JP2003110341A - Magnetic core member of antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize comparative miniaturization, while improving the strength against impact load. SOLUTION: This magnetic core member for a radiowave clock is constituted of an amorphous laminate 23, in which a plurality of amorphous foils 23a having magnetism are laminated. A part of the laminate 23, around which part a coil 26 is wound is covered with an insulating film 24. The amorphous laminated foil 23a is annealed. The insulating film 24 has thermal resistance, and the plural amorphous foils 23a are annealed respectively in the state that the laminate 23 is coated with the insulating film 24. The plural amorphous foils 23a are bonded to each other and laminated. After the plural amorphous foils 23a are bonded with each other by using thermosetting plastics, the plural amorphous foils 23a are annealed respectively. The coil 26 is wound around the part except both ends of a magnetic core member 22, an antenna 21 for a radiowave clock is formed, and a radiowave clock is obtained by using the antenna 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic core member of an antenna used in a radio-controlled timepiece that receives a predetermined radio wave including time information and adjusts the time.

[0002]

2. Description of the Related Art Since a clock exhibits its function by accurately ticking the time, not only a table clock or wall clock provided indoors and a wrist watch directly attached to a person's arm, but also an outdoor clock provided in a public facility such as a park. Even if there is, it is required to display the time accurately. Conventionally, a radio-controlled timepiece is known as a timepiece that accurately displays the time. This radio-controlled timepiece has a built-in antenna for receiving a predetermined radio wave, and is configured to receive a predetermined radio wave including time information, correct the time, and display the corrected accurate time.

As shown in FIG. 5, an antenna 1 conventionally used in this radio-controlled timepiece has a magnetic core member 2 made of a ferrite rod.
And a coil 3 wound around the magnetic core member 2.
Since the magnetic core member 2 made of a ferrite rod is relatively brittle and easily broken, the table clocks, wall clocks, and outdoor clocks installed outdoors have a relatively large internal space. Synthetic rubbers 4 and 4 as absorbing elastic bodies are fitted to both ends of the magnetic core member 2 and housed in a predetermined case 6, and mounting plates 6a and 6a formed integrally with the case 6 are screwed. By doing so, the antenna 1 is provided inside the timepiece 7. When the antenna 1 is attached via the case 6 as described above, even if an impact load is applied to the timepiece 7, the elastic bodies 4 and 4 absorb the impact and the magnetic core member 2 made of a ferrite rod is cracked or chipped. There is no such thing.

On the other hand, a wristwatch, which is a radio-controlled timepiece (not shown) attached directly to the wrist, is composed of a frame portion, a glass lid and a back lid, and the antenna is provided on the outer surface of the case. Since a wristwatch is attached to a human arm, it is required to be relatively small and lightweight. Based on this requirement, the antenna for a radio-controlled timepiece has a small diameter and a short length. We are trying to downsize the wristwatch. However, if the ferrite rod is made smaller in diameter and shorter in length, it may be cracked by the shock load caused by the fall of the radio-controlled watch, in which case the coil inductance will decrease and it will not be possible to receive radio waves at the target frequency (40 kHz). There was a risk of disappearing. Further, an antenna used in a wristwatch needs a flange that restricts the width direction of a coil wound around a magnetic core member, and also needs a means for fixing both ends of the coil.

In order to solve these problems, as an antenna used in a wristwatch, a plurality of ferrite bodies are housed in a hollow frame part made of synthetic resin, and flanges are formed at both ends of the frame part to form a coil width. A bar antenna structure is proposed in which the direction is regulated and the ferrite bodies are connected and held in a line by a frame portion with a gap (Japanese Patent Laid-Open No. 8-271659). In this bar antenna structure, since the frame portion is bent and elastically deformed in the gap between the ferrite bodies, the bar antenna bent in the gap can be elastically gently curved as a whole. As a result, even if an impact load is applied to the wristwatch, the bar antenna elastically bends and absorbs, so that the ferrite body is not cracked or damaged. Further, an antenna in which a plurality of amorphous foils are inserted in a frame similar to that used for ferrite and a winding is wound outside the frame is also known.

[0006]

However, a structure for mounting an antenna through the above-mentioned conventional case and Japanese Patent Laid-Open No. 8-2
The bar antenna structure of a radio-controlled timepiece disclosed in Japanese Patent No. 71659 requires a new member such as an elastic body and a case and a frame portion in addition to a conventional antenna in which a coil is directly wound around a ferrite rod, and the unit price is pushed up. There is.
Further, in the case of being used for a wristwatch, there is a problem that the outer diameter of the entire wristwatch is increased due to the antenna itself becoming larger than before due to the presence of the frame portion. Also, for an antenna in which multiple amorphous foils are inserted in a frame similar to that used for ferrite and the winding is wound outside the frame, the size of the antenna should be slightly reduced by using amorphous foil instead of ferrite. However, it still has a frame, which is still too large for a wristwatch. In this case, it is possible to directly wind the laminated amorphous foil without the frame, but since the cut amorphous foil has sharp edges, the laminated amorphous foil is directly wound without using the frame. That is, there is a problem that the insulating layer of the winding is broken by the sharp edge of the amorphous foil to cause a short circuit. An object of the present invention is to provide a relatively small magnetic core member for an antenna while improving the strength against an impact load.

[0007]

The invention according to claim 1 is
As shown in FIG. 1, an amorphous foil 23a having magnetism
Is an improvement of a magnetic core member of an antenna for a radio-controlled timepiece, which is composed of an amorphous laminated body 23 in which a plurality of layers are laminated. The characteristic structure is that the portion around which the coil 26 of the laminated body 23 is wound is covered with the insulating film 24. In the invention according to claim 1, since the magnetic core member 22 is provided with the amorphous laminated body 23 formed by laminating a plurality of amorphous foils 23a that are relatively flexible and are not likely to be cracked, a ferrite sintered body is used. The mechanical strength can be improved as compared with the conventional one. In this case, the edges of the amorphous foil 23a are relatively sharp,
Since the portion around which the coil 26 of the amorphous laminate 32 in which the amorphous foil 23a is laminated is wound is covered with the insulating film 24, the sharp amorphous foil 23 is formed.
The coil 26 does not come into direct contact with the ridge of a, and thus the wound coil 26 can be effectively prevented from being short-circuited.

The invention according to claim 2 is the invention according to claim 1, which is a magnetic core member of an antenna in which a plurality of amorphous foils 23a are respectively annealed. In the invention according to the second aspect, by annealing the amorphous foil 23a, the magnetic characteristics of the amorphous foil 23a are recovered to obtain the magnetic characteristics required by the amorphous laminate 23.

The invention according to claim 3 is the invention according to claim 2, wherein the insulating film 24 has heat resistance, and the laminate 23 is covered with the insulating film 24. The amorphous foils 23a are magnetic core members of the annealed antenna. In the invention according to claim 3, even if the insulating film 24 having heat resistance is formed on the amorphous laminate 23 and then annealed, the insulating film 24 is not deteriorated by the heat of annealing. Further, by performing annealing of the plurality of amorphous foils 23a in a state in which the laminated body 23 is covered with the insulating film 24, strain generated in the amorphous foil 23a when the insulating film 24 covers the laminated body 23 is suppressed. Can be removed, and when annealing is performed after the coil 26 is wound,
The amorphous foil 23 is provided both when the insulating film 24 covers the laminate 23 and when the coil 26 is wound.
It is possible to remove the strain generated in a.

The invention according to claim 4 relates to claims 1 to 3.
It is the invention which concerns on either one, It is a magnetic core member of the antenna by which a plurality of amorphous foils 23a were stuck mutually and laminated. In the invention according to claim 4, slipping between the plurality of amorphous foils 23a is prohibited, and the entire amorphous laminate 23 obtained by adhering the amorphous foils 23a to each other is fixed. The magnetic core member 22 obtained by coating the above with the insulating film 24 becomes rigid, and the work of winding the coil 26 thereafter becomes easy.

The invention according to claim 5 is the invention according to claim 4, wherein the plurality of amorphous foils 23a are bonded to each other with thermosetting plastic and then the plurality of amorphous foils 23a are annealed. Is a magnetic core member. In the invention according to claim 5, if the amorphous foil is bonded and then annealed, the strain generated in the manufacturing process of the amorphous foil, the subsequent cutting and laminating processes is eliminated, and the laminated member becomes a rigid member. No strain is generated during the process. Adhesion in this case may be carried out by dissolving the plastic before thermosetting in a solution, coating it on an amorphous foil, drying and heating by laminating pressure and curing, or dipping the laminated amorphous foil in liquid plastic before curing. Then, it may be impregnated and then cured. In the case of immersion, it is preferable to reduce the pressure so as to ensure the impregnation. Further, if the effect of the plastic is combined with the annealing by heating, the annealing step can be omitted.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a first embodiment of the present invention will be described with reference to the drawings. This embodiment will be described using a radio-controlled timepiece used as a wristwatch. 3 and 4
As shown in FIG.
2, a drive unit 13 housed in the drive unit 13, a display unit 14 driven by the drive unit 13 to display the time, and a controller 17 housed in the case 12 and controlling the drive unit 13. The case 12 includes a frame portion 12a, a glass lid 12b, and a back lid 12c. The frame portion 12a is made of a metal in a circular ring shape, the glass lid 12b is made of an electrically insulating material (glass plate) in a disc shape, and the back lid 12c is made of an electrically insulating material (plastic or the like) in a disc shape. It The display unit 14 includes a scale plate 14a, a short hand 14b driven by the drive unit 13 and rotating on the scale plate 14a,
It consists of a long hand 14c and a second hand (not shown).

The antenna 21 according to the present invention is provided along the outer surface of the frame portion 12a. The antenna 21 receives a radio wave including time information, and is connected to the controller 17 housed in the case 12. As shown in FIGS. 1 and 2, the antenna 21 includes a rod-shaped magnetic core member 22.
It is made by winding the coil 26 around the both ends of the coil. As shown in FIG. 4, a board 17a extending from the controller 17 to the antenna 21 through the frame portion 12a.
Is provided and the antenna 21 is bonded to the substrate 17a. Both ends 26 of the coil 26 wound around the magnetic core member 22
The a and 26b are soldered to the board 17a so that both ends of the coil 26 are electrically connected to the controller 17. A cover 1 formed of an electrically insulating material (plastic or the like) so as to cover the antenna 21 on the side of the frame 12a.
8 is attached. The radio wave received by the antenna 21 is a radio wave including time information of Japanese standard time emitted based on an atomic clock of the Communications Research Laboratory of the Ministry of Posts and Telecommunications (hereinafter, this radio wave is referred to as a standard radio wave). Note that reference numeral 1 in FIG.
Reference numerals 2d and 12d denote a pair of receiving members projectingly provided on the frame portion 12a, and both ends of the band 19 are pivotally attached to the receiving members 12d and 12d, respectively.

The magnetic core member 22 of the present invention used in such a radio-controlled timepiece 11 comprises an amorphous laminated body 23 in which a plurality of amorphous foils 23a are laminated, and the characteristic point is that the coil 26 of the laminated body 23 is wound. The part to be covered is covered with the insulating film 24. In this embodiment, for example, a number of rectangular amorphous foils 23a cut into a predetermined shape are laminated to have a predetermined thickness, and a portion of the laminated body 23 in contact with a winding is covered with an insulating film 24. For this coating, an insulating tape having an adhesive on one surface is wrapped around the surface of the laminated body 23 to form the insulating film 24, or the laminated body 23 is inserted into a heat-shrinkable tape and heat-shrinked to cover a predetermined surface. Then, the insulating film 24 is formed, and the laminate 23 is fixed at the same time.

In the magnetic core member 22 of the antenna for a radio-controlled timepiece constructed in this manner, the coil 26 is wound around a portion of the amorphous laminate 23 covered with the insulating film 24 except for both ends thereof. It functions as 21, and can reliably receive the standard radio wave. Further, an amorphous laminated body 23 in which the magnetic core member 22 is laminated with an amorphous foil 23a which is relatively flexible and is not likely to be broken.
Since it is formed by the method described above, the mechanical strength thereof can be improved as compared with the conventional case using a ferrite sintered body, and even if the radio-controlled timepiece 11 having the antenna 21 is accidentally dropped and a shock load acts, the antenna 21 is not damaged.

Further, in the radio-controlled timepiece antenna 21, the coil 26 is wound directly around the magnetic core member 22, and the bobbin which has been conventionally required is not required. Therefore, both weight and volume can be reduced as compared with the conventional antenna using the bobbin. In this case, the edges of the amorphous foil 23a are relatively sharp, but the portion of the amorphous laminate 32 in which the amorphous foil 23a is laminated around the coil 26 is covered with the insulating film 24, so that the amorphous foil 23a is sharp. The coil 26 does not come into direct contact with the edge of the foil 23a, so that the wound coil 26 can be effectively prevented from being short-circuited.

The amorphous laminated body 23 is preferably annealed. That is, when the amorphous foils are cut to prepare a plurality of the amorphous foils 23a as described above, the strain caused by the cutting remains in each of the amorphous foils 23a, and the plurality of the amorphous foils 23a
The magnetic properties in each of the above deteriorate. This strain can be removed by annealing, and the original magnetic characteristics of the amorphous foil 23a can be restored by the annealing.

Further, it is more preferable that the annealing is performed in a state in which a plurality of cut amorphous foils 23a are laminated to obtain an amorphous laminate 23. That is, when the amorphous foil 23a is annealed, its characteristics are recovered, but on the other hand, the amorphous foil 23a itself becomes brittle, and when the amorphous foil 23a itself before being annealed is annealed, the subsequent laminating work and the insulating film 24 are formed. The amorphous foil 23a may be damaged during the work. Therefore, by annealing the amorphous laminated body 23 obtained by laminating a plurality of cut amorphous foils 23a, the magnetic characteristics of the amorphous foil 23a are recovered and the magnetic characteristics required by the amorphous laminated body 23 are obtained. Therefore, it is possible to prevent the amorphous foil 23a that constitutes the laminated body 23 from being damaged.

Further, as shown in this embodiment, the insulating tape having relatively excellent heat resistance is used as the amorphous laminate 2.
When the insulating film 24 is wound around the insulating film 24, the insulating film 24 can be formed by annealing after forming the insulating film 24.
Is not deteriorated by the heat of annealing. Therefore, the amorphous laminated body 23 can be annealed after the insulating film 24 is formed or after the insulating film 24 and the coil 26 are formed, and strain generated in the amorphous foil 23a during the formation of the insulating film 24 can be reduced. Can be removed, and when annealing is performed after the coil 26 is wound,
It is also possible to remove the strain generated in the amorphous foil 23a both during the formation of the insulating film 24 and the winding of the coil 26.

Next, a second embodiment of the present invention will be shown. The amorphous laminate 23 in this embodiment is obtained by laminating a plurality of amorphous foils 23a and laminating them. A plurality of amorphous foils 23a
An adhesive made of thermosetting plastic is used to bond the two together. Specifically, the amorphous laminated body 23 according to the above-described first embodiment obtained by laminating a plurality of amorphous foils 23a is covered with the insulating film 24 in a portion other than both ends thereof, Immerse in the thermosetting plastic melt. Then, the plastic melt enters the gaps in which the plurality of amorphous foils 23a forming the amorphous laminate are laminated. And
By pulling up the laminate 23 from the plastic melt and heating it, the plastics that have entered the gaps between the laminated amorphous foils 23a are cured, and the plurality of amorphous foils 23a are adhered to each other by the thermosetting plastic.

In the magnetic core member 22 of the antenna for a radio-controlled timepiece constructed as described above, the magnetic core member 22 can have rigidity. That is, the amorphous foil 23a is relatively flexible, and even if such an amorphous foil 23a is laminated to obtain the amorphous laminate 23, when the plurality of amorphous foils 23a are allowed to slide with each other, the amorphous foil 23a is amorphous. The laminated body 23 also becomes flexible. When the amorphous laminated body 23 is flexible, it is difficult to wind the coil 26 thereafter. On the other hand, when a plurality of amorphous foils 23a are adhered to each other, slipping between the plurality of amorphous foils 23a is prohibited, and the entire amorphous laminate 23 obtained by adhesively laminating the amorphous foils 23a is fixed. , This amorphous laminate 2
The magnetic core member 22 obtained by covering the portions other than both ends of 3 with the insulating film 24 becomes rigid, and the work of winding the coil 26 thereafter becomes easy.

In this embodiment, a thermosetting plastic is used as an adhesive for adhering a plurality of amorphous foils 23a to each other, and the amorphous laminate 23 is applied to the thermosetting plastic melt. The plastic that has been impregnated and has entered the gaps in which the amorphous foils 23a are stacked is heat-cured to bond the plurality of amorphous foils 23a to each other. Therefore, heating to cure the plastic also anneals the amorphous laminate 23 at the same time, and it is possible to omit the work of annealing the amorphous laminate 23 in a separate step.

In the above-described second embodiment, the thermosetting plastic is used as the adhesive for adhering a plurality of amorphous foils 23a to each other. As the adhesive that adheres to the adhesive, an adhesive made of a solvent and a plastic dissolved in the solvent may be used. Even with such an adhesive,
The adhesive is impregnated with the amorphous laminated body 23, and then pulled up and heated to vaporize the solvent in the adhesive that has penetrated into the gaps in which the amorphous foils 23a are laminated. Can be glued to each other. Further, the heating for vaporizing the solvent also anneals the amorphous laminate 23 at the same time, which makes it possible to omit the work of annealing the amorphous laminate 23 in another step.

Further, in the above-mentioned first and second embodiments, the amorphous laminated body 23 formed in the shape of a square rod by laminating a plurality of rectangular amorphous foils 23a having the same shape and size is explained. The laminated body 23 may be formed in a plate shape by laminating a plurality of rectangular amorphous foils 23a having the same shape and size.

[0025]

EXAMPLES Next, examples of the present invention will be described in detail together with comparative examples. <Example 1> An antenna 21 shown in Fig. 1 was produced. That is,
An amorphous sheet having a thickness of 15 μm (manufactured by Aramid Chemical Co .; trade name “METGLAS2705M”) was cut into a length of 23 mm and a width of 3 mm to prepare 30 rectangular amorphous foils 23a. The 30 amorphous foils 23a were annealed by being heated to 350 ° C. in the atmosphere and left for 30 minutes, and then laminated to obtain an amorphous laminate 32. After that, the laminated body 23 has a width of 23 m.
Insulation tape consisting of m of polyimide is wound twice and 23
An insulating film 24 having a width dimension of mm was formed.
The magnetic core member 22 thus formed has a diameter of 0.14.
A mm coated wire was wound 600 times to obtain an antenna 21 for a radio-controlled timepiece. This radio clock antenna 21 is referred to as the first embodiment.

<Embodiment 2> The same amorphous sheet as that of Embodiment 1 is used, and the same procedure as that of Embodiment 1 is carried out.
30 square-shaped amorphous foils 23a having the same shape and size as the above were prepared. The 30 amorphous foils 23a were used in Example 1
After annealing in the same procedure as above, 30 amorphous foils 23a were laminated while applying a rubber adhesive and
It was dried for 4 hours to obtain an amorphous laminate 32 in which 30 pieces of the amorphous foils 23a were adhered to each other. Then, the same insulating tape as in Example 1 was applied to the laminated body 23 in Example 1.
The insulating film 24 was formed by winding in the same manner as in. The magnetic core member 22 thus formed has a diameter of 0.14 mm.
The radio wave clock antenna 21
Got This radio clock antenna 21 is referred to as the second embodiment.

<Embodiment 3> The same amorphous sheet as that of Embodiment 1 is used, and the same procedure as that of Embodiment 1 is carried out.
30 square-shaped amorphous foils 23a having the same shape and size as the above were prepared. The 30 amorphous foils 23a were used in Example 1
After being annealed in the same procedure as above, they were laminated, and the same insulating tape as in Example 1 was wound around this laminated body 32 in the same manner as in Example 1 to form the insulating film 24. After that, the whole is impregnated with a polyimide varnish, and after taking out from the varnish, the polyimide varnish that has penetrated into the gaps in which the amorphous foils 23a are laminated is cured by heating at 200 ° C for 30 minutes in the atmosphere, so that 30 amorphous foils 23a are formed. Glued to each other. A coated conductor wire having a diameter of 0.14 mm was wound around the magnetic core member 22 thus formed 600 times to obtain an antenna 21 for a radio-controlled timepiece. This radio clock antenna 21 is referred to as the third embodiment.

<Embodiment 4> The same amorphous sheet as in Embodiment 1 is used, and the same procedure as in Embodiment 1 is followed.
30 square-shaped amorphous foils 23a having the same shape and size as the above were prepared. The 30 amorphous foils 23a were laminated without annealing, and the same insulating tape as in Example 1 was wound around this laminated body 32 in the same manner as in Example 1 to produce the insulating film 2.
4 was formed. After that, the whole is impregnated with polyimide varnish and taken out from the varnish.
The polyimide varnish that has penetrated into the gaps in which the amorphous foils 23a are stacked is heated and cured by heating for 3 minutes to
The 0 amorphous foils 23a were bonded to each other, and the 30 amorphous foils 23a were each annealed. The magnetic core member 22 thus formed has a diameter of 0.
A coated wire of 14 mm was wound 600 times to obtain an antenna 21 for a radio-controlled timepiece. The radio clock antenna 21 is referred to as the fourth embodiment.

<Embodiment 5> The same amorphous sheet as that of Embodiment 1 is used, and the same procedure as that of Embodiment 1 is carried out.
30 square-shaped amorphous foils 23a having the same shape and size as the above were prepared. The 30 amorphous foils 23a were laminated without annealing, and the same insulating tape as in Example 1 was wound around this laminated body 32 in the same manner as in Example 1 to produce the insulating film 2.
4 was formed. A coil 26 was formed by winding a coated conductor wire having a diameter of 0.14 mm 600 times around the magnetic core member 22 on which the insulating film 24 was formed. After that, the whole is impregnated with the polyimide varnish, heated at 360 ° C. in the air and left for 30 minutes to heat and cure the polyimide varnish that has penetrated into the gaps in which the amorphous foils 23a are laminated, so that the 30 amorphous foils 23a are separated from each other. And adhere to 30
Each of the amorphous foils 23a was annealed. The radio-controlled timepiece antenna 21 thus formed is referred to as Example 5.

Comparative Example 1 Using the same amorphous sheet as in Example 1, the same procedure as in Example 1 was carried out.
Thirty square amorphous foils 23a of the same shape and size were prepared, and the thirty amorphous foils 23a were annealed in the same procedure as in Example 1. On the other hand, length 23 mm, width 8.4
A bobbin for winding having a plastic frame of mm and thickness of 5.9 mm was separately prepared. This bobbin has a diameter of 0.
After forming a coil 26 by winding a 14 mm covered conductor wire 600 times, 30 pieces of the amorphous foil 23 prepared in advance are prepared.
The a was laminated and inserted into the frame to complete the radio-controlled timepiece antenna 21. A radio-controlled timepiece antenna having a bobbin in this manner was used as Comparative Example 1.

<Comparative Example 2> A winding bobbin made of plastic was prepared by insert-molding a cylindrical magnetic core member made of soft ferrite having a diameter of 3 mm and a length of 23 mm on the shaft core. A coated conductor having a diameter of 0.14 mm was wound around this bobbin 400 times to obtain an antenna 21 for a radio-controlled timepiece. A radio-controlled timepiece antenna having a magnetic core member made of ferrite in this manner was used as Comparative Example 2.

<Comparative Example 3> The same amorphous sheet as in Example 1 was used, and the same procedure as in Example 1 was used.
30 square-shaped amorphous foils 23a having the same shape and size as the above were prepared. The 30 amorphous foils 23a were used in Example 1
After annealing in the same procedure as above, the layers were laminated to obtain a magnetic core member composed only of an amorphous laminate. A coated conductor having a diameter of 0.14 mm was wound 600 times around this magnetic core member not covered with an insulating film to obtain an antenna for a radio-controlled timepiece. This radio clock antenna 21 was used as Comparative Example 3.

<Comparative Test> Examples 1 to 5 and Comparative Examples 1 to 1
The L value and Q value of the radio timepiece antenna 3 of Example 3 were measured by an impedance analyzer 4395A (manufactured by Hewlett-Packard Co.) and the external dimensions were measured by a caliper. After that, these antennas were connected to a radio-controlled timepiece, and it was checked whether the time adjustment function of the radio-controlled timepiece worked. The results are shown in Table 1.

[0034]

[Table 1]

<Evaluation> As is clear from the results shown in Table 1,
The radio-controlled timepiece antennas in Comparative Examples 1 and 2 are
Although the time correction function of the radio-controlled clock worked normally, Example 1
It can be seen that the external dimensions are larger than the antennas of ~ 5. It is considered that this is because a bobbin for forming the coil is separately required. The antenna of Comparative Example 3 has the same external dimensions as those of Example 1.
Although it is almost the same as the ~ 5 antenna, the coil is short-circuited. This is because the coil is wound directly around the amorphous laminated body in which this amorphous foil is laminated,
It is considered that the coil touched the edge of the sharp amorphous foil and the coating was damaged. On the other hand, although the radio timepiece antennas in Examples 1 to 5 were smaller than the antennas in Comparative Examples 1 and 2, the time adjustment functions of the radiowave timepieces worked normally. This is because the portion of the amorphous laminate 32 around which the coil 26 is wound is covered with the insulating film 24, and the sharp amorphous foil 23a is formed.
It is considered that this is due to the fact that the coil 26 does not directly touch the ridge.

[0036]

As described above, according to the present invention, since the magnetic core member is provided with the amorphous laminated body formed by laminating a plurality of amorphous foils which are relatively flexible and have no risk of cracking, the ferrite The mechanical strength of the sintered body can be improved as compared with the conventional one. Although the edges of the amorphous foil are relatively sharp, the magnetic core member of the present invention covers the portion of the laminated body around which the coil is wound with an insulating film, so that the coil directly contacts the edges of the sharp amorphous foil. There is no such thing. Therefore, it is possible to effectively prevent a short circuit of the wound coil.

In this case, if the amorphous foil is annealed, the magnetic characteristics of the amorphous foil are restored before the cutting process, the magnetic characteristics required by the amorphous laminate can be surely obtained, and the insulating film has heat resistance. In this case, due to its heat resistance, even if the insulating film is annealed after being formed into an amorphous laminate, the insulating film is not deteriorated by the heat of annealing. As a result, it becomes possible to anneal the amorphous laminate after forming the insulating film, it is possible to remove the strain generated in the amorphous foil at the time of forming the insulating film, and to anneal after the coil is wound. In the case of carrying out, it becomes possible to remove the strain generated in the amorphous foil both at the time of forming the insulating film and winding the coil.

If a plurality of amorphous foils are adhered to each other, slippage between the plurality of amorphous foils is prohibited, and the entire amorphous laminate obtained by adhering and laminating the amorphous foils is fixed. The magnetic core member becomes rigid and the work of winding the coil thereafter can be facilitated. At this time, if an adhesive consisting of a thermosetting plastic or a solvent and a plastic dissolved in the solvent is used, the adhesive that has penetrated into the gaps in which the amorphous foils are laminated is heat-cured so that a plurality of amorphous foils are mutually bonded. By adhering to the adhesive, heating to cure the adhesive also anneals the amorphous laminated body at the same time, and it becomes possible to omit the work of annealing the amorphous laminated body in a separate step.

[Brief description of drawings]

FIG. 1 is a diagram showing an antenna according to an embodiment of the present invention.
A-A line sectional view.

FIG. 2 is a perspective view of the antenna.

FIG. 3 is a front view of a radio-controlled timepiece having the antenna.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5A is a front view showing a state in which the conventional antenna is housed in a case for mounting. (B) A longitudinal sectional view showing a state in which the antenna is attached via a case.

[Explanation of symbols]

11 radio clock 21 antenna 22 Magnetic core member 23 Amorphous laminate 23a amorphous foil 24 Insulating film 26 coils

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masami Miyake             1-12-14 Koishikawa, Bunkyo-ku, Tokyo Mitsubishi             Material Co., Ltd. RF-ID Business Center             -In (72) Inventor Seiro Yawata             1-12-14 Koishikawa, Bunkyo-ku, Tokyo Mitsubishi             Material Co., Ltd. RF-ID Business Center             -In F term (reference) 2F002 AA01 AA03 AA12 AB01 AB06                       AC01 AC04 BB04 FA16 GA06

Claims (5)

[Claims] 1. A magnetic core member of an antenna for a radio-controlled timepiece, which comprises an amorphous laminate (23) in which a plurality of magnetic amorphous foils (23a) are laminated, in which a coil (26) of the laminate (23) is wound. A magnetic core member for an antenna, characterized in that the rotated portion is covered with an insulating film (24). 2. A magnetic core member for an antenna according to claim 1, wherein a plurality of amorphous foils (23a) are respectively annealed. 3. A plurality of amorphous foils (23a) are annealed in a state that the insulating film (24) has heat resistance and the laminate (23) is covered with the insulating film (24). The magnetic core member of the antenna according to claim 2. 4. The magnetic core member for an antenna according to claim 1, wherein a plurality of amorphous foils (23a) are laminated by being adhered to each other. 5. A magnetic core member for an antenna according to claim 4, wherein the plurality of amorphous foils (23a) are bonded to each other with a thermosetting plastic, and then the plurality of amorphous foils (23a) are annealed.