JP2001088759A - Hub dynamo for bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply sufficient electric power even when power generating quantity is reduced by using a space not used in a hub dynamo. SOLUTION: A secondary battery 28a to store electric power generated by a generator 34 is stored in a hub body 6 in a hub dynamo to generate electric power by a generator 34 provided in the hub body 6 by rotation of a front wheel 3 by supporting the hub body 6 provided on the front wheel 3 on a hub shaft 16 free to rotate. It is possible to efficiently use a space in the hub dynamo by providing the secondary battery in the hub dynamo, to supply sufficient electric power even when generated electric power is small by supplying electric power by using the secondary battery and to supply stable electric power regardless of travelling speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a generator built in a bicycle hub.

[0002]

2. Description of the Related Art As a conventional hub dynamo which is a generator for a bicycle, as shown in Japanese Patent Application Laid-Open No. 9-132185, a hub provided on wheels is rotatably supported on a hub axle. It is known that a magnet, which is located at the center and has N poles and S poles alternately, is fixed to the inner surface of the hub, and a stator including an iron core and a power generation coil is attached to the hub shaft so as to face the magnet. However, it has a useless space that is not used on both sides of the magnet and the stator in the hub body.

[0003] By the way, such a hub dynamo generates power by the rotation of wheels, but the amount of power generation depends on the number of rotations of the wheels, so that the amount of power generation decreases when the bicycle is driven at a low speed. Therefore, if a headlight or taillight that is turned on only by the generator is connected to the hub dynamo, sufficient power will not be supplied when the vehicle is traveling at low speed, and the vehicle may become dark and unable to travel safely. there were.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bicycle hub dynamo capable of supplying sufficient electric power by using an unused space in the hub dynamo even if the amount of generated power is small. I do.

[0005]

Means for Solving the Problems A first method for solving the above problems is described below.
Means for a hub dynamo rotatably supporting a hub body provided on wheels on a hub axle, and a hub dynamo generating power by a generator provided in the hub body by rotation of the wheel, wherein a secondary battery storing power generated by the generator. Is stored in the hub body.

[0006] Thus, the secondary battery can be provided by utilizing the space not conventionally used in the hub body, and the generated power can be stored, and the power stored in the secondary battery can be used.

In the above configuration, it is desirable that the charging circuit for the secondary battery is also provided in the hub.

Thus, the charging circuit does not need to be provided outside the hub body, and can be housed in the hub body and handled integrally.

The output terminal of the secondary battery is connected to a load of a bicycle.

[0010] Thus, the electric power stored in the secondary battery can be used for the load of the bicycle.

[0011]

1 to 5 show an embodiment of the present invention, and a description will be given below with reference to these drawings.

Reference numeral 1 denotes a front fork of a bicycle. As shown in FIG. 3, a front wheel 3 having a hub dynamo 2 as a center is attached thereto, and a headlight 5 which is turned on by the power generation of the hub dynamo 2 via a mounting piece 4 is provided. Installed. Hereinafter, the configuration of the hub dynamo 2 will be described.

Reference numeral 6 denotes a hub body connected to the rim 7 of the front wheel 3 via spokes 8, and as shown in FIG. 1, a cylindrical case 10 having one end (left side) opened, and covers the opening of the case 10. It is composed of a cap 11. This hub body 6
A magnet 13 having N poles and S poles alternately is fixed to the inner surface of the cylindrical case 10 via a yoke 12 so as to approach the bottom side of the cylindrical case 10, and a large space is formed on the cap 11 side. The hub body 6 serves as a rotor. The recess 1 into which the outer ring of the ball bearing 14 is inserted is formed on both sides of the hub body 6.
5, the hub body 6 is sandwiched by the ball bearings 14 so that the movement in the left-right direction is restricted.

Numeral 16 denotes a hub axle having both ends protruding from the hub body 6 and penetrating through the hub body 6. The shaft 17 is threaded over its entire length, and an aluminum material is provided with both ends exposed to the shaft 17. And a sleeve 18 formed by die-casting.

At both ends of the sleeve 18 are formed step portions 19 into which the inner ring of the ball bearing 14 is press-fitted.
Supports the hub body 6 rotatably via the ball bearing 14. A wiring groove 20 is formed in the step 19 on the cap 11 side so that a power supply line 21 described later can be passed between the ball bearing 14 and the shaft 17. The sleeve 18 has a bottom portion (right side) of the case 10 between the ball bearings 14.
Is formed with a flange 22.

Reference numeral 23 denotes a power generating coil provided in the hub body 6 so as to face the magnet 13, and is surrounded by an iron core 24.
The iron core 24 is attached to the flange 22 of the sleeve 18 with a caulking pin 29. The power generation coil 23 and the iron core 24 constitute a stator together with the hub shaft 16. The generator and the stator constitute the generator 34.

A mounting plate 25 is attached to the flange 22. A cylindrical leg 25b extending from the bottom 25a contacting the side surface of the iron core 24 to the flange 22 side extends toward the flange 22 side. You.

On the other hand, on one end side of the cap 11, a battery accommodating portion 25c formed of a side wall 25c1 extending from the bottom portion 25a toward the cap 11 and an L-shaped claw 25c2 formed at the tip of the side wall 25c1 is formed. Have been. In this battery housing 25c, a secondary battery body 28 for housing four secondary batteries 28a in a case 28b is inserted along the side wall 25c1, and the battery housing 25c is inserted between the claw 25c2 and the bottom plate 25a. It is pinched by the elasticity of.

On the other end of the hub shaft 16, a board mounting portion 25d to which a circuit board 27 having a charging circuit 32 described later is mounted is formed. The board mounting portion 25d supports the circuit board 27 by a support portion 25d1 standing upright from the bottom plate 25a, and a step 25d2 provided at an end portion of the support portion 25d1 is brought into contact with the outer periphery of the circuit board 27, so that one Mounting screw 53.

The mounting plate 25 holds the secondary battery body 28 between the battery housing portions 25c and connects the circuit board 27 to the board mounting portion 25c.
d, the circuit board 27 is set to the wiring groove 20 side,
It is inserted into the case 10 through the hub axle 16 and attached to the flange 22 with attachment screws 26 (see FIG. 3) inserted through bosses (not shown). Thereby, the secondary battery body 2
8 and the circuit board 27 can be handled as a single body, making it easier to handle. When attaching the mounting plate 25, the leg 2
5b abuts on the outer periphery of the flange 22 to regulate the radial movement of the mounting plate 25.

Reference numeral 30 denotes an output terminal portion disposed outside the hub body 6 on the side of the cap 11 of the hub shaft 16, and internally provided with an output terminal 31 connected to the headlight 5. The output terminal 31 is connected to the circuit board 27 via the power supply line 21.

Next, a case where the hub dynamo 2 having the above configuration is connected to the headlight 5 via the switch 40 will be described with reference to the circuit diagram of FIG.

Reference numeral 32 denotes a charging circuit provided on the circuit board 27, and has a rectifying circuit 33 in which a diode is formed by a bridge circuit. A generator 34 is connected to an input side of the rectifier circuit 33 by lead wires 35 and 36, and an output terminal 31 is connected to one of output sides via a resistor 38 and a power supply line 21. The other is connected to a vehicle body ground 39 via a lead wire 37 and a mounting screw 26.

The secondary battery 28a is connected to the lead wires 50, 5
1 is connected between the output terminal 31 and the vehicle body ground 39, and charges the secondary battery 28a with the DC voltage rectified by the rectifier circuit 33.

The switch 40 in the headlight 5 is provided closer to the output terminal 31 than the headlight 5. The switch 40 supplies power from the output terminal 31 to the headlight 5 when the contact 40a is closed, turns on the headlight 5 and
When 0a is opened, the power supply from the output terminal 31 is cut off, and the headlight 5 is turned off.

Next, the operation will be described.

When the headlight 5 does not need to be lit, such as in the daytime, the vehicle travels with the contact 40a of the switch 40 opened, and the AC voltage generated by the generator 34 is rectified by the rectifier circuit 33, 28a.

When the headlight 5 needs to be lit, such as at night, the vehicle is driven such that the switch 40 is closed and power from the generator 34 is supplied to the headlight 5.

At this time, when the vehicle runs at a speed higher than a predetermined speed, the headlight 5 is turned on by the power generated by the generator 34, and the secondary battery 28a is also charged.

On the other hand, when the vehicle runs at a speed lower than a predetermined speed,
Although the power generated by the generator 34 is reduced, the power is supplied from the secondary battery 28a to turn on the headlight 5 brightly.

As described above, the headlight 5 is independent of the traveling speed.
Power can be supplied to the headlight 5 at a low speed, and sufficient power is not supplied to the headlight 5 because the power generation amount is small, so that it is possible to prevent the headlight 5 from becoming dark and unsafe traveling.

In the above embodiment, the switch 40
Although the headlights 5 are turned on and off in the above, an illuminance detection circuit 42 that detects ambient brightness and turns on and off may be used instead of a switch as shown in FIG.

In this case, since a direct current is applied to the illuminance detection circuit 42, there is no need to provide a DC power supply circuit for operating the illuminance detection circuit 42.

In the above embodiment, the output terminal 3
Although the headlight 5 is connected to 1, the invention is not limited to this, and electrical equipment (load) of the bicycle such as a taillight may be connected.

[0035]

According to the first aspect of the present invention, by providing a secondary battery in the hub dynamo, the space in the hub dynamo can be effectively used, and power is supplied using the secondary battery. Even when the generated power is small, sufficient power can be supplied, and stable power can be supplied.

According to the second aspect of the present invention, the charging circuit comprises:
There is no need to provide it outside the hub body, and it can be housed inside the hub body and handled integrally, making it easy to handle and
Wiring can be simplified.

According to the third aspect of the present invention, the electric power stored in the secondary battery can be used for a bicycle load.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a bicycle hub dynamo of the present invention.

FIG. 2 is a side view when the cap of the hub dynamo is removed.

FIG. 3 is a side view of a front wheel portion of the bicycle to which the hub dynamo is attached.

FIG. 4 is a circuit diagram when the hub dynamo is connected to a headlight of a bicycle which is turned on / off by a switch.

FIG. 5 is a circuit diagram when the hub dynamo is connected to a headlight of a bicycle which is turned on and off according to ambient brightness.

[Description of Signs] 3 Front wheel (wheel) 5, 41 Headlight (load) 6 Hub body 16 Hub shaft 23 Generator coil 28a Secondary battery 31 Output terminal 32 Charging circuit 34 Generator

Claims (3)

[Claims] 1. A hub dynamo that rotatably supports a hub body provided on a wheel on a hub axle and generates power by a generator provided in the hub body by rotation of the wheel, a secondary dynamo storing the power generated by the generator. A bicycle dynamo for bicycles, wherein batteries are stored in the hub body. 2. The bicycle hub dynamo according to claim 1, wherein the charging circuit for the secondary battery is also provided in the hub body. 3. The bicycle hub dynamo according to claim 1, wherein an output terminal of the secondary battery is connected to a load of the bicycle.