JP4111966B2 - Bicycle dynamo and bicycle lighting device equipped with the bicycle dynamo - Google Patents

Description

  The present invention relates to a bicycle dynamo having a structure in which a voltage suppression element for suppressing an output voltage of a dynamo is mounted. The present invention also relates to a bicycle lighting device using such a dynamo.

  A bicycle dynamo has a rotor including a permanent magnet rotating in conjunction with rotation of a bicycle wheel, a stator core having a pole piece opposed to the magnetic pole of the permanent magnet, and magnetic lines of force of the permanent magnet pass through the pole piece. And a stator including a coil arranged at a position, and has a structure in which electric power is obtained by generating electric power by rotating a wheel. As the speed of the bicycle increases, the number of rotations of the wheels also increases, so the output voltage increases. Dynamo power is supplied to the headlight bulb, but since the bulb has a voltage that breaks, the dynamo voltage must be kept below the bulb's break voltage.

For this reason, it is known to use a voltage suppression element such as a varistor to suppress the output voltage of the dynamo below the disconnection voltage of the headlight bulb even when the speed of the bicycle increases. (Patent Document 1)
Japanese Patent Laid-Open No. 1-283039

    Voltage suppression elements such as varistors need to be cooled because they generate heat. In the thing of patent document 1, a voltage suppression element is attached to the dynamo support body formed with heat conductors, such as the aluminum die-casting which supports a dynamo body, and heat_generation | fever of a voltage suppression element is radiated to a dynamo support body It is designed to cool. Here, the dynamo body includes a rotor, a stator, a coil, and the like.

    In patent document 1, since the voltage suppression element is attached to the dynamo support body away from the dynamo body, the wiring process is troublesome and the assemblability is poor.

    An object of the present invention is to suppress the output voltage of the dynamo even when the bicycle becomes high speed, and to cool the heat generated by the voltage suppressing element, the dynamo is excellent in assembling without troublesome wiring processing. Is to provide.

    Another object of the present invention is to provide a bicycle lighting device that can protect a taillight even when the headlight is disconnected due to the life of the headlight.

In order to solve the above problems, the dynamo for bicycles of the present invention is
A rotor core including a permanent magnet disposed inside a hub body of a bicycle and rotating in conjunction with rotation of a wheel, a stator core disposed on a hub shaft and having a pole piece facing the magnetic pole of the permanent magnet, and magnetic lines of the permanent magnet Having a stator including a coil disposed at a position passing through the pole piece,
The stator core is a pair of left and right, and the coil is accommodated therein, and each stator core is composed of a disk body and the pole pieces bent inwardly at equal intervals on the outer periphery of the disk body,
A voltage suppression element for suppressing the output voltage of the dynamo is attached to the outer surface of the stator core disk body via an earth lead plate for grounding one end of the coil, and the voltage suppression element is attached to the ground lead plate. A holder that is held so as to be held is integrally formed, and heat generated from the voltage suppression element is radiated to the stator core to suppress a temperature rise of the voltage suppression element.

A voltage suppression circuit is formed by connecting a resistor in series with the voltage suppression element, and a holder for holding the voltage suppression circuit is integrally formed on the ground lead plate, and the voltage suppression circuit is formed on the ground lead plate. It can also be installed.

    As the voltage suppression element, a Zener diode can be exemplified in addition to the varistor as in Patent Document 1 described above.

    In order to solve the above-mentioned problems, a bicycle lighting device according to the present invention is configured to supply the power of the bicycle dynamo to the headlight and taillight of the bicycle.

    According to the bicycle dynamo of the present invention, the voltage suppression element is attached to the stator core, and heat generated from the voltage suppression element is radiated to the stator core to suppress the temperature rise, and the voltage suppression element is attached to a position close to the coil. Therefore, the wiring process is facilitated, and the dynamo main body including the stator and the rotor can be assembled in advance by forming a voltage suppressing element into a unit, thereby improving the assemblability.

In addition, the voltage suppression element is attached to the stator core through an earth lead plate for grounding one end of the coil, so that an existing component called an earth lead plate can be effectively used for mounting the voltage suppression element. Can do. If the holder for holding the voltage suppression element is integrally formed on the ground lead plate, the voltage suppression element can be attached without increasing the number of parts.

    Also, if a resistor is connected in series with the voltage suppression element to form a voltage suppression circuit, and this circuit is attached to the ground lead plate, the resistor can also consume power, and the power consumed by the voltage suppression element can be reduced accordingly. Thus, heat generation of the voltage suppression element can be suppressed.

    Further, according to the bicycle lighting device of the present invention, even if the bulb of the headlight is disconnected due to its life or the like, and the load of the dynamo becomes only the taillight, the voltage suppression element suppresses the increase in voltage, Can be protected.

    The bicycle dynamo of the present invention will be described by taking the hub dynamo (10) as an example. FIG. 1 shows a state in which the hub dynamo (10) is mounted on the front wheel portion of the 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 (90) arranged on the rear wheel side (see FIG. 9). 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).

  The outer periphery of the hub axle (11) is threaded with a male screw. As shown in Fig. 2, the hub axle (11) is fastened to the front forks (44) (44) with nuts (45) (45) on both sides. A cylindrical hub body (12) is rotatably disposed on the hub shaft (11) via bearings (54) and (54). 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. 4, the core (18) is configured 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 core (18) is preferably formed of a powder sintered material such as ferrite or a pure iron-based electromagnetic soft iron material. It is desirable that one slit (26) of the slit opened in the core (18) is opened so as to reach the inner surface of the cylinder and is electrically insulated in the circumferential direction. 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). As shown in FIG. 7 and FIG. 8, one end of the winding coil (22) is led to the output terminal (22c) via the lead wire (22b) and the lead wire (22d), and from the output terminal (22c) to the head Connected to one end of the lamp (46) and tail lamp (90), the other end (22a) of the coil (22) is connected to the hub shaft (11) via the ground lead plate (38), as described later, It is electrically connected to the other end of the headlight (46) and the taillight (90) via 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. 4, 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. 5, 6, and 7, the stator cores (16) and (17) have pole pieces (74) and (75) bent inwardly on the outer periphery of the disc body (78) at equal intervals 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. 5 and 7, 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. It has been established. A lead wire (22b) connected to one end of the winding coil (22) is drawn out through the slot (15) of one stator core (16). (See Figure 7)
The stator includes a coil bobbin (20) containing a core (18) and a wound coil (22) between stator cores (16) and (17), and a nut (30 which is screwed with a hub shaft on the hub shaft (11). ) (31) is positioned and fixed on the hub shaft (11). One nut (30) (on the right side in FIG. 2) is integrally formed with a sleeve (32) that is in sliding contact with the one bearing (54). The other nut (31) is also integrally formed with a sleeve (33) in sliding contact with the other bearing (54). A washer (36) is interposed between the nut (31) and the stator core (17), and the ground lead plate (38) is interposed between the nut (30) and the stator core (16).

  There are insulating sheets (not shown) between the disk body (78) of the stator core (16) and the earth lead plate (38) and between the disk body (78) of the stator core (17) and the washer (36), respectively. Intervened. This is intended to suppress the generation of eddy currents in the disk body (78) of the stator core (16) (17) by the slot (15) provided in the disk body (78). This is to prevent the plate (38) and the washer (36) from short-circuiting the slot (15) and inhibiting the suppression of eddy currents.

  The ground lead plate (38) is made of a conductive metal plate. As shown in FIGS. 7 and 8, the ground terminal (37) bent in the hub axial direction is connected to the ground side of the coil (22). The end (22a) is connected. A nut (30) abuts on the ground lead plate (38), and the vehicle body is grounded from the nut (30) through the hub shaft (11) and the metal front fork (44).

  The ground terminal (37) is connected to one end (63) of a voltage suppression circuit (62) constituted by a series circuit of an AC Zener diode (66) serving as a voltage suppression element and a resistor (61). The Zener diode (66) and the resistor (61) are connected via the connection fitting (64). At the other end of the voltage suppression circuit (62), the output side of the coil (22) is connected to the anti-connector (64) side of the resistor (61) via a lead wire (22b). The other end of the voltage suppression circuit (62) is further connected to the output terminal (22c) via the connection fitting (65) and the lead wire (22d). A groove (39) serving as a passage for guiding the lead wire (22d) to the output terminal (22c) is formed in the nut (30) in contact with the ground lead plate (38).

  A holder (67) for holding a Zener diode (66) is erected on the ground lead plate (38). The holder (67) is bent inward as shown in FIG. 8, and holds the zener diode (66) so as to be held therein. The Zener diode (66) is molded from a synthetic resin and insulated from the ground lead plate (38).

    The resistor (61) and the connection fittings (64) (65) are passed through the insulating tube (68). The outside of the insulating tube (68) is held by two holders (69) (69) standing on the ground lead plate (38) so as to be held in the same manner as the Zener diode (66). . The two holders (69) and (69) in FIG. 8 show a state before bending, and actually, the holders (68) are bent in the same manner as the holder (67) to hold the insulating tube (68). In FIG. 8, the inside of the insulating tube (68) is shown through.

    Four cylindrical protrusions (80) that contact the outer periphery of the hexagon nut (30) are formed on the disk body (78) of the stator core (16) that contacts the ground lead plate (38). The ground lead plate (38) is formed with a long hole (81), a round hole (82), and a notch (83) for allowing the protrusions (80) to escape.

    A method of assembling the stator on the hub shaft (11) will be described. First, the nut (30) is set at a predetermined position on the hub axle (11). The output terminal (22c) faces upward so that it is convenient to supply power to the headlamp (46) located above the output terminal (22c). Therefore, the position of the groove (39), which is a passage for guiding the lead wire (22d) of the nut (30) to the output terminal (22c), is also in a fixed direction, so the nut (30) is determined. It is attached to the hub shaft (11) so as to be in the predetermined position.

    Thereafter, a pair of stator cores (16), (17) having a core (18) and a winding coil (22) set therein (the ground lead plate holding the voltage suppression circuit (62) (the stator core (16)) 38) is passed from the opposite side of the nut (30) through the hub shaft (11) as indicated by the arrow F in FIG. 6, and four cylindrical projections (formed on the stator core (16)) 80) is brought into contact with the outer periphery of the hex nut 30 as shown in FIG.

    Thereafter, the nut (31) is tightened through the washer (36) to fix the stator core (16) (17) in a predetermined position. When the nut (31) is tightened, the stator core (16) (17) is prevented from rotating by the cylindrical protrusion (80) hitting the outer periphery of the hexagon nut (30).

    Inside the hub body (12), as shown in FIGS. 2 and 4, a permanent magnet (14) constituting a rotor is mounted via a yoke (85). The permanent magnet (14) is alternately magnetized with N and S poles so as to face the pole pieces (74) and (75) of the stator cores (16) and (17).

    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). Magnetic flux passing through the pole piece (74) of one stator core (16), the disk body (78), the core (18), the disk body (78) of the other stator core (17), and the pole piece (75) facing each other. Will occur. 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.

    The generated electric power is supplied to the headlight (46) and the taillight (90). FIG. 9 shows an electrical circuit. The hub dynamo (10) has 6 [V] and 3 [W], the headlight (46) has 6 [V] and 2.4 [W], and the taillight has 6 [V] and 0.6 [W] bulbs are used. In parallel with the hub dynamo (10), a voltage suppression circuit (62) composed of a series circuit of an alternating current zener diode (66) and a resistor (61) is connected. FIG. 10 shows an equivalent circuit in FIG.

    As the bicycle speed increases, the generated voltage also increases. However, by adjusting the number of turns of the coil (22) of the hub dynamo (10), the generated voltage is suppressed even if the speed increases as shown by curve A in FIG. The bulbs of the headlight (46) and taillight (90) are protected from being blown out.

    However, if the lamp is used for a long time, the bulb of the headlamp (46) will run out due to its life. FIG. 12 shows a case where the bulb of the headlamp (46) is blown and only the tail lamp (90) is used as a load. FIG. 13 shows an equivalent circuit thereof. In this case, the function of the voltage suppression circuit (62) suppresses the generated voltage even when the speed increases, as shown by curve B in FIG. 11, and protects the light bulb of the tail lamp (90) from being blown out.

    FIG. 14 shows the characteristics when the voltage suppression circuit (62) is not provided. The curve A shows the coil of the hub dynamo (10) when both the headlight (46) and the taillight (90) are normally lit. By adjusting the number of turns in (22), the generated voltage is suppressed even if the speed increases. However, when the bulb of the headlight (46) is blown out, the load is only the taillight (90), and as shown by curve B, the output voltage increases steadily as the speed increases, and the disconnection voltage of the taillight (90) This shows the state where the taillight (90) is broken.

    In the present invention, the output voltage is suppressed and the tail lamp (90) is protected by the action of the voltage suppression circuit (62), particularly the AC Zener diode (66), but the Zener diode (66) generates heat. If the Zener diode (66) generates heat and the temperature becomes too high, the voltage suppression characteristics will be affected and must be cooled.

    Therefore, in the present invention, since the Zener diode (66) is attached to the stator core (16) via the conductive ground lead plate (38) as described above, the heat generated by the Zener diode (66) It is cooled by being conducted to the stator core (16) through 38), and the temperature rise is suppressed and protected.

    In addition, the voltage suppression circuit (62) is configured not only with the Zener diode (66) but also with the resistor (61), so the resistor (61) consumes power and the power consumed by the Zener diode (66). And the heat generation of the Zener diode (66) is suppressed as much as possible.

    The voltage suppression circuit (62) composed of the Zener diode (66) and the resistor (61) is attached to the stator core (16) close to the coil (22) via the ground lead plate (38), so that the wiring process is facilitated. . In the assembly, the voltage suppression circuit (62) can be assembled in advance to the dynamo body including the stator and the rotor to form a unit, and the assemblability can be improved.

    Further, since the existing ground lead plate (38) is used to attach the voltage suppression circuit (62) to the stator core (16), existing components can be used effectively. And since the holder (67) (69) (69) for holding the voltage suppression circuit (62) such as the Zener diode (66) is formed on the ground lead plate (38), without increasing the number of parts, The voltage suppression circuit (62) can be easily attached.

It is an enlarged view of the front-wheel part of the bicycle carrying the dynamo (hub dynamo) of this invention. It is the figure which represented the hub dynamo in the cross section by half from the axial center of the hub axis | shaft. It is the side view seen from the right side in FIG. 2 of the hub dynamo. It is sectional drawing orthogonal to the axial center of the hub dynamo. It is the left (left side in FIG. 2) side view of the stator of the same hub dynamo. It is a front view of the state which attached the stator on the hub axis | shaft of the same hub dynamo. It is the side view seen from the right side in FIG. 6 of the hub dynamo. It is a disassembled perspective view of the earth lead board and voltage suppression circuit of the same hub dynamo. It is an electric circuit diagram of the lighting device for bicycles of the present invention. It is an equivalent circuit diagram of the illumination device. It is an output voltage characteristic view of the illumination device. It is an electric circuit diagram of the state where the headlamp of the lighting device is blown out. It is an equivalent circuit of the state of FIG. It is an output voltage characteristic view of a conventional bicycle lighting device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hub dynamo 14 Permanent magnet 74 Pole piece 75 Pole piece 16 Stator core 17 Stator core 22 Coil 66 Zener diode (voltage suppression element)
12 Hub body 11 Hub shaft 38 Ground lead plate 67 Holder 69 Holder 61 Resistor 62 Voltage suppression circuit 46 Headlight 90 Taillight

Claims (3)

A rotor core including a permanent magnet disposed inside a hub body of a bicycle and rotating in conjunction with rotation of a wheel, a stator core disposed on a hub shaft and having a pole piece facing the magnetic pole of the permanent magnet, and magnetic lines of the permanent magnet A dynamo for a bicycle having a stator including a coil disposed at a position passing through the pole piece,
The stator core is a pair of left and right and the coil is housed therein, and each stator core is composed of a disk body and the pole pieces bent inwardly at equal intervals on the outer periphery of the disk body,
A voltage suppression element that suppresses the output voltage of the dynamo is attached to the outer surface of the stator core disk body through an earth lead plate for grounding one end of the coil on the vehicle body. A bicycle dynamo in which a holder for holding a suppression element is integrally formed, and heat generated from the voltage suppression element is radiated to a stator core to suppress a temperature rise of the voltage suppression element. 2. A bicycle according to claim 1 , wherein a resistor is connected in series with the voltage suppression element to form a voltage suppression circuit, and a holder for holding the voltage suppression circuit is integrally formed on the ground lead plate . Dynamo. A bicycle lighting device that supplies the power of the bicycle dynamo according to claim 1 to a headlight and a taillight of the bicycle.