JP5964096B2 - Small generators and electronic watches - Google Patents

Description

  The present invention relates to a small generator and an electronic timepiece suitable for a power source of a small electronic device such as a wristwatch device that generates electric power by kinetic energy obtained by a rotating weight or the like.

  2. Description of the Related Art In a small electronic device such as an electronic wristwatch that is suitable for carrying, a portable electronic device that can eliminate battery replacement or eliminate the battery itself by incorporating a generator has been put into practical use. Such a generator generates electric power by an electromagnetic induction effect of a permanent magnet magnetic flux and a coil, converts the obtained AC power into DC power, and supplies it to an electronic device. Generally, a diode is used for conversion from AC to DC. However, since the diode has an internal loss, it is required to generate a voltage higher than the internal loss, and various diodes have been proposed.

  Specifically, as a conventional small generator, in order to obtain electric power for operating an electronic wristwatch by the movement of a rotating weight, a rotor is rotated at a high speed by a speed increasing mechanism combined with a gear and wound around a stator iron core. There has been proposed a generator that generates an induced electromotive force in a coil that has been made (for example, Patent Document 1).

  As another example, a plurality of permanent magnets are arranged on the outer periphery of the rotating shaft of the rotary weight so that the magnetic poles are alternately arranged in the circumferential direction, and the claw pole type iron is arranged on the outer side in the radial direction facing the permanent magnet. There has been proposed a small generator composed of a core (an iron core obtained by bending a claw-shaped magnetic pole piece) and a coil fitted into the iron core (for example, Patent Document 2).

JP 2008-76301 A Japanese Patent Publication No. 2-35547

  However, since the conventional small generator requires a gear for the speed increasing mechanism, the cost increases. Moreover, in the small power generator, electronic timepiece components such as a stepping motor for driving hands and a driving wheel train driven by the step motor must be assembled together with the components of the generator on the main plate. That is, since the assembly requires highly skilled techniques such as adjustment of parts, it takes time and effort to manufacture a small generator.

  Another example of the small power generator is advantageous in that a multi-pole permanent magnet is disposed on the rotating shaft, and therefore, a high-magnification speed increase is not required as compared with a conventional small power generator. However, since the permanent magnet and the stator core are opposed to each other in the radial direction of the rotating shaft, it is necessary to ensure the axial length in order to obtain the magnetic flux, and there is a problem that the thickness of the device increases.

  Therefore, the present invention has been made in view of the above problems, and provides a small generator and an electronic timepiece that are capable of power generation at a high voltage and that are inexpensive and more compact / lightweight. Objective.

  In order to solve the above-mentioned problems, a first feature of the present invention is a small power generator, which is a rotating weight that is swiveled by human movement, and is wound in a cylindrical shape around the axis of the rotating weight. And a permanent magnet provided on a surface of the rotary weight extending in a direction perpendicular to the axis of the rotary weight, and a position spaced apart from the permanent magnet along the axial direction of the rotary weight. A magnetic path forming section having a first magnetic pole tooth and a second magnetic pole tooth arranged, and a connecting portion that connects the first magnetic pole tooth and the second magnetic pole tooth through the inner peripheral surface of the coil. The permanent magnets are arranged such that the magnetic poles alternately change along the turning direction of the rotary weight, and the first magnetic pole teeth and the second magnetic pole teeth are each formed in a comb-teeth shape. And the adjacent tooth portions are arranged with a gap between each other, and the first magnet That the teeth of the toothed portion and the second magnetic pole teeth of the teeth are configured by combining to engage alternately in a plate shape and gist.

  According to such a feature, the first magnetic pole teeth and the second magnetic pole teeth facing the respective magnetic poles of the permanent magnet are alternately reversed for each magnetic pole pitch of the permanent magnets. The direction of the magnetic flux interlinking with the coil is also reversed. For this reason, even a slight swiveling motion of the rotary weight causes many inversions of the coil interlinkage magnetic flux, and the coil can induce a high voltage. For example, when a permanent magnet is magnetized with different magnetic poles alternately at an angle of 3.2 °, one circumference of 360 ° is magnetized with 112 poles. It becomes possible to switch the magnetic poles at a speed 56 times that of a permanent magnet magnetized to two poles as used in a conventional small generator. Therefore, a high voltage can be obtained without increasing the rotation of the rotary weight. In addition, a permanent magnet is provided on the surface of the rotary weight extending in a direction perpendicular to the axis of the rotary weight, and the first magnetic pole teeth and the second magnetic pole teeth are provided at positions facing the permanent magnet and the rotary weight in the axial direction. Yes. Therefore, the permanent magnet can be opposed to the first magnetic pole teeth and the second magnetic pole teeth in a wide area in the plane direction of the rotary weight, and a large amount of magnetic flux can be linked to the coil without increasing the thickness of the permanent magnet. be able to. Therefore, since the small generator can be formed thin, further downsizing / lightening can be achieved.

According to a second aspect of the present invention, in the small power generator according to the first aspect of the present invention, each of the first magnetic pole teeth and the second magnetic pole teeth is formed by laminating a plurality of plate materials. Is the gist.
According to such a feature, even multi-pole magnetic pole teeth with a small magnetic pole pitch can be stamped by using a thin plate material, and magnetic pole teeth can be manufactured at low cost. In addition, by using a thin steel plate to a thickness that does not saturate the magnetic flux and using an electromagnetic steel plate in which the surface of each plate is electrically insulated, the eddy current can be reduced and the efficiency of the generator can be improved.

A third feature of the present invention is summarized in that, in the small generator according to the first and second features of the present invention, the permanent magnet is formed in a fan-shaped flat shape having an inner angle of 180 ° or less. .
According to this feature, since the permanent magnet functions as a weight of the rotating weight, the thickness of the rotating weight can be reduced, and the generator can be downsized.

According to a fourth aspect of the present invention, in the electronic timepiece, the small generator according to any one of the first to third aspects of the present invention, and a timepiece module that is driven based on electric energy generated by the small generator. The clock module is housed on the inner peripheral side of the magnetic path forming portion.
According to this feature, the electronic timepiece module can be manufactured by a dedicated process, and the generator can be assembled later. Thereby, the movement for an electronic timepiece with a built-in generator can be easily manufactured without using a specially advanced assembling technique, and the assembling can be simplified. Further, since the electronic timepiece module is accommodated inside the magnetic path forming portion of the generator, the timepiece is not made thick. Therefore, it can be assembled into a harmonious and elegant watch exterior.

  According to the small power generator of the present invention, it is possible to provide a small power generator and an electronic timepiece that are inexpensive, smaller and lighter while securing a high voltage even from the rotation of a rotating weight caused by the movement of a person's arm. be able to.

It is sectional drawing which shows the state which attached the small generator which concerns on 1st Embodiment to the electronic timepiece module. It is a disassembled perspective view of the electronic timepiece module shown in FIG. It is a top view which expands and shows a part of magnetic pole tooth. It is explanatory drawing about the magnetization state at the time of generating electric power with a small generator. It is sectional drawing which shows the state which attached the small generator in 2nd Embodiment to the electronic timepiece module. It is a perspective view which shows the state which attached the small generator in 2nd Embodiment to the electronic timepiece module. It is a top view when a small generator is assembled | attached to timepiece exterior components.

Hereinafter, a preferred embodiment (first embodiment) of a small generator of the present invention will be described in detail with reference to FIGS. 1 to 3.
(1) Outline of Embodiment First, an outline of a small generator according to the present embodiment and an electronic timepiece equipped with the small generator will be described.
FIG. 1 shows a cross-sectional view of a state where the small generator 20 is attached to the electronic timepiece module 9. FIG. 2 is an exploded perspective view of the small generator 20 shown in FIG.

  The small power generator 20 extends in a direction perpendicular to the axis of the rotating weight 1, the rotating weight 1 that pivots by human movement, the coil 8 wound in a cylindrical shape around the axis of the rotating weight 1. A permanent magnet 2 provided on the surface of the rotating weight, and a magnetic path forming portion 6 disposed below the permanent magnet 2. The magnetic path forming part 6 is arranged so as to surround the first magnetic pole teeth 3 and the second magnetic pole teeth 4 and the coil 8 which are arranged to face the permanent magnet 2 in the axial direction of the rotary weight with a predetermined interval. 3 and a connecting portion 5 that connects the second magnetic pole teeth 4 to each other. Moreover, the permanent magnet 2 is arrange | positioned so that a magnetic pole may be alternately formed over the circumference direction of the turning surface of a rotary weight. The first magnetic pole teeth 3 and the second magnetic pole teeth 4 are formed by combining individual teeth so that they are formed in a comb shape and are alternately meshed with a gap therebetween.

  According to the small power generator 20 having the above-described configuration, the first magnetic pole teeth 3 and the second magnetic pole teeth 4 facing the respective magnetic poles of the permanent magnet 2 are magnetized so that the magnetic poles excited by the rotation of the permanent magnet 2 are permanent magnets. Since the magnetic field is alternately reversed every two magnetic pole pitches, the direction of the magnetic flux linked to the coil is also reversed. Therefore, even if it is a slight turning motion of the rotary weight 1, the coil interlinkage magnetic flux is reversed many times, and the coil 8 can induce a high voltage. For example, when the permanent magnet 2 is magnetized with different magnetic poles alternately at an angle of 3.2 °, one circumference of 360 ° is magnetized with 112 poles. It is possible to switch the magnetic poles at a speed 56 times that of a permanent magnet magnetized to two poles as used in a conventional small generator. Therefore, a high voltage can be obtained without increasing the rotation of the rotary weight 1. In addition, a permanent magnet 2 is provided on the surface of the rotary weight 1 extending in a direction perpendicular to the axis of the rotary weight 1, and the first magnetic pole teeth and the second magnetic pole teeth are disposed at positions facing the permanent magnet 2 and the rotary weight 1 in the axial direction. It has magnetic pole teeth. Therefore, the permanent magnet 2 can be opposed to the first magnetic pole teeth and the second magnetic pole teeth in a wide area in the plane direction of the rotary weight 1, and a large amount of magnetic flux can be generated by the coil 8 without increasing the thickness of the permanent magnet 2. Can be interlinked. Therefore, the small generator 20 can be formed thinner.

(2) Details of Embodiment As shown in FIG. 1, the rotary weight 1 is rotatably arranged via a rotary weight presser 10 provided with a ball bearing in the electronic timepiece module 9. The rotating weight 1 includes a disk-shaped rotating weight inner peripheral portion 1b that is attached to the rotating weight retainer 10 and extends radially outward, a rotating weight outer peripheral thin portion 1c, and a rotating weight outer peripheral thick portion 1a. Here, the inner periphery 1b of the rotary weight is made of a nonmagnetic material SUS304 or the like. Moreover, the rotating weight outer periphery thin part 1c and the rotating weight thick part 1a are comprised with magnetic material SUS430 grade | etc.,. Moreover, as shown in FIG. 2, the rotating weight outer peripheral thick part 1a is provided with the fan-shaped thick part with an internal angle of 180 degrees or less. As a result, the center of gravity of the rotary weight 1 is separated from the center of rotation.

The permanent magnet 2 has an annular shape and is bonded and fixed to the surfaces of the rotating weight outer peripheral thick part 1a and the rotating weight thin part 1c facing the first magnetic pole teeth 3 and the second magnetic pole teeth 4. The permanent magnet 2 can use various permanent magnets. Specific examples of the permanent magnet 2 include a neodymium magnet mainly composed of Nd (neodymium), Fe (iron), and B (boron), and a samarium cobalt magnet.
The permanent magnet 2 has a plurality of magnetic poles alternately magnetized in the circumferential direction of the turning surface of the rotary weight 1.

  FIG. 3 shows an enlarged plan view of a part of the magnetic pole teeth. As shown in FIG. 3, the first magnetic pole teeth 3 and the second magnetic pole teeth 4 are flat plates formed by press-cutting an electromagnetic steel plate, and the first magnetic pole teeth 3 and the second magnetic pole teeth processed into the same shape. Two teeth 4 are stacked in the thickness direction. Thus, the first magnetic pole teeth 3 and the second magnetic pole teeth 4 are formed by laminating a plurality of plate materials. Thereby, even if it is a multi-pole magnetic pole tooth with a small magnetic pole pitch, press punching can be performed by using a thin plate material, and the magnetic pole tooth can be manufactured at low cost. In addition, by laminating thin plate materials to a thickness that does not saturate the magnetic flux, and using electromagnetic steel plates in which the surface of each plate material is electrically insulated, the eddy current can be reduced and the efficiency of the small generator 20 can be improved. .

  The first magnetic pole tooth 3 has an annular base end portion 3a on the inner peripheral side, and the tooth portions 3b formed in a comb-teeth shape from the base end portion 3a toward the outer periphery have an equal angular pitch. It is distracted. On the other hand, the second magnetic pole tooth 4 has an annular base end portion 4a on the outer peripheral side, and the tooth portions 4b formed in a comb-teeth shape from the base end portion 4a toward the inner periphery have an equal angular pitch. It is distracted. The tooth portions 3b and 4b of the first magnetic pole tooth 3 and the second magnetic pole tooth 4 are arranged so as to alternately mesh with each other with a gap therebetween at equal intervals.

  Further, in the present embodiment, there are 63 first magnetic pole teeth 3 and second magnetic pole teeth 4 respectively. Therefore, when the first magnetic pole teeth 3 and the second magnetic pole teeth 4 are alternately meshed, a total of 126 tooth portions are arranged.

  The base end portion 3a of the first magnetic pole tooth 3 is fitted and fixed to one end portion of a cylindrical inner peripheral portion 5c of the connection portion 5 formed of a magnetic material. The other end portion of the inner peripheral portion 5c is fixed to the inner peripheral surface of the annular bottom portion 5b of the connecting portion 5 formed of a magnetic material. The base end portion 4a of the second magnetic pole tooth 4 is externally fitted and fixed to the cylindrical outer peripheral portion 5a of the connection portion 5 formed of a magnetic material. The other end of the outer periphery 5a is fixed to the outer periphery of the bottom 5b.

  In general, a generator using magnetic pole teeth generates cogging torque, which hinders efficient rotation of the rotary weight. In general, the cogging torque is such that the number of iron core pole teeth (tooth portion) is n times 9 (the number of iron core pole teeth (tooth portion) = 9 × n, n = the number of iron core pole teeth (tooth portion) / 9). In addition, it is known that the value becomes smaller when the number of magnetic poles of the permanent magnet is n times 9 ± 1 (the number of magnetic poles of the permanent magnet = (9-1) × n). Accordingly, when confirming the case of the present embodiment, the total number of tooth portions of the first magnetic pole teeth 3 and the second magnetic pole teeth 4 is 126, so n = number of iron core magnetic pole teeth (tooth portions) / 9 = 126 / 9 = 14. Therefore, it can be seen that the number of iron core magnetic pole teeth (tooth portion) is 14 times nine. Further, when n = 14 is applied and the number of magnetic poles of the permanent magnet is calculated, the number of magnetic poles of the permanent magnet = (9-1) × 14 = 112. Therefore, it can be seen that the number of magnetic poles of the permanent magnet is n times 9 ± 1. From these things, the small generator 20 of this embodiment becomes small in cogging torque, and can rotate a rotary weight with high efficiency.

  The magnetic path forming part 6 includes a connecting part 5 including an outer peripheral part 5a, a bottom part 5b, and an inner peripheral part 5c, and a first magnetic pole tooth 3 and a second magnetic pole tooth 4. Here, the connecting portion 5 includes an annular bottom portion 5b forming a bottom surface, a cylindrical inner peripheral portion 5c connected to the inner edge of the bottom portion 5b and extending upward, and an upper portion connected to the outer edge of the bottom portion 5b. And a cylindrical inner peripheral portion 5c extending toward the bottom.

A coil bobbin 7 and a coil 8 wound around the coil bobbin 7 are accommodated inside the magnetic path forming unit 6.
The inner peripheral end of the bottom 5b is fixed to the electronic timepiece module 9, and the winding terminal of the coil 8 is connected to the timepiece circuit through a rectifier circuit in the electronic timepiece module 9 (not shown).

(Generator operation)
Next, the operation of the small generator 20 will be described with reference to FIG. FIG. 4 is an explanatory diagram of the magnetization state when generating power with a small generator. As indicated by arrows in FIG. 4, the magnetic flux of the permanent magnet 2 is in the direction of the N pole → the second magnetic pole tooth 4 → the connecting portion 5 → the first magnetic pole tooth 3 → the N pole adjacent to the S pole (not shown). Flow and interlink with the coil 8. On the other hand, when the rotary weight rotates from the state of FIG. 4 by an angle 2π (rad) / the total number of magnetic poles of the permanent magnet, the magnetic poles existing in the first magnetic pole teeth and the second magnetic pole teeth in the state of FIG. It faces the magnetic pole of the permanent magnet 2. In this state, the magnetic flux of the permanent magnet 2 in the direction opposite to the arrow in FIG. 4 is in the direction of the S pole adjacent to the N pole → the first magnetic pole tooth 3 → the connecting portion 5 → the second magnetic pole tooth 4 → the N pole. Flow and interlink with the coil 8.

As described above, when the rotary weight 1 and the permanent magnet 2 are turned along with the movement of the human arm, the generator 20 generates power by alternately switching the direction of the magnetic flux interlinking with the coil.
The first magnetic pole teeth 3 and the second magnetic pole teeth 4 do not have to be electromagnetic steel plates, but may be any magnetic material. In addition, the first magnetic pole teeth 3 and the second magnetic pole teeth 4 are formed by laminating two magnetic pole teeth, but one or more may be laminated.

(3) Second Embodiment A second embodiment of the present invention will be described with reference to FIGS.
FIG. 5 shows a cross-sectional view of the small generator according to the second embodiment attached to an electronic timepiece module. FIG. 6 is a perspective view in which a small generator according to another embodiment is attached to an electronic timepiece module. Instead of the disk-shaped rotating cone 1 and the annular permanent magnet 2, a substantially sector-shaped rotating weight 11 and a substantially sector-shaped permanent magnet 12 as shown in FIGS. 5 and 6 may be used. In particular, the permanent magnet 12 is preferably formed in a substantially fan-shaped flat shape with an inner angle of 180 ° or less. Thereby, since the permanent magnet 12 has a function as the weight of the rotary weight 11, the thickness of the rotary weight 11 can be made thin, and the small generator 20 can be made smaller.

  The rotary weight 11 includes a rotary weight outer peripheral portion 11a formed of a magnetic material SUS430 and the like, and a rotary weight inner peripheral portion 11b formed of a nonmagnetic material SUS304 and the like.

With this configuration, the generator can be reduced in size. The specific gravity of the samarium-cobalt magnet of the permanent magnet 12 is 8.4, and the specific gravity of the magnetic material SUS430 of the outer periphery 11a of the rotary weight is 7.7. Therefore, the specific gravity of the permanent magnet 12 is larger than the specific gravity of the rotating weight 11a. Therefore, the rotary weight 11 can obtain the same moment of inertia even if the volume is reduced. From this, the generator can be reduced in size.
The small power generators of all the embodiments shown in the present invention can be used for an electronic timepiece.

  FIG. 7 is a plan view when the generator 20 is assembled to the watch exterior part 30. The electronic timepiece includes a small generator 20 and a timepiece module 9 that is driven based on electric energy generated by the small generator 20. The timepiece module 9 is accommodated on the inner peripheral side of the magnetic path forming unit 6. Thereby, for example, the electronic timepiece module 9 can be manufactured by a dedicated process, and the generator can be assembled later. Thereby, the movement for an electronic timepiece with a built-in generator can be easily manufactured without using a specially advanced assembling technique, and the assembling can be simplified. Moreover, since the electronic timepiece module 9 is accommodated inside the magnetic path forming portion 6 of the small generator 20, the timepiece can be thinned. Therefore, it can be assembled into a harmonious and elegant watch exterior.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.
For example, in the above-described embodiment, an electronic watch is illustrated as an example of a product on which a small generator is mounted, but it may be used for a mobile phone or the like.

DESCRIPTION OF SYMBOLS 1, 11 Rotating weight 2, 12 Permanent magnet 3 1st magnetic pole tooth 3a, 4a Base end part 3b, 4b Tooth part 4 2nd magnetic pole tooth 5 Connection part 5a Outer part 5b Bottom part 5c Inner part 6 Magnetic path formation part 7 Coil bobbin 8 Coil 9 Electronic clock module 10 Rotary weight holder 20 Small generator 30 Clock exterior parts

Claims (4)

A rotating spindle that swivels with human movement;
A coil wound in a cylindrical shape around the axis of the rotating weight;
A permanent magnet provided on the surface of the rotating weight extending in a direction perpendicular to the axis of the rotating weight;
A first magnetic pole tooth and a second magnetic pole tooth disposed opposite to each other at a position apart from the permanent magnet along the axial direction of the rotating weight, the first magnetic pole tooth and the first magnetic pole tooth passing through the inner peripheral surface of the coil A magnetic path forming portion having a connection portion for connecting the second magnetic pole teeth,
The permanent magnet is arranged such that the magnetic poles alternately change along the turning direction of the rotary weight,
The first magnetic pole teeth and the second magnetic pole teeth are each composed of a plurality of tooth portions formed in a comb-tooth shape, and the adjacent tooth portions are arranged with a gap therebetween, and the first magnetic pole teeth The teeth of the second magnetic pole teeth and the teeth of the second magnetic pole teeth are combined so that they are alternately meshed to form a flat plate shape ,
The rotary weight is constituted by sector in a by rotating weight inner peripheral portion formed of a non-magnetic material and rotating spindle outer peripheral portion made of a magnetic material, the permanent magnet is provided on the rotary spindle outer periphery Rukoto A small generator characterized by.   2. The small generator according to claim 1, wherein each of the first magnetic pole teeth and the second magnetic pole teeth is formed by laminating a plurality of plate materials. 3. The small generator according to claim 1, wherein the permanent magnet is formed of a neodymium magnet or a samarium cobalt magnet and is formed in a fan-shaped flat shape having an inner angle of 180 ° or less. A small generator according to any one of claims 1 to 3, and a timepiece module that is driven based on electric energy generated by the small generator,
The electronic timepiece is characterized in that the timepiece module is accommodated on an inner peripheral side of the magnetic path forming portion.

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