JP7121974B2 - Lead ball sheet, lead ball sheet manufacturing method, lead ball sheet installation method - Google Patents

Description

The present invention relates to radiation shielding technology.

There are radiation devices that emit radiation for various purposes. Radiation equipment includes X-ray imaging equipment that irradiates a patient with X-rays for diagnostic imaging of lesions, radiation therapy equipment that irradiates X-rays and gamma rays to the affected area for treatment of the affected area, and X-ray imaging equipment that measures the atomic structure of a sample. There are X-ray diffractometers and the like that irradiate a sample with X-rays for analysis by line diffraction.

In a radiation equipment room in which a radiation equipment is installed, it is necessary to shield radiation inside the room. As a radiation shielding method, there is a method of providing a lead plate in a room and shielding the radiation with the lead plate.

As another radiation shielding method, Patent Document 1 discloses that a cylindrical shielding wall is provided around the reactor pressure vessel, and the inside of the shielding wall is filled with a shielding member made of a radiation absorbing material. A method is described for shielding radiation by

JP-A-9-211169

FIG. 1 is a perspective view for explaining a radiation shielding method using lead plates 21 and 22. FIG.
When the lead plates 21 and 22 are used as a radiation shielding method, a gap 23 is created at the seam of the lead plates 21 and 22 . Therefore, in order to prevent leakage of radiation from the gap 23, it is necessary to place a lead plate 100 covering the gap 23 on the lead plates 21 and 22. FIG.

Since gaps 23 are generated at a plurality of locations in the radiation apparatus room, the amount of radiation shielding required for each gap 23 is different, and the thickness of the lead plate 100 required for each gap 23 is different. The thickness of the lead plate 100 is adjusted by stacking the lead plates 100A to 100C with a predetermined thickness according to the required radiation shielding amount of the gap 23 in which the lead plate 100 is installed.

Specifically, on the lead plate 100A serving as the base material, in the area covering the gap 23 (in the case of FIG. 1, the area on the left end side of the lead plate 100A), the required number of lead plates according to the required shielding amount of radiation. 100B and 100C are attached and laminated.

In this method, it is necessary to adjust the thickness of the lead plates 100 by adhering the required number of lead plates 100B and 100C to each of the lead plates 100 corresponding to the gaps 23. Therefore, production of the lead plates 100 is troublesome. There was a problem.

FIG. 2 is a perspective view for explaining another radiation shielding method using lead plates 21 and 22. FIG.
In order to save the trouble of adjusting the thickness of the lead plate 100 for each gap 23 , there is also a method of using a lead plate 110 having a thickness that can correspond to all the gaps 23 in each gap 23 .

In this method, the area of the lead plate 110 that does not cover the gap 23 (the area on the right side in FIG. 2) becomes thicker, and in the first place, the thickness of the lead plate 110 at each gap 23 is more than necessary for the required shielding amount of radiation. thickness. Therefore, in this method, the weight of the lead plate 110 becomes unnecessarily large, which is a big disadvantage in terms of transportation and production.

The radiation shielding method of Patent Literature 1 has the problem that the production cost of the shielding wall is high and it takes time to produce it on site.

An object of the present invention is to provide a highly versatile radiation shielding member capable of shielding radiation.

The lead ball sheet of the present invention is characterized by being formed of a plurality of solid lead balls joined together.

Since the lead ball sheet of the present invention is formed by joining lead balls, it can be formed in any shape and can be made lighter than a lead plate. In the lead ball sheet of the present invention, since the lead balls are solid, the radiation shielding ability per thickness can be increased and the thickness can be reduced as compared with the case where the lead balls are hollow. That is, the lead ball sheet of the present invention can be made thin and light, can be transported easily and can be easily installed, and can minimize the amount of lead used.
When the lead ball sheet of the present invention is used as a shielding member in place of a conventional lead plate, for example, by forming it into an L-shape in plan view, seams that occur at the inside corners when conventional lead plates are installed are eliminated. be able to. In addition, since the lead ball sheet of the present invention can be installed immediately after being transported to the site, the installation cost can be reduced as compared with Patent Document 1 in which a shielding wall is formed and the inside is filled with a shielding member.
When the lead ball sheet of the present invention is used to cover the joints of a shielding member such as a lead plate, by making only the part that covers the joints thicker, it is possible to use the minimum necessary amount of lead to create a thin sheet. In addition, it can be made light, and the workability at the time of transportability and installation can be improved.
The lead ball sheet of the present invention can be formed into an arbitrary shape simply by putting lead balls into a mold and joining them with an adhesive, and has good productivity.

The lead ball sheet of the present invention preferably has a stepped portion at the end.

The lead ball sheet of the present invention can be used to cover the joints of shielding members such as lead plates. can be done. In the lead ball sheet of the present invention, when the lead ball sheet is formed using a mold, the end portion is provided with a stepped portion, so that the lead ball sheet can be easily removed from the mold.

The method for producing a lead ball sheet according to the present invention includes putting a plurality of solid lead balls into a mold, putting an adhesive in the mold, joining the plurality of lead balls together with the adhesive, and A lead ball sheet is formed from balls, and the lead ball sheet is removed from the mold.

According to the present invention, the lead ball sheet can be formed into any shape simply by putting the lead ball into a mold and bonding with an adhesive, and the productivity of the lead ball sheet can be improved. The produced lead ball sheet has the same functions and effects as the invention of the lead ball sheet described above.

In the lead ball sheet manufacturing method of the present invention, it is preferable that the sheet-side stepped portion is formed at the end of the lead ball sheet by the mold having the mold-side stepped portion at the open end of the inner surface.

The lead ball sheet produced by the present invention can be used to cover the joints of the shielding members, and since the thickness required to cover the joints of the shielding members can be formed by the stepped portion, the volume can be minimized. . In the present invention, since the stepped portion is provided at the end of the lead ball sheet, the lead ball sheet can be easily removed from the mold.

In the lead ball sheet installation method of the present invention, a lead ball sheet formed by a plurality of solid lead balls joined together and having a stepped portion at an end thereof covers a gap between adjacent wall portions by the stepped portion. It is characterized in that it is installed on the wall in a posture.

In the present invention, the gap between the walls is closed by using a thin and light lead ball sheet that uses the minimum necessary amount of lead, so that workability when installing the lead ball sheet can be improved.

1 is a perspective view for explaining a conventional radiation shielding method using a lead plate; FIG. FIG. 10 is a perspective view for explaining another conventional radiation shielding method using a lead plate; It is a perspective view which shows the outline of the lead ball sheet|seat in this embodiment. FIG. 4 is a perspective view of a lead ball sheet for covering gaps between lead plates; It is a perspective view for demonstrating the installation example of a lead ball sheet|seat. It is a figure which shows a mode that a lead ball is thrown into a type|mold. It is a figure which shows a mode that an adhesive agent is injected|thrown-in to a type|mold. It is a figure which shows the lead ball sheet|seat taken out from the type|mold. It is a perspective view of a lead ball sheet. 1 is a perspective view of a lead ball sheet mold; FIG.

Hereinafter, embodiments will be described with reference to the drawings.
FIG. 3 is a perspective view showing an outline of the lead ball sheet 1A.
The lead ball sheet 1A can be used as a shielding member for radiation such as X-rays, gamma rays and beta rays. The lead ball sheet 1A is formed of a plurality of lead balls 10 that are bonded together with an adhesive. The lead ball sheet 1A can be formed into any shape. The lead ball sheet 1A is formed in a sheet shape with a substantially uniform thickness. The lead ball 10 is solid and preferably has a diameter within the range of 0.1 to 0.5 mm.

Since the lead ball sheet 1A of this embodiment is formed by joining the lead balls 10, it can be made lighter than the lead plate.
In the lead ball sheet 1A of the present embodiment, the lead ball 10 is solid, so compared to the case where the lead ball 10 is hollow, the radiation shielding ability per thickness can be increased, and the thickness of the lead ball sheet 1A can be reduced. . That is, the lead ball sheet 1A of the present embodiment can be thin and light, and can be transported and installed with good workability.

FIG. 4 is a perspective view of the lead ball sheet 1B. In FIG. 4, in order to show the edge shape of the lead ball sheet 1B, the contour line of the lead ball sheet 1B is drawn as a straight line.
The lead ball sheet 1B is used to cover the gap 23 between the lead plates 21 and 22 (see FIG. 5).
One surface 11 (the surface on the right side in FIG. 4) of the lead ball sheet 1B is formed flat. The other surface 12 (the left surface in FIG. 4) of the lead ball sheet 1 is formed in a flat shape, and at the end (upper end in FIG. 4) in one direction (vertical direction in FIG. 4) of the surface, , a step portion 13 protruding from the other surface 12 is formed. The stepped portion 13 has a stepped shape that becomes higher toward the end of the lead ball sheet 1B. The edge portion of the lead ball sheet 1B is thickened by the step portion 13. - 特許庁The step portion 13 may have three or more steps. The size of the steps and the length of each step in the one direction can be appropriately set. The stepped portion 13 may have a single step, that is, instead of the stepped portion 13, a protruding portion that simply protrudes from the other surface 12 may be formed.

FIG. 5 is a perspective view for explaining an installation example of the lead ball sheet 1B.
In a radiation equipment room in which radiation equipment such as a dental X-ray equipment is installed, lead plates 21 and 22 are provided inside the inner walls as radiation shielding members such as X-rays to prevent leakage of radiation to the outside of the room. is planned. Between the lead plates 21 and 22 that are adjacent to each other in a posture perpendicular to each other, a gap 23 is formed along the vertical direction in FIG.

In this embodiment, the lead ball sheet 1B is placed on the lead plate 21 in such a posture that the gap 23 is covered by the stepped portion 13 and the extending direction of the stepped portion 13 is parallel to the gap 23 . Preferably, the surface 11 of the lead ball sheet 1B on which the stepped portion 13 does not protrude is attached to the lead plate 21 with double-sided tape or adhesive. A bracket may be attached to the lead ball sheet 1B, and the lead ball sheet 1B may be placed on the lead plate 21 using the bracket.

In this embodiment, the stepped portion 13 can sufficiently shield the radiation in the gap 23 portion, and the leakage of the radiation from the gap 23 can be prevented.
In this embodiment, the lead ball sheet 1B can be installed simply by abutting the lead ball sheet 1B against the inside corners of the lead plates 21 and 22 and pasting it on the lead plate 21, and the lead ball sheet 1B can be easily installed.

To manufacture the lead ball sheet 1B, first, as shown in FIG. 6, a plurality of solid lead balls 10 are put into the opening of the mold 3B. The mold 3B is box-shaped with an opening formed at one end (upper end in FIG. 6). A surface 31 of the mold 3B corresponds to one surface 11 (FIG. 4) of the lead ball sheet 1B and is planar.

A surface 32 of the mold 3B facing the surface 31 is formed flat as a whole corresponding to the other surface 12 (FIG. 4) of the lead ball sheet 1B, and a stepped portion 13 of the lead ball sheet 1B is formed on one end side. A stepped portion 321 (mold-side stepped portion) corresponding to the (sheet-side stepped portion) is formed. Since the internal space of the mold 3B expands toward the opening of the mold 3B due to the stepped portion 321, it is easy to remove the lead ball sheet 1B from the mold 3B.

A sheet material 33 is attached to the inner surface of the mold 3B. The adhesive, which will be described later, has high releasability with respect to the sheet material 33 .

Subsequently, as shown in FIG. 7, a water-soluble adhesive, for example, is poured into the mold 3B through the opening until the mold 3B is filled. Then, by drying the adhesive, the plurality of lead balls 10 are bonded to each other by the adhesive. As a result, a lead ball sheet 1B composed of a plurality of lead balls 10 is formed in the mold 3B. The adhesive should be one that contains a solvent that dissolves the adhesive.

Subsequently, as shown in FIG. 8, the lead ball sheet 1B can be manufactured by removing the lead ball sheet 1B from the mold 3B.

When molten lead is put into a mold to form a lead plate, the lead must be melted at a high temperature, which is costly. In the lead ball sheet 1B of this embodiment, the lead balls 10 can be put into the mold 3B as they are, so the manufacturing cost can be reduced and the manufacturing is easy.

Since the lead ball sheet 1B is formed of a plurality of lead balls 10, there are many voids, and the amount of lead used can be suppressed. In addition, since the lead ball sheet 1B can be provided with the stepped portion 13 only in the area necessary for shielding radiation by the mold 3B, the required minimum volume can be achieved, and from this point as well, the amount of lead used can be suppressed. can be done.

Alternatively, a bag-like sheet material 33 may be laid on the inner surface of the mold 3B, the lead ball sheet 1B may be taken out from the mold 3B together with the sheet material 33 after the adhesive is dried, and then the lead ball sheet 1B may be taken out from the sheet material 33.

After the lead ball sheet 1B is used, the lead ball 10 can be reused by removing the adhesive that bonds the lead ball sheets 1B together with a solvent. If the lead ball 10 is not intended to be reused, an adhesive that does not contain a solvent that dissolves the adhesive may be used.

FIG. 9 is a perspective view of the lead ball sheet 1C. In FIG. 9, illustration of the shape of each lead ball 10 is omitted, and only the outer shape of the lead ball sheet 1C is drawn.
The lead ball sheet 1C is provided as a wall-like radiation shielding member in the radiation equipment room. The lead ball sheet 1C is formed by bonding a plurality of lead balls 10 with an adhesive. The lead ball sheet 1C has wall portions 21C and 22C orthogonal to each other, and is formed in an L shape in plan view.

When the lead plates 21 and 22 are provided perpendicular to each other, a gap 23 is formed at the seam of the lead plates 21 and 22, and the lead plates 100 and 110 (FIGS. 1 and 2) or the lead ball sheet 1B covering the gap 23 are provided. need to be installed. However, by installing the lead ball sheet 1C in place of the lead plates 21 and 22, the gap 23 is not generated and the installation of the lead plates 100 and 110 or the lead ball sheet 1B can be eliminated.

FIG. 10 is a perspective view of the mold 3C for the lead ball sheet 1C.
The die 3C of the lead ball sheet 1C is L-shaped in plan view and is box-shaped with one end (upper end in FIG. 10) open. A sheet material 33 (not shown) is provided on the inner surface of the mold 3C. The manufacturing method of the lead ball sheet 1C is similar to that of the lead ball sheet 1B. First, the lead ball 10 and the adhesive are put into the mold 3C. Subsequently, the adhesive is cured by drying or the like to adhere and join the lead balls 10 to form the lead ball sheet 1C in the mold 3C. After that, the lead ball sheet 1C is manufactured by removing the lead ball sheet 1C from the mold 3C.

As the lead-ball sheet 1C serving as the shielding member provided in the radiation apparatus room, an L-shaped one in plan view was exemplified, but the shape of the lead-ball sheet 1C can be formed into any shape by the mold 3C, and can be flat. may

In the above-described embodiment, as an example of using the lead ball sheet 1B, an example of using it to cover the gap 23, which is the seam between the lead plates 21 and 22 that are installed perpendicular to each other, has been described. However, the lead ball sheet 1B may be used to cover the gap 23 between the parallel lead plates 21 and 22 . The lead ball sheet 1B can also be formed into any shape by the mold 3B.

1A to 1C... lead ball sheet, 3B, 3C... mold, 10... lead ball, 13... step portion (sheet side step portion), 21, 22... lead plate (wall portion), 321... step portion (mold side step portion ).

Claims (4)

1. A lead ball sheet comprising a plurality of solid lead balls joined together and having a stepped portion at an end. Put several solid lead balls in the mold,
placing an adhesive in the mold to bond the plurality of lead balls together with the adhesive, forming a lead ball sheet with the plurality of lead balls;
A method for producing a lead ball sheet, characterized in that the lead ball sheet is removed from the mold. 3. The method of manufacturing a lead ball sheet according to claim 2 , wherein the sheet-side stepped portion is formed at the end of the lead ball sheet by the mold having the mold-side stepped portion at the open end of the inner surface. A manufacturing method of a lead ball sheet. A lead ball sheet formed by a plurality of solid lead balls joined together and having a stepped portion at an end thereof is placed on the wall portion in such a posture as to cover a gap between adjacent wall portions by the stepped portion. The installation method of the lead ball sheet characterized.

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