JP2004053509A - Electron beam irradiation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a phenomenon wherein an irradiation object floats from a mesh conveyor caused by rebounding of cooling wind for window foil cooling from a beam catcher. <P>SOLUTION: This electron beam irradiation device is used for catching an electron beam 12 taken out from an electron beam accelerator 10, and is equipped with the beam catcher 38a having a structure cooled by a coolant flowing in a coolant passage 40. The beam catcher 38a has a roof-shaped part 44 having an angle section elongated in the Y-direction along a center bridge 28 and pointed on the center bridge 28 side on the position opposite to the center bridge 28 of an irradiation window 22. A downward flow of the cooling wind 34 for window foil 26 cooling can be set free in the lateral direction by the roof-shaped part 44. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electron beam irradiation apparatus used to irradiate a sheet-like irradiation target on a mesh conveyor with an electron beam, and to perform processing such as crosslinking, modification, curing, and sterilization of the irradiation target. The present invention relates to a means for preventing a phenomenon in which an object to be irradiated is lifted from a mesh conveyor by a cooling wind for cooling a window foil rebounding from a beam catcher.
[0002]
[Prior art]
FIG. 8 shows a conventional example of this type of electron beam irradiation apparatus. FIG. 9 shows an example around the irradiation window in FIG. 8 together with an object to be irradiated below. The electron beam irradiating apparatus includes a mesh conveyor 4 having a wire mesh 6 on which a sheet-shaped object 2 is placed and transported in a certain direction (here, the X direction). There is provided an electron beam accelerator 10 for irradiating the irradiated object 2 with an accelerated electron beam 12 and subjecting the irradiated object 2 to processing such as crosslinking, modification, curing, and sterilization. The sheet-shaped object 2 includes a thin plate or a film.
[0003]
More specific examples of the mesh conveyor 4 are a wire mesh belt conveyor or a wire mesh chain conveyor. The mesh conveyor 4 (more specifically, the wire mesh 6) is driven in the X direction by a driving roller 8 in this example.
[0004]
In this example, the electron beam accelerator 10 accelerates an electron beam 12 generated by an electron source 14 with an acceleration tube 16, and performs reciprocating scanning in a Y direction orthogonal to the X direction with a scanner 18. Through the irradiation window 22 provided at the tip end of 20 (that is, the electron beam take-out part), the light is taken out (output) into an irradiation atmosphere (for example, the atmosphere).
[0005]
The irradiation window 22 separates the atmosphere inside and outside of the electron beam accelerator 10 (the inside is vacuum, the outside is, for example, the atmosphere), and includes a window foil 26 that allows the electron beam 12 to pass therethrough and a frame body 24 that holds the window foil 26. Have. The opening of the frame 24 serves as an electron beam outlet 27.
[0006]
In this example, the electron beam accelerator 10 takes out the electron beam 12 having a relatively wide width in the X direction, and accordingly, the width in the X direction of the electron beam outlet 27 of the irradiation window 22 is also relatively wide. . For this purpose, a center bar 28 for supporting the window foil 26 and extending in the Y direction is provided at the center of the irradiation window 22 in the X direction. Therefore, the electron beam take-out port 27 is divided into two parts in the X direction by the central beam 28. Such an irradiation window 22 is also called a double window. Since the temperature of the central beam 28 rises due to the irradiation of the electron beam 12, in order to suppress the temperature, the central beam 28 generally has a refrigerant flow path 30 as shown in this example, and a refrigerant flowing therethrough (for example, cooling). Water, the same applies hereinafter).
[0007]
The window foil 26 generates heat due to transmission loss of the electron beam 12. Although the window foil 26 is normally cooled by a refrigerant flowing through a refrigerant flow path (not shown) provided in the frame 24 and a refrigerant flow path 30 provided in the central crosspiece 28, the cooling is not sufficient. is not. Therefore, in this example, a cooling air 34 for cooling the window foil 26 of each of the two divided (that is, two) electron beam outlets 27 of the irradiation window 22 is blown inward from opposing positions in the X direction. A pair of nozzles 32 are provided to cool the window foil 26 more effectively. As shown in FIG. 9, both nozzles 32 extend in the Y direction so as to correspond to the length of each electron beam outlet 27 in the Y direction, and inwardly face each other with the irradiation window 22 interposed therebetween. Are located. A cooling air 34 (for example, compressed air) is supplied to each nozzle 32 from a blower or the like (not shown) through a cooling air duct 36 connected to the nozzle 32.
[0008]
A beam catcher 38 is provided at a position facing the irradiation window 22 with the mesh conveyor 4 (more specifically, the wire mesh 6) interposed therebetween. The beam catcher 38 receives the electron beam 12 from the electron beam accelerator 10 when the object 2 is not below the irradiation window 22 and prevents the electron beam 12 from hitting an undesired place. It is. The conventional beam catcher 38 has a flat plate shape and is arranged (for example, parallel) along the mesh conveyor 4. The beam catcher 38 is structured to be cooled by a refrigerant in order to suppress a rise in temperature due to the irradiation of the electron beam 12. In this example, the beam catcher 38 has a coolant channel 40 and is cooled by the coolant flowing therethrough.
[0009]
[Problems to be solved by the invention]
In the above-mentioned electron beam irradiation apparatus, the cooling air 34 blown inward from both nozzles 32 collides with each other near the center of the irradiation window 22, that is, below the central beam 28, and below the central beam 28. A downward flow is formed. When the object 2 is not present, the downward flow hits the beam catcher 38 through the mesh conveyor 4 (more specifically, the wire mesh 6) and rebounds upward. Since the mesh conveyor 4 has a net shape, the cooling air 34 is well passed through.
[0010]
In this state, when the sheet-shaped object 2 is conveyed below the irradiation window 22 by the mesh conveyor 4, the cooling air 34 rebounds, that is, by the cooling air 34 from below, for example, as shown in FIG. As shown in the example, the vicinity of the tip 2a of the irradiation target 2 is lifted from the mesh conveyor 4. The irradiation target 2 in the form of a sheet is easy to receive the cooling air 34 and is usually light, so that the vicinity of the tip 2a is easily lifted.
[0011]
When the vicinity of the tip 2a of the irradiation target 2 is lifted by the cooling air 34 from below in this way, the electron beam irradiation processing and transport of the irradiation target 2 are adversely affected. For example, (1) the distance between the irradiation target 2 and the irradiation window 22 changes, and the amount of electron beam irradiation on the irradiation target 2 changes from the target. As a result, normal processing of the irradiation object 2 cannot be performed. (2) When the irradiation target 2 rises significantly, the irradiation target 2 deviates from the mesh conveyor 4 or the conveyance of the irradiation target 2 stops, and the normal conveyance of the irradiation target 2 becomes impossible. .
[0012]
When the tip 2a of the irradiation target 2 passes near the center of the irradiation window 22, the downward flow of the cooling air 34 from above is blocked by the irradiation target 2 itself, and the downward flow hits the beam catcher 38. The phenomenon of bouncing no longer occurs. Moreover, since the irradiation target 2 is pressed against the mesh conveyor 4 by the downward flow, the irradiation target 2 does not rise from the mesh conveyor 4.
[0013]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent a phenomenon in which an object to be irradiated is lifted off a mesh conveyor due to the above-described cooling air for cooling a window foil rebounding from a beam catcher.
[0014]
[Means for Solving the Problems]
The first electron beam irradiation apparatus according to the present invention includes a ridge-shaped portion extending along the central beam and having a sharp central beam side at a position on the beam catcher facing the central beam of the irradiation window. It is characterized in that it is provided (claim 1).
[0015]
According to the first electron beam irradiation apparatus, the downward flows of the cooling air blown from the pair of nozzles and formed to collide with each other below the center crosspiece of the irradiation window pass through the mesh conveyor and form a ridge of the beam catcher. And flows along the slope, thereby being released in an oblique lateral direction or lateral direction. Therefore, it is possible to prevent the downward flow of the cooling wind from hitting the beam catcher and bouncing upward again. As a result, it is possible to prevent a phenomenon that the irradiation target is lifted off the mesh conveyor due to the rebound of the cooling wind.
[0016]
The second electron beam irradiation device according to the present invention is arranged between the beam catcher and the mesh conveyor, receives the electron beam taken out of the electron beam accelerator, and is cooled by a refrigerant. An upper beam catcher having a structure and having an opening extending along the center bar at a position facing the center bar of the irradiation window is further provided (claim 2). ).
[0017]
According to the second electron beam irradiation apparatus, the downward flows of the cooling air blown from the pair of nozzles and formed to collide with each other below the center bar of the irradiation window pass through the mesh conveyor and further pass through the upper beam catcher. Through the opening, it reaches the beam catcher below. Even if the downward flow bounces off this beam catcher, it always bounces in a direction that spreads more than the original downward flow, so the cooling air that bounces off the upper beam catcher and is prevented from flowing upward, and the upper beam catcher and the beam below it Escape laterally between the catchers along both beam catchers. As a result, it is possible to prevent a phenomenon that the irradiation target is lifted off the mesh conveyor due to the rebound of the cooling wind.
[0018]
A third electron beam irradiation apparatus according to the present invention is provided between the beam catcher and the mesh conveyor, and has a gap extending along the central beam at a position facing the central beam of the irradiation window. Two windbreak plates arranged so as to be formed between them, an open state in which the two windbreak plates are driven to make the width of the gap not less than the width of the irradiation window, A windbreak plate driving unit that switches to an intermediate state in which the width of the gap is reduced, and a signal indicating detection of the tip by detecting that the tip of the irradiation target has come to a predetermined position before the entrance end of the irradiation window. Object detection means for outputting an electron beam, electron beam output detection means for detecting that an electron beam is being output from the electron beam accelerator, and outputting a signal indicating that the electron beam is being output, and irradiation by the mesh conveyor. Detects the transport speed of the A conveyance speed detection unit that outputs a signal representing a conveyance speed, and a control device that controls the windbreak plate driving unit in response to signals from the irradiation target detection unit, the electron beam output detection unit, and the conveyance speed detection unit. Equipped,
The control device is configured to control the tip of the irradiation object based on a signal representing the detection of the tip and based on the distance between the irradiation object detection means and the entrance end of the irradiation window and the transport speed. A first function for determining the arrival timing at which the light arrives at the entrance end of the irradiation window, and based on the arrival timing, and based on the width between the entrance end and the exit end of the irradiation window and the transport speed. A second function for determining a passage timing at which the tip of the irradiation object comes to an exit end of the irradiation window, and a period during which a signal indicating that the electron beam is being output is being output, wherein the arrival timing and the passage A third function of maintaining the windbreak plate in the intermediate state during the period between the timing and the intermediate state, and maintaining the windbreak plate in the open state during the period before and after the timing. (Claim 4).
[0019]
According to the third electron beam irradiation apparatus, the descending flows of the cooling air blown from the pair of nozzles and formed to collide with each other below the center bar of the irradiation window pass through the mesh conveyor, and are further cooled by two windshields. Through the gap between the plates, it reaches the beam catcher below.
[0020]
The two windshields are switched by the windshield driving unit between an open state in which the width of the gap is equal to or greater than the width of the irradiation window and an intermediate state in which the width of the gap is smaller than that. This switching is automatically performed under the control of the control device.
[0021]
That is, during the period when the signal indicating that the electron beam is being output is being output (that is, during the period when the electron beam is being output from the electron beam accelerator), and during the period between the arrival timing and the passing timing ( That is, the windbreak plate is maintained in the intermediate state (during the period in which the tip of the irradiation object moves from the entrance end to the exit end of the irradiation window), and is maintained in the open state before and after that.
[0022]
With such a control, when the tip of the irradiation object passes below the irradiation window, the windbreak plate is maintained in the intermediate state, so the downward flow of the cooling air flows through the gap between the windshield plates in the intermediate state. Reach the beam catcher below it. Even if the downward flow bounces off with this beam catcher, it always bounces in a direction that spreads more than the original downward flow, so the cooling wind that bounces hits the intermediate state windbreak plate and is prevented from flowing upward, and the intermediate state windbreak plate Escape laterally along the beam catcher below it. As a result, it is possible to prevent a phenomenon that the irradiation target is lifted off the mesh conveyor due to the rebound of the cooling wind.
[0023]
Moreover, during the period before and after the period when the tip of the irradiation object is moving below the irradiation window, that is, during the period when the rising near the tip of the irradiation object due to the downward flow of the cooling air does not matter, the windproof plate is provided. Is maintained in the open state, so that the electron beam output from the electron beam accelerator hits the beam catcher thereunder through the gap of the open windbreak plate. That is, since the electron beam output from the electron beam accelerator is prevented from hitting the windshield, overheating of the windshield can be prevented. As a result, the structure of the windbreak plate can be simplified, for example, as a simple plate.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a view showing an example of an electron beam irradiation apparatus according to the present invention. FIG. 2 is a perspective view showing an example of the beam catcher in FIG. Parts that are the same as or correspond to those of the conventional example shown in FIGS. 8 and 9 are denoted by the same reference numerals, and differences from the conventional example will be mainly described below.
[0025]
This electron beam irradiation device is provided with a beam catcher 38a having the following structure as an alternative to the beam catcher 38 described with reference to FIG. 8, that is, for receiving the electron beam 12 extracted from the electron beam accelerator 10. . That is, the beam catcher 38a extends in the Y direction along the central beam 28 at a position facing, for example, the central beam 28 of the irradiation window 22 on the central portion of the flat plate portion 42, for example. It has a structure in which a ridge-like portion 44 having a pointed mountain-like cross section is provided.
[0026]
Although the illustration of the refrigerant flow path 40 is omitted in FIG. 2, the beam catcher 38a also has a structure that is cooled by the refrigerant flowing through the refrigerant flow path 40, similarly to the beam catcher 38.
[0027]
The width W in the X direction of the base of the ridge 44 ₁ Is such that the downward flow of the cooling air 34 from the irradiation window 22 hits the two slopes 44 a of the ridge 44.
[0028]
The beam catcher 38a, like the conventional beam catcher 38, receives the electron beam 12 output from the electron beam accelerator 10 by the flat plate portion 42 and the ridge portion 44, and prevents the electron beam 12 from hitting an undesired place. It has the effect of doing.
[0029]
Moreover, before the tip 2a of the irradiation target 2 is conveyed below the center bar 28 of the irradiation window 22, the tip 2a is blown from the pair of nozzles 32 and collides with each other below the center bar 28 of the irradiation window 22. The descending flow of the cooling air 34 formed together hits the ridge-like portion 44 of the beam catcher 38a through the mesh conveyor 4 and flows along the two slopes 44a as shown in the illustrated example, thereby obliquely extending in the lateral direction. Escaped sideways. Therefore, it is possible to prevent the downward flow of the cooling air 34 from hitting the beam catcher 38a and rebounding upward. As a result, the phenomenon in which the vicinity of the tip 2a of the irradiation target 2 is lifted by the rebound of the cooling air 34 and the irradiation target 2 rises from the mesh conveyor 4 can be prevented. As a result, it is possible to prevent an adverse effect on the electron beam irradiation processing and transport of the irradiation target 2 as described above.
[0030]
In the electron beam irradiation apparatus shown in FIG. 3, an upper beam catcher 46 is disposed between (eg, in parallel with) the flat-plate-shaped beam catcher 38 and the mesh conveyor 4 described in FIG. The upper beam catcher 46 also receives the electron beam 12 from the electron beam accelerator 10 when the object 2 is not below the irradiation window 22, and has a structure cooled by a refrigerant. In this example, the upper beam catcher 46 has a coolant channel 50 and is cooled by the coolant flowing therethrough.
[0031]
In addition, the upper beam catcher 46 has an opening 48 extending in the Y direction along the center bar 28 at a position facing the center bar 28 of the irradiation window 22, also with reference to FIG. The lower part of the opening 48 is covered by the beam catcher 38.
[0032]
The width W of the opening 48 of the upper beam catcher 46 in the X direction. ₂ Is such that the downward flow of the cooling air 34 from the irradiation window 22 passes through the opening 48. More preferably, the width should be the minimum width through which the descending flow can pass.
[0033]
The upper beam catcher 46 cooperates with the lower beam catcher 38 to receive the electron beam 12 output from the electron beam accelerator 10 and to prevent the electron beam 12 from hitting an undesired place. .
[0034]
Moreover, before the tip 2a of the irradiation target 2 is conveyed below the center bar 28 of the irradiation window 22, the tip 2a is blown from the pair of nozzles 32 and collides with each other below the center bar 28 of the irradiation window 22. The descending flow of the cooling air 34 formed together reaches the beam catcher 38 thereunder through the mesh conveyor 4 and further through the opening 48 of the upper beam catcher 46 as shown in the illustrated example. Even if the descending flow is bounced off by this beam catcher 38, it always bounces in a direction wider than the original descending flow, so that the cooled cooling air 34 hits the upper beam catcher 46 and is blocked from flowing upward. It escapes laterally along the beam catchers 46, 38 between the beam catchers 38 thereunder. As a result, the phenomenon in which the vicinity of the tip 2a of the irradiation target 2 is lifted by the rebound of the cooling air 34 and the irradiation target 2 rises from the mesh conveyor 4 can be prevented. As a result, it is possible to prevent an adverse effect on the electron beam irradiation processing and transport of the irradiation target 2 as described above.
[0035]
The upper beam catcher 46 includes a first upper beam catcher 46a and a second upper beam catcher 46b that are divided (separated) in the X direction with a gap therebetween, as in the example illustrated in FIG. You may comprise. The two upper beam catchers 46a and 46b are arranged on the same plane, and a gap between the two upper beam catchers 46a and 46b is the opening 48. The other parts are the same as those of the upper beam catcher 46, and the description thereof will not be repeated.
[0036]
The electron beam irradiation apparatus shown in FIG. 6 includes two windbreak plates 52 arranged (for example, in parallel) between the flat beam catcher 38 and the mesh conveyor 4 described in FIG. ing. Referring to FIG. 7 as well, the two windbreak plates 52 are formed so as to form a gap 54 extending in the Y direction along the center bar 28 at a position facing the center bar 28 of the irradiation window 22 therebetween. Are arranged on the same plane. The width W of the gap 54 in the X direction ₃ Is variable by the following means.
[0037]
That is, the electron beam irradiation apparatus drives the two windshields 52 in the front-back direction in the X direction as shown by the arrow B (see FIG. 7), and ₃ To the width W of the irradiation window 22 ₄ And the width W of the gap 54 is larger than the open state. ₃ Is provided with a windbreak plate drive unit 56 for switching to an intermediate state in which is reduced. In this example, one windbreak plate drive unit 56 is provided for each windbreak plate 52, but one drive unit that drives the two windbreak plates 52 as described above may be provided. The windbreak plate driving unit 56 is, for example, an air cylinder.
[0038]
As described above, the width W of the gap 54 in the open state ₃ To the width W of the irradiation window 22 ₄ When it is set to the degree or more, the electron beam 12 output from the irradiation window 22 hardly hits the open windshield 52 if its spread is ignored.
[0039]
The width W of the gap 54 in the intermediate state ₃ Is the width W of the opening 48 of the upper beam catcher 46 described above. ₂ As in the case of (1), the descending flow of the cooling air 34 from the irradiation window 22 passes through the gap 54. More preferably, the width should be the minimum width through which the descending flow can pass.
[0040]
The electron beam irradiation apparatus shown in FIG. 6 further includes the following detection means.
[0041]
That is, it is detected that the tip 2a of the irradiation target 2 on the mesh conveyor 4 has come to a predetermined position (upstream side) before the entrance end 22a of the irradiation window 22, and the signal S representing the detection of the tip is detected. ₁ The photoelectric switch 58 is provided as an example of the irradiation object detection unit that outputs the signal. The photoelectric switch 58 can detect the arrival of the tip 2a by being shielded from light by the tip 2a of the irradiation object 2 conveyed by the mesh conveyor 4. The distance L between the photoelectric switch 58 and the entrance end 22a of the irradiation window 22 may be large, for example, several tens cm to several meters, or may be small, for example, several cm to several tens cm. . It may be almost 0. The irradiation object detection means may be other than the photoelectric switch 58, for example, a micro switch or the like.
[0042]
A signal S indicating that the electron beam is being output from the electron beam accelerator 10 when the electron beam 12 is being output is detected. ₂ The electron beam current I flowing through the acceleration power supply 60 ₁ Is provided. When a DC acceleration voltage for accelerating the electron beam 12 is applied to the accelerating tube 16 from the accelerating power source 60 for accelerating the electron beam 12, the electron beam 12 is taken out through the irradiation window 22 and irradiated onto the irradiation target 2, the beam catcher 38, and the like. , The electron beam current I ₁ Flows. The current measuring device 62 calculates the electron beam current I ₁ Of the electron beam current I. ₁ Is greater than or equal to a predetermined value (for example, 0), it is possible to detect that the electron beam 12 is being output. However, the electron beam output detecting means may be a device other than the current measuring device 62, for example, a detector that receives the electron beam 12 extracted from the irradiation window 22 and detects the electron beam 12.
[0043]
A signal S indicating the transport speed v of the irradiation object 2 by the mesh conveyor 4 and indicating the transport speed v ₃ As an example of the conveying speed detecting means for outputting the driving speed, a motor 64 with an encoder for driving the driving roller 8 of the mesh conveyor 4 is provided. Since there is a fixed relationship between the rotation speed of the motor 64 and the transfer speed v of the mesh conveyor 4, the transfer speed v of the irradiation target 2 by the mesh conveyor 4 can be detected based on the rotation speed of the motor 64. . However, the transport speed detecting means may be a device other than the motor 64 with the encoder, for example, a tachometer for detecting the rotational speed of the driving roller 8 or other rollers constituting the mesh conveyor 4.
[0044]
The electron beam irradiation apparatus shown in FIG. ₁ , S ₂ And S ₃ And a control device 66 for controlling the windbreak plate driving section 56 in response to the control signal. The control device 66 has at least first to third functions described below.
[0045]
(1) First function
This corresponds to the signal S representing the tip detection. ₁ And the distance 2 between the photoelectric switch 58 and the entrance end 22a of the irradiation window 22 and the transport speed v of the irradiation target 2, the tip 2a of the irradiation target 2 Arrival timing t coming to the unit 22a ₁ Is a function to calculate and obtain. More specifically, the timing of the tip detection by the photoelectric switch 58 is t ₀ Then, the arrival timing t ₁ Can be obtained by the following equation.
[0046]
(Equation 1)
t ₁ = T ₀ + L / v
[0047]
In that case, the signal S ₃ Directly represents the transport speed v, the signal S ₃ May be used in the above calculation as it is, or when not directly expressed, the signal S ₃ May be converted to the transport speed v and used in the above calculation (the same applies to the second function described below).
[0048]
(2) Second function
This is because the arrival timing t ₁ And the width W between the entrance end 22a and the exit end 22b of the irradiation window 22 ₄ And a passage timing t at which the tip 2a of the irradiation target 2 comes to the exit end 22b of the irradiation window 22 based on the transport speed v of the irradiation target 2 ₂ Is a function to calculate and obtain. More specifically, the passage timing t ₂ Can be obtained by the following equation.
[0049]
(Equation 2)
t ₂ = T ₁ + W ₄ / V
[0050]
(3) Third function
This is the signal S indicating that the electron beam is being output. ₂ Is being output, and the arrival timing t ₁ And passage timing t ₂ The function is to maintain the windbreak plate 52 in the above-mentioned intermediate state during the period between the above and during the period before and after that. In order to execute this control function, the control device 66 controls the windbreak plate driving unit 56.
[0051]
In other words, the third function is performed while the electron beam 12 is being output from the electron beam accelerator 10 and the tip 2 a of the irradiation target 2 is moved from the entrance end 22 a to the exit end of the irradiation window 22. 22b, the windshield 52 is maintained in the intermediate state, and before and after that, ie, before the tip 2a of the irradiation target 2 comes to the entrance end 22a of the irradiation window 22 and at the exit end. After passing through 22b, the windproof plate 52 is to be kept open.
[0052]
During the period when the electron beam 12 is not output from the electron beam accelerator 10, the electron beam irradiation processing is not performed on the irradiation target 2, so that the windshield 52 may be maintained in the intermediate state. , May be maintained in an open state, which is optional.
[0053]
In the electron beam irradiation apparatus shown in FIG. 6, when the tip 2 a of the irradiation target 2 passes below the irradiation window 22 by the above-described control by the control device 66, the windshield 52 is maintained in the intermediate state. Therefore, the downward flow of the cooling air 34 reaches the beam catcher 38 thereunder through the gap 54 between the windshields 52 in the intermediate state. Even if the descending flow is bounced off by the beam catcher 38, it always bounces in a direction that spreads more than the original descending flow. The space between the windbreak plate 52 and the beam catcher 38 below the windbreak plate 52 is laterally released along the both 52 and 38. As a result, the phenomenon in which the vicinity of the tip 2a of the irradiation target 2 is lifted by the rebound of the cooling air 34 and the irradiation target 2 rises from the mesh conveyor 4 can be prevented. As a result, it is possible to prevent an adverse effect on the electron beam irradiation processing and transport of the irradiation target 2 as described above.
[0054]
Moreover, during the period before and after the period in which the tip 2a of the irradiation target 2 is moving below the irradiation window 22, that is, floating near the tip 2a of the irradiation target 2 due to the downward flow of the cooling air 34 does not matter. During the period, the windshield 52 is maintained in the open state, so that the electron beam 12 output from the electron beam accelerator 10 hits the beam catcher 38 thereunder through the gap 54 of the open windshield 52. That is, since the electron beam 12 output from the electron beam accelerator 10 is prevented from hitting the windshield 52, overheating of the windshield 52 can be prevented. As a result, the structure of the windbreak plate 52 can be simplified, for example, as a simple plate.
[0055]
Although the electron beam accelerator 10 has been described above by way of example of a scanning type that scans the electron beam 12, it is not necessarily limited thereto, and may be a non-scanning type that does not scan the electron beam 12.
[0056]
【The invention's effect】
Since the present invention is configured as described above, it has the following effects.
[0057]
According to the first aspect of the present invention, the downward flow of the cooling air for cooling the window foil is released obliquely or laterally by the ridge portion provided in the beam catcher, and the downward flow of the cooling air hits the beam catcher. Since it can be prevented from bouncing upward again, it is possible to prevent the object to be irradiated from rising off the mesh conveyor due to the bouncing of the cooling air.
[0058]
According to the second or third aspect of the present invention, an upper beam catcher having the above-mentioned opening is provided, and the downward flow of the cooling air for cooling the window foil is supplied to the upper beam catcher and the beam catcher thereunder. Can be released in the horizontal direction along both beam catchers, and it is possible to prevent a phenomenon in which the irradiated object rises from the mesh conveyor due to the rebound of the cooling wind.
[0059]
According to the fourth aspect of the present invention, the windshield is provided with the windshield, the windshield driving unit, the detecting means, and the control device. Since the state is maintained, the downward flow of the cooling air for cooling the window foil can be released laterally along the both between the windbreak plate in the intermediate state and the beam catcher thereunder. As a result, it is possible to prevent a phenomenon that the irradiation target is lifted off the mesh conveyor due to the rebound of the cooling wind.
[0060]
Moreover, during the period before and after the period when the tip of the irradiation object is moving below the irradiation window, that is, during the period when the rising near the tip of the irradiation object due to the downward flow of the cooling air does not matter, the windproof plate is provided. Is maintained in an open state, it is possible to prevent the electron beam output from the electron beam accelerator from hitting the windbreak plate and overheating the windbreak plate. As a result, the structure of the windbreak plate can be simplified, for example, as a simple plate.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of an electron beam irradiation apparatus according to the present invention.
FIG. 2 is a perspective view showing an example of a beam catcher in FIG.
FIG. 3 is a diagram showing another example of the electron beam irradiation apparatus according to the present invention.
FIG. 4 is a plan view showing an example around an upper beam catcher in FIG. 3;
FIG. 5 is a plan view showing another example around the upper beam catcher in FIG. 3;
FIG. 6 is a view showing still another example of the electron beam irradiation apparatus according to the present invention.
FIG. 7 is a plan view showing an example around a windbreak plate in FIG. 6;
FIG. 8 is a diagram showing an example of a conventional electron beam irradiation device.
9 is a plan view showing an example around an irradiation window in FIG. 8 together with an object to be irradiated below.
[Explanation of symbols]
2 Irradiated object
2a Tip
4 mesh conveyor
10 electron beam accelerator
12 electron beam
22 Irradiation window
26 Window foil
27 Electron beam outlet
28 Chuo Pier
32 nozzles
34 Cooling air
38, 38a Beam catcher
44 Ridge
46 Upper beam catcher
48 opening
52 Windbreak board
54 gap
56 Windbreak plate drive
66 Control device

Claims (4)

A mesh conveyor having a wire mesh and carrying a sheet-shaped object to be irradiated thereon and transporting the object in the X direction; an electron beam accelerator for irradiating the object to be irradiated on the mesh conveyor with an accelerated electron beam; An irradiation window provided in an electron beam extraction unit of the electron beam accelerator and having a window foil through which an electron beam is transmitted, and an electron beam extraction port divided into two in the X direction by a center beam in the X direction; A pair of nozzles for blowing inwardly cooling air to cool the window foil of the outlet from the opposing position in the X direction from the opposing position in the X direction, and the mesh conveyer is provided at a position opposing the irradiation window. An electron beam irradiation apparatus that receives an electron beam extracted from the electron beam accelerator and has a beam catcher configured to be cooled by a refrigerant.
An electron beam irradiator, wherein a ridge-like portion extending along the central beam and having a sharp central beam side is provided on the beam catcher at a position facing the central beam of the irradiation window. A mesh conveyor having a wire mesh and carrying a sheet-shaped object to be irradiated thereon and transporting the object in the X direction; an electron beam accelerator for irradiating the object to be irradiated on the mesh conveyor with an accelerated electron beam; An irradiation window provided in an electron beam extraction unit of the electron beam accelerator and having a window foil through which an electron beam is transmitted, and an electron beam extraction port divided into two in the X direction by a center beam in the X direction; A pair of nozzles for blowing inwardly cooling air to cool the window foil of the outlet from the opposing position in the X direction from the opposing position in the X direction, and the mesh conveyer is provided at a position opposing the irradiation window. An electron beam irradiation apparatus that receives an electron beam extracted from the electron beam accelerator and has a beam catcher configured to be cooled by a refrigerant.
It is arranged between the beam catcher and the mesh conveyor, receives the electron beam extracted from the electron beam accelerator, has a structure cooled by a refrigerant, and has a central beam of the irradiation window. An electron beam irradiation apparatus, further comprising an upper beam catcher having an opening extending along the center beam at a position facing the center beam. 3. The electron beam irradiation apparatus according to claim 2, wherein the upper beam catcher includes first and second upper beam catchers, and a gap between the two is the opening. A mesh conveyor having a wire mesh and carrying a sheet-shaped object to be irradiated thereon and transporting the object in the X direction; an electron beam accelerator for irradiating the object to be irradiated on the mesh conveyor with an accelerated electron beam; An irradiation window provided in an electron beam extraction unit of the electron beam accelerator and having a window foil through which an electron beam is transmitted, and an electron beam extraction port divided into two in the X direction by a center beam in the X direction; A pair of nozzles for blowing inwardly cooling air to cool the window foil of the outlet from the opposing position in the X direction from the opposing position in the X direction, and the mesh conveyer is provided at a position opposing the irradiation window. An electron beam irradiation apparatus that receives an electron beam extracted from the electron beam accelerator and has a beam catcher configured to be cooled by a refrigerant.
Two sheets are provided between the beam catcher and the mesh conveyor, and are arranged at positions facing the center beam of the irradiation window so as to form a gap extending along the center beam therebetween. A windshield, an open state in which the two windshields are driven to make the width of the gap not less than the width of the irradiation window, and an intermediate state in which the width of the gap is made smaller than the open state. A plate driving unit, an irradiation object detection unit that detects that the front end of the irradiation object has come to a predetermined position before the entrance end of the irradiation window, and outputs a signal indicating the detection of the front end, and the electron beam. An electron beam output detection unit that detects that an electron beam is being output from the accelerator and outputs a signal indicating that the electron beam is being output; and detects a transport speed of the irradiation target by the mesh conveyor and indicates the transport speed. Transfer speed to output signal Means leaving the irradiated object detecting means, and a control device for controlling the windbreak plate driving unit in response to a signal from the electron beam output detecting means and the conveying speed detecting means,
The control device is configured to control the tip of the irradiation object based on a signal representing the detection of the tip and based on the distance between the irradiation object detection means and the entrance end of the irradiation window and the transport speed. A first function for determining the arrival timing at which the light arrives at the entrance end of the irradiation window, and based on the arrival timing, and based on the width between the entrance end and the exit end of the irradiation window and the transport speed. A second function for determining a passage timing at which the tip of the irradiation object comes to an exit end of the irradiation window, and a period during which a signal indicating that the electron beam is being output is being output, wherein the arrival timing and the passage A third function of maintaining the windbreak plate in the intermediate state during a period between the timing and the intermediate state, and maintaining the windbreak plate in the open state during the period before and after the timing. Electron beam irradiation equipment.

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