JP2006014538A - Hub-type dynamo and bicycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hub-type dynamo for suppressing the generation of an eddy current in a stator core and improving the power generation efficiency, and to provide a bicycle for mounting it. <P>SOLUTION: In a hub-type cycle dynamo, a slot 15 is provided and opened in outer circumferences of the stator cores 16, 17 on a hub shaft 11, and communicates from a center shaft hole 13 to the outer circumferences, and an insulation sheet 82 is interposed between positioning members 30, 31 on the hub shaft 11 for fixing the stator cores 16, 17. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hub dynamo and a bicycle including the hub dynamo.

As a power generation hub dynamo for a bicycle, as shown in FIG. 2, a pair of stator cores (16), (17) are arranged on the hub axle (11) of the front wheel or rear wheel of the bicycle, and the interior of the stator cores (16), (17) A coil bobbin (20) wound with a wound coil (22) is accommodated to form a stator, and a hub body (12) rotatably supported with respect to the hub shaft (11) is opposed to the stator. A hub dynamo (10) in which a permanent magnet (14) is arranged to constitute a rotor has been implemented (Patent Document 1).
The permanent magnet (14) is configured by alternately arranging N poles and S poles in the circumferential direction (see FIG. 3), and the stator cores (16) and (17) are opposed to either the N pole or the S pole on the outer periphery thereof. The pole pieces to be projected are projected at the pole pitch of the permanent magnet (14). Therefore, when one stator core (16) faces the north pole of the permanent magnet (14), the other stator core (17) faces the south pole, and the north pole → stator core (16) → hub shaft (11). The magnetic path of the connecting portion → stator core (17) → S pole is formed.
The electrical end of the winding coil (22) is connected to a bicycle lamp (not shown) via a lead wire (22b) or the like.

The power generation of the hub dynamo (10) is performed as follows.
When the wheel is rotated, the permanent magnet (14) attached to the hub body (12) that rotates integrally with the wheel rotates. The magnetic flux emitted from the permanent magnet (14) alternates between a state in which one of the opposed stator cores (16) and (17) is an N pole and the other is an S pole, and a state in which one is an S pole and the other is an N pole. Repeatedly generate alternating magnetic flux in the magnetic path. Due to this alternating magnetic flux, a current flows through the winding coil (22) to generate electricity.

The alternating magnetic flux generated in the stator cores (16) and (17) goes around the stator cores (16) and (17) as shown by thick arrows in FIG.
Eddy currents are generated in the stator cores (16) and (17) as the alternating magnetic flux passes. Since this eddy current reduces power generation efficiency, it is necessary to suppress the generation of eddy current as much as possible.
Accordingly, as shown in FIGS. 10 to 12, the side surface disk body (78) of the stator core (16) (17) has a groove hole (15) extending from the central hole (13) through which the hub shaft (11) passes to the outer peripheral edge. And the generation of eddy currents is suppressed by dividing the disc body (78) at one location.

JP 2001-327139 A

However, as shown in FIGS. 13 to 15, the stator cores 16 and 17 are positioned by the sleeve 32 and the nut 35 disposed on the hub shaft 11 with the stator cores 16 and 17 interposed therebetween. The bearing surface of the hexagonal head (33) of the sleeve (32) that is fixed and the washer (36) on the nut (35) side is attached to the disc body (78) of the stator core (16) (17). Directly touch and straddle the slot (15).
For this reason, the slot (15) of the stator core (16) (17) is partially connected by the sleeve (32) and the washer (36), and the effect of suppressing the generation of eddy current is not sufficiently exhibited. The applicant noticed that.

  An object of the present invention is to provide a hub dynamo capable of effectively suppressing generation of eddy current in a stator core and improving power generation efficiency, and a bicycle equipped with the hub dynamo.

In the hub dynamo (10) of the present invention, the permanent magnet (14) is disposed inside the hub body (12), and the hub shaft (11) is provided with a plurality of pole pieces ( 74) (75) provided on the circumference of two stator cores (16) (17), and a winding coil (22) disposed between the stator cores (16) (17), the stator core (16) ( 17) In a hub dynamo in which two stator cores (16) are positioned and fixed on the hub shaft (11) by positioning members (30) and (31) provided on the hub shaft (11) across
The stator core (16) (17) is provided with a groove hole (15) from the hole (13) through which the hub shaft (11) passes to the outer peripheral edge, and is positioned facing the outer surface of both stator cores (16) (17). An insulator (80) is interposed between the members (30) and (31), and the conductors on the positioning and fixing member side are positioned on the stator cores (16) and (17). To prevent it from crossing over.

  In the bicycle of the present invention, the hub dynamo (10) is mounted on the front wheel or the rear wheel, and the hub dynamo (10) is electrically connected to the headlight (46) and / or the taillight.

The stator cores (16) and (17) are electrically cut off in the circumferential direction by the slots (15), respectively. In addition, the conductor on the positioning member (30) (31) side for fixing the stator core (16) (17) on the hub shaft (11) is in direct contact with the stator core (16) (17) and the groove ( Since it does not straddle 15), the effect of electrical interruption of the stator cores 16, 16 by the slot 15 is not impaired. For this reason, the power generation efficiency of the hub dynamo (10) can be improved. Therefore, the hub dynamo (10) can be reduced in size and weight, and the torque required for power generation can be reduced.

  The bicycle of the present invention is equipped with the hub dynamo (10) excellent in power generation efficiency as a generator, and the torque required for power generation is small, and the hub dynamo (10) can be downsized. This reduces the weight of the bicycle and reduces the stepping force required for power generation.

FIG. 1 shows a state in which the hub dynamo (10) of the present invention is mounted on a front wheel portion of a bicycle (40).
In the bicycle (40), the hub axle (11) that rotatably supports the front wheel (42) is attached to the front fork (44), and the hub dynamo (10) is arranged on the side of the front wheel (42). Electric power is supplied to the headlight (46) and the taillight (not shown) arranged on the rear wheel side. The front fork (44) is supported by the main body frame (48), and a handle (50) and a front basket (52) are attached to the upper end of the front fork (44).

  As shown in FIG. 2, both sides of the hub shaft (11) are fastened with nuts to the front forks (44) and (44), and the hub shaft (11) is connected via bearings (54) and (54). A cylindrical hub body (12) is rotatably provided. A plurality of spokes (56) are attached to the hub body (12), and a tire (60) is attached to the outer periphery of the spoke (56) via a rim (58) as shown in FIG. ing.

  A stator is provided on the hub shaft (11). As shown in FIG. 2, the stator includes a thick cylindrical core (18), a winding coil (22), and a pair of stator cores (16) and (17).

As shown in FIG. 3, the core (18) is formed by opening a plurality of slits (24) and (26) inward from the outer peripheral surface over the entire length in the axial direction. In order to reduce the magnetic resistance of the core (18), the thickness in the radial direction of the core (18) is preferably 7 to 9 mm. Also, a powder sintered material such as ferrite or pure iron-based electromagnetic soft iron It is desirable to form from material. By forming the core (18) to be thick, the cross-sectional area of the core (18) can be increased, and a reduction in magnetic resistance can be achieved.
The depth of the slit (24) opened in the core (18) is preferably 6 to 7 mm, and one slit (26) is opened so as to reach the inner surface of the cylinder and is electrically insulated in the circumferential direction. Is desirable. This is because eddy currents are generated in the core (18) by the alternating magnetic flux passing through the core (18), and the current flow in the circumferential direction of the core (18) is caused by the slits (24) and (26). This is because it is possible to suppress the generation of eddy currents in the circumferential direction of the core (18) and to prevent a decrease in power generation efficiency due to eddy currents.

A coil bobbin (20) around which a coil (22) is wound is fitted on the outer periphery of the core (18). One end of the winding coil (22) is connected to the headlamp (46) via the lead wire (22b), and the other end (22a) of the coil (22) is connected to the ground lead plate (38) as described later. Is connected to the hub shaft (11) through the front, and is electrically connected to the headlamp (46) through the front fork (44).
The coil bobbin (20) is formed of a synthetic resin, and as shown in FIG. 2, the cross section opened toward the outer periphery has a U-shaped annular body. As shown in FIG. 3, one or a plurality of ribs (28) are provided on the inner peripheral surface of the coil bobbin (20), and each rib (28) has a slit (24) and / or a core (18). Or it fits into the slit (26), and the core (18) is detented and positioned.

Stator cores (16) and (17) are disposed on the left and right sides of the core (18). As shown in FIGS. 3, 4, and 5, the stator cores 16, 17 are arranged on the outer circumference of the disc body 78 with equally spaced magnetic pole pieces 74, 75 in the circumferential direction. Projected to The pole piece (74) of one stator core (16) is formed so as to fit between the pole pieces (75) and (75) of the opposing stator core (17). The stator cores (16) and (17) can be made of general structural rolled steel.
As shown in FIGS. 4 to 6, the disc body (78) of the stator cores (16) and (17) has a groove hole (15) extending from the center hole (13) through which the hub shaft (11) passes to the outer peripheral edge. Has been.
A lead wire (22b) extending from the winding coil (22) is drawn out through the slot (15) of one stator core (16).

The stator includes a coil bobbin (20) containing a core (18) and a wound coil (22) between stator cores (16) and (17), and is positioned by positioning members (30) and (31) on the hub shaft (11). It is positioned and fixed on the hub axle (11).
In the embodiment, one positioning member (30) is a contact member (32a) provided on the hub shaft (11), and the other positioning member (31) is a nut (35), specifically a nut (35), a washer ( 36) and a spring washer (37).

The contact member (32a) serves as a stopper for determining the position of the end portion of the stator on the hub shaft (11). In the embodiment, the contact member is formed by screwing the sleeve (32) onto the hub shaft (11). (32a). A hexagonal head (33) is formed on the stator side of the sleeve (32).
The sleeve (32) is provided with a groove (34) for fitting the lead wire (22b) of the winding coil (22) and drawing it out of the hub dynamo (10).
As shown in FIGS. 7 and 9, an earth lead plate (38) is interposed between the sleeve (32) and the stator core (16) facing the sleeve, and the coil (22) is attached to the earth lead plate (38). ) Is connected to one end (22a).
As shown in FIGS. 6 and 9, the disc body (78) of the stator core (16) on the sleeve (32) side is prevented from rotating with a distance between opposite sides of the hexagon head (33) of the sleeve (32). A protrusion (79) is provided.

A feature of the present invention is that an insulator (80) is interposed between the positioning members (30) and (31) facing the outer surfaces of the stator cores (16) and (17), so that the stator cores (16) and (17) This is to prevent the conductor on the positioning and fixing member side (30) (31) side from contacting and straddling the stator core (16) (17) through the groove (15).
The insulator (80) of the example is an insulating sheet (82).
The insulating sheet (82) on the sleeve (32) side shown in FIGS. 6 and 9 has a substantially rectangular shape with the opposite side length of the hexagonal head (33) of the sleeve (32) as the width, and has a hub shaft at the center. A hole (83) through which (11) passes is opened.
The insulating sheet (82) on the nut (35) side shown in FIG. 4 has a circular shape larger than the diameter of the washer (36), and a hole (83) through which the hub shaft (11) passes is formed in the center. .

An insulating sheet (82) fitted to the hub shaft (11) is interposed between the ground lead plate (38) (conductor) and the stator core (16).
An insulating sheet (82) fitted to the hub axle (11) is interposed between the other stator core (17) and the washer (36) (conductor), and the nut (35) is tightened to tighten the spring washer (37) and The stator core (17) is pressed against the sleeve (32) through the washer (36), and the stator core (16) (17) with the core (18) and coil bobbin (20) sandwiched between the sleeve (32) and nut Position and fix on the hub axle (11) with (35).

  However, when the bicycle (40) is run and the wheel (front wheel (42)) is rotated, the rotor rotates relative to the stator of the hub dynamo (10). As a result, the permanent magnet (14) rotates and moves outside the pole pieces (74) and (75) of the stator cores (16) and (17).

When the pole piece (74) of one stator core (16) is opposed to the N pole of the permanent magnet (14), the pole piece (75) of the other stator core (17) is the S pole of the permanent magnet (14). 2, the pole piece (74) of one stator core (16) → the disk body (78) → the core (18) → the disk body of the other stator core (17) facing each other, as indicated by a thick arrow in FIG. 78) → Magnetic flux passing through the pole piece (75) is generated.
Further, when the front wheel (42) rotates, the pole piece (74) of one stator core (16) faces the S pole, and the pole piece (75) of the other stator core (17) faces the N pole. On the contrary, the magnetic flux is generated through the pole piece (75) of the stator core (17) → the disk body (78) → the core (18) → the disk body (78) of the opposing stator core (16) → the pole piece (74). .
As the front wheels (42) rotate, the poles of the permanent magnets (14) facing the pole pieces (74), (75) of the stator cores (16), (17) change, and the magnetic flux is generated alternately. It becomes an alternating magnetic flux.

Current is generated in the winding coil (22) by the alternating magnetic flux passing through the stator cores (16), (17) and the core (18), and electric power is generated.
At this time, an eddy current tends to be generated in the stator cores 16 and 17 as the alternating magnetic flux passes. However, the stator core (16) (17) is provided with a groove hole (15) extending from the central hole (13) to the outer periphery, and the stator core (16) (17) is divided in the circumferential direction at one place. However, the ground lead plate (38) and the washer (36) on the positioning member (30) (31) side for tightening the stator from both sides and fixing it on the hub shaft (11) include the insulating sheet (82) Is prevented from straddling the slot (15) in contact with the stator cores (16), (17), so that the circumferential direction of the disk bodies (78), (78) of the stator cores (16), (17) Generation of eddy current can be effectively suppressed, and power generation efficiency can be improved.
In the case of the example, the power generation efficiency could be increased by about 2.6%, with the voltage of 5.7 V being 5.85 V, compared to the case without the insulating sheet (82).
Therefore, the hub dynamo (10) can be reduced in size and weight, and the torque required for power generation can be reduced.

  The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof. Moreover, each part structure of this invention is not restricted to the said Example, A various deformation | transformation is possible within the technical scope as described in a claim.

For example, the ground lead plate (38) can be provided on the nut (35) side.
Further, the ground lead plate (38) can be omitted, and one end (22a) of the winding coil can be directly connected to the sleeve (32) or the nut (35) by soldering or the like, or one end of the winding coil can be connected. (22a) may be connected to a conductor disposed on the sleeve (32) side or the nut (35) side and in contact with the hub shaft (11).

  Further, the insulator (80) interposed between the stator cores (16) (17) and the positioning members (30) (31) is not limited to the insulating sheet (82). For example, an insulating layer made of resin coating or the like can be formed on the seating surface of the hexagonal head (33) of the sleeve (32) and the seating surface of the washer (36) on the stator core (17) side.

  Further, the slot (15) of the disk body (78) of the stator core (16) (17) is provided so as to extend from the central hole (13) to the outer peripheral edge. If it extends outward from the hole (13), it has an effect of suppressing the generation of eddy current.

It is an enlarged view of the front-wheel part of the bicycle carrying a hub dynamo. It is the figure which represented the hub dynamo in the cross section from the axial center of the hub axis | shaft. It is sectional drawing orthogonal to the axial center of a hub dynamo. It is a left view of a stator. It is a right view of a stator. It is a right view of a stator. It is a front view of the state which attached the stator to the hub axle. It is a left view same as the above. It is a right view same as the above. It is a front view of the conventional stator. It is a right view same as the above. It is a left view same as the above. It is a front view of the state which attached the stator to the hub axle of the prior art example. It is a right view same as the above. It is a left view same as the above.

Explanation of symbols

10 Hub dynamo
11 Hub axle
12 Hub body
16 Stator core
17 Stator core
22 coils
30 Positioning member
31 Positioning member
32 sleeves
36 nuts
80 Insulator

Claims (7)

A permanent magnet (14) is arranged inside the hub body (12), and a plurality of pole pieces (74) (75) facing the magnetic poles of the permanent magnet (14) are provided on the circumference of the hub shaft (11). Two stator cores (16) (17) and a winding coil (22) disposed between the stator cores (16) (17), and a hub shaft (11) sandwiching the stator cores (16) (17) In the hub dynamo in which the two stator cores (16) and (17) are positioned and fixed on the hub shaft (11) by the positioning members (30) and (31) provided above,
The stator core (16) (17) is provided with a groove hole (15) from the hole (13) through which the hub shaft (11) passes to the outer peripheral edge, and both the stator cores (16) (17) and the positioning member (30) ( 31) and an insulator (80) is interposed between the conductors on the positioning and fixing member side of the stator cores (16) and (17) so as to contact the stator cores (16) and (17). The hub dynamo is preventing.   One positioning member (30) is a contact member (32a) provided on the hub shaft (11), and the other positioning member (31) is a nut (35) screwed to the hub shaft (11). The hub dynamo according to Item 1.   The hub dynamo according to claim 1 or 2, wherein the contact member (32a) is a sleeve (32) screwed into the hub shaft (11).   An earth lead plate (38) is provided on one of the positioning members, and one end (22a) of the winding coil (22) is electrically connected to the earth lead plate (38), and the winding coil (22) The hub dynamo according to any one of claims 1 to 3, wherein the other end is drawn out from the hub body (12) by a lead wire (22b).   The insulator (80) is an insulating sheet (82) (82) disposed on the hub axle (11) and in contact with the positioning members (30) (31). Hub dynamo.   The hub dynamo according to any one of claims 1 to 4, wherein the insulator (80) is an insulating layer applied to a member in contact with the stator core (16) (17) by coating or the like.   The hub dynamo (10) according to any one of claims 1 to 6 is mounted on a front wheel or a rear wheel, and the hub dynamo (10) is electrically connected to the headlight (46) and / or the taillight. Bicycle.

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