JP2012095255A - Method for manufacturing magnetic core of antenna element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in which a conventional magnetic core of an antenna element for use in a radio-controlled clock or the like includes a lamination of alternating layers of amorphous foil and an adhesive, and thus has low productivity and high production costs.SOLUTION: In a method, according to the invention, for manufacturing a magnetic core 1 of an antenna element, the magnetic core 1 includes a lamination of a plurality of thin films 1a made of an iron-based or cobalt-based amorphous magnetic alloy. Laser beams are applied to the plurality of laminated thin films 1a of the magnetic core 1 of the antenna element so as to form laser-welded portions 2 in a plurality of positions on sides of the plurality of laminated thin films 1a and bond the thin films 1a together.

Description

  The present invention relates to a method for manufacturing a magnetic core of an antenna element used as a transmission / reception antenna such as a radio timepiece.

  Conventionally, the method of laminating the magnetic core of this type of antenna element is to laminate a plurality of thin film iron-based amorphous magnetic alloys or cobalt-based amorphous magnetic alloys. The outside of the laminated magnetic core is wound with a coil with an insulating tape or the like as an antenna element.

For example, the magnetic core constituting the inductor 1 disclosed above includes a main magnetic core 2 made of a laminate of a plurality of magnetic metal thin plates 7 and auxiliary magnetic cores 3 arranged at both ends of the main magnetic core. The auxiliary magnetic core 3 is made of a solidified magnetic powder. A coil conductor 4 is wound around the main magnetic core 2 via an insulator such as an insulating case 8. The inductor 1 includes a magnetic core having a main magnetic core 2 and an auxiliary magnetic core 3, and a coil having a coil conductor 4 wound around the main magnetic core 2 (see Patent Document 1), and a radio timepiece. The antenna structure includes a soft magnetic magnetic core member 45 curved in an arc shape and a coil 50 wound around a central portion in the extending direction of the magnetic core member, and is accommodated in the case 10. In this antenna structure, the magnetic core member 45 has outer peripheral surfaces 52 and 54 extending in a non-arc shape so as to be positioned on the inner peripheral side as approaching the tip at at least one of the end portions exposed from the coil 50. . The arc-shaped curved magnetic core member 45 is formed by laminating a plurality of soft magnetic thin pieces 43, 44, and the inner circumferential soft magnetic thin piece 43 is longer in the circumferential direction than the outer peripheral soft magnetic thin piece 44. Each of the soft magnetic thin pieces 43 and 44 is formed by laminating a plurality of soft magnetic foil bodies 41 and 42 (see Patent Document 2), and a magnetic core member of a radio-controlled timepiece antenna includes a magnetic amorphous foil 23a. A plurality of amorphous laminates 23 are laminated. A portion of the laminate 23 around which the coil 26 is wound is covered with an insulating film 24. The amorphous laminated foil 23a is annealed. The insulating film 24 has heat resistance, and the plurality of amorphous foils 23 a are annealed with the insulating film 24 covering the laminate 23. A plurality of amorphous foils 23a are bonded and laminated together. After the plurality of amorphous foils 23a are bonded to each other with thermosetting plastic, the plurality of amorphous foils 23a are annealed respectively. A coil 26 is wound around a portion excluding both ends of the magnetic core member 22 to form a radio timepiece antenna, and a radio timepiece is obtained using the antenna 21 (see Patent Document 3).
JP 2007-255101 A JP 2006-214770 A JP 2003-110341 A

  However, those described in Patent Documents 1 to 3 are antenna elements used for radio timepieces and the like, and the magnetic core is formed by laminating a plurality of amorphous foils. As a result, the productivity is poor and the cost is high.

  The manufacturing method of the magnetic core of the antenna element of the present invention is an antenna element in which a plurality of thin films formed of an iron-based amorphous magnetic alloy or a cobalt-based amorphous magnetic alloy are laminated as a result of diligent research in view of the aforementioned problems. A magnetic core, which is formed by irradiating a plurality of thin films stacked on the core core of an antenna element with a laser beam, and forming laser welded portions at a plurality of positions on the side surfaces of the stacked thin films. is there.

  In the manufacturing method of the magnetic core of the antenna element of the present invention, a plurality of thin films laminated on the magnetic core of the antenna element are irradiated with a laser beam, and laser welds are provided at a plurality of locations on the side surfaces of the laminated thin films. Since it is formed and fixed, there is no need for time and effort to interpose an adhesive, and it is possible to weld by simply irradiating the laminated iron-based amorphous magnetic alloy or cobalt-based amorphous magnetic alloy thin film with a laser beam. The invention is remarkably improved and can be manufactured at a low cost, and damage due to the laser welded portion 2 can be ignored. Therefore, the accuracy is good, and it is an epoch-making and highly practical invention.

  The manufacturing method of the magnetic core of the antenna element of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory side view of the antenna element manufactured by implementing the manufacturing method of the magnetic core of the antenna element of the present invention. .

  The present invention relates to a method for manufacturing a magnetic core of an antenna element used as a transmission / reception antenna such as a radio timepiece, and the manufacturing method of the magnetic core of the antenna element of the present invention includes an iron-based amorphous magnetic alloy or a cobalt-based alloy. A magnetic core 1 of an antenna element in which a plurality of thin films 1a formed of an amorphous magnetic alloy is laminated, and the plurality of thin films 1a in which the magnetic core 1 of the antenna element is laminated is irradiated with a laser beam, The laser welded portions 2 are formed and fixed at a plurality of locations on the side surfaces of the laminated thin films 1a.

  That is, as shown in FIG. 1, the magnetic core of the antenna element of the present invention is a thin film 1a of about 20 μm formed of an iron-based amorphous magnetic alloy or a cobalt-based amorphous magnetic alloy, and includes 20 thin films 1a. It is what is laminated to some extent.

  Then, a laser beam is applied to the magnetic core 1 of the antenna element in which the plurality of thin films 1a are laminated to form a laser welded portion 2 and fixed.

  The irradiation of the laser beam is performed at a plurality of locations only on the side surfaces of the laminated thin films 1a, and the laser welds 2 are formed and fixed only on the side surfaces of the laminated thin films 1a.

  In other words, the magnetic core 1 of the antenna element is formed by laminating a plurality of thin films 1a formed of an iron-based amorphous magnetic alloy or a cobalt-based amorphous magnetic alloy, and laser welding portions at a plurality of locations on the side surfaces of the laminated thin films 1a. 2 is provided.

  The damaged portion of the iron-based amorphous magnetic alloy or the cobalt-based amorphous magnetic alloy thin film 1a by the laser welded portion 2, that is, the portion that has been recrystallized is about 20 μm as measured by a public institution, As a result of actually manufacturing and experimenting with the antenna element according to the present invention, there was no obstacle in use and the damage was in a negligible range.

  Then, as described above, the coil core B is wound around the magnetic core 1 fixed by the laser welding part 2 and the coil B is wound to form an antenna element.

  In the present invention, a plurality of thin films laminated on the magnetic core of the antenna element are irradiated with a laser beam, and laser welds are formed at a plurality of locations on the side surfaces of the laminated thin films. There is no need for labor to intervene the agent, welding can be performed simply by irradiating the laminated iron-based amorphous magnetic alloy or cobalt-based amorphous magnetic alloy thin film with a laser beam, significantly improving productivity, and manufacturing at low cost, Since the damage caused by the laser welded portion 2 can be ignored, a method for manufacturing a magnetic core of an antenna element with good accuracy is provided.

  FIG. 1 is an explanatory diagram for explaining a method of manufacturing a magnetic core of an antenna element according to the present invention.

DESCRIPTION OF SYMBOLS 1 Magnetic core 1a Thin film 2 Laser welding part A Insulation tape B Coil

Claims (1)

  A magnetic core of an antenna element in which a plurality of thin films formed of an iron-based amorphous magnetic alloy or a cobalt-based amorphous magnetic alloy are laminated, and the plurality of thin films in which the magnetic cores of the antenna element are laminated are irradiated with a laser beam. And the manufacturing method of the magnetic core of the antenna element characterized by forming and adhering the laser welding part in several places of the side surface of this laminated several thin film.

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