JP2014213657A - Dynamo for bicycle and bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dynamo for a bicycle capable of downsizing an outer diameter, reducing in thickness and reducing in weight.SOLUTION: In a dynamo for a bicycle; a magnet holding part 20 is provided on a wheel 3 side; an iron core holding part 22 is provided on a fork 2 side; a plurality of magnets 19 are arranged at the magnet holding part 20; a plurality of cores 21 wound with a coil 46 are arranged at the iron core holding part 22; the magnet 19 has an N pole and an S pole in a hub axial direction A; a first pole piece 31 comes into contact with one of the N pole and the S pole, and a second pole piece 32 comes into contact with the other pole; the first pole piece 31 has a first expansion part 31b expanded inwardly in a radial direction B of the wheel 3; the second pole piece 32 has a second expansion part 32b expanded outwardly in the radial direction B; and in the hub axial direction A, the core 21 and the first and the second expansion parts 31b and 32b face with each other.

Description

  The present invention relates to a bicycle dynamo that supplies power to a light, and a bicycle including the bicycle dynamo.

  Conventionally, as this type of bicycle dynamo, for example, there is a dynamo 103 provided between a front wheel 101 and a front fork 102 of a bicycle as shown in FIG. In this dynamo 103, a fixed side housing 104 is fixed to an axle 106 by a lock nut 105, and a coil 107 is disposed inside the fixed side housing 104. Further, a rotation side housing 109 is attached to the spoke 108 of the front wheel 101, and a magnet 110 is provided inside the rotation side housing 109.

  The coil 107 is formed in an annular shape so as to surround the axle 106. In addition, the magnet 110 has a multipolar structure in which a plurality of magnet pieces in which the N pole and the S pole are polarized and magnetized are fixed in an annular shape so that the polarities of adjacent magnet pieces are different from each other. It arrange | positions so that the outer peripheral side of the coil 107 may be surrounded.

  According to this, when the front wheel 101 rotates, it rotates around the coil 107 with the magnet 110 fixed together with the front wheel 101, and the magnetic flux acting on the coil 107 changes, so that an electromotive force is generated in the coil 107 due to electromagnetic induction. Current flows.

  The dynamo 103 configured as described above is described in Patent Document 1 below.

JP-A-10-108428

  In the conventional type, the coil 107 is disposed between the magnet 110 and the cylindrical portion 111 a of the hub 111 in the radial direction B of the wheel 101. For this reason, it is necessary to ensure a large space 113 between the magnet 110 and the cylindrical portion 111a of the hub 111 in the radial direction B, and the inner diameter 115 of the magnet 110 increases, and the outer diameter 116 of the dynamo 103 increases accordingly. However, there is a problem that weight reduction becomes difficult.

  An object of the present invention is to provide a bicycle dynamo and a bicycle that can be reduced in weight by reducing the outer diameter.

In order to achieve the above object, the dynamo for bicycles according to the first invention is provided with a magnet holding part on one of the wheel side and the hawk side and an iron core holding part on the other side,
In the magnet holding part, a plurality of magnets are arranged in the circumferential direction of the wheel so as to surround the hub,
The iron core holding part is arranged in the circumferential direction of the wheel so that a plurality of cores wound with coils surround the hub,
In the magnet, one side surface in the hub axial direction is one of the north and south poles, and the other side opposite is the other pole.
The first pole piece contacts one side of the magnet,
The second pole piece contacts the other side of the magnet,
The first pole piece has a first extension portion extended inward in the radial direction of the wheel from the contact portion with the magnet,
The second pole piece has a second extension portion extended outward in the radial direction of the wheel from the contact portion with the magnet,
The first and second extension portions face the side surfaces of the magnet holding portion in the hub axis direction,
In the hub axial direction, the core and the first and second extension portions face each other.

  According to this, when the wheel rotates, either the magnet holding part or the iron core holding part rotates with the wheel, and either the magnet of the magnet holding part or the core of the iron core holding part rotates. Rotates relative to the other. When the position of the magnet and the position of the core overlap in the rotation direction, the first and second extension portions and the core face each other in the hub axial direction, and the magnetic flux of the magnet passes from the N pole to the first pole piece. The first pole piece passes through the core, passes from the core through the second pole piece second extension part, and reaches the S pole of the magnet from the second pole piece.

  Further, when the position of the magnet and the position of the core are shifted in the rotation direction, the magnetic flux of the magnet does not pass through the core. Thus, according to the rotation of the wheel, a state in which the magnetic flux of the magnet passes through the core and a state in which the magnetic flux does not pass through are repeatedly generated alternately to become an alternating magnetic flux, and a current flows through the coil to generate power.

  Further, the core and the magnet can be opposed to each other in the hub axial direction by bringing the first and second pole pieces into contact with the magnet. Thereby, it is not necessary to secure a space for disposing the core between the magnet and the hub in the radial direction of the wheel, and the outer diameter of the dynamo can be reduced and the dynamo can be reduced in weight.

In the bicycle dynamo of the second invention, the first extension portion of the first pole piece and the second extension portion of the second pole piece are arranged in a plane perpendicular to the hub axis.
According to this, since the thickness of the magnet in the hub axis direction can be reduced, the thickness of the magnet holding portion can be reduced, and the dynamo can be further reduced in weight.

In the dynamo for bicycles according to the third invention, the magnet holding portion is provided on the wheel,
The iron core holding part is fixed to the hawk side,
The first and second expansion portions face the outer surface of the magnet holding portion in the hub axis direction,
The core faces the first and second expansion portions from the outside in the hub axis direction.

  According to this, when a wheel rotates, a magnet holding part rotates with respect to an iron core holding part with a wheel, and a magnet rotates with respect to a core. When the position of the magnet overlaps the position of the core in the rotational direction, the first and second extension portions face the core in the hub axial direction, and the magnetic flux of the magnet passes from the N pole through the first pole piece, The first pole piece passes through the core, passes from the core through the second pole piece second extension part, and reaches the S pole of the magnet from the second pole piece.

  Further, when the position of the magnet deviates from the position of the core in the rotation direction, the magnetic flux of the magnet does not pass through the core. Thus, according to the rotation of the wheel, a state in which the magnetic flux of the magnet passes through the core and a state in which the magnetic flux does not pass through are repeatedly generated alternately to become an alternating magnetic flux, and a current flows through the coil to generate power.

In the dynamo for bicycles according to the fourth aspect of the invention, the iron core holding part is fixed to the hawk side with a hub nut together with the wheel.
According to this, when attaching a wheel to a hawk side with a hub nut, since an iron core holding part can also be fixed with a wheel, an iron core holding part can be attached easily.

  In the bicycle dynamo of the fifth invention, the iron core holding portion is disposed at a position overlapping the fork in the hub axial direction, and is formed in a predetermined range excluding the fork in the circumferential direction of the wheel. Is.

  A sixth aspect of the present invention is a bicycle comprising the bicycle dynamo according to any one of the first to fifth aspects of the present invention.

  As described above, according to the present invention, the bicycle dynamo can be reduced in weight by reducing the outer diameter of the bicycle dynamo.

It is a side view of the front wheel of the bicycle provided with dynamo in an embodiment of the invention. It is sectional drawing in the up-down direction of dynamo. It is a VV arrow line view in FIG. It is a WW arrow directional view in FIG. It is the side view which removed the magnet cover of the magnet holding part of dynamo and showed the inside of a magnet holding part. FIG. 3 is an XX arrow view in FIG. 2. It is a partially expanded sectional view which shows the attachment structure of the magnet attachment board and magnet cover of the magnet holding | maintenance part of a dynamo. It is a YY arrow line view in FIG. It is a ZZ arrow line view in FIG. It is a schematic diagram which shows arrangement | positioning of the magnet and core of a dynamo seen from the outer side in the radial direction of a wheel. It is a XX arrow line view in FIG. It is sectional drawing in the up-down direction of the dynamo with which the conventional bicycle was equipped.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, reference numeral 1 denotes a bicycle, a front hawk 2 (an example of a hawk), a front wheel 3 (an example of a wheel), a headlamp 4 attached to the front hawk 2, and a headlamp 4. It has a dynamo 5 and the like for supplying electric power.

  The headlamp 4 is equipped with a light sensor and a vibration sensor, and is configured to automatically turn on the headlamp 4 based on the detection of the light sensor when the surroundings become dark during traveling. The front hawk 2 has a pair of left and right hawk legs 7. The front wheel 3 includes a hub 9 provided at the center of rotation, a plurality of spokes 10 provided radially from the hub 9, an annular rim 11 provided at the outer peripheral end of the spoke 10, and a rim 11. The tire 12 is fitted externally.

  As shown in FIG. 2, the hub 9 has a cylindrical hub body 14 provided with flanges 13 at both ends, and a hub shaft 15 inserted through the hub body 14. The hub body 14 is rotatably supported by the hub shaft 15 via a bearing. The hub shaft 15 is attached and fixed between the lower end portions of both fork legs 7 of the front fork 2 by hub nuts 16 screwed to both ends. Thereby, the front wheel 3 is rotatably attached to the front fork 2.

  As shown in FIGS. 1 and 3, the stay 52 that supports the front car 51 and the stay 54 that supports the mudguard 53 are attached and fixed to the lower end portion of the fork foot 7 together with the front wheel 3 by the hub nut 16. . Both stays 52 and 54 are provided substantially in the vertical direction and in the horizontal direction, and are substantially orthogonal to each other. The hawk leg 7 is provided in an oblique direction between the stays 52 and 54.

  As shown in FIG. 2, the dynamo 5 has a magnet holding part 20 that holds a plurality of magnets 19 and an iron core holding part 22 that holds a plurality of cores 21. The magnet holding part 20 is provided on the front wheel 3. Further, the iron core holding part 22 is fixed to the front fork 2 side by the hub nut 16 together with the front wheel 3.

  The magnet holding unit 20 includes an annular magnet mounting plate 25, a magnet cover 26 that is detachably attached to the magnet mounting plate 25, and a fixing means 27 that fixes the magnet mounting plate 25 to the front wheel 3. Yes. The magnet mounting board 25 is made of, for example, a nonmagnetic material such as resin, and is applied to the spoke 10 of the front wheel 3 from the outer side in the hub axial direction A. One end of the hub 9 passes through the central opening of the magnet mounting board 25.

  As shown in FIGS. 2 and 6, a plurality of positioning protrusions 30 for positioning the magnet mounting plate 25 in the radial direction B and the circumferential direction C of the front wheel 3 are provided on the inner surface of the magnet mounting plate 25. ing. These positioning protrusions 30 are circumferentially arranged at regular intervals so as to surround the flange 13 of the hub 9, whereby the magnet mounting plate 25 is positioned in the radial direction B of the front wheel 3. Further, the positioning protrusion 30 is in contact with the two spokes 10 intersecting in a V-shape, whereby the magnet mounting plate 25 is positioned in the circumferential direction C of the front wheel 3.

  As shown in FIGS. 2 and 5, each of the magnets 19 is fitted in a recess 29 formed in the magnet mounting plate 25 and surrounds the hub 9 so as to surround the hub 9 at a predetermined interval in the circumferential direction C. It is arranged every other circle. The magnet 19 has an N-pole on the outer side surface (an example of one side surface) in the hub axial direction A, and an S-pole on the opposite inner side surface (an example of the other side surface).

  As shown in FIGS. 2, 5, and 7, the first pole piece 31 is in contact with the outer side surface of each magnet 19, that is, the north pole, and the second pole piece 32 is placed on the inner side surface of each magnet 19, that is, the south pole. It is in contact. Each first pole piece 31 has a first contact portion 31a in surface contact with the N pole of the magnet 19 and a first extension extended inward in the radial direction B of the front wheel 3 from the first contact portion 31a. Part 31b. Each of the second pole pieces 32 has a second contact portion 32a in surface contact with the S pole of the magnet 19 and a second contact portion 32a extended outward in the radial direction B of the front wheel 3 from the second contact portion 32a. 2 expansion part 32b. The first and second pole pieces 31 and 32 are made of a material that allows magnetism, for example, a metal such as iron.

  A ring 33 for separating the first pole piece 31 and the second pole piece 32 from the outside of the magnet 19 in the radial direction B of the front wheel 3 so that the first pole piece 31 and the second pole piece 32 do not contact each other. Is inserted. The ring 33 is made of, for example, a nonmagnetic material such as copper, aluminum, or resin, and is fitted into the magnet mounting board 25.

  The magnet cover 26 is made of, for example, a non-magnetic material such as stainless steel, has a plurality of claws 35 on the outer peripheral edge, and connects the outer surface, inner peripheral surface, outer peripheral surface, and magnet 19 of the magnet mounting plate 25. Covering. As shown in FIGS. 6 and 7, the claw 35 is engaged with the inner surface of the magnet mounting plate 25 in the hub axial direction A, so that the magnet cover 26 is not detached from the magnet mounting plate 25. It is attached to the magnet mounting board 25.

  As shown in FIGS. 2 and 4, the first and second expansion portions 31 b and 32 b face the outer surface of the magnet holding portion 20 in the hub axial direction A, and are formed on the magnet cover 26. The opening window 36 is exposed to the outside of the magnet cover 26. As shown in FIGS. 2 and 11, the first extension portion 31 b and the second extension portion 32 b are arranged in a virtual plane 39 orthogonal to the axis 17 of the hub 9.

  As shown in FIGS. 2 and 6, the fixing means 27 includes an annular fixing bracket 37 cut at one place, and a plurality of fixing screws 38 for fastening the fixing bracket 37 to the magnet mounting plate 25. Yes. The fixed bracket 37 sandwiches the plurality of spokes 10 with the magnet mounting plate 25, whereby the magnet mounting plate 25 is attached and fixed to the plurality of spokes 10.

   As shown in FIGS. 2 and 9, the iron core holding portion 22 includes a fan-shaped iron core mounting member 41 and an iron core cover 42 that is detachably attached to the iron core mounting member 41. The iron core mounting member 41 has an arc-shaped inner peripheral plate 41a, an arc-shaped outer peripheral plate 41b, and a fan-shaped inner plate 41c provided between the inner peripheral plate 41a and the outer peripheral plate 41b. . The iron core cover 42 is made of, for example, a non-magnetic material such as stainless steel, and is attached to the iron core attaching member 41 by a plurality of fixing screws 43 and covers the outer surface of the iron core attaching member 41.

  Moreover, the iron core cover 42 has the fitting part 42a fitted in the inner peripheral board 41a in the center part. A through hole 44 is formed in the fitting portion 42 a, and the hub shaft 15 is inserted into the through hole 44. Thereby, the iron core cover 42 is fixed to the hawk leg 7 by the hub nut 16.

  As shown in FIGS. 2, 8, and 9, each of the plurality of cores 21 is housed inside the iron core mounting member 41 and surrounds the hub 9, and is spaced at predetermined intervals in the circumferential direction C of the front wheel 3. Is arranged. A coil 46 is wound around each core 21 via a coil bobbin 45. The coils 46 of each core 21 are connected in series. The core 21 is configured by laminating electromagnetic steel plates in order to reduce iron loss and increase power generation efficiency.

  The core 21 faces the first and second expansion portions 31b and 32b from the outside in the hub axial direction A. 2 and 9, both ends of each core 21 in the radial direction B of the front wheel 3 are respectively exposed to the outside from a plurality of opening windows 49 formed in the inner plate 41c of the iron core mounting member 41. Exposed. The exposed portions 21a and 21b of the core 21 are opposed to the first and second extension portions 31b and 32b.

  As shown in FIG. 2, the iron core holding portion 22, that is, the iron core mounting member 41 and the iron core cover 42 are arranged in a position overlapping with one of the fork legs 7 of the front fork 2 in the hub axis direction A. As shown in FIG. 3, in the circumferential direction C of the front wheel 3, it is formed in a fan shape in a predetermined range D of about 270 ° excluding the location of one of the fork legs 7 and the stays 52 and 54. Similarly, a plurality of cores 21 are arranged in a predetermined range D within the iron core mounting member 41.

  One end of the coil 46 is connected to the output terminal 47, and the other end is in contact with the iron core cover 42 and grounded to the vehicle body of the bicycle 1. The output terminal 47 is attached to the coil bobbin 45 of the core 21. The output terminal 47 and the headlamp 4 are electrically connected via a cord 48.

Hereinafter, the operation of the above configuration will be described.
When the bicycle 1 is run and the front wheel 3 rotates, the magnet holding unit 20 rotates with respect to the iron core holding unit 22 together with the front wheel 3, and the magnet 19 rotates with respect to the core 21. As shown in FIGS. 10 and 11, when the position of the magnet 19 overlaps the position of the core 21 in the rotational direction of the front wheel 3, the first and second expansion portions 31 b and 32 b are the core in the hub axial direction A. 11, the magnetic flux of the magnet 19 passes from the N pole through the first pole piece 31, from the first extension 31 b of the first pole piece 31 through the core 21, and through the core 21. From the second pole piece 32 to the S pole of the magnet 19 through the second extension 32b of the second pole piece 32.

  Further, when the position of the magnet 19 is shifted from the position of the core 21 in the rotation direction of the front wheel 3, the magnetic flux of the magnet 19 does not pass through the core 21. As described above, according to the rotation of the front wheel 3, the state in which the magnetic flux of the magnet 19 passes through the core 21 and the state in which the magnetic flux does not pass alternately occur repeatedly, and becomes an alternating magnetic flux. The The current generated in the coil 46 in this manner flows from the output terminal 47 through the cord 48 and is supplied to the headlamp 4, and the headlamp 4 is automatically turned on according to the ambient brightness.

  Further, the core 21 and the magnet 19 can be opposed to each other in the hub axial direction A by bringing the first and second pole pieces 31 and 32 into contact with the N pole and the S pole of the magnet 19. Thereby, as shown in FIG. 2, it is not necessary to secure a space for disposing the core 21 between the magnet 19 and the hub 9 in the radial direction B of the front wheel 3, and the outer diameter E of the dynamo 5. The dynamo 5 can be reduced in weight.

  Further, since the thickness t (see FIG. 11) of the magnet 19 in the hub axis direction A can be reduced, the thickness T (see FIG. 2) of the magnet holding portion 20 can be reduced, and the dynamo 5 is further reduced. The weight can be reduced.

  Further, when the front wheel 3 is attached to the fork foot 7 of the front fork 2 with the hub nut 16, the iron core holding portion 22 is inserted via the iron core cover 42 by inserting the hub shaft 15 into the through hole 44 of the iron core cover 42. Since the front wheel 3 and the fork foot 7 can be fixed together, the iron core holding part 22 can be easily attached.

  As shown in FIGS. 2 and 6, the magnet mounting plate 25 is positioned in the radial direction B and the circumferential direction C of the front wheel 3 by the positioning protrusion 30, so that the magnet mounting plate 25 is positioned with respect to the front wheel 3. It is possible to prevent displacement in the radial direction B and the circumferential direction C.

  In the above embodiment, as shown in FIG. 2, the outer surface of the magnet 19 is an N pole and the inner surface of the magnet 19 is an S pole, but the N pole and the S pole may be reversed. Moreover, you may arrange | position so that the N pole and S pole of the adjacent magnet 19 may be replaced | exchanged alternately.

  In the above embodiment, the first extended portion 31 b of the first pole piece 31 is expanded inward in the radial direction B of the front wheel 3, and the second extended portion 32 b of the second pole piece 32 is extended in the radial direction of the front wheel 3. Although expanded outward in B, the first expanded portion 31b may be expanded outward and the second expanded portion 32b expanded inward.

  In the above embodiment, the magnet holding part 20 is provided on the front wheel 3 and the iron core holding part 22 is provided on the fork foot 7 of the front fork 2. However, the magnet holding part 20 is provided on the fork leg 7 and the iron core holding part. 22 may be provided on the front wheel 3.

  In the above embodiment, the magnet holding part 20 is provided on the front wheel 3 and the iron core holding part 22 is provided on the front fork 2. However, the magnet holding part 20 is provided on the rear wheel and the iron core holding part 22 is provided on the rear fork. It may be provided. Or the magnet holding | maintenance part 20 may be provided in a rear fork, and the iron core holding | maintenance part 22 may be provided in a rear wheel.

  In the present invention, electricity generated by the dynamo is supplied to the headlamp, but may be supplied to an electrical device other than the headlamp (for example, a taillight).

1 Bicycle 2 Front Hawk (Hawk)
3 Front wheels
5 Dynamo 9 Hub 16 Hub nut 17 Axis 19 Magnet 20 Magnet holder 21 Core 22 Iron core holder 31 First pole piece 31b First extension part 32 Second pole piece 32b Second extension part 39 Plane 46 Coil A Hub axis Direction B Front wheel radial direction C Front wheel circumferential direction D Predetermined range

Claims (6)

A magnet holding part is provided on either the wheel side or the hawk side and an iron core holding part is provided on the other side,
In the magnet holding part, a plurality of magnets are arranged in the circumferential direction of the wheel so as to surround the hub,
The iron core holding part is arranged in the circumferential direction of the wheel so that a plurality of cores wound with coils surround the hub,
In the magnet, one side surface in the hub axial direction is one of the north and south poles, and the other side opposite is the other pole.
The first pole piece contacts one side of the magnet,
The second pole piece contacts the other side of the magnet,
The first pole piece has a first extension portion extended inward in the radial direction of the wheel from the contact portion with the magnet,
The second pole piece has a second extension portion extended outward in the radial direction of the wheel from the contact portion with the magnet,
The first and second extension portions face the side surfaces of the magnet holding portion in the hub axis direction,
A bicycle dynamo characterized in that the core and the first and second extension portions face each other in the hub axial direction. The bicycle dynamo according to claim 1, wherein the first extension part of the first pole piece and the second extension part of the second pole piece are arranged in a plane perpendicular to the hub axis. The magnet holding part is provided on the wheel,
The iron core holding part is fixed to the hawk side,
The first and second expansion portions face the outer surface of the magnet holding portion in the hub axis direction,
The bicycle dynamo according to claim 1 or 2, wherein the core faces the first and second expansion portions from the outside in the hub axial direction. The bicycle dynamo according to claim 3, wherein the iron core holding part is fixed to the hawk side with a hub nut together with the wheel. The iron core holding portion is disposed at a position overlapping the fork in the hub axis direction, and is formed in a predetermined range excluding the fork portion in the circumferential direction of the wheel. Item 5. A bicycle dynamo according to item 4. A bicycle comprising the bicycle dynamo according to any one of claims 1 to 5.

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