Electron beam irradiation device

Abstract

To provide a shielding structure that is easy to maintain and does not require high molding precision. [Solution] The electron beam irradiation device (100) comprises an electron beam generator (4) that generates an electron beam, a transport cylinder (5) that transports the paper (P) so that it passes through the irradiation region (IR) irradiated by the electron beam by holding and rotating a part of the paper (P) to be irradiated by the electron beam, and a shielding structure (8) provided around the irradiation region (IR) in the transport cylinder (5) to shield the radiation. The shielding structure (8) has a plurality of first members (81) whose sides facing the outer circumferential surface (51b) of the transport cylinder (5) are formed in a concave shape. The plurality of first members (81) are arranged to cover the outer circumferential surface (51b).

Description

Technical Field

[0001] The present disclosure relates to an electron beam irradiation apparatus that irradiates an object to be irradiated with an electron beam.

Background Art

[0002] In an electron beam irradiation apparatus, an object to be irradiated is conveyed so as to pass through an irradiation region where an electron beam is irradiated, thereby irradiating the object to be irradiated with the electron beam. Further, in an electron beam irradiation apparatus, since radiation is generated along with the irradiation of the electron beam, the radiation is shielded so that the radiation does not leak to the outside.

[0003] For example, Patent Document 1 describes an electron beam irradiation apparatus that holds a printed matter as an object to be irradiated by a gripper device provided on the surface of a rotating cylinder and conveys it so as to pass through an electron beam irradiation region. In the electron beam irradiation apparatus, shielding means for shielding X-rays is provided around the electron beam irradiation region in the cylinder.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since the shielding means in the above electron beam irradiation apparatus is large-sized due to the large size of the cylinder, it is correspondingly formed large and heavy. Therefore, for the daily maintenance of the shielding means, a heavy machine for attaching and detaching the shielding means to and from the electron beam irradiation apparatus is required. However, in the site where the electron beam irradiation apparatus is installed, such a heavy machine is often not equipped, so the maintenance of the shielding means is difficult.

[0006] Furthermore, in the electron beam irradiation apparatus described above, the presence of a gripper device on the cylinder causes the material to be printed to lift off the surface of the cylinder, and the gripper device protrudes from the surface of the cylinder. For this reason, it is necessary to maintain a certain distance between the surface of the cylinder and the shielding means. However, it is difficult to accurately form the inner surface shape of the shielding means in order to maintain such a distance.

[0007] One aspect of this disclosure aims to provide a shielding structure that is easy to maintain and does not require high molding precision. [Means for solving the problem]

[0008] To solve the above problems, an electron beam irradiation apparatus according to one aspect of the present disclosure comprises: an electron beam generator that generates an electron beam; a cylindrical body that holds and rotates a part of the object to be irradiated by the electron beam, thereby transporting the object to be irradiated so that it passes through the irradiation region to which the electron beam is irradiated; and a shielding structure provided around the irradiation region of the cylindrical body for shielding radiation, wherein the shielding structure has a plurality of first members whose sides facing the outer circumferential surface of the cylindrical body are formed in a concave shape, and the plurality of first members are arranged to cover the outer circumferential surface. [Effects of the Invention]

[0009] According to one aspect of this disclosure, it is possible to provide a shielding structure that is easy to maintain and does not require high molding precision. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view showing the configuration of an electron beam irradiation apparatus according to one embodiment of the present disclosure. [Figure 2] This is a perspective view showing the configuration of the main components of the electron beam irradiation apparatus described above. [Figure 3] This is a front view showing the configuration of the first member of the shielding structure in the electron beam irradiation apparatus described above. [Figure 4] This is a front view showing the configuration of the second member of the shielding structure described above. [Figure 5] This is a front view showing the configuration of the shielding structure according to the first modified example of the electron beam irradiation apparatus described above. [Figure 6] This is a front view showing the configuration of the shielding structure according to a second modified example of the electron beam irradiation apparatus described above. [Modes for carrying out the invention]

[0011] [Embodiment] One embodiment of this disclosure will be described in detail below.

[0012] <Configuration of the electron beam irradiation device> Figure 1 is a cross-sectional view showing the configuration of the electron beam irradiation apparatus 100 according to this embodiment. Figure 2 is a perspective view showing the configuration of the main parts of the electron beam irradiation apparatus 100. Figure 3 is a front view showing the configuration of the first member 81 of the shielding structure 8 in the electron beam irradiation apparatus 100. Figure 3 is a front view showing the configuration of the second member 82 of the shielding structure 8.

[0013] As shown in Figures 1 and 2, the electron beam irradiation device 100 irradiates paper P (object to be irradiated) with an electron beam generated by the electron beam generator 4 for printing. To this end, the electron beam irradiation device 100 transports the paper P so that it passes through the irradiation area IR where the electron beam is irradiated by rotating the transport cylinder 5 (cylindrical body). The electron beam irradiation device 100 also shields the radiation generated when the electron beam irradiates the transport cylinder 5 (metal) with a shielding structure 8. The electron beam irradiation device 100 comprises a housing 1, a shielding cover 2, a pair of support members 3, an electron beam generator 4, a transport cylinder 5, a supply cylinder 6, a discharge cylinder 7, a shielding structure 8, and a shielding plate 9.

[0014] The housing 1 is a structure that covers the transport cylinder 5, supply cylinder 6, discharge cylinder 7, shielding structure 8, and shielding plate 9. The housing 1 has a bottom plate 1a and a pair of partition plates 1b. The pair of partition plates 1b are formed to rise from the rear and front edges of the electron beam irradiation device 100 on the bottom plate 1a and to face each other.

[0015] The housing 1 has its left and right sides open in FIG. 1 in order to supply the paper P to the supply cylinder 6 and receive the paper P from the discharge cylinder 7. Also, the upper part of the housing 1 is open so as to facilitate maintenance of the shielding structure 8, the conveyance cylinder 5, etc.

[0016] In FIG. 1, only the partition plate 1b on the back side is shown, and the partition plate 1b on the front side is omitted. Also, the structure of the housing 1 described above is merely an example and is not limited to such a structure.

[0017] The shielding cover 2 is a box-shaped cover that shields the electron beam generator 4. The basic structure of the shielding cover 2 is formed of lead, and the inner and outer surfaces of the basic structure are covered with a stainless steel layer for rust prevention and strength assurance.

[0018] The pair of support members 3 are members that support the shielding structure 8 described later. The pair of support members 3 are fixed to the inner surfaces of the pair of partition plates 1b by bolt fastening so as to be arranged at positions facing each other. The pair of support members 3 have a plurality of brackets 31, 32 for supporting the shielding structure 8. The brackets 31, 32 are fixed to the facing surfaces of the pair of support members 3 by bolt fastening.

[0019] The electron beam generator 4 accelerates the wide electron beam generated by the electron source 42 in the vacuum chamber 41 by an electric field due to the application of a DC high voltage. The electron beam generator 4 irradiates the electron beam obliquely downward to the irradiation region IR by passing the accelerated electron beam through the metal foil provided on the irradiation window 43.

[0020] The conveyance cylinder 5 conveys the sheet-like paper P supplied from the supply cylinder 6 so as to pass through the irradiation region IR by holding and rotating it. The conveyance cylinder 5 has a cylinder body 51 and a pair of gripping mechanisms 52.

[0021] The cylinder body 51 has central shafts 51a at both ends. One end of the central shaft 51a is rotatably supported by a partition plate 1b shown on the rear side of the housing 1, and is rotationally driven by a drive mechanism (not shown) fixed to the rear side of this partition plate 1b. The other end of the central shaft 61a is rotatably supported by a partition plate 1b not shown on the front side of the housing 1.

[0022] A pair of recesses 51c are provided on the outer circumferential surface 51b of the cylinder body 51. The pair of recesses 51c are formed to be located on opposite sides of the central axis 51a. In other words, the pair of recesses 51c are spaced at an angle of 180° with respect to the central axis 51a.

[0023] The pair of gripping mechanisms 52 are mechanisms that hold a portion of the paper P by gripping one end of the paper P. The gripping mechanisms 52 are located inside the recess 51c. The gripping mechanisms 52 have a fixed part 52a, a movable part 52b, and a support shaft 52c. The fixed part 52a is fixed to the bottom surface of the recess 51c. The movable part 52b is movable relative to the fixed part 52a and is tapered, becoming narrower as it approaches the tip. The movable part 52b is driven by a drive device (not shown). The support shaft 52c supports the movable part 52b so that it can rotate relative to the fixed part 52a.

[0024] In the gripping mechanism 52 configured in this way, the movable part 52b rotates toward the inner surface of the recess 51c, thereby gripping one end of the paper P with the inner surface. The movable part 52b also rotates toward the opposite side of the inner surface, thereby separating from the inner surface and releasing the paper P.

[0025] The supply cylinder 6 holds and rotates the paper P supplied from a paper introduction mechanism (not shown) to a predetermined first transfer position, where it transfers the paper P to the transport cylinder 5. For this reason, the supply cylinder 6 is positioned upstream of the transport cylinder 5 in the direction of paper P transport. The supply cylinder 6 has a cylinder body 61 and a pair of gripping mechanisms 62.

[0026] The cylinder body 61 is a cylindrical body and has central shafts 61a at both ends. The central shafts 61a are rotatably supported by a pair of partition plates 1b and are rotationally driven by a drive mechanism (not shown). The outer circumferential surface 61b of the cylinder body 61 is provided with a pair of recesses 61c having a structure similar to the pair of recesses 51c. The pair of gripping mechanisms 62 are mechanisms that hold one end of the paper P by gripping it. The gripping mechanism 62 has a fixed part 62a, a movable part 62b, and a support shaft 62c, and operates in the same way as the gripping mechanism 52.

[0027] The discharge cylinder 7 holds the paper P received from the transport cylinder 5 at a predetermined second transfer position and rotates, thereby transporting the paper P to a transfer position with a paper discharge mechanism (not shown), and at that transfer position, it transfers the paper P to the paper discharge mechanism. For this reason, the discharge cylinder 7 is positioned downstream of the transport cylinder 5 in the direction of transport of the paper P. The discharge cylinder 7 has a cylinder body 71 and a pair of gripping mechanisms 72.

[0028] The cylinder body 71 is a cylindrical body and has central shafts 71a at both ends. The central shafts 71a are rotatably supported by a pair of partition plates 1b and are rotationally driven by a drive mechanism (not shown). The outer circumferential surface 71b of the cylinder body 71 is provided with a pair of recesses 71c having a structure similar to the pair of recesses 51c. The pair of gripping mechanisms 72 are mechanisms that hold one end of the paper P by gripping it. The gripping mechanism 72 has a fixed part 72a, a movable part 72b, and a support shaft 72c, and operates in the same manner as the gripping mechanism 72.

[0029] The shielding structure 8 is a structure that shields against radiation generated when an electron beam is irradiated onto the irradiation area IR. The shielding structure 8 is provided around the irradiation area IR in the transport cylinder 5. Specifically, the shielding structure 8 is provided in a first range and a second range. The first range is the area from the end of the irradiation area IR on the supply cylinder 6 side to the vicinity of the first transfer position described above. The second range is the area from the end of the irradiation area IR on the discharge cylinder 7 side to the vicinity of the second transfer position described above. The shielding structure 8 has a plurality of first members 81, a plurality of second members 82, a plurality of third members 83, and a plurality of fourth members 84.

[0030] The first member 81 has a concave shape on the side facing the outer peripheral surface 51b of the cylinder body 51. The first member 81 is formed in an elongated shape with a length slightly longer than the width of the outer peripheral surface 51b. The first member 81 is positioned to cover the outer peripheral surface 51b in the vicinity of the first transfer position described above and in a predetermined range from the outer surface of the lower end of the shielding cover 2 on the discharge cylinder 7 side to the second transfer position described above.

[0031] As shown in Figure 3, the first member 81 has an opposing portion 81a (first opposing portion) and a pair of side portions 81b (first side portions). The opposing portion 81a is a flat plate-shaped portion that faces the outer peripheral surface 51b. The pair of side portions 81b are portions that extend from both ends of the opposing portion 81a toward the outer peripheral surface 51b. The side portions 81b have a width narrower than the width of the opposing portion 81a.

[0032] It is desirable that adjacent first members 81 be arranged so that the side ends of their respective side portions 81b are in contact with each other without any gaps. However, due to manufacturing errors inherent in each of the first members 81, gaps may occur between their side ends.

[0033] The first member 81 is composed of a main body portion 811 and an outer covering portion 812. The main body portion 811 is provided across the opposing portion 81a and the side portion 81b, and forms the main body of the first member 81. The main body portion 811 is made of lead. The outer covering portion 812 is formed to cover the surface of the main body portion 811, except for both end faces of the first member 81. The outer covering portion 812 is made of stainless steel to ensure strength and corrosion resistance.

[0034] The second member 82 is positioned to block the space between adjacent first members 81. The second member 82 straddles the adjacent ends of the first members 81, i.e., the ends of the side portions 81b, and the side facing the first members 81 is formed in a concave shape. The second member 82 is formed in an elongated shape having the same length as the first members 81.

[0035] As shown in Figure 4, the second member 82 has an opposing portion 82a (second opposing portion) and a pair of side portions 82b (second side portions). The opposing portion 82a is a flat plate-shaped portion that faces the outer peripheral surface 51b. The pair of side portions 82b are formed to extend from both ends of the opposing portion 82a, facing the inner surface of one side portion 81b of the two adjacent first members 81 and the inner surface of the other side portion 81b, respectively. The side portions 82b have a width narrower than the width of the opposing portion 82a.

[0036] The second member 82 may be arranged independently of the first member 81. Furthermore, the second member 82 may be arranged such that only one side portion 82b faces the inner surface of the side portion 81b of one of the first members 81. For example, the second member 82 arranged on the supply cylinder 6 side is positioned to block the space between the first member 81 and the shielding plate 9. Also, the second member 82 does not have to be the same shape as the first member 81; for example, it may be flat.

[0037] The second member 82 is composed of a main body portion 821 and an outer covering portion 822. The main body portion 821 is provided across the opposing portion 82a and the side portion 82b, and forms the main body of the second member 82. The main body portion 821 is made of lead. The outer covering portion 822 is formed to cover the surface of the main body portion 821, except for both end faces of the second member 82. The outer covering portion 822 is made of stainless steel, just like the outer covering portion 812 of the first member 81.

[0038] The third member 83 is provided one each near the supply cylinder 6 side of the irradiation window 43 in the electron beam generator 4, the supply cylinder 6 side end of the shielding structure 8, and the discharge cylinder 7 side end of the shielding structure 8. The third member 83 is formed in an elongated shape having the same length as the first member 81. The third member 83 is formed in a shape such that the cross section of the plane perpendicular to the longitudinal direction of the third member 83 forms an L shape, with a portion facing the outer peripheral surface 51b and a portion facing the inner surface of the side portion 81b of the first member 81.

[0039] The fourth member 84 is provided in the area between the vicinity of the irradiation window 43 and the inner surface of the lower end of the shielding cover 2 on the discharge cylinder 7 side, and also at the end of the shielding structure 8 on the discharge cylinder 7 side. The fourth member 84 is formed in an elongated and flat shape having the same length as the first member 81.

[0040] Although not shown in the figures, the third member 83 and the fourth member 84, like the first member 81 and the second member 82, are composed of a main body made of lead and an outer casing made of stainless steel.

[0041] The shielding plate 9 shields the space between the second member 82 on the first transfer position side in the shielding structure 8 and the inner surface of the lower end of the shielding cover 2 on the supply cylinder 6 side. Like the first member 81, the shielding plate 9 is composed of a main body made of lead and an outer cover made of stainless steel.

[0042] <Operation of the electron beam irradiation device> The operation of the electron beam generator 4, configured as described above, will now be explained. The supply cylinder 6 rotates in the direction of the arrow while holding the paper P received from the paper introduction mechanism described above with the gripping mechanism 62, and at the first handover position, it releases the grip on the paper P and hands the paper P over to the transport cylinder 5. The transport cylinder 5 rotates in the direction of the arrow while holding the paper P with the gripping mechanism 52 and transports the paper P. The paper P is irradiated with an electron beam by passing through the irradiation area IR.

[0043] When the transport cylinder 5 transports the paper P to the second transfer position, it releases its grip on the paper P at the second transfer position and transfers the paper P to the discharge cylinder 7. The discharge cylinder 7 rotates in the direction of the arrow while holding the paper P with the gripping mechanism 72, and transfers the paper P to the paper discharge mechanism described above.

[0044] When an electron beam is irradiated onto the paper P in the irradiation region IR, radiation is generated. Radiation has the property that its intensity decreases as it changes direction of propagation as it travels through the air. Therefore, the radiation emitted from the irradiation region IR is reflected by the shielding structure 8 and the outer surface 51b, and when it reaches the space between the first member 81 and the second member 82, its intensity decreases as it bends and travels between them. Consequently, even if there is a gap between adjacent first members 81, the intensity of the radiation leaking from that gap is sufficiently attenuated to the point that it does not affect the human body.

[0045] <Effects of electron beam irradiation device> In the electron beam generator 4, the shielding structure 8 is formed by arranging a plurality of first members 81 to cover the outer circumferential surface 51b of the transport cylinder 5. This allows the shielding structure 8 to be configured to be disassembled and assembled. Therefore, routine maintenance such as cleaning the shielding structure 8 can be easily performed. Furthermore, since the shielding structure 8 can be easily removed from the housing 1, maintenance of the transport cylinder 5, such as lubricating the gripping mechanism 52, can also be easily performed.

[0046] Furthermore, the side of the first member 81 facing the outer circumferential surface 51b is formed in a concave shape. As a result, the sides of multiple first members 81 facing the outer circumferential surface 51b have an uneven shape. In such a shielding structure 8, assuming a configuration without a second member 82, it is sufficient to arrange the first members 81 so that a predetermined distance, for example 10 mm, between the convex portion near the outer circumferential surface 51b and the outer circumferential surface 51b is secured with specified precision. Therefore, it is not required to form the distance with the outer circumferential surface 51b with high precision over the entire surface of the shielding structure 8 facing the outer circumferential surface 51b. Thus, the manufacturing cost of the electron beam generator 4 can be reduced.

[0047] Thus, although the electron beam generator 4 includes the first member 81, even if it does not include the second member 82, it is an invention that can solve the above-mentioned problem of providing a shielding structure that is easy to maintain and does not require high formation precision.

[0048] The first member 81 has the aforementioned opposing portion 81a and a pair of side portions 81b. As a result, when radiation generated in the irradiated IR region strikes the inner surfaces of the opposing portion 81a and the pair of side portions 81b, it is reflected in various directions depending on the angle of incidence. This changes the direction of radiation propagation, thereby attenuating the intensity of the radiation.

[0049] The shielding structure 8 has a plurality of second members 82. The second members 82 are provided to block the space between adjacent first members, thereby reducing radiation leakage from between adjacent first members 81. The shielding structure 8 can be disassembled and assembled even with the presence of the second members 82. Therefore, maintenance of the shielding structure 8 and the transport cylinder 5 can be easily performed. In this way, the electron beam irradiation device 100 can be improved in maintainability by including the shielding structure 8.

[0050] Furthermore, the second member 82 straddles the adjacent ends (ends of the side portions 81b) of the adjacent first member 81, and the side facing the first member 81 is formed in a concave shape. This creates a curved path between the first member 81 and the second member 82. When radiation enters this path, it changes direction multiple times as it travels. Therefore, the intensity of the radiation can be significantly attenuated.

[0051] Specifically, the second member 82 has the aforementioned opposing portion 82a and a pair of side portions 82b. As a result, radiation is reflected by striking the inner surfaces of the opposing portion 81a and side portions 82b of the first member 81 and the opposing portion 82a and side portions 82b of the second member 82. Therefore, the direction of radiation propagation can be changed many times. Consequently, the intensity of the radiation can be significantly attenuated.

[0052] In the shielding structure 8 having the second member 82, the surface of the opposing portion 82a of the second member 82 is located closest to the outer circumferential surface 51b. Therefore, the second member 82 only needs to be positioned so that the distance between the surface of the opposing portion 82a and the outer circumferential surface 51b is secured with the specified precision.

[0053] <Variations> Modified versions of the shielding structure 8 will now be described. Figure 5 is a front view showing the configuration of the first modified shielding structure 8A. Figure 6 is a front view showing the configuration of the second modified shielding structure 8B.

[0054] As shown in Figure 5, the shielding structure 8A has multiple first members 85 and multiple second members 86 instead of the multiple first members 81 and multiple second members 82 described above.

[0055] Like the first member 81, the first member 85 is formed with a concave shape on the side facing the outer circumferential surface 51b of the conveying cylinder 5, and is also formed in an elongated shape. The first member 85 is positioned in approximately the same location as the first member 81.

[0056] The first member 85 has an opposing portion 85a (first opposing portion) and a pair of side portions 85b (first side portions). The opposing portion 85a faces the outer peripheral surface 51b and is a curved portion that is convex on the side opposite to the side facing the outer peripheral surface 51b. The pair of side portions 85b are formed to extend from both ends of the opposing portion 85a toward the outer peripheral surface 51b. The side portions 85b have a width narrower than the width of the opposing portion 85a. Like the first member 81, the first member 85 is composed of a main body made of lead and an outer casing made of stainless steel.

[0057] The second member 86 is positioned to block the space between adjacent first members 85 and is formed in an elongated shape having the same length as the first members 85. The second member 86 straddles the adjacent ends of the first members 85, i.e., the ends of the side portions 85b, and the side facing the first members 85 is formed in a concave shape.

[0058] The second member 86 has an opposing portion 86a (second opposing portion) and a pair of side portions 86b (second side portions). The opposing portion 86a is a curved portion that faces the outer peripheral surface 51b and is convex on the side facing the outer peripheral surface 51b. The pair of side portions 86b are formed to extend from both ends of the opposing portion 86a, facing the inner surface of one side portion 85b of the adjacent first member 85 and the inner surface of the other side portion 85b, respectively. The side portions 86b have a width narrower than the width of the opposing portion 86a.

[0059] The shielding structure 8A, configured as described above, has a first member 85 and a second member 86, and is configured to be disassembled and assembled, just like the shielding structure 8. Therefore, the electron beam irradiation device 100 equipped with the shielding structure 8A can improve maintainability, just like the electron beam irradiation device 100 equipped with the shielding structure 8.

[0060] Furthermore, the curved path formed between the first member 85 and the second member 86 allows for attenuation of radiation intensity, similar to the shielding structure 8. Moreover, the opposing portion 85a of the first member 85 and the opposing portion 86a of the second member 86 are formed in a curved shape. As a result, radiation is reflected in various directions from the inner surfaces of the opposing portions 85a and 86a, respectively. Therefore, the likelihood of increasing the number of times the radiation changes direction is increased. Consequently, an enhanced effect in attenuating radiation intensity can be expected.

[0061] Furthermore, the first member 85 may have only an opposing portion 85a and not a pair of side portions 85b. Similarly, the second member 86 may have only an opposing portion 86a and not a pair of side portions 86b. Moreover, the shapes of the opposing portions 85a and 86a are not limited to curved surfaces, but may be polygonal, pointed, or any other shape. Additionally, the second member 86 may not have the same shape as the first member 85, but may be, for example, flat.

[0062] As shown in Figure 6, the shielding structure 8B, like the shielding structure 8, has a plurality of first members 81, but instead of a plurality of second members 82, it has a plurality of second members 87. The second members 87 are positioned on the opposing portion 81a side of the first members 81 and are arranged to block the space between adjacent first members 81. Furthermore, the second members 87 have the same shape as the first members 81, and like the first members 81, the side facing the outer peripheral surface 51b is formed in a concave shape.

[0063] The shielding structure 8B, configured as described above, has a first member 85 and a second member 87, and is configured to be disassembled and assembled, just like the shielding structure 8. Therefore, the electron beam irradiation device 100 equipped with the shielding structure 8B can improve maintainability, just like the electron beam irradiation device 100 equipped with the shielding structure 8.

[0064] Furthermore, by the second member 87 blocking the space between adjacent first members 81, radiation leaking from between them can be shielded. In addition, by reflecting radiation on the inner surface of the second member 87, the direction of propagation of radiation leaking from between adjacent first members 81 can be changed. Therefore, the intensity of the radiation can be attenuated.

[0065] Furthermore, the shielding structure 8B may also have a second member 82, similar to the shielding structure 8. Also, the second member 87 does not have to be the same shape as the first member 81; for example, it may be flat.

[0066] 〔summary〕 An electron beam irradiation apparatus according to a first aspect of the present disclosure comprises: an electron beam generator that generates an electron beam; a cylindrical body that holds and rotates a part of the object to be irradiated by the electron beam, thereby transporting the object to be irradiated so that it passes through an irradiation region to be irradiated by the electron beam; and a shielding structure provided around the irradiation region of the cylindrical body for shielding radiation, wherein the shielding structure has a plurality of first members, the side facing the outer circumferential surface of which is concave, and the plurality of first members are arranged to cover the outer circumferential surface of the cylindrical body.

[0067] According to the above configuration, a shielding structure having multiple first members can be configured to be separable and assembled. This makes it easy to perform routine maintenance on the shielding structure.

[0068] Furthermore, since the first member is formed with a concave shape on the side facing the outer surface of the cylindrical body, when it is positioned to cover the outer surface, the side of the shielding structure facing the outer surface becomes uneven. In such a shielding structure, it is sufficient to ensure a predetermined distance from the outer surface with a specified precision only for the convex portion close to the outer surface. Therefore, it is not necessary to form a high-precision distance from the outer surface over the entire side of the shielding structure facing the outer surface.

[0069] In the first embodiment, the electron beam irradiation apparatus according to a second aspect of the present disclosure may have a first opposing portion facing the outer peripheral surface and a pair of first side portions formed to extend toward the outer peripheral surface from both ends of the first opposing portion.

[0070] According to the above configuration, radiation is reflected by striking the inner surfaces of the first opposing part and the first side part. This changes the direction of radiation propagation. Therefore, the radiation can be attenuated.

[0071] In the third aspect of the present disclosure, the electron beam irradiation apparatus may, in the second aspect, have a plurality of second members that block the space between adjacent first members.

[0072] According to the above configuration, it is possible to reduce the amount of radiation leaking from between adjacent first members.

[0073] In the electron beam irradiation apparatus according to the fourth aspect of the present disclosure, in the third aspect, the second member may straddle the adjacent ends of adjacent first members, and the side facing the first member may be formed in a concave shape.

[0074] According to the above configuration, a curved path is formed between the first member and the second member. When radiation enters this path, it changes direction multiple times as it travels. Therefore, the radiation can be significantly attenuated.

[0075] In the fifth aspect of the present disclosure, the electron beam irradiation apparatus may have, in the fourth aspect, a second member having a second opposing portion facing the outer peripheral surface, and a pair of second side portions formed to extend from both ends of the second opposing portion toward the inner surface of one of the adjacent first members and the inner surface of the other first side portion, respectively.

[0076] In the above configuration, radiation is reflected by striking the inner surfaces of the first opposing portion and first side portion of the first member, and the opposing portion and second side portion of the second member. This allows the radiation to change direction multiple times. Therefore, the radiation can be significantly attenuated.

[0077] [Additional Notes] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in each embodiment are also included within the technical scope of this disclosure. [Explanation of symbols]

[0078] 4. Electron beam generator 5. Conveying cylinder (cylindrical body) 8,8A,8B Shielding structure 51b Outer surface 81 First Member 82, 86, 87 Second member 81a, 85a Opposing section (1st opposing section) 81b, 85b Lateral section (first lateral section) 82a, 86a Opposing section (second opposing section) 82b, 86b Lateral section (second lateral section) 100 Electron beam irradiation equipment P Paper (object to be irradiated) IR irradiation area

Claims

1. An electron beam generator that generates an electron beam, A cylindrical body that holds and rotates a portion of the object to be irradiated by the electron beam, thereby transporting the object to be irradiated so that it passes through the irradiation area to which the electron beam is irradiated, The cylindrical body comprises a shielding structure provided around the irradiation area for shielding radiation, The shielding structure has a plurality of first members, the side facing the outer circumferential surface of the cylindrical body being formed in a concave shape, An electron beam irradiation device in which a plurality of the first members are arranged to cover the outer surface.

2. The electron beam irradiation apparatus according to claim 1, wherein the first member has a first opposing portion facing the outer peripheral surface and a pair of first side portions formed to extend toward the outer peripheral surface from both ends of the first opposing portion.

3. The electron beam irradiation apparatus according to claim 2, wherein the shielding structure has a plurality of second members that close the space between adjacent first members.

4. The electron beam irradiation apparatus according to claim 3, wherein the second member straddles the adjacent ends of the first members and the side facing the first members is formed in a concave shape.

5. The electron beam irradiation apparatus according to claim 4, wherein the second member has a second opposing portion facing the outer peripheral surface, and a pair of second side portions formed to extend from both ends of the second opposing portion, facing the inner surface of one of the adjacent pair of first members and the inner surface of the other first side portion, respectively.

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