JP5378723B2 - Electron beam irradiation apparatus and coated wire manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electron irradiation device and a method for hardening a covered conductor, without using a filament, at reduced running cost. <P>SOLUTION: An electron irradiation device 1 includes: a microwave generating section 2; a plasma generating section 3 for generating plasma by, under reduced pressure, applying gas to a microwave generated by the microwave generating section 2; and an electron acceleration section 4 for, under reduced pressure, accelerating electrons contained in the plasma generated by the plasma generating section 3. The electron acceleration section 4 has a container 41 kept under reduced pressure and a differential pumping device 40a, 40b for pumping and depressurizing the interior of the container 41. Provided in the container 41 are an electron accelerating electrode 51, a first mesh electrode 52 constituted by a mesh opposed to the electron accelerating electrode 51 and disposed in an orifice 47 communicating with the plasma generating section 3, and a second mesh electrode 53 constituted by a mesh disposed between the electron accelerating electrode 51 and the first mesh electrode 52 in parallel with the first mesh electrode 52. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an electron beam irradiation apparatus for irradiating an object to be irradiated with an electron beam, and a covered electric wire having a conductive wire and a covering portion made of an organic polymer that covers the outer peripheral surface of the conductive wire. The present invention relates to a method for producing a coated electric wire that promotes a crosslinking reaction of a polymer.

  A covered electric wire having a conductive wire and a covering portion made of an organic polymer that coats the outer peripheral surface of the conductive wire is irradiated with electrons by, for example, an electron beam irradiation device, and the organic polymer is cross-linked by the electrons. The reaction is promoted to improve characteristics such as heat resistance and wear resistance of the covering portion.

  Such an electron beam irradiation apparatus includes, for example, a filament as an electron source, an energization means for discharging electrons from the filament by energizing and heating the filament, and a filament disposed below the filament. Consists of an accelerating tube that accelerates emitted electrons internally by an accelerating electrode, and a scanning tube that converges and scans the accelerated electrons connected to the accelerating tube internally by an electromagnetic coil and irradiates the coated portion of the covered electric wire Is done.

  The filament described above deteriorates over time during use and breaks. However, if the filament breaks during the manufacture of the electric wire, the cross-linking reaction of the covered electric wire being manufactured is not performed at the time of the filament breakage. There was a problem that the yield was reduced due to the occurrence. Furthermore, since the facility is stopped and the filament is replaced, there is a problem that it has a great influence on planned product production.

As a technique for solving such a problem, an electron beam irradiation apparatus (see, for example, Patent Document 1) capable of predicting the life of a filament has been proposed. The electron beam irradiation apparatus includes an adjusting unit that adjusts an AC frequency of the energizing unit so that an amount of electrons per unit time generated in the filament is constant, and a measuring unit that measures a change in the frequency. The lifetime of the filament is predicted from the measurement result by the measuring means. Thus, by predicting the life of the filament, it is possible to systematically replace the filament before the filament deteriorates over time and breaks, thereby improving the production yield and mass productivity of the covered wire. it can.
JP 2001-242299 A

  However, since the electron beam irradiation device described above cannot prevent the filament itself from being broken, there is a problem that the running cost and the replacement work due to the replacement of the filament are troublesome.

  The present invention aims to solve such problems. That is, an object of the present invention is to provide an electron beam irradiation apparatus and a method for curing a coated electric wire that reduce running costs without using a filament.

  In order to solve the above-mentioned problems and achieve the object, the present invention described in claim 1 includes a microwave generating unit that generates a microwave, and the microwave generated by the microwave generating unit into a gas under reduced pressure. An electron beam irradiation apparatus comprising: a plasma generating unit that generates plasma upon application; and an electron accelerating unit that accelerates electrons in the plasma generated in the plasma generating unit under reduced pressure, wherein the electron accelerating unit includes: A container maintained at a reduced pressure; and a decompression device that evacuates and decompresses the inside of the container; and, in the container, a positive electrode that accelerates the electrons, and a plasma generation opposite to the positive electrode A negative electrode composed of a net disposed at a communication port with a portion, and a ground electrode composed of a net disposed in parallel with the negative electrode between the positive electrode and the negative electrode, It is provided an electron beam irradiation apparatus characterized.

  According to a second aspect of the present invention, there is provided the electron beam irradiation apparatus according to the first aspect, wherein the electron accelerating unit includes an object to be irradiated with accelerated electrons, the positive electrode in the container. The electron beam irradiation apparatus is characterized in that an irradiated object support portion positioned between the electrode and the ground electrode is provided.

  According to a third aspect of the present invention, there is provided the electron beam irradiation apparatus according to the second aspect, wherein the electron accelerating portion includes one cylindrical body in a direction intersecting with each other via the space of the electron accelerating portion. And the other cylindrical body are provided, respectively.

  According to a fourth aspect of the present invention, there is provided the electron beam irradiation apparatus according to the third aspect, wherein the decompression device is provided at an end of the cylindrical body. It is.

  According to a fifth aspect of the present invention, in the electron beam irradiation apparatus according to the third or fourth aspect, the long object to be irradiated is arranged in the one cylindrical body. This is a featured electron beam irradiation apparatus.

  The present invention described in claim 6 is the electron beam irradiation apparatus according to any one of claims 1 to 5, wherein the pressure in the container is 0.1 to 0.3 Pa. The electron beam irradiation apparatus is characterized in that an interval between the plus electrode and the ground electrode is 10 to 50 mm.

  According to a seventh aspect of the present invention, there is provided the electron beam irradiation apparatus according to the sixth aspect, wherein an interval between the plus electrode and the ground electrode is 15 to 35 mm. Device.

The present invention described in claim 8 irradiates electrons to a coated electric wire having a conducting wire and a coating portion made of an organic polymer that coats the outer peripheral surface of the conducting wire to carry out a crosslinking reaction of the organic polymer. in the method for manufacturing a covered electric wire to promote, by applying a microwave to the gas to generate plasma, negative electrode placed in this order from the plasma generation side, the ground electrode, and, by the positive electrode, by the negative electrode from in the plasma after drawn out electrons by the ground electrode from in the plasma to remove particles positively charged to cure the coated portion by irradiating the electrons are accelerated by the positive electrode coating portion of the covered wire It is a manufacturing method of the covered electric wire characterized by this.

  According to the first aspect of the present invention, the microwave generator that generates the microwave, and the plasma generator that generates the plasma by applying the microwave generated by the microwave to the gas under reduced pressure, And an electron accelerating unit for accelerating the electrons in the plasma generated in the plasma generating unit under reduced pressure, so that the electrons in the plasma can be accelerated and irradiated to the object. Therefore, it is not necessary to use a filament as an electron source, and therefore it is possible to eliminate the running cost and labor required for replacement work when the filament is disconnected.

  According to the invention described in claim 1, the electron accelerating unit has a container maintained at a reduced pressure, and a decompression device that evacuates and decompresses the inside of the container. Is arranged in parallel with the negative electrode between the positive electrode and the negative electrode. And a ground electrode composed of a mesh body, so that the inside of the container is depressurized by a decompression device to reduce the argon gas in the electron accelerating portion, and the negative electrode has a positive charge in the plasma. Therefore, the electrons are efficiently accelerated without colliding with the positively charged particles or argon atoms, so that the voltage of the electron acceleration electrode can be set relatively low. When Moni, power consumption can be reduced.

  According to the second aspect of the present invention, the electron accelerating unit is provided with the irradiated object supporting unit that positions the irradiated object irradiated with the accelerated electrons between the plus electrode and the ground electrode in the container. Therefore, the irradiated object is reliably positioned between the positive electrode and the ground electrode, that is, in the region where the electrons are accelerated, and therefore, the irradiated electrons can be reliably irradiated with the accelerated electrons. .

  According to the invention described in claim 3, since the electron acceleration part is provided with one cylindrical body and the other cylindrical body in directions intersecting with each other through the space of the electron acceleration part, A long object to be irradiated can be arranged in the cylindrical body, or a decompression device can be connected to the cylindrical body. Therefore, the operability and ease of handling of the electron beam irradiation apparatus can be improved.

  According to the invention described in claim 4, since the decompression device is provided at the end of the cylindrical body, the inside of the container is surely exhausted and decompressed, so that the electrons are efficiently accelerated. be able to.

  According to the invention described in claim 5, since the long object to be irradiated is arranged in one cylindrical body, the object to be irradiated is surely positioned in the space in the electron accelerating portion. The irradiated object can be reliably irradiated with the accelerated electrons.

  According to the invention described in claim 6, since the pressure in the container is 0.1 to 0.3 Pa, and the distance between the plus electrode and the ground electrode is 10 to 50 mm, The irradiated object can be positioned between the ground electrode. In addition, electrons can be efficiently accelerated between the plus electrode and the ground electrode, and an irradiation object positioned between the plus electrode and the ground electrode can be irradiated with a high-energy electron beam.

  According to the invention described in claim 7, since the distance between the plus electrode and the ground electrode is 15 to 35 mm, electrons can be accelerated more efficiently between the plus electrode and the ground electrode. The irradiated object positioned between the plus electrode and the ground electrode can be irradiated with a higher energy electron beam.

  According to the eighth aspect of the present invention, a microwave is applied to a gas to generate plasma, positively charged particles are removed from the plasma by a negative electrode, and electrons are extracted from the plasma by a ground electrode. After that, by accelerating this electron with the positive electrode and irradiating the coating part of the covered electric wire to cure the coating part, it is possible to eliminate the running cost and the trouble of the replacement work due to replacement at the time of filament breakage, The negative electrode eliminates the positively charged particles in the plasma, and the electrons are efficiently accelerated without colliding with the positively charged particles or argon atoms. The voltage can be set relatively low, and the power consumption can be reduced.

  Hereinafter, an electron beam irradiation apparatus according to an embodiment of the present invention will be described with reference to FIGS. An electron beam irradiation apparatus 1 according to an embodiment of the present invention includes, for example, a conductive wire made of a conductive metal material such as copper or a copper alloy, and an organic high material such as polyvinyl chloride or polyethylene covering the outer peripheral surface of the conductive wire. The covered electric wire 5 as an irradiated object having a covering portion composed of molecules is irradiated with electrons. When electrons are irradiated to the covering portion of the covered electric wire 5, the cross-linking reaction of the organic polymer is promoted, the covering portion is cured, and the heat resistance and mechanical properties of the covering portion are improved.

  As shown in FIG. 1, the electron beam irradiation apparatus 1 includes a microwave generator 2 that generates a microwave, and the microwave generated by the microwave generator 2 into argon gas (corresponding to a gas) under reduced pressure. It has a plasma generator 3 that generates plasma by applying it, and an electron accelerator 4 that accelerates electrons in the plasma generated by the plasma generator 3 under reduced pressure.

  The microwave generating unit 2 includes a solid state oscillator 21 and a double slag tuner 22 connected to the solid state oscillator 21 through a coaxial cable 23. The solid state oscillator 21 has an oscillator body, an amplifier, and an isolator. The solid state oscillator 21 generates a microwave (1 to 100 GHz), and this microwave is propagated to the double slag tuner 22 by the coaxial cable 23. The double slag tuner 22 performs microwave impedance matching. That is, the double slag tuner 22 optimizes the power supplied to the plasma generating unit 3 by adjusting the reflected power from the plasma generating unit 3 to the minimum value, and effectively supplies the microwave to the plasma generating unit 3. .

  The plasma generation unit 3 includes a surftron 31 connected to the double slag tuner 22 via the coaxial cable 33 and a plasma generation tube 32 through which microwaves propagate from the surftron 31. The surfertron 31 propagates the microwave supplied from the double slag tuner 22 via the coaxial cable 33 to the outer surface of the plasma generation tube 32. The surftron 31 is made of metal and is formed in a box shape having a donut cross section. The Surfertron 31 includes a bottomed cylindrical outer cylinder portion 31a, a cylindrical inner cylinder portion 31b disposed in the outer cylinder portion 31a, and a bottomed cylindrical lid that covers the opening of the outer cylinder portion 31a. A movable portion 31d having a flat plate donut shape disposed between the outer cylindrical portion 31a and the inner cylindrical portion 31b.

  A coaxial cable 33 from the double slag tuner 22 is attached to the outer cylindrical portion 31a so as to penetrate the outer peripheral wall of the outer cylindrical portion 31a. The coaxial cable 33 protrudes into the outer cylindrical portion 31a, and the outer cylindrical portion 31a. Microwave is propagated inside. In the present embodiment, the outer cylindrical portion 31a is formed with an outer diameter of about 6.8 cm, an inner diameter of about 5.8 cm, and a length in the axial direction of about 5.0 cm.

  The inner cylinder part 31b is arranged coaxially with the outer cylinder part 31a in the outer cylinder part 31a, and is slightly shorter than the outer cylinder part 31a. Holes are provided in the center of the bottom surface of the outer cylinder part 31a and the center of the lid part 31c, respectively, and the inside of the inner cylinder part 31b communicates with the outside through the holes. A plasma generation tube 32 is disposed in the inner cylinder portion 31b. The microwave propagated into the outer cylinder part 31a is propagated to the outer surface of the plasma generating tube 32 from the gap 35 between the inner cylinder part 31b and the lid part 31c. In the present embodiment, the inner cylinder portion 31b is formed with an outer diameter of about 1.6 cm, an inner diameter of about 1.2 cm, and a length in the axial direction of about 4.8 cm.

  The movable portion 31d is provided so as to be movable in a direction approaching the lid portion 31c. Leaf spring-like shield fingers made of copper are provided on the outer peripheral portion and the inner peripheral portion of the movable portion 31d, respectively. The shield fingers provided on the outer peripheral portion of the movable portion 31d are in contact with the inner surface of the outer cylindrical portion 31a of the surftron 31, and the shield fingers provided on the inner peripheral portion of the movable portion 31d are in contact with the outer surface of the inner cylindrical portion 31b. To prevent microwave leakage. Microwave impedance matching is achieved by moving the movable portion 31d having the above-described configuration. That is, the power supplied to the plasma generation tube 32 is optimized by finely adjusting the reflected power, and the microwave is efficiently propagated to the plasma generation tube 32.

  The plasma generating tube 32 is made of, for example, quartz, glass, ceramic or the like, and is formed in a cylindrical shape. The plasma generating tube 32 is arranged in the inner cylinder portion 31b of the surftron 31 with a slight gap (about 0.5 mm) from the inner surface of the inner cylinder portion 31b. A gauge port 32a is attached to an opening at one end in the longitudinal direction of the plasma generating tube 32, and a stainless steel tube 34 for supplying argon gas is connected through the gauge port 32a. (About 2.7 to 6.7 Pa) is supplied. The other end of the plasma generation tube 32 in the longitudinal direction is connected to the acceleration tube main body 42 of the electron acceleration unit 4. In the present embodiment, the plasma generating tube 32 is formed with an outer diameter of about 1.1 cm, an inner diameter of about 0.7 cm, and a length in the axial direction of about 20.0 cm.

  The plasma generating tube 32 having the above-described configuration is exhausted and depressurized by differential exhaust devices 40a and 40b, which will be described later, provided in the electron acceleration unit 4. Then, a microwave is propagated from the surftron 31 to the outer surface of the plasma generating tube 32, and the microwave is applied to the argon gas in the plasma generating tube 32, and the argon gas is ionized to generate plasma. The plasma is composed of Ar + (hereinafter referred to as argon ions), electrons, argon atoms, argon radicals, and the like. In the present embodiment, argon gas is ionized to generate plasma, but helium, oxygen, nitrogen, or the like can also be used.

  As shown in FIGS. 1 to 3, the electron acceleration unit 4 includes a container 41 that is maintained at a reduced pressure, and differential exhaust devices 40 a and 40 b (corresponding to a pressure reducing device) that exhaust the inside of the container 41 to reduce the pressure. Have. The container 41 is made of, for example, quartz, glass, ceramics, or the like. As shown in FIG. 2, the container 41 is connected to the above-described plasma generating tube 32 and has a thick cylindrical accelerating tube main body 42 having a diameter larger than that of the plasma generating tube 32 and a cylindrical shape protruding from the outer peripheral surface of the accelerating tube main body 42. Plasma generation of the object support portions 43a and 43b (corresponding to one cylindrical body), the device connection portions 44a and 44b (corresponding to the other cylindrical body), the mesh electrode support portion 45, and the acceleration tube main body 42 And a cylindrical electron acceleration electrode support 46 protruding from the outer surface away from the tube 32.

  The acceleration tube main body 42 is arranged coaxially and in series with the plasma generation tube 32, and the inside of the acceleration tube main body 42 and the inside of the plasma generation tube 32 communicate with each other through a communication port 47. The plasma generated in the plasma generation tube 32 enters the acceleration tube main body 42 from the plasma generation tube 32 through the communication port 47. In the present embodiment, the acceleration tube main body 42 is formed with an outer diameter of about 6.8 cm, an inner diameter of about 5.8 cm, and a length in the axial direction of about 5.0 cm.

  A pair of irradiated object support portions 43 a and 43 b are provided so as to protrude from the outer peripheral surface of the acceleration tube main body 42 in a direction orthogonal to the direction E in which electrons are accelerated. The pair of irradiated object support portions 43a and 43b extend in opposite directions so as to position the axis of the accelerating tube main body 42 therebetween, and are provided linearly as a whole. The pair of irradiated object support portions 43 a and 43 b is disposed between an electron acceleration electrode 51 and a second mesh electrode 53 described later. Gauge ports 48 (FIG. 3) are attached to the tips of the pair of irradiated object support portions 43a and 43b, and the respective gauge ports 48 are grounded. One irradiated object support portion 43 a is connected to the differential exhaust device 40 b via the gauge port 48.

  In the irradiated object support portions 43a and 43b having the above-described configuration, a covered electric wire 5 (long irradiated object) and the like are arranged as shown in FIG. The irradiated object support portions 43 a and 43 b position the covered electric wire 5 irradiated with accelerated electrons between the electron acceleration electrode 51 and the second mesh electrode 53 in the container 41. The covered electric wire 5 is irradiated with electrons on the outer peripheral surface of the covering portion while being moved by the electric wire moving means 7 in the irradiated object support portions 43a and 43b. The wire moving means 7 includes a wire supply portion 71 and a wire take-up portion 72 disposed on one irradiated object support portion 43a side, and a roller attached to the other irradiated object support portion 43b via a gauge port 48. Part 73.

  The electric wire supply part 71 is distribute | arranged to the atmospheric pressure area | region. The electric wire supply unit 71 includes a drum around which the covered electric wire 5 before being irradiated with electrons is wound and supported rotatably. The covered electric wire 5 drawn out from the electric wire supply unit 71 sequentially passes through the differential exhaust device 40b and the gauge port 48 and enters one irradiated object support unit 43a.

  The wire winding unit 72 is arranged in the atmospheric pressure region. The electric wire take-up unit 72 includes a drum around which the covered electric wire 5 that has been irradiated with electrons is wound and is rotatably supported, and a drive unit that rotates the drum. The covered wire 5 drawn out from the one object support portion 43a and sequentially passing through the gauge port 48 and the differential exhaust device 40b is wound around the wire winding portion 72.

  The roller unit 73 includes a case 73a connected to the gauge port 48 attached to the other irradiated object support unit 43b, and a plurality of rollers 73b rotatably supported in the case 73a. The covered electric wire 5 is disposed on the outer peripheral surface of the roller 73b.

  After the covered electric wire 5 is pulled out from the electric wire supply unit 71, it passes through one irradiation object support part 43 a, the acceleration tube main body 42, and the other irradiation object support part 43 b sequentially (track A), and the roller part 73. Then, the light passes through the other irradiated object support 43b, the acceleration tube main body 42, and the one irradiated object support 43a sequentially (path B), and is wound around the wire winding unit 72. . That is, the covered electric wire 5 automatically moves from the route A to the route B via the roller portion 73 and reciprocates in the pair of irradiated object support portions 43a and 43b. At this time, electrons are irradiated to one outer peripheral surface in the radial direction of the covering portion in the acceleration tube main body 42 of the path A, and electrons are irradiated to the other outer peripheral surface in the radial direction of the covering portion in the path B. Electrons are irradiated to the entire outer peripheral surface of the part.

  As shown in FIG. 1 and the like, a pair of device connection portions 44a and 44b are provided so as to protrude from the outer peripheral surface of the acceleration tube main body 42 in a direction orthogonal to the direction E in which electrons are accelerated. The pair of device connection portions 44a and 44b extend in opposite directions so as to position the axis of the acceleration tube main body 42 therebetween, and are provided in a straight line as a whole. A pair of apparatus connection part 44a, 44b and a pair of to-be-irradiated object support part 43a, 43b are provided in the mutually orthogonal direction (cross | intersection), and are provided on the same plane. Stainless steel gauge ports 49 are respectively attached to the tips of the pair of device connection portions 44a and 44b, and each gauge port 49 is grounded. One device connection portion 44 a is connected to the differential exhaust device 40 a via the gauge port 49, and the other device connection portion 44 b is connected to the vacuum gauge sensor via the gauge port 49.

  As shown in FIG. 2, a pair of mesh electrode support portions 45 are provided so as to protrude from the outer peripheral surface of the acceleration tube main body 42 in a direction orthogonal to the direction E in which electrons are accelerated. The pair of mesh electrode support portions 45 protrude in opposite directions so as to position the axial center of the acceleration tube main body 42 therebetween, and are provided at intervals from each other in the direction E in which electrons are accelerated. Yes. The mesh electrodes 52 and 53 are supported by supporting mesh electrodes 52 and 53, which will be described later, through the mesh electrode support 45. Note that the tip of the mesh electrode support 45 is kept airtight.

  The electron acceleration electrode support 46 is provided so as to protrude from the outer peripheral surface of the acceleration tube main body 42 in a direction parallel to the direction E in which electrons are accelerated. A column 51a of an electron acceleration electrode 51, which will be described later, is passed through the electron acceleration electrode support 46 to support the electron acceleration electrode 51. Note that the tip of the electron acceleration electrode support 46 is kept airtight.

  In the container 41 having the above-described configuration, an electron acceleration electrode 51 (corresponding to a plus electrode) for accelerating electrons and a communication port between the plasma generation tube 32 of the plasma generation unit 3 facing the electron acceleration electrode 51. 47 is parallel to the first mesh electrode 52 between the first mesh electrode 52 (corresponding to the negative electrode) and the electron acceleration electrode 51 and the first mesh electrode 52. And a second mesh electrode 53 (corresponding to a ground electrode) made of a net disposed on the surface.

  The electron acceleration electrode 51 is formed in a flat plate shape and is larger than the inner diameter of the communication port 47. The electron acceleration electrode 51 is arranged in a direction orthogonal to the direction E in which electrons are accelerated. At the center of one outer surface of the electron accelerating electrode 51, a thin columnar column 51a protruding from the outer surface is provided. The column 51 a protrudes outside the container 41 and is connected to the DC voltage power source 54. A high voltage (about 5 kV) is applied to the electron accelerating electrode 51 by the DC voltage power source 54 through the support column 51a, and the electrons passing through the first and second mesh electrodes 52 and 53 are indicated by an arrow E. Accelerate along.

  The first and second mesh electrodes 52 and 53 are formed in a flat plate shape and are provided larger than the inner diameter of the communication port 47. The first and second mesh electrodes 52 and 53 are arranged in the container 41 so as to cover the communication port 47 with the plasma generating tube 32, and are arranged in a direction orthogonal to the direction E in which electrons are accelerated. Yes. The first and second mesh electrodes 52 and 53 are arranged along the direction E in which electrons are accelerated, and are opposed to each other with a space therebetween. The first and second mesh electrodes 52 and 53 are configured by a net, and electrons and the like are provided so as to pass through the gaps of the net. On the outer edges of the first and second mesh electrodes 52 and 53, thin columnar columns 52a and 53a protruding from the outer edges are provided. The support columns 52 a and 53 a protrude outside the container 41.

  The first and second mesh electrodes 52 and 53 are made of, for example, stainless steel or tungsten. Tungsten can more reliably prevent sputtering of the electrode surface by argon ions. In the present embodiment, the first and second mesh electrodes 52 and 53 are made of SUS304 (stainless steel containing Cr 18% and Ni 8%), and have a diameter of about 2 cm (first mesh electrode 52) and 3 cm (second Mesh electrode 53), wire diameter of 0.03 mm, spacing of 5 mm, and 400 mesh are used.

  The distance between the electron acceleration electrode 51 and the second mesh electrode 53 is preferably 10 to 50 mm. If the distance is less than 10 mm, it is difficult to position the covered electric wire 5 between the electron acceleration electrode 51 and the second mesh electrode 53 (cannot be positioned). Moreover, when the said space | interval is larger than 50 mm, as shown in FIG. 6 showing the result of Example 2 mentioned later, an electron is accelerated efficiently (when the pressure in the container 41 is 0.1-0.3 Pa). It is difficult to irradiate the covered electric wire 5 with a high-energy electron beam that reliably crosslinks the covered portion of the covered electric wire 5.

  Further, the interval is more preferably 15 to 35 mm. As a result, as shown in FIG. 6, electrons can be accelerated more efficiently (acceleration voltage can be increased to about 40 kV or more when the pressure in the container 41 is 0.1 to 0.3 Pa). The coated electric wire 5 can be irradiated with a high-energy electron beam that reliably crosslinks the covered portion 5.

  The support 52a of the first mesh electrode 52 described above is connected to the DC variable voltage power supply 55, and a negative voltage (about −10V to −100V) is applied to the first mesh electrode 52. As will be described later, the voltage applied to the first mesh electrode 52 is a value that captures positively charged argon ions and allows negatively charged electrons to pass through. The second mesh electrode 53 described above is grounded, and provides a reference potential for accelerating electrons. The second mesh electrode 53 extracts only electrons from the plasma attracted to the electron acceleration unit 4 and allows only the electrons to pass therethrough.

  The inside of the container 41 and the inside of the plasma generation tube 32 are depressurized by the differential exhaust devices 40a and 40b, and the plasma generated in the plasma generation tube 32 is drawn from the inside of the plasma generation tube 32 into the container 41 as a whole. Then, argon ions in the plasma are attracted to the first mesh electrode 52 and captured on the outer surface of the first mesh electrode 52. The electrons in the plasma pass through the first mesh electrode 52, are extracted from the plasma by the second mesh electrode 53, and are accelerated toward the electron acceleration electrode 51 by the electron acceleration electrode 51. A plasma converging magnet (not shown) is provided between the plasma generating unit 3 and the first mesh electrode 52, and the plasma generated by the plasma converging magnet is converged and collides with the wall in the container 41. Prevents plasma loss due to

  The pressure of the argon plasma in the plasma generating tube 32 described above is about 2.7 to 6.7 Pa, and the pressure of the argon plasma in the container 41 is about 0.1 to 1.3 Pa. In addition, the pressure in the container 41 is preferably 0.1 to 0.3 Pa in order to efficiently accelerate electrons in the container 41. Thereby, as shown in FIG. 6 showing the result of Example 2 described later, electrons are efficiently accelerated (when the distance between the electron acceleration electrode 51 and the second mesh electrode 53 is 16 mm, 33 mm, and 50 mm). The accelerating voltage can be increased to about 20 kV or more), and the coated electric wire 5 can be irradiated with a high-energy electron beam that reliably crosslinks the coated portion of the coated electric wire 5.

  Even if the electrons are accelerated, if the electrons collide with other particles or the like, they cannot reach the electron accelerating electrode 51. Therefore, in order to eliminate argon gas, the inside of the container 41 and the inside of the plasma generation tube 32 are provided with a differential exhaust device 40a, The air is exhausted and reduced in pressure by 40b. Argon atoms and argon radicals present in a minute amount in the plasma are exhausted by the differential exhaust devices 40a and 40b. A first mesh electrode 52 is provided in order to exclude argon ions in the plasma. By eliminating argon atoms, argon radicals, and argon ions in the plasma, electrons are efficiently accelerated toward the electron acceleration electrode 51 and irradiated onto the covered electric wire 5.

  As described above, by eliminating the argon ions by the first mesh electrode 52, the electrons are prevented from colliding with the argon ions when being accelerated by the electron acceleration electrode 51, and only the electrons are reliably used for electron acceleration. Accelerated by the electrode 51. If the argon ions are not excluded, the electrons collide with the argon ions and the argon atoms and are not sufficiently accelerated, and the coated portion of the covered electric wire 5 to be described later is not cross-linked, and the argon ions collide with the coated portion and are covered. The part will undergo thermal deformation.

  When the electron beam irradiation apparatus 1 having the above-described configuration is used to irradiate electrons to the covered portion of the covered electric wire 5, first, a microwave is generated by the microwave generating portion 2, and the microwave is transmitted through the slag tuner. The microwave is propagated to the plasma generator 3 by being propagated to the surftron 31. Then, a microwave is applied to the argon gas supplied into the plasma generating tube 32 to ionize the argon gas to generate plasma.

  The plasma is drawn into the accelerating tube main body 42 through the communication port 47 because the container 41 connected to the plasma generating tube 32 through the communication port 47 is decompressed by the differential exhaust devices 40a and 40b. Argon ions in the plasma are removed by the first mesh electrode 52, and electrons in the plasma are extracted by the second mesh electrode 53 and accelerated along the arrow E by the electron acceleration electrode 51. At this time, when the covered electric wire 5 reciprocally moves in the second mesh electrode 53 and the pair of irradiated object support portions 43a and 43b, the outer peripheral surface of the covered portion is irradiated with the electric wire, and an organic polymer crosslinking reaction occurs. This improves the heat resistance and mechanical properties of the coating.

  According to this embodiment, the microwave generator 2 that generates microwaves, the plasma generator 3 that generates plasma by applying the microwaves generated by the microwave generator 2 to a gas under reduced pressure, Since it has the electron acceleration part 4 which accelerates the electron in the plasma which generate | occur | produced in the plasma generation part 3 under pressure reduction, the electron in plasma can be accelerated and can be irradiated to an irradiation object, It is not necessary to use a filament as an electron source. Therefore, it is possible to eliminate the running cost and the labor required for the replacement work when the filament is disconnected.

  The electron acceleration unit 4 includes a container 41 that is maintained at a reduced pressure, and differential exhaust devices 40a and 40b that exhaust the inside of the container 41 to reduce the pressure, and the container 41 includes an electron acceleration that accelerates electrons. A first mesh electrode 52 composed of a mesh body disposed in a communication port 47 facing the electron generating electrode 51, the electron accelerating electrode 51, and the plasma generating unit 3; Between the mesh electrode 52 and the second mesh electrode 53 made of a net disposed in parallel with the first mesh electrode 52, the inside of the container 41 is provided by the differential exhaust devices 40 a and 40 b. Is reduced in pressure, and the argon gas in the electron accelerating unit 4 is reduced, and the first mesh electrode 52 eliminates positively charged particles in the plasma. Colliding with argon atoms It electrons are efficiently accelerated without, therefore, the voltage it is possible to set a relatively low electron acceleration electrode 51, power consumption can be reduced.

  The electron accelerating unit 4 is provided with irradiated object support parts 43a and 43b for positioning the irradiated object irradiated with the accelerated electrons between the electron acceleration electrode 51 and the second mesh electrode 53 in the container 41. Therefore, the object to be irradiated is reliably positioned between the electron acceleration electrode 51 and the second mesh electrode 53, that is, the region in which the electrons are accelerated. Irradiation can be ensured.

  Since the electron accelerating unit 4 is provided with the irradiated object support units 43a and 43b and the device connection units 44a and 44b in the direction intersecting with each other through the space of the electron accelerating unit 4, the irradiated object support is provided. It is possible to arrange a long object to be irradiated in the parts 43a and 43b, or to connect the differential exhaust devices 40b and 40a to the object support part 43a and the equipment connection part 44a. The operability and ease of handling of the irradiation apparatus 1 can be improved.

  Since the differential exhaust devices 40b and 40a are provided at the ends of the object support portion 43a and the device connection portion 44a, respectively, the inside of the container 41 is surely exhausted and depressurized. It can be accelerated efficiently.

  Since the covered electric wires 5 are arranged in the irradiated object support portions 43a and 43b, the covered electric wires 5 are surely positioned in the space in the electron accelerating portion 4, and for this reason, the electrons accelerated by the covered electric wires 5 are used. Can be reliably irradiated.

  The pressure in the container 41 is 0.1 to 0.3 Pa, and the distance between the electron acceleration electrode 51 and the second mesh electrode 53 is 10 to 50 mm. The covered electric wire 5 can be positioned between the second mesh electrode 53 and the gap. Moreover, the electrons can be efficiently accelerated between the electron acceleration electrode 51 and the second mesh electrode 53, and the covered electric wire positioned between the electron acceleration electrode 51 and the second mesh electrode 53. 5 can be irradiated with a high-energy electron beam.

  Since the distance between the electron acceleration electrode 51 and the second mesh electrode 53 is 15 to 35 mm, the electrons are accelerated more efficiently between the electron acceleration electrode 51 and the second mesh electrode 53. The coated electric wire 5 positioned between the electron acceleration electrode 51 and the second mesh electrode 53 can be irradiated with a higher energy electron beam.

  A plasma is generated by applying a microwave to the argon gas, positively charged particles are removed from the plasma by the first mesh electrode 52, and electrons are extracted from the plasma by the second mesh electrode 53. Thereafter, the electrons are accelerated by the electron accelerating electrode 51 and irradiated on the covered portion of the covered electric wire 5 so that the covered portion is cured, so that the running cost and the labor required for the replacement work when the filament is broken can be eliminated. In addition, the first mesh electrode 52 eliminates the positively charged particles in the plasma, and the electrons are efficiently accelerated without colliding with the positively charged particles or argon gas. In addition, the voltage of the electron acceleration electrode 51 can be set relatively low, and the power consumption can be reduced.

Example 1
Assembling the electron beam irradiation apparatus 1 described in the above-described embodiment, the incident power from the microwave generator 2 is set to 60 W, and the double slag tuner 22 is adjusted so as to eliminate the reflected power from the surftron 31, Argon plasma was generated in the plasma generation tube 32. Then, a voltage of −100 V was applied to the first mesh electrode 52, the second mesh electrode 53 was grounded, and electrons were extracted from the argon plasma to the electron acceleration unit 4. A Langmuir probe electrode (probe surface area 25 mm ² ) connected to a four-quadrant power source is installed in the container 41, and the argon plasma pressure in the container 41 is 0.13 Pa, 0.80 Pa, 1.07 Pa, 2.0 Pa, The voltage applied to the electron acceleration electrode 51 is changed to 4.0 Pa, and the voltage applied to the Langmuir probe electrode is swept under each condition by changing the voltage applied to the electron acceleration electrode 51 to 0 V, 100 V, 200 V, and 300 V. A voltage characteristic curve was obtained. The measurement results were analyzed to calculate the electron temperature and floating potential under each condition.

(Electronic temperature)
The electron temperature is ΔV when the voltage change amount when the current value I ₁ in the exponential function region of the current-voltage characteristic curve becomes e times (about 2.7 times),
Electron temperature (Te) = Voltage change (ΔV) (Unit: eV)
Indicated by

  The calculation result of the electron temperature is shown in FIG. Compared with the case where the voltage of the electron acceleration electrode 51 was set to 0 V, all the electron temperatures were high, and it was confirmed that the electrons were accelerated. Furthermore, it has been shown that the electrons are composed of high temperature electrons (FIG. 4A) and low temperature electrons (FIG. 4B). The electron temperature of the high temperature electrons greatly depends on the pressure of the argon plasma and the voltage of the electron acceleration electrode 51. When the pressure of the argon plasma is 1.3 Pa or less and the voltage of the electron acceleration electrode 51 is 100 V or more, it exceeds 30 eV. It was.

(Floating potential)
The floating potential is a voltage when the current of the current-voltage characteristic curve becomes zero. The calculation result of the floating potential is shown in FIG. The floating potential was proportional to the voltage of the electron acceleration electrode 51, and it was confirmed that the electrons were accelerated.

(Example 2)
Assembling the electron beam irradiation apparatus 1 described in the above-described embodiment, the incident power from the microwave generator 2 is set to 60 W, and the double slag tuner 22 is adjusted so as to eliminate the reflected power from the surftron 31, Argon plasma was generated in the plasma generation tube 32. Then, a voltage of −100 V is applied to the first mesh electrode 52, the second mesh electrode 53 is grounded, a voltage of 5 kV is applied to the electron acceleration electrode 51, and the electron acceleration unit 4 is extracted from the argon plasma. Pulled out an electron. The pressure of the argon plasma in the container 41 is changed between 0.1 and 10 Pa, and the distance between the electron acceleration electrode 51 and the second mesh electrode 53 is changed to 16 mm, 33 mm, 50 mm, and 55 mm, and each condition is changed. The voltage (acceleration voltage) applied to the electron acceleration electrode 51 by the accelerated electrons was measured from the numerical value displayed on the DC voltage power source 54.

(Acceleration voltage)
The measurement result of the acceleration voltage is shown in FIG. As shown in FIG. 6, when the pressure of the argon plasma in the container 41 is 0.1 to 0.3 Pa, the distance between the electron acceleration electrode 51 and the second mesh electrode 53 is 16 mm, 33 mm, and 50 mm. The acceleration voltage was about 20 kV or more, and the electrons were efficiently accelerated to obtain a high energy electron beam. Further, at this time, if the distance between the electron acceleration electrode 51 and the second mesh electrode 53 is 16 mm and 33 mm, the acceleration voltage becomes about 40 kV or more, and the electrons are accelerated more efficiently, so that a higher energy electron beam is generated. I was able to get it.

  In the embodiment described above, the irradiated object is the covered electric wire 5, but the irradiated object may be another long irradiated object such as an optical fiber, or the non-long irradiated object. It may be. In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, various modifications can be made without departing from the scope of the present invention.

It is a block diagram which shows the electron beam irradiation apparatus concerning one Embodiment of this invention. It is a perspective view which shows the electron acceleration part shown by FIG. It is a block diagram which shows the state by which the covered electric wire was distribute | arranged to the electron acceleration part shown by FIG. (A) It is a graph which shows the relationship between the pressure of the pressure in a container, the voltage of the electrode for electron acceleration, and the electron temperature of a high temperature electron. (B) It is a graph which shows the relationship between the pressure in the container, the voltage of the electrode for electron acceleration, and the electron temperature of a low temperature electron. It is a graph which shows the relationship between the voltage in a container, the voltage of the electrode for electron acceleration, and a floating potential. It is a graph which shows the pressure in a container, the space | interval of the electrode for electron acceleration, and a 2nd mesh electrode, and an acceleration voltage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electron beam irradiation apparatus 2 Microwave generation part 3 Plasma generation part 4 Electron acceleration part 5 Covered electric wire (long irradiation object)
40a, 40b Differential exhaust device (pressure reduction device)
41 container 43a, 43b irradiated object support part (one cylindrical body)
44a, 44b Device connection part (the other cylindrical body)
47 Communication port 51 Electron acceleration electrode (plus electrode)
52 First mesh electrode (negative electrode)
53 Second mesh electrode (ground electrode)

Claims (8)

A microwave generator for generating a microwave, a plasma generator for generating a plasma by applying the microwave generated by the microwave to a gas under reduced pressure, and electrons in the plasma generated by the plasma generator An electron acceleration unit for accelerating under reduced pressure,
The electron acceleration unit has a container maintained at a reduced pressure, and a decompression device that exhausts and decompresses the inside of the container; and
In the container, there are a positive electrode for accelerating the electrons, a negative electrode composed of a net disposed opposite to the positive electrode and connected to a plasma generating portion, the positive electrode and the negative electrode An electron beam irradiation apparatus, characterized in that a ground electrode composed of a net disposed in parallel with the negative electrode is provided between them.   The electron accelerating unit is provided with an irradiated object supporting unit that positions an irradiated object irradiated with accelerated electrons between the plus electrode and the ground electrode in the container. The electron beam irradiation apparatus according to claim 1.   3. The electron according to claim 2, wherein the electron accelerating portion is provided with one cylindrical body and the other cylindrical body in directions intersecting with each other through the space of the electron accelerating portion. X-ray irradiation device.   The electron beam irradiation apparatus according to claim 3, wherein the decompression device is provided at an end of the cylindrical body.   5. The electron beam irradiation apparatus according to claim 3, wherein the long object to be irradiated is arranged in the one cylindrical body.   The pressure in the container is set to 0.1 to 0.3 Pa, and the distance between the plus electrode and the ground electrode is set to 10 to 50 mm. The electron beam irradiation apparatus as described in any one.   The electron beam irradiation apparatus according to claim 6, wherein an interval between the plus electrode and the ground electrode is 15 to 35 mm. In the method of manufacturing a covered electric wire that accelerates the crosslinking reaction of the organic polymer by irradiating electrons to the covered electric wire having a conductive wire and a covering portion composed of an organic polymer that covers the outer peripheral surface of the conductive wire,
Gas by applying a microwave to generate plasma, negative electrode placed in this order from the plasma generation side, the ground electrode, and, by the positive electrode, to remove the particles positively charged by said negative electrode from in the plasma after drawn out electrons by the ground electrode from in the plasma Te, production of covered electric wire, characterized in that curing the coating portion by irradiating the electrons are accelerated by the positive electrode coating portion of the covered wire Method.

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