JPS6349094Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a load torque adjusting device for a bicycle power generation lamp.

Riding a bicycle without lights at night is prohibited to prevent danger, and conventionally there are power-generating lamps using a pulley on a rotating shaft that is brought into contact with the tire as the bicycle wheel rotates. However, as the speed of the bicycle increases, conventional power-generating lamps have maximum torque at initial speed, and as the speed increases, they become lighter due to inertia, but the load on the power-generating lamp increases and fatigue increases, causing it to go off. The high speed causes a high current to flow, causing the bulb to burn out. That is, as shown in FIG. 7, in the conventional bicycle power generation lamp 1, a shaft 3 fixed to a pulley 2 is rotatably inserted into the container body 1 via a bearing 5, and a magnet 4 is attached to the lower end of the shaft 3 by a yoke. It is located and fixed in the center of 7.

Therefore, when the pulley 2 rotates at high speed, a proportionally high current flows, causing the light bulb to burn out. Note that 6 is a coil and 8 is a terminal.

For this reason, some power-generating lamps for sports bicycles are equipped with an attachment pulley that is operated manually to increase the outside diameter of the pulley, but power-generating lamps for general bicycles are equipped with an attachment pulley. I can't see anything.

The present invention was made to eliminate the above-mentioned drawbacks, and its purpose is to ensure a constant current even at high speeds without changing the diameter of the pulley.

In the present invention, a rotating shaft 3 having an inclined groove 12 on the circumferential surface is rotatably supported on a bearing 5 of a power generation container 1, and a coil 6 and a yoke 7 provided inside the container 1 are connected inwardly. is the inclined groove 1 provided inside.
a magnet 14 which is adapted to fit into the inclined groove 12 of the shaft 3, and the magnet 1;
4 is provided with a spring that applies a constant urging force,
A power generation lamp for a bicycle, characterized in that the magnet 4 changes its positional relationship with the yoke 7 by a thrust parallel to the rotating shaft 3 generated during rotation, and changes the number of interlinked magnetic fluxes to the coil 6. This is a load torque adjustment device.

Embodiments of the present invention will be described below based on the drawings.

The present invention is shown in Fig. 3.
(Denoted with the same reference numerals as the conventional example. The same applies to the main components hereinafter.) A shaft 3 is supported, with a pulley 2 crimped or fixed with a nut (not shown) on a bearing 5 provided in a cylindrical portion a. The shaft 3 is provided with an inclined groove 12 so as to be rotatable. On the other hand, the magnet 4 has an inner circumferential inclined groove 1 corresponding to the inclined groove 12.
3 is provided, and the magnet 4 is loosely fitted onto the shaft 3. Then, the magnet 4 is located at the center of the yoke 7 (point A in the figure), and a lower spring 9 guided by the shaft 3 is provided between the lower surface of the magnet 4 and the lower end 17 of the shaft 3. An upper spring 10 is provided between the upper surface and a stopper 11 fitted into the inclined groove 12 of the shaft 3, and the upper and lower surfaces of the magnet 4 are held between the upper and lower springs 9 and 10. Coils 6 are provided on both sides of the inner diameter of the container body 1, as shown in FIG. A terminal 8 is insulated and fixed to the outside of the container body 1.

The magnet 4 may be formed into a truncated cone shape as shown in FIG. 6 so as to further increase the rate of change in the amount of magnetic flux, which will be described later. Further, the material of the inclined groove may be a resin material in order to reduce frictional resistance.

Next, the functions and effects of the present invention will be explained.

As shown in FIG. 1, the pulley 2 is brought into contact with a bicycle tire 16 and rotates as the tire rotates.

In Figure 3, magnet 4 at low load torque
Since the thrust force F caused by the load torque is small, the magnet 4 is located at the center of the yoke 7 due to its own weight and the reaction force of the upper spring 10 (point A in Fig. 3).
The magnetic flux easily flows to the yoke 7, and therefore the maximum magnetic flux can be obtained. Since the generated voltage can be obtained even at a low rotational speed, sufficient illuminance can be ensured even at low speeds (see FIG. 5). In FIG. 6, 14 is a lamp and 15 is a conductor.

When the shaft 3 starts rotating at a high speed in the state shown in Fig. 3, a relative rotation occurs between the shaft 3 and the magnet 4, and this rotation increases the thrust force F generated parallel to the rotating shaft 3. And this will be added to magnet 4. This increased thrust F overcomes the own weight and the reaction force of the upper spring 10,
The magnet 4 moves from point A in FIG. 3 to point B in FIG. 2 via the inclined grooves 12 and 13.

At this time, the magnetic flux emitted from the magnet 4 and the coil 6
The number of linkages with the magnet 4 decreases as the magnet 4 moves upward, and even if the rotational speed of the shaft 3 increases, the generated voltage does not increase.

Next, when the rotation changes from high speed to low speed, the weight of the magnet 4 and the upper spring 10
The reaction force is overcome, and the magnet 4 moves downward through the inclined grooves 12 and 13, increasing the amount of power generated by increasing the number of interlinked magnetic fluxes to compensate for the decrease in rotational speed. Therefore, the movement of the magnet 4 acts to balance the amount of power generated during high rotation and low rotation.

As mentioned above, according to the present invention, when load torque is generated between the shaft and the magnet, a part of this torque becomes thrust and changes the amount of magnetic flux to the yoke by determining the positional relationship between the magnet and the yoke. This adjusts the load torque, which not only prevents the bulb from burning out while riding at high speeds like in the past, but also reduces the effort required to ride the bicycle and allows for safe riding at night without the risk of riding without a light. can be done. Further, the structure is simple and can be manufactured at low cost.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. Fig. 1 is a front view showing the installed state of the generator, Fig. 2 is a sectional view of the invention at high load torque, and Fig. 3 is a cross-sectional view of the invention at low load torque. The sectional view of the same as above, Fig. 4 is the 3rd
5 is a circuit diagram, FIG. 6 is a sectional view showing another embodiment of the magnet, and FIG. 7 is a sectional view of a conventional product. 1 is a power generation container body, 2 is a pulley, 3 is a shaft, 4 is a magnet, 5 is a bearing, 6 is a coil,
7 is a yoke, 8 is a terminal, 9 is a lower spring, 10 is an upper spring, 11 is a stopper, 1
2 is an inclined groove, 13 is an inner inclined groove, 14 is a lamp,
15 is a conductor, 16 is a tire, 17 is a lower end, a is a cylinder, and F is a thrust force.

Claims (1)

[Scope of utility model registration request] A rotating shaft having an inclined groove on the circumferential surface is rotatably supported on the bearing of the power generation container body, and a coil and a yoke provided inside the container body include:
A magnet is provided with an internally provided inclined groove that fits into the inclined groove of the shaft, and a spring that applies a constant biasing force to the magnet. A load torque adjusting device for a bicycle power generation lamp, characterized in that the positional relationship with the yoke is changed to change the number of magnetic flux linkages to the coil.