concave portion 300 Filling material 351, 352 Concave portions 411, 412 Concave portion 921 Crosslinked polyethylene chips C1, C2 Center lines P1, P2 Intersection point V1 , V2, V3 dividing line

Claims (3)

A method for manufacturing a shield for shielding neutrons, comprising:
An obtaining step of obtaining a chip of the crosslinked polyethylene from the wire or cable that includes crosslinked polyethylene as an insulator and that has been scrapped from the wire or cable;
a molding step of filling a mold with a filling material made from the chips obtained in the obtaining step and molding the mold ;
The mold is
The shielding body is formed in a substantially rectangular parallelepiped shape having a first surface and a second surface opposite to the first surface, and the first surface and the second surface are formed in the lateral direction and the longitudinal direction, respectively. is molded to a dimensional ratio of 1:2,
A pair of concave portions is formed at positions of intersections of a pair of dividing lines that do not coincide with the center line in the longitudinal direction and the center line in the lateral direction, out of the three dividing lines that divide into four equal parts in the longitudinal direction. Having an uneven shape formed on one surface and forming a pair of convex portions on the second surface at the positions of the respective intersections,
The pair of protrusions of the first shield can fit into the pair of recesses of the second shield.
A method of manufacturing a shield, characterized by: 2. The shield according to claim 1, wherein in the molding step, the chip obtained in the obtaining step is filled into the mold as the filling material, and the mold is heated to mold. Production method. 3. The method of manufacturing a shield according to claim 2, wherein in the molding step, the mold is heated while the filling material filled in the mold is pressurized.

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