JP7343916B2 - Electron beam irradiation device - Google Patents

Description

The present invention relates to an electron beam irradiation device.

BACKGROUND ART Electron beam irradiation devices are used for the purpose of irradiating objects to be irradiated with electron beams generated by the device, for example, to improve the properties of materials, add functionality, or sterilize or sterilize materials. BACKGROUND ART Electron beam irradiation devices, particularly scanning type electron beam irradiation devices, include an acceleration tube that converges and accelerates thermoelectrons generated from a filament in a vacuum to form an electron beam (see, for example, Patent Document 1).

The accelerating tube has a filament provided at one axial end thereof, and a plurality of accelerating electrodes arranged in parallel at equal intervals in the axial direction. The accelerating electrode has an inner protruding piece that protrudes inside the tube body of the accelerating tube, and an outer electrode portion that protrudes outside the tube body. In the plurality of accelerating electrodes of the accelerating tube, a gradually higher voltage is applied to each outer electrode portion as the distance from the filament increases, and an electric field for accelerating the electron beam is generated in each inner protruding piece. When a high-power electron beam is required, all accelerating electrodes of the accelerating tube are used.

On the other hand, when a low-output electron beam is required, acceleration of the electron beam by the accelerating electrodes after a predetermined number from the filament side becomes unnecessary. In this case, in order to keep the voltage applied to the accelerating electrodes after a predetermined number constant, a short-circuiting device attached to the accelerating tube can use a conductor to short-circuit the accelerating electrodes after that so that they have the same potential. being done.

Japanese Patent Application Publication No. 2003-59698

By the way, the above-mentioned short circuit device has a structure in which a movable joint is moved in the axial direction of the accelerator tube using, for example, a feed screw mechanism, and a conductor fixed to the movable joint is moved forward and backward in the same direction. By enabling a conductor moving forward and backward in the axial direction of the accelerating tube to contact a plurality of accelerating electrodes simultaneously, it is possible to short-circuit the accelerating electrodes after a predetermined number at the same time to have the same potential. Here, the accelerating tube has a structure that is long in the same direction in order to arrange a plurality of accelerating electrodes in the axial direction, and the feed screw is also elongated. Therefore, there was a concern as to whether the movements of the movable joints, conductors, etc. operated by long feed screws would be performed reliably.

An electron beam irradiation device that solves the above problems includes an acceleration tube including a plurality of acceleration electrodes arranged in parallel in the axial direction for generating an electric field for accelerating an electron beam, and an acceleration electrode located outside the acceleration tube in the radial direction. A plurality of shield rings are arranged in parallel in the axial direction so as to form pairs with each other, and each of the shield rings is electrically connected to the accelerating electrodes of the pair, and the shield rings are arranged between the acceleration tube and the shield ring, and a feed screw mechanism for short-circuiting the accelerating electrodes that are unnecessary for accelerating the electron beam with a conductor that advances and retreats in the axial direction in order to change the number of accelerating electrodes that function to accelerate the electron beam. an electron beam irradiation device comprising a short-circuiting device, the output of the electron beam being adjusted by the operation of the feed screw mechanism of the short-circuiting device, wherein the feed screw mechanism of the short-circuiting device has its own axial direction. A feed screw arranged parallel to the axial direction of the accelerating tube and rotationally driven by a drive source; and rotation of the feed screw moves in the axial direction to move the conductor forward and backward in the axial direction. and a movable member that allows the movable member to preferentially contact each of the acceleration electrode and the shield ring when the movable member swings in a direction perpendicular to the axis of the feed screw. is provided on the movable member.

According to the above aspect, the short-circuit device provided along with the acceleration tube moves the movable member along the axial direction of the acceleration tube by rotation of the feed screw of the feed screw mechanism, and the conductor for short-circuiting the acceleration electrodes. advance and retreat. When the movable member swings in a direction perpendicular to the axis of the feed screw during its axial movement, the guide member provided in the movable member can preferentially contact each of the accelerating electrode and the shield ring. In other words, it is possible to fully demonstrate the guide function of the guide member, so that the posture of the movable member can be stabilized when moving and when it is stopped. As a result, the reliability of the electron beam irradiation device can be fully expected to be improved through the operation of short-circuiting the accelerating electrodes by the short-circuiting device.

In the electron beam irradiation device, the guide member is capable of contacting each of the acceleration electrode and the shield ring at at least two places when the movable member swings in a direction perpendicular to the axis of the feed screw. It has several parts.

According to the above aspect, when the movable member swings in the direction perpendicular to the axis of the feed screw, each part of the guide member can come into contact with each of the accelerating electrode and the shield ring at at least two places. This makes the posture of the movable member more stable when it moves and when it stops, and it can be expected that the operation of the short circuit device will be fully improved.

In the above electron beam irradiation device, the guide member has a length that can abut at least two lengths of the accelerating electrode and the shield ring, depending on the position, three or more lengths in the axial direction. .

According to the above aspect, the length of the guide member in the axial direction is optimized, and the guide member can come into contact with the accelerating electrode and the shield ring at least two times, and depending on the position, three times or more. This also makes the posture of the movable member more stable when it moves and when it stops, and it is fully expected that the operation of the short circuit device will be improved.

In the above electron beam irradiation device, each of the plurality of accelerating electrodes is provided with a bearing, the plurality of bearings are arranged in parallel in the axial direction, and the movable member is configured to move the plurality of accelerating electrodes supported by the bearing. The movable member has a protruding portion extending in the axial direction, and the protruding portion of the movable member has a length that can support two bearings, and depending on the position, three or more bearings in the axial direction. It is configured.

According to the above aspect, the axial length of the protruding portion of the movable member is optimized, and the protruding portion is supported by two bearings arranged in the axial direction, or by three or more depending on the position. This also makes the posture of the movable member more stable when it moves and when it stops, and it is fully expected that the operation of the short circuit device will be improved.

In the above electron beam irradiation device, the feed screw mechanism arranges the feed screw so that its axial direction is directed in the vertical direction, and uses a left-handed screw for the feed screw to move the movable member upward. At times, a pressing force is generated on the movable member in a direction toward the accelerating electrode.

According to the above aspect, a left-handed screw is used as the feed screw, and a pressing force is generated on the movable member in a direction toward the acceleration electrode when the movable member moves upward. Since the bearing that supports the movable member and the contact part with the conductor that operates integrally with the movable member are provided on the accelerating electrode side, the bearing and the contact part etc. can function more reliably when the movable member moves upward. You can expect it.

According to the electron beam irradiation device of the present invention, the operation of the short circuit device attached to the accelerating tube can be made more reliable, and the reliability of the device can be improved.

FIG. 1 is a schematic configuration diagram of an electron beam irradiation device in one embodiment. It is a schematic block diagram of the acceleration tube part and the short circuit device in the same embodiment. It is a top view of an acceleration tube part and a short circuit device in the same embodiment. It is a partially enlarged plan view of the acceleration tube part and the short circuit device in the same embodiment. It is a side view of the acceleration tube part and a short circuit device in the same embodiment. It is a partially enlarged side view of the acceleration tube part and the short circuit device in the same embodiment. FIG. 7 is a partially enlarged plan view of an accelerating tube section and a short circuit device in a comparative example. FIG. 6 is a partially enlarged side view of an accelerating tube section and a short circuit device in the same comparative example.

Hereinafter, one embodiment of an electron beam irradiation device will be described.
[Overall configuration of electron beam irradiation device]
The electron beam irradiation device 10 of this embodiment shown in FIG. 1 is a scanning type electron beam irradiation device. The electron beam irradiation device 10 includes a filament 11 made of, for example, tungsten that emits thermoelectrons. The filament 11 emits electrons by heating itself based on the power supply from the filament power supply 12. The filament 11 is provided at one end of the acceleration tube 13. Note that the acceleration tube 13 of this embodiment is arranged with one end side of the acceleration tube 13 in the direction of the axis L1 facing upward.

The acceleration tube 13 has a cylindrical shape with a closed upper end where the filament 11 is placed. The acceleration tube 13 has a plurality of acceleration electrodes 14 arranged in parallel in the direction of its own axis L1. The accelerating electrode 14 generates an electric field that converges the electrons emitted from the filament 11 and accelerates them downward, which is the other end side in the axis L1 direction, based on the power supply from the accelerating electrode power source 15. let That is, in the accelerating tube 13, the electric field generated at the accelerating electrode 14 causes a downward electron flow, that is, an electron beam e. The detailed configuration of the accelerator tube 13 and the short circuit device 40 (see FIG. 2, etc.), which will be described later, for adjusting the output of the electron beam e provided in conjunction with the accelerator tube 13 will be described later.

A scanning tube 16 is connected to the acceleration tube 13 at its lower end. The acceleration tube 13 and the scanning tube 16 communicate with each other through an internal space 17, and the electron beam e advances from the accelerating tube 13 toward the scanning tube 16 in the internal space 17. The scanning tube 16 has a narrow upper end and a shape that widens toward the bottom. The scan tube 16 is provided with a scan coil 18 at its narrow upper end. The scanning coil 18 deflects the direction of the electron beam e generated by the accelerator tube 13 based on the energization thereof, that is, scans the electron beam e.

A substantially rectangular opening window 19 is provided at the lower end of the scanning tube 16, for example. A substantially rectangular window foil 20 is attached to the opening window portion 19. The window foil 20 is a very thin metal foil, and is made of, for example, a titanium-based metal material. The window foil 20 has the function of sealing the opening window portion 19 while transmitting the electron beam e. In other words, the internal space 17 spanning the acceleration tube 13 and the scanning tube 16 is configured as a sealed space. The internal space 17 is kept in a vacuum state, for example, by driving a vacuum pump 21 connected to the scanning tube 16, at least during the period when the electron beam e is generated.

The filament power source 12, accelerating electrode power source 15, scanning coil 18, and vacuum pump 21 described above are controlled by a control device 22. The control device 22 controls the output of the electron beam e through the power sources 12 and 15, controls the scanning of the electron beam e through the scanning coil 18, and controls the vacuum in the internal space 17 of the acceleration tube 13 and the scanning tube 16 through the vacuum pump 21. Make adjustments, etc.

Then, the electron beam e emitted through the window foil 20 attached to the opening window portion 19 is irradiated onto the object 24 to be irradiated, which is transported in the transport direction x by the transport device 23, for example. In this case, the electron beam irradiation device 10 is arranged such that the longitudinal direction of the substantially rectangular opening window portion 19 is directed in the transport orthogonal direction y of the transport device 23. A predetermined scan of the electron beam e including the transport direction x and the transport orthogonal direction y is performed, and a substantially rectangular irradiation area A corresponding to the opening window portion 19 is irradiated. The effect of irradiating the object 24 with the electron beam e can be expected to be, for example, improving the properties of the material, adding functionality, and sterilizing/sterilizing the material.

[Detailed configuration of accelerator tube and short circuit device]
The accelerator tube 13 and the short circuit device 40 provided therewith will be explained. Note that FIG. 2 schematically shows the accelerating tube 13 and the short-circuiting device 40, and FIGS. 3 to 6 show the actual structures of the accelerating tube 13 and the short-circuiting device 40.

As shown in FIGS. 2 and 3, the acceleration tube 13 includes an insulating tube body 30 having a cylindrical shape long in the direction of the axis L1, and a plurality of acceleration electrodes 14 are integrated into the tube body 30. ing. The plurality of accelerating electrodes 14 have the same shape and are arranged in parallel at equal intervals in the direction of the axis L1. The accelerating electrode 14 has an inner protrusion piece 14 a that protrudes inward from the tube body 30 and an outer electrode portion 14 b that protrudes to the outside of the tube body 30 . The inner protrusion piece 14a is shown in FIG. 2, and is not shown in FIGS. 3 and 4.

A plurality of shield rings 31 are supported on the radially outer side of the acceleration tube 13 by a support member (not shown) so as to form pairs with the plurality of acceleration electrodes 14, respectively (see FIG. 3). The shield ring 31 is made of a metal material and is electrically connected to the accelerating electrode 14 through a connecting conductor 32 that may be integrated with or separate from the accelerating electrode 14 . The shield ring 31 is provided to alleviate the electric field around the acceleration tube 13.

A predetermined gap S is provided between the shield ring 31 and the acceleration electrode 14 in the radial direction (see FIG. 3). This gap S is also continuous in the direction of the axis L1 of the acceleration tube 13, and a short circuit device 40 is arranged in a space where the gap S is continuous in the direction of the axis L1. In FIG. 2, in order not to complicate the drawing, the radial positions of the shield ring 31, the short-circuiting device 40, and the contact portions 34, which will be described later, provided on the accelerating electrode 14 are shown at different positions from the actual structure shown in FIG. 3 and the like.

As shown in FIGS. 3 and 4, a bearing 33 is provided on the outer electrode portion 14b of each accelerating electrode 14. That is, a plurality of bearings 33 are provided for the acceleration tube 13 and are arranged at equal intervals in the direction of the axis L1 of the acceleration tube 13. Each bearing 33 has a pair of rolling elements 33a that can roll, and the pair of rolling elements 33a sandwich a convex portion 44b provided on a movable joint 44 of the short circuit device 40, which will be described later. The pair of rolling elements 33a of each bearing 33 supports the movable joint 44 via the protruding portion 44b while allowing smooth movement in the direction of the axis L1 by rolling.

Further, a contact portion 34 is provided on the outer electrode portion 14b of each accelerating electrode 14, with a distance from the bearing 33. That is, a plurality of contact portions 34 are provided for the acceleration tube 13 and are arranged at equal intervals in the direction of the axis L1 of the acceleration tube 13. Note that the contact portion 34 of this embodiment is omitted for the several acceleration electrodes 14 from the top end of the acceleration tube 13, and is provided for each of the subsequent acceleration electrodes 14 up to the bottom end.

Each contact portion 34 includes a pair of contacts 34a each having a substantially spherical shape, and a pair of support springs 34b that respectively support each contact 34a. When a first conductor 45 provided on a movable joint 44 (described later) of the short-circuiting device 40 is located, each contact 34a elastically conducts the first conductor 45 with a pair of contacts 34a supported by support springs 34b. be held between. Further, the contact 34a and support spring 34b of each contact portion 34 are made of a conductive metal material. In each contact portion 34, a pair of contacts 34a are electrically connected to the acceleration electrode 14 via support springs 34b, respectively. In other words, when the pair of contacts 34a sandwich the first conductor 45, they come into elastic and electrical contact with each other, and the first conductor 45 and the accelerating electrode 14 having the contact portion 34 sandwiching the first conductor 45 are connected to each other. electrically connected. Further, the pair of contacts 34a of each contact portion 34 can continuously hold and contact the first conductor 45, which moves in the vertical direction together with the movable joint 44. When the first conductor 45 contacts the plurality of contacts 34a at the same time, the plurality of acceleration electrodes 14 are short-circuited to each other through the first conductor 45 and have the same potential.

In addition, in the contacts 34a of this embodiment, the external shape of the pair of contacts 34a, the length of the support spring 34b, etc. are optimized, and the first conductor 45 is always clamped at approximately the center in the width direction. Care has been taken to make this possible. Care has been taken to ensure that the contact 34a and the first conductor 45 are always in a stable contact state.

The short-circuiting device 40 changes the number of accelerating electrodes 14 not short-circuited or short-circuited to have the same potential as the ground potential from time to time. The short-circuiting device 40 can suppress the acceleration of the electron beam e after the short-circuited accelerating electrode 14, and is therefore provided along with the accelerating tube 13 to adjust the output of the electron beam e.

As shown in FIGS. 2 to 6, the short circuit device 40 includes a feed screw mechanism 41. As shown in FIGS. The feed screw mechanism 41 has a feed screw 42 made of a long rod-shaped male thread. In the feed screw mechanism 41, the feed screw 42 is rotatably supported such that the axial direction of the feed screw 42 is parallel to the direction of the acceleration tube 13 and the axis L1. The feed screw 42 has a lower end connected to a drive motor 43 (see FIG. 2), and is rotationally driven by the drive motor 43. A movable joint 44 is screwed to the feed screw 42 through its own screw hole 44a. Since the movable joint 44 is non-rotatably supported around the feed screw 42 by the bearing 33 on the acceleration tube 13 side, when the feed screw 42 rotates, the feed screw 42 moves in the axial direction, that is, the acceleration tube 13 is moved in the direction of axis L1. Further, by changing the rotation direction of the feed screw 42, upward or downward movement of the movable joint 44 along the axis L1 direction of the acceleration tube 13 can be switched.

Moreover, the feed screw 42 of this embodiment is configured with a left-hand thread instead of a general right-hand thread. Therefore, when the movable joint 44 is rotated to move it upward, a pressing force is generated against the movable joint 44 in a direction toward the accelerating electrode 14 side. In other words, the accelerating electrode 14 side is provided with a bearing 33 and a contact portion 34, which will be described later, and consideration is given to ensure that the bearing 33 and the contact portion 34 function more reliably, especially when the movable joint 44 moves upward. .

Movable joint 44 is made from an insulating material. The movable joint 44 has a protruding portion 44b on the surface facing the acceleration tube 13 side. The protruding portion 44b has a rectangular cross section, for example, and extends along the axial direction of the screw hole 44a of the movable joint 44, that is, the axial direction of the feed screw 42. In a side view of the acceleration tube 13 (see FIG. 6), the protruding portion 44b is set to have a length X1 spanning approximately three of the acceleration electrodes 14 scattered in the direction of the axis L1 of the acceleration tube 13. . The movable joint 44 has at least two protruding portions 44b scattered in the direction of the axis L1 of the acceleration tube 13, and depending on the position, three portions of the protruding portions 44b at the bearings 33 of the accelerating electrode 14 at each time during its movement process. This is a supported configuration. That is, since the movable joint 44 is supported by at least two bearings 33, and depending on the position, three bearings 33, the posture of the movable joint 44 is more stable when moving and when stopped.

A first conductor 45 is attached to the movable joint 44 via a first mounting plate 46 in correspondence with the contact portion 34 on the acceleration tube 13 side. The first mounting plate 46 is made of a metal plate material. The first conductor 45 is made of a conductive metal material and has a flexible long strip shape. One end 45a of the first conductor 45 is fixed to the lower part of the first mounting plate 46 (see FIG. 6). One end portion 45a of the first conductor 45 moves together with the movable joint 44 in the vertical direction along the axis L1 direction of the acceleration tube 13.

The first conductor 45 has its other end 45b connected to a first winder 47 (see FIG. 2), and is provided so that it can be wound up by the first winder 47. The first conductor 45 has shape memory properties such that it can be wound by a first winder 47, for example. When the above-described movable joint 44 moves upward away from the first winder 47, the first conductor 45 whose one end portion 45a moves integrally with the movable joint 44 resists winding around the first winder 47. and extends in the axial direction. On the other hand, when the movable joint 44 moves downward toward the first winder 47, the first conductor 45 wraps around the first winder 47 and contracts in the axial direction. The first conductor 45 contacts the contact portions 34 of the acceleration electrodes 14 scattered in the direction of the axis L1 of the acceleration tube 13, and in this case moves forward and backward in the vertical direction as the movable joint 44 moves, while being held between the pair of contacts 34a. .

A first guide 48 is attached to the first mounting plate 46 between itself and the movable joint 44 . The first guide 48 is made of an insulating material and has a rectangular plate shape, for example. In a plan view of the acceleration tube 13 (see FIG. 4), the first guide 48 has its own tip 48a facing the acceleration electrode 14 side. The tip end 48a of the first guide 48 does not come into contact with the accelerating electrode 14, or comes into contact when the movable joint 44 swings in the direction perpendicular to the axis of the feed screw 42. The first guide 48 restricts further movement of the movable joint 44 due to vibration or the like.

In addition, in a side view of the acceleration tube 13 (see FIG. 6), the first guide 48 is set to have a length X2 spanning approximately three of the acceleration electrodes 14 scattered in the direction of the axis L1 of the acceleration tube 13. ing. The first guide 48 can come into contact with at least two accelerating electrodes 14, and depending on the position, it can come into contact with three or four accelerating electrodes 14. In other words, the first guide 48 can stably contact the accelerating electrodes 14 scattered in the direction of the axis L1, and thus contributes to stabilizing the posture of the movable joint 44 during movement and when stopped.

Further, a second guide 49 is attached to the first mounting plate 46 between itself and the first conductor 45 . The second guide 49 is made of an insulating material and has a rectangular plate shape, for example. In a plan view of the acceleration tube 13 (see FIG. 4), the second guide 49 has its own tip 49a facing the shield ring 31 side. The tip 49a of the second guide 49 does not come into contact with the shield ring 31, or comes into contact when the movable joint 44 swings in the direction perpendicular to the axis of the feed screw 42. The second guide 49 restricts further movement of the movable joint 44 due to vibration or the like.

Further, in a side view of the acceleration tube 13 (see FIG. 6), the second guide 49 is set to have the same length X2 as the first guide 48. The second guide 49 can also come into contact with at least two shield rings 31, and depending on the position, can come into contact with three or four shield rings 31. Further, the second guide 49 is provided at the same vertical position as the first guide 48. The second guide 49 can also stably abut against the shield rings 31 scattered in the direction of the axis L1, and thus contributes to stabilizing the posture of the movable joint 44 during movement and when stopped.

A second conductor 50 is attached to the movable joint 44 on the opposite side of the first attachment plate 46 via a second attachment plate 51 . The second mounting plate 51 is made of a conductive metal plate material. The second conductor 50 is made of a conductive metal material and has a flexible long strip shape. One end 50a of the second conductor 50 is fixed to the lower part of the second mounting plate 51 (see FIG. 6). The one end portion 50a of the second conductor 50 also moves integrally with the movable joint 44 in the vertical direction along the axis L1 direction of the acceleration tube 13.

The second conductor 50 has its other end 50b connected to a second winder 52 (see FIG. 2), and is provided so that it can be wound up by the second winder 52. The second conductor 50, like the first conductor 45, has shape memory properties such that it can be wound by a second winder 52, for example. Therefore, when the above-described movable joint 44 moves upward, the second conductor 50 extends in the axial direction against the winding around the second winder 52, and when the movable joint 44 moves downward, the second conductor 50 50 is contracted in the axial direction while being wound around the second winder 52. Similarly to the first conductor 45, the second conductor 50 also moves forward and backward in the vertical direction as the movable joint 44 moves.

A contact spring 53 is fixed to the upper part of the second mounting plate 51. Contact spring 53 is made of a conductive metal material. The contact spring 53 is electrically connected to the second conductor 50 through the second mounting plate 51. The contact spring 53 has its own tip 53a facing the shield ring 31 side. The tip portion 53a of the contact spring 53 comes into elastic and electrical contact with the shield ring 31 when the shield ring 31 is positioned. As described above, the shield ring 31 is electrically connected to the accelerating electrode 14 located at the same axial position through the connecting conductor 32 (see FIG. 3). Further, the contact spring 53 is electrically connected to the second conductor 50. Therefore, when the contact spring 53 comes into contact with the shield ring 31, the corresponding acceleration electrode 14 is electrically connected to the second conductor 50.

Note that when the contact spring 53 is electrically connected to any shield ring 31, that is, any corresponding acceleration electrode 14, one end 45a of the first conductor 45 is electrically connected to the acceleration electrode 14 located one step below. (See Figure 6). That is, the contact spring 53 and the one end portion 45a of the first conductor 45 are configured in a positional relationship such that they are simultaneously electrically connected to each of the acceleration electrodes 14 adjacent to each other in the vertical direction.

Further, a third guide 54 is attached to the second mounting plate 51. The third guide 54 is made of an insulating material and has a rectangular plate shape, for example. In a plan view of the acceleration tube 13 (see FIG. 4), the third guide 54 has a first end 54a facing the acceleration electrode 14 side and a second end 54b facing the shield ring 31 side. The first and second ends 54a and 54b of the third guide 54 are not in contact with the accelerating electrode 14 and the shield ring 31, respectively, or when the movable joint 44 swings in the direction perpendicular to the axis of the feed screw 42, etc. They touch each other. The third guide 54 restricts further movement of the movable joint 44 due to vibration or the like.

Further, in a side view of the acceleration tube 13 (see FIG. 6), the third guide 54 is set to have the same length X2 as the first and second guides 48 and 49. The third guide 54 can also come into contact with at least two accelerating electrodes 14 and shield rings 31, and depending on the position, it can come into contact with three or four accelerating electrodes 14 and shield rings 31. . Further, the third guide 54 is provided at the same vertical position as the first and second guides 48 and 49. The third guide 54 can also stably contact the acceleration electrodes 14 and the shield ring 31 that are scattered in the direction of the axis L1, contributing to stabilizing the posture of the movable joint 44 when moving and when stopped. do.

Further, the third guide 54 and the first and second guides 48 and 49 described above are connected to the accelerating electrode 14 and the shield ring 3 which are surrounding members, such as when vibration occurs in the direction perpendicular to the axis of the feed screw 42 in the movable joint 44. The configuration is such that they contact each other preferentially. In other words, the configuration is such that a part of the movable joint 44, the first and second mounting plates 46, 51, etc. do not come into contact with the accelerating electrode 14 and the shield ring 31. Therefore, the guiding functions of the first to third guides 48, 49, and 54 are fully exhibited. Incidentally, the portions of the first to third guides 48, 49, and 54 that can come into contact with surrounding members are configured with curved surfaces.

The other ends 45b and 50b of the first conductor 45 and the second conductor 50 are respectively grounded via a detection circuit 55 including an ammeter (not shown) (see FIG. 4). Therefore, each acceleration electrode 14 electrically connected to the first and second conductors 45 and 50 has the same potential as the ground potential. Note that in the detection circuit 55, current detection of the first and second conductors 45 and 50 is performed in separate systems, and it is possible to detect each of the beam current and scattering state of the electron beam e.

[Operation (effect) of this embodiment]
The operation of this embodiment will be explained.
In adjusting the output of the electron beam e emitted from the electron beam irradiation device 10, when setting the output to the maximum, the short circuit device 40 arranges the movable joint 44 at the lowest position. In this case, the contact spring 53 may or may not be in contact with the shield ring 31 located at the lowest end. That is, there is no short-circuited part of the accelerating electrodes 14 by the short-circuiting device 40, and all the accelerating electrodes 14 are made to have independent and different potentials. Thereby, all of the accelerating electrodes 14 function to accelerate the electron beam e, and the generated electron beam e has a maximum output.

In order to adjust the electron beam e to a lower output than the maximum output, the shorting device 40 reduces the number of accelerating electrodes 14 that cause the movable joint 44 to function to accelerate the electron beam e according to its desired output. (See Figure 2). That is, the short circuit device 40 moves the movable joint 44 upward to a position where the contact spring 53 contacts the shield ring 31 connected to the accelerating electrode 14 according to the desired output, and then stops. As a result, the acceleration electrode 14 connected to the shield ring 31 with which the contact spring 53 comes into contact is brought to the ground potential by the second conductor 50. Furthermore, the acceleration electrode 14 located one step below is brought to the ground potential by the first conductor 45 . Furthermore, if there is an accelerating electrode 14 after that, the accelerating electrode 14 is short-circuited by the first conductor 45, and both become at ground potential. The plurality of accelerating electrodes 14 that are at ground potential do not function to accelerate the electron beam e.

In such output adjustment of the electron beam e, the short circuit device 40 drives its own feed screw mechanism 41 to move the movable joint 44 up and down in order to change the number of accelerating electrodes 14 that contribute to acceleration of the electron beam e. I'm letting you do it. In this embodiment, the movable joint 44 is provided with first to third guides 48, 49, and 54 (see FIG. 4), and the distal end 48a of the first guide 48 and the first end 54a of the third guide 54 are connected to each other. Two locations can come into contact with the accelerating electrode 14 side. Furthermore, two locations, the tip end 49a of the second guide 49 and the second end 54b of the third guide 54, can come into contact with the shield ring 31 side. That is, when the movable joint 44 swings in the direction perpendicular to the axis of the feed screw 42, the first to third guides 48, 49, and 54 preferentially abut against the accelerating electrode 14 and the shield ring 31, which are the surrounding members. Therefore, the guiding functions of the first to third guides 48, 49, and 54 are fully exhibited, and the posture of the movable joint 44 when moving and stopping becomes stable, resulting in stable operation. The feed screw mechanism 41 is particularly useful because the feed screw 42, which is in the shape of a long rod, is likely to tilt or bend, and play is likely to occur between the feed screw 42 and the movable joint 44.

Further, the first to third guides 48, 49, and 54 can come into contact with at least two accelerating electrodes 14 and shield rings 31, and depending on the position, three or four accelerating electrodes 14 and shield rings 31 can come into contact with each other. It has a sufficient length to be able to come into contact with the ring 31 (see FIG. 6). Therefore, even if the accelerating electrodes 14 and the shield ring 31 are scattered in the direction of the axis L1, the posture of the movable joint 44 when moving and stopping is controlled by the guiding functions of the first to third guides 48, 49, and 54. It is stable and the operation becomes more stable.

Here, in the comparative example shown in FIGS. 7 and 8, in the direction of the axis L1 of the acceleration tube 13, the protruding portion 44x of the movable joint 44 corresponds to one bearing 33 scattered in the direction of the axis L1, or two depending on the position. The length is set to be X3, which is supported by two parts. Furthermore, a guide 60 corresponding to the first guide 48 is provided on the first mounting plate 46 side of the movable joint 44, and a guide corresponding to the second guide 49 is omitted. The guide 61 corresponding to the third guide 54 on the second mounting plate 51 side is small. In other words, the tip 60a of the guide 60 and the end 61a of the guide 61 can come into contact with the accelerating electrode 14 at two locations, but the contact of the guide with the shield ring 31 is not particularly considered. Furthermore, in the direction of the axis L1 of the acceleration tube 13, each guide 60, 61 is set to a length X4 that can contact two acceleration electrodes 14 and does not contact any more acceleration electrodes 14.

Therefore, when the movable joint 44 swings in the direction perpendicular to the axis of the feed screw 42, the posture of the movable joint 44 when moving and when stopped is unstable compared to the embodiment. Furthermore, the first mounting plate 46 gets caught on the accelerating electrodes 14 and the shield ring 31 scattered in the direction of the axis L1, so that stable operation cannot be expected compared to the embodiment. Note that the contact portion 34x using the short support spring 34bx and the large contactor 34ax makes contact with the first conductor 45 shifted from the center in the width direction to the end side. Therefore, when the movable joint 44 swings, there is a possibility that a stable contact state between the contact portion 34x and the first conductor 45 cannot be guaranteed.

On the other hand, the feed screw mechanism 41 of the short-circuiting device 40 of the present embodiment has a stable operation in which the operation of the movable joint 44 eliminates some of the concerns of the comparative example, and through the operation of the short-circuiting device 40. This contributes to improving the reliability of the electron beam irradiation device 10.

[Effects of this embodiment]
The effects of this embodiment will be explained.
(1) The short circuit device 40 provided along with the acceleration tube 13 moves the movable joint 44 along the axis L1 direction of the acceleration tube 13 by rotation of the feed screw 42 of the feed screw mechanism 41, and the acceleration electrode 14 is moved. The first and second conductors 45 and 50 for short-circuiting are moved back and forth. When the movable joint 44 swings in the direction perpendicular to the axis of the feed screw 42 during movement in the direction of the axis L1, the first to third guides 48, 49, 54 provided in the movable joint 44 move the acceleration electrode 14 and the shield ring. It is possible to make preferential contact with each of 31. In other words, since it becomes possible to fully demonstrate the guide function of each guide 48, 49, 54, it is possible to stabilize the posture of the movable joint 44 when it moves and when it stops. Thereby, through the operation of short-circuiting the accelerating electrodes 14 by the short-circuit device 40, it is possible to fully expect the reliability of the electron beam irradiation device 10 to be improved.

(2) When the movable joint 44 swings in the direction perpendicular to the axis of the feed screw 42, each part (48a, 49a, 54a, 54b) of each guide 48, 49, 54 moves to the acceleration electrode 14 and the shield ring 31, respectively. It is possible to make contact at two places each. This makes the posture of the movable joint 44 more stable when it moves and when it stops, and it can be expected that the operation of the short circuit device 40 will be sufficiently improved.

(3) The length X2 of each guide 48, 49, 54 in the axis L1 direction is optimized, and each guide 48, 49, 54 has a length corresponding to at least two of the acceleration electrode 14 and the shield ring 31, and depending on the position, three. With the above, contact is possible. This also makes it possible to further stabilize the posture of the movable joint 44 when it moves and when it stops, and it is fully expected that the operation of the short circuit device 40 will be improved.

(4) The length X1 of the protruding portion 44b of the movable joint 44 in the axis L1 direction is optimized, and the protruding portion 44b is equal to two bearings 33 aligned in the axis L1 direction, or depending on the position, three or more lengths. I'm trying to get support. This also makes it possible to further stabilize the posture of the movable joint 44 when it moves and when it stops, and it is fully expected that the operation of the short circuit device 40 will be improved.

(5) A left-handed thread is used for the feed screw 42, so that a pressing force is generated on the movable joint 44 in a direction toward the accelerating electrode 14 side when the movable joint 44 moves upward. Since the bearing 33 that supports the movable joint 44 and the contact portion 34 with the first conductor 45 that operates integrally with the movable joint 44 are provided on the accelerating electrode 14 side, the bearing is more securely supported when the movable joint 44 moves upward. 33 and the contact portion 34 can be expected to function.

[Example of change]
This embodiment can be modified and implemented as follows. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

- In the above embodiment, the movable joint 44 was provided with three guide members, the first to third guides 48, 49, and 54, but the number of guide members may be two or less, or four or more. When the movable joint 44 swings in the direction perpendicular to the axis of the feed screw 42, it is sufficient that the guide member can contact the accelerating electrode 14 and the shield ring 31 preferentially.

- In the above embodiment, the tip portion 48a and the first end portion 54a of the first and third guides 48 and 54 can come into contact with the accelerating electrode 14, and the second and third guides 49 and 54 can come into contact with each other. Two places, the tip end 49a and the second end 54b, were able to come into contact with the shield ring 31. The guide member may contact the accelerating electrode 14 and the shield ring 31 at one location, or at three or more locations. Preferably, the guide member is capable of contacting the accelerating electrode 14 and the shield ring 31 at two or more locations, respectively.

- In the embodiment described above, each guide 48, 49, 54 is set to a length X2 in the axis L1 direction that allows contact with at least two of the accelerating electrode 14 and the shield ring 31, and depending on the position, three or more. However, the length in the axial direction may be changed as appropriate. Further, each guide 48, 49, 54 may be set to have a different axial length.

- In the above embodiment, the length X1 is set so that the convex portion 44b of the movable joint 44 is supported by two bearings 33 arranged in the direction of the axis L1, and depending on the position, by three or more bearings. , the length in the axial direction may be changed as appropriate.

- In the above embodiment, the protruding portion 44b of the movable joint 44 is supported by the pair of rolling elements 33a of the bearing 33, but the support configuration of the movable joint 44 is not limited to this, and may be modified as appropriate. Good too.

- In the above embodiment, the contact structure is such that the first conductor 45 is held between the pair of contacts 34a of the contact portion 34, but the contact structure with the first conductor 45 is not limited to this, and may be changed as appropriate. good.

- In the above embodiment, two conductors were used as the first and second conductors 45 and 50, but a configuration using one conductor may be used.
- In the above embodiment, flexible conductors were used as the first and second conductors 45 and 50, but deformably assembled conductors, linear conductors, etc. may also be used.

- In the above embodiment, the first and second conductors 45 and 50 had shape memory properties such that they were wound around the first and second winders 47 and 52 by themselves, but the shape memory properties were not changed. It is also possible to adopt a structure in which winding and unwinding are performed by the driving force of a drive motor or the like using a conductor that does not have a conductor.

- The individual shapes and configurations of the movable members including the movable joint 44 of the above embodiment may be changed as appropriate.
- In the above embodiment, a left-hand thread was used for the feed screw 42, but a general right-hand thread may be used.

- In the above embodiment, the drive motor 43 was used as a drive source for rotationally driving the feed screw 42, but a drive source other than the motor may be used.
- In the above embodiment, the acceleration tube 13 is arranged so that the direction of the axis L1 (in this case, the axial direction of the feed screw 42) is in the vertical direction, but it may be arranged in the diagonal direction or the horizontal direction.

The technical ideas that can be understood from the above embodiment and modifications will be described.
(a) an acceleration tube including a plurality of acceleration electrodes arranged in parallel in the axial direction for generating an electric field for accelerating an electron beam; It is provided in an electron beam irradiation device including a plurality of shield rings arranged in parallel in the direction and electrically connected to each of the accelerating electrodes forming a pair,
In order to change the number of accelerating electrodes that are disposed between the accelerating tube and the shield ring and function to accelerate the electron beam from time to time, the accelerating electrodes that are unnecessary for accelerating the electron beam are A short-circuiting device including a feed screw mechanism that short-circuits a conductor that advances and retreats in the axial direction,
The feed screw mechanism includes a feed screw that is arranged such that its axial direction is parallel to the axial direction of the acceleration tube and is rotationally driven by a drive source, and a feed screw that is rotated in the axial direction by rotation of the feed screw. a movable member that moves to move the conductor forward and backward in the axial direction,
The movable member is provided with a guide member that can preferentially contact each of the acceleration electrode and the shield ring when the movable member swings in a direction perpendicular to the axis of the feed screw.
Short circuit device for electron beam irradiation equipment.

10...Electron beam irradiation device 13...Acceleration tube 14...Acceleration electrode 31...Shield ring 33...Bearing 40...Short circuit device 41...Feed screw mechanism 42...Feed screw 43...Drive motor (drive source)
44...Movable joint (movable member)
44b... Convex portion 45... First conductor (conductor)
48...First guide (guide member)
48a...Tip (part that can be touched)
49...Second guide (guide member)
49a...Tip (part that can be touched)
50...Second conductor (conductor)
54...Third guide (guide member)
54a...first end (abuttable part)
54b...Second end (abuttable part)
e...Electron beam L1...Axis X1...Length X2...Length

Claims (5)

an acceleration tube including a plurality of acceleration electrodes arranged in parallel in the axial direction for generating an electric field for accelerating an electron beam;
a plurality of shield rings arranged in parallel in the axial direction so as to form pairs with the acceleration electrodes on the radially outer side of the acceleration tube, and each shield ring is electrically connected to the pair of acceleration electrodes;
In order to change the number of accelerating electrodes that are disposed between the accelerating tube and the shield ring and function to accelerate the electron beam from time to time, the accelerating electrodes that are unnecessary for accelerating the electron beam are An electron beam irradiation device comprising a short-circuiting device including a feed screw mechanism that short-circuits a conductor that advances and retreats in the axial direction, and in which the output of the electron beam is adjusted by the operation of the feed screw mechanism of the short-circuiting device. ,
The feed screw mechanism of the short-circuiting device includes a feed screw arranged such that its axial direction is parallel to the axial direction of the acceleration tube and rotationally driven by a drive source, and a feed screw that is rotated by the rotation of the feed screw. a movable member that moves in the axial direction to move the conductor forward and backward in the axial direction;
The movable member is provided with a guide member that can preferentially contact each of the acceleration electrode and the shield ring when the movable member swings in a direction perpendicular to the axis of the feed screw.
Electron beam irradiation equipment. The guide member has a portion that can come into contact with each of the acceleration electrode and the shield ring at at least two places when the movable member swings in a direction perpendicular to the axis of the feed screw. ,
The electron beam irradiation device according to claim 1. The guide member has a length that can come into contact with at least two, depending on the position, three or more of the acceleration electrode and the shield ring in the axial direction.
The electron beam irradiation device according to claim 1 or claim 2. Each of the plurality of accelerating electrodes is provided with a bearing, and the plurality of bearings are arranged in parallel in the axial direction, and the movable member is a protruding portion extending in the axial direction that is supported by the bearing. It has
The protruding portion of the movable member is configured to have a length that can support two of the bearings in the axial direction, and depending on the position, three or more of the bearings.
The electron beam irradiation device according to any one of claims 1 to 3. The feed screw mechanism is configured to arrange the feed screw so that its axial direction is directed in the vertical direction, and uses a left-handed screw for the feed screw so that it approaches the accelerating electrode side when the movable member moves upward. The movable member is configured to generate a pressing force in a direction on the movable member;
The electron beam irradiation device according to any one of claims 1 to 4.

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