JP3014253B2 - Bicycle headlight device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle headlight device for lighting a headlight with power generated by a generator.

[0002]

2. Description of the Related Art Conventionally, there have been the following two types of generators used for lighting a headlight of a bicycle. A generator that stands up and held when not in use and rotates the power generation roller when the power generation roller is pressed against the front wheel tires by a tilting operation during use, and generates AC power generated at a voltage proportional to the rotation of the power generation roller.

[0003] A stator is provided on the axle of the front wheel, and a rotor is rotatably provided on the axle hub. The rotation of the front wheel causes the rotor to rotate, and constantly generates alternating current power having a voltage proportional to the rotation of the rotor. Generator. This generator is called a hub dynamo. For details of this technique, see, for example, Japanese Patent Application Laid-Open No. 3-213481.
See Japanese Unexamined Patent Application Publication No. 59-27784 and Japanese Utility Model Publication No. 59-26784. As a bicycle headlight device for automatically turning on a headlight when the surroundings are dark using generated power supplied from any of the above-described generators, for example, Japanese Patent Application Laid-Open No. 50-125573 is disclosed. There was one disclosed in the gazette.

[0004]

By the way, in the above-mentioned conventional bicycle headlight device, the headlight is turned on and off by a switching element based on the output of the photodetector. Therefore, when the sun goes down, the surroundings gradually darken, and when the output of the photodetector exceeds a preset value, the switching element is turned on. Voltage is suddenly applied from the generator. This means that the load suddenly increases when viewed from the generator side. Therefore, the generator operates so as to suddenly supply current to the load, so that the bicycle driver suddenly becomes heavier with the pedals, and the load is suddenly increased.

[0005] In addition, a bicycle may run under a street light installed at a predetermined interval or in a shopping street where the surrounding area is relatively brightly illuminated by a light. In such a case, a photodetector is used. The headlight is turned off every time when the output becomes less than the set value. Therefore, for the same reason as described above, the pedals suddenly become heavier or lighter, which is a considerable burden on the bicycle driver.

[0006] Furthermore, the headlight of a bicycle is, of course, intended to illuminate the road ahead during night driving to facilitate driving, but it is also important to inform surrounding vehicles and the like of their existence. Purpose. Especially at dusk, it is not dark enough to turn on the headlights for driving, so the switching element does not work and the headlights may not turn on, which is the most difficult time to see. Nevertheless, the presence of a bicycle cannot be appealed to surrounding vehicles. In addition, the headlight is turned on even though it is not enough to turn on the headlight, so that a useless load is imposed on the driver. Further, even when a bicycle runs under a street light or a shopping street at night, the bicycle may be buried in the irradiation light of the headlight of the following automobile. In addition, even in the daytime,
Bicycles generally have a low presence to drivers of surrounding vehicles and the like.

However, in the conventional bicycle headlight device, the headlight is simply turned on and off based on the output of the photodetector. Therefore, there is a disadvantage that the bicycle is not sufficiently visible to a driver such as a vehicle traveling around the bicycle, and is dangerous. The present invention has been made under such a background, without imposing a sudden and unnecessary burden on the driver,
It is another object of the present invention to provide a bicycle headlight device capable of sufficiently appealing to a surrounding vehicle or the like in any situation.

[0008]

SUMMARY OF THE INVENTION A bicycle headlight device according to the present invention includes a generator for generating electric power by driving a bicycle pedal, a rectifying circuit for rectifying the electric power generated by the generator, and detecting ambient brightness. a light detecting element, is characterized by the pedal load comprises a pedal load adjusting means for adjusting at all times up <br/> down through the generator according to a detection result of the light detection element.

[0009]

According to the above configuration, the rectifier circuit supplies the headlight with DC power according to the detection result of the photodetector at all times while the bicycle is running. It lights up with the brightness. Thus, when the surroundings are bright and low headlight brightness is required, the bicycle pedal is light.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a configuration of a bicycle headlight device according to a first embodiment of the present invention. The generator 1 is constituted by the above-mentioned hub dynamo.
Of course, the generator 1 having the above-described configuration may be used as the generator 1, but in such a case, the generator roller is always pressed against the front wheel tire. The rectifier circuit 2 is configured by a bridge circuit composed of four diodes, and rectifies full-wave power generated by the generator 1. The capacitor 3 is a rectifier circuit 2
Is interposed between the positive output terminal P and the negative output terminal N to smooth the full-wave rectified power output from the rectifier circuit 2.

The transistor 4 has a collector connected to the positive output terminal P of the rectifier circuit 2 and an emitter connected to the headlight 5.
Is connected to one end. The other end of the headlight 5 is a rectifier circuit 2
Is connected to the negative output terminal N of The differential amplifier 6 is used as a voltage follower, and its output terminal is connected to the base of the transistor 4.

Further, between the positive output terminal P and the negative output terminal N of the rectifier circuit 2, a resistor 7 and a cadmium sulfide cell (hereinafter referred to as a CdS cell) connected in cascade to apply a bias to the transistor 4. ) 8 is inserted. The CdS cell 8 is one type of a photoconductive element whose resistance value decreases and changes almost in proportion to the received light illuminance. The value of the resistor 7 and the characteristics of the CdS cell 8 indicate that the transistor 4 is in a conductive state with a slight base current value even when the light receiving illuminance of the CdS cell 8 is maximum, that is, when the resistance value of the CdS cell 8 is minimum. Choose something that gives That is, while the bicycle is running, the headlight 5 is always slightly lit. The Zener diode 9 is for preventing an overvoltage from being applied to the headlight 5 and includes a resistor 7 and a CdS cell 8.
And the negative output terminal N of the rectifier circuit 2. Here, the transistor 4, the differential amplifier 6, and the resistor 7 determine the pedal load of the driver by using a Cd which is a photodetector.
A pedal load adjusting means for increasing / decreasing and adjusting via the generator 1 according to the detection result of the s cell 8 is constituted.

In such a configuration, first, when the bicycle is stopped, the rotor of the generator 1 does not rotate because the front wheels of the bicycle are not rotating, and the generated voltage of the generator 1 is 0V. Therefore, the headlight 5 does not turn on. Next, during the day,
When the driver gets on a bicycle and starts pedaling in a sufficiently bright surrounding, the rotor of the generator 1 rotates due to the rotation of the front wheel of the bicycle, and alternating-current power generated in proportion to the rotation of the rotor is generated. I do. Thus, after the generated power is full-wave rectified by the rectifier circuit 2, the capacitor 3
Therefore, a predetermined DC voltage is applied to both ends of the cascade-connected resistor 7 and CdS cell 8. Therefore, the voltage divided by the resistor 7 and the CdS cell 8 is applied to the base of the transistor 4 via the differential amplifier 6, and a predetermined base current flows through the transistor 4, so that the transistor 4 is turned on and the headlight is turned on. The lamp 5 lights up at a predetermined luminance.

Next, at dusk or in bad weather even in the daytime, the surroundings gradually darken, and C
As the received light illuminance of the dS cell 8 decreases, the resistance value of the CdS cell 8 increases accordingly. As a result, the voltage divided by the resistor 7 and the CdS cell 8 also increases, so that the base current supplied to the base of the transistor 4 also increases. Therefore, the emitter current of the transistor 4, that is, the current supplied to the headlight 5 also increases, and the headlight 5 lights up with higher luminance. That is, C
The luminance of the headlight 5 changes according to the received illuminance of the dS cell 8. However, since the Zener diode 9 is provided, the voltage divided by the resistor 7 and the CdS cell 8 does not exceed the Zener voltage.
Does not exceed the luminance corresponding to the Zener voltage.

In addition, when traveling under a street light installed at a predetermined interval or in a place such as a shopping street, the received light illuminance of the CdS cell 8 changes due to the influence of the street light or the lighting of the shop, etc. Although the brightness of the lamp 5 changes, even when the received illuminance of the CdS cell 8 is maximum, that is, even when the resistance value of the CdS cell 8 is minimum, the transistor 4 is turned on with a slight base current value. Since the characteristics of the resistor 7 and the CdS cell 8 are selected, the brightness of the headlight 5 does not fall below the brightness in the daytime.

Therefore, a driver such as a vehicle around the bicycle can fully view the bicycle with the headlight 5 in any situation. In addition, since the transistor 4 is always in a conductive state during running, the load of the generator 1 does not suddenly change. Therefore, the bicycle driver can avoid a sudden load because the pedal does not suddenly become heavy or light.

Next, a second embodiment of the present invention will be described. FIG. 2 is a circuit diagram showing a configuration of a bicycle headlight device according to a second embodiment of the present invention. In FIG. 2, parts corresponding to those in FIG.
The description is omitted. The difference between the bicycle headlight device shown in this figure and the bicycle headlight device shown in FIG. 1 is that a diode 10 is provided instead of the rectifier circuit 2 and the grounding side of the generator 1
The negative terminal of the capacitor 3, the other end of the headlight 5, the other end of the CdS cell 8, and the anode of the Zener diode 9 are commonly grounded.

The diode 10 performs half-wave rectification of the power generated by the generator 1. Therefore, the energy utilization efficiency of the generator 1 is half that of the first embodiment described above, but the voltage drop (about 0.7 V) due to the diode 10 is equal to the voltage drop (about 0.7 V) of the rectifier circuit 2 of the first embodiment. (About 1.4 V), and there is an advantage that the grounding structure may be the same as the conventional one. Since the operation is the same as that of the first embodiment, the description is omitted.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the design can be changed within the scope of the present invention. The present invention is included in the present invention. For example, in the above-described first and second embodiments, the transistor 4 is used as an element for supplying a current to the headlight 5, and the CdS cell 8 is used as a photodetector for detecting ambient brightness. However, the present invention is not limited to these examples. In short, any device that can supply a current or a voltage corresponding to the brightness of the surroundings to the headlight 5 while the bicycle is running can be used.

[0020]

As described above, according to the present invention, the pedal load is constantly increased or decreased according to the detection result of the light detecting element by the pedal load adjusting means. Instead, the load of the generator, that is, the pedal load changes in proportion to the brightness of the headlight. That is,
When the surroundings are bright and the brightness of the headlight is not so required, the pedal load is reduced, so that no unnecessary burden is imposed on the driver. Further, in any situation, it is possible to sufficiently appeal to the surrounding vehicles and the like. Therefore, it is possible to drive safely both in the daytime and at night.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of a bicycle headlight device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram illustrating a configuration of a bicycle headlight device according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Generator 2 Rectifier circuit 3 Capacitor 4 Transistor 5 Headlight 6 Differential amplifier 7 Resistance 8 CdS cell 9 Zener diode 10 Diode

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Makoto Uchida 1-268, Hirosawa-cho, Kiryu-shi, Gunma Mitsuha Electric Works Co., Ltd. (56) References JP-A-5-77774 (JP, A JP-A-5-147469 (JP, A)

Claims (1)

(57) [Claims] 1. A generator that generates electric power by driving a bicycle pedal, a rectifier circuit that rectifies the electric power generated by the generator, a light detection element that detects ambient brightness, and a pedal load that is connected to the light detection element. A bicycle headlight device comprising: a pedal load adjusting unit that constantly adjusts the amount of increase or decrease via the generator according to a detection result.