GB2266418A

GB2266418A - Control apparatus for an electic generator of a bicycle

Info

Publication number: GB2266418A
Application number: GB9308235A
Authority: GB
Inventors: Masashi Nagano
Original assignee: Shimano Inc
Current assignee: Shimano Inc
Priority date: 1992-04-22
Filing date: 1993-04-21
Publication date: 1993-10-27
Also published as: GB9308235D0; DE4313223C2; DE4313223A1; JP3378268B2; JPH05294273A

Abstract

The generator 1 is switchable between a generating state and a non-generating state, in which no power or only a small amount of power is generated, by a controller 2 responsive to detection of the need to supply power to an operating device 7. An ambient light sensor 3 may be used to detect the need to power a headlight 7. The sensor 3 may be a solar battery which is also used to charge a battery 4b supplying power to controller 2 and to a solenoid 23. A lock 21 is released on energisation of solenoid 23 so that the generator magnet M then remains stationary and the generator is in its non- generating state. An auxiliary generator (14), (Figs 4, 5), may be used instead of battery 4b to energise controller 2 and solenoid 23. This auxiliary generator may also be dispensed with if the generator 1 produces a small amount of power in its non-generating state. An alternative arrangement renders the generator 1 operative to power a radio (16), (Fig 6), when controller 2 senses that a radio switch (17) is on. Other ways of rendering generator 1 non-operative include causing the stator coil C to rotate with the magnet M (Fig 7), varying the coil C/magnet M spacing (Fig 8), and inserting a magnetism blocking element (18), (Fig 9), between the coil C and magnet M. <IMAGE>

Description

2266418 CONTROL APPARATUS FOR AN ELECTRIC GENERATOR OF A BICYCLE The

present invention relates to a control apparatus for controlling a generator in an electric system of a bicycle, wherein the generator is switchable between a generating state for performing a generating function and a non-generating state for stopping or suppressing the generating function.

A generator as noted above is disclosed in Japanese Utility Model Publication No. 56-21664, for example. This generator includes a magnet fixed to a wheel hub, and a coil switchable between a state fixed to a bicycle frame and a state rotatable with the magnet. The coil is switchable by a manually operable switch mechanism between the fixed state or generating state and the rotatable state or non-generating state.

When the electric system of the bicycle does not require a power supply, the switch mechanism is operated to switch the generator to the nongenerating state. This avoids the loss of cyclist's effort occurring when the cyclist pedals the bicycle with the generator driven in the generating state. The cyclist manually operates the switch mechanism on his or her decision. Whenever the cyclist decides that the power supply is not needed, he or she carries out a troublesome operation to switch the generator to the non-generating state.

An object of the present invention is to provide a control apparatus for controlling, without burdening the cyclist, a generator switchable between a generating state for performing a generating function and a nongenerating state for stopping or suppressing the generating function.

The above object is fulfilled, according to the present invention, by a control apparatus comprising detecting means for detecting a necessity to supply power to an operating device in an electric system, and generator control means operable on a result of detection by the detecting means to place a generator selectively in a generating state and in a nongenerating state.

With the above construction, when a power supply is needed, the generator control means automatically switches the generator to the generating state in response to information received from the detecting means. As a result, power is generated and supplied to the operating device with a run of the bicycle. When the power supply is not needed, the generator control means automatically switches the generator to the non-generating state in response to information received from the detecting means. As a result, little or no power is generated regardless of a run of the bicycle. The term non-generating state used herein refers to a reduction in the power for operating the generator below an ordinary level for power generation, and includes a state in which the generator operates on reduced power to generate a small amount of electricity.

According to the present invention, the cyclist can pedal the bicycle without a heavy load of driving the generator when the power supply is not needed. It is unnecessary to manually control the generator to turn the power supply on and off. The operating device may be a head light, and the detecting means may be a light sensor for detecting ambient light.

In this case, the head light may be turned on automatically in the nighttime.

The generator includes a coil and a magnet for generating an electric current through the well-known interaction therebetween. Thus, in a preferred embodiment of the invention, the generator control means may include a switch mechanism for switching the coil and magnet between a state capable of relative movement and a state incapable of relative movement. The generator control means may include a switch mechanism for selectively inserting a magnetism blocking element between the coil and magnet. Further, the generator control means may include a switch mechanism for selectively varying a distance between the coil and magnet.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which:- Fig. 1 is a block diagram of an electric system of a bicycle having a generator control device according to one embodiment of the present invention.

Fig. 2 is a schematic view of a generator.

Fig. 3 is a block diagram of another embodiment of the invention.

Fig. 4 is a block diagram of a further embodiment.

Fig. 5 is a schematic view showing a mechanism for switching the generator.

Fig. 6 is a block diagram of a still further embodiment.

Fig. 7 is a schematic view of a switching mechanism in a different embodiment.

Fig. 8 is a schematic view of a switching mechanism in another embodiment.

Fig. 9 is a schematic view of a switching mechanism in yet another embodiment.

Fig. 1 is a block diagram of an electric system of a bicycle. As shown in Fig. 1, the electric system includes a generator 1, a controller 2 for controlling the generator 1, a solar battery 3 connected to the controller 2, and a power source 4 also connected to the controller 2. The generator 1 supplies power to a head light 7 through a lighting circuit 6 having a light switch 5.

As shown in Fig. 2, the generator 1 includes a coil C and a permanent magnet M mounted in a hub barrel 8. The generator 1 is assembled along with the hub to a bicycle frame (not shown), to generate power as a wheel rotates relative to the frame.

As clearly seen in Fig. 2, the coil C is mounted on a hub spindle 10 through a support 9 not to be rotatable relative to the hub spindle 10. The magnet M has an annular configuration surrounding the coil C, and is supported by a support 11 rotatable about the hub spindle 10. A lock element 21 is attached to a side wall of the hub barrel 8 to be slidable axially of the hub spindle 10. When the lock element 21 is moved to a lock position with one end thereof engaging the support 11, the magnet M and hub barrel 8 are interconnected by the lock element 21 to be rotatable together. The hub spindle 10 is fixed tight to the bicycle frame not to be rotatable relative to the bicycle frame, whereby the coil C is supported to be unrotatable. With rotation of the wheel relative to the bicycle frame, the magnet M and coil C rotate relative to each other to generate an electric current flowing through the coil C.

As shown in Fig. 2, a switch mechanism 20 is attached to the hub barrel 8 for controlling the generating function of the generator 1 in response to signals from the controller 2. The switch mechanism 20, controller 2, solar battery 3 and power source 4 act to turn the head light 7 on and off appropriately and automatically.

Specifically, as shown in Fig. 2, the switch mechanism 20 includes the lock element 21, a control element 22 and an electromagnetic solenoid 23 attached to the hub barrel 8. The solenoid 23 is operable to switch the generator 1 between a generating state and a non-generating state. That is, the solenoid 23, when energized, pushes the control element 22 to pivot about a pivotal axis 23 provided by the hub barrel 8, whereby the control element 22 slides the lock element 21 away from the magnet M. Then, the lock element 21 moves to an unlock position with the one end thereof disengaged from a recess l l a of the support 11. The hub barrel 8 is now rotatable relative to the magnet M, and the latter applies a magnetic force to the coil C whereby the magnet M and coil C become unrotatable relative to each other. Consequently, the generator 1 assumes the non-generating state to generate no electricity regardless of rotation of the hub barrel 8. When de-energized, the solenoid 23 releases the control element 22, whereby a locking spring 25 causes the control element 22 to pivot toward a lock position, sliding the lock element 21 toward the magnet M. In the lock position the lock element 21 engages the support 11 with the one end thereof lying in the recess l la of the support 11. The magnet M and hub barrel 8 are thereby interconnected. With rotation of the hub barrel 8, the magnet M and coil C rotate relative to each other. Consequently, the generator 1 assumes the generating state to generate electric power with rotation of the hub barrel 8.

The power source 4 includes a charging circuit 4a and chargeable battery 4b. The solar battery 3 receives light and generates power, and the charging circuit 4a charges the chargeable battery 4b with the power received from the solar battery 3.

The generator controller 2 includes a control circuit 2a, and a drive circuit 2b for driving the electromagnetic solenoid 23. When the solar battery 3 acting as a detecting device detects a necessity to supply lighting power, the switch mechanism 20 responds to this detection result and automatically switches the generator 1.

Specifically, the control circuit 2a is operable by the power supplied from the chargeable battery 4b. When the solar battery 3 generates power, the control circuit 2a determines from information received from the solar battery 3 that it is not necessary to turn on the head light 7 and power is not needed therefor. When the solar battery 3 does not generate power, the control circuit 2a determines from information received from the solar battery 3 that it is necessary to turn on the head light 7 and power is needed therefor. When the control circuit 2a determines that power is needed, the drive circuit 2b automatically de-energizes the solenoid 23 in response to a signal inputted from the control circuit 2a. As a result, the generator 1 assumes the generating state. When the control circuit 2a determines that power is not needed, the drive circuit 2b automatically energizes the solenoid 23 in response to a signal inputted from the control circuit 2a. As a result, the generator 1 assumes the non-generating state.

In using this electric system, the light switch 5 is closed in advance. During the daytime when the solar battery 3 receives light, the controller 2 operates by the power supplied from the battery 4b to cause the switch mechanism 20 to place the generator 1 in the non-generating state. Thus, -7the generator 1 does not generate power regardless of rotation of the wheel. The head light 7 is not lit though the light switch 5 is closed. The cyclist can ride the bicycle with no extra effort to drive the generator 1. During the nighttime when the solar battery 3 does not receive light, the controller 2 causes the switch mechanism 20 to place the generator 1 in the generating state. Thus, the generator 1 now generates power with rotation of the wheel. The head light 7 is automatically lit since the light switch 5 is closed.

Fig. 3 is a block diagram of a bicycle electric system in another embodiment of the invention. This embodiment includes a light sensor 12 and a battery 13 in place of the solar battery 3 and power source 4.

In this embodiment, the light sensor 12 receives light and outputs an electric signal to the control circuit 2a. In response to this signal, the control circuit 2a operable by the power received from the battery 13 detects a necessity to supply lighting power. In response to the decision made by the control circuit 2a, the drive circuit 2b controls the power from the battery 13 to operate the electromagnetic solenoid 23. Thus, the light sensor 12 acts as a detecting device for detecting a necessity to supply lighting power, and in response to the detection result the generator controller 2 operable by the battery 13 drives the switch mechanism 20 to switch the generator 1.

Fig. 4 is a block diagram of a bicycle electric system in a further embodiment of the invention. This embodiment includes a controlling generator 14 mounted along with the lighting generator 1 in the hub barrel 8. This dispenses with the solar battery or other battery acting as the power source for the generator controller 2.

In this embodiment, as shown in Fig. 5, the controlling generator 14 -8includes a permanent magnet M1 and a coil Cl rotatable relative to each other whenever the hub barrel 8 rotates. With rotation of the wheel, the controlling generator 14 constantly generates electric power and supplies it to the generator controller 2. The control circuit 2a of the controller 2 is operable by the power received from the controlling generator 14, with the light sensor 12 acting as the detecting device for detecting a necessity to supply lighting power. In response to the decision made by the control circuit 2a, the drive circuit 2b controls the power supply from the controlling generator 14 to operate the electromagnetic solenoid 23. Thus, the generator controller 2 is operable by using the power generated by the controlling generator 14 as controlling power, to control the switch mechanism 20 to switch the generator 1 in response to the light sensor 12 acting as the detecting device for detecting a necessity to supply lighting power.

With this embodiment, the cyclist pedals the bicycle constantly driving the controlling generator 14 regardless of the necessity to supply lighting power. However, the power generated by the controlling generator 14 constitutes a slight power compared with the lighting power generated by the generator 1. The cyclist may pedal the bicycle with only a small driving load compared with the case of driving the lighting generator 1.

Fig. 6 is a block diagram of a bicycle electric system in a still further embodiment of the invention. In this embodiment, the power generated by the generator 1 is supplied to a radio 16 through a power supply circuit 15.

The generator controller 2 is operable by the power supplied from a battery 13. The radio 16 is turned on and off by a radio switch 17 acting as a detecting device for detecting a necessity to supply power to the radio 16. In response to a detection result received from the radio switch 17, the controller 2 controls the power from the battery 13 to operate the switch -9mechanism 20 and switch the generator 1.

That is, when the radio switch 17 is turned on, the radio switch 17 transmits information to the control circuit 2a, and the latter determines a necessity to supply power to the radio 16. In response to a control signal from the control circuit 2a, the drive circuit 2b automatically deenergizes the electromagnetic solenoid 23. As a result, the generator 1 assumes the generating state to supply power to the radio 16. When the radio switch 17 is turned off, the control circuit 2a determines from information from the radio switch 17 that the power supply to the radio 16 is unnecessary. In response to a control signal from the control circuit 2a, the drive circuit 2b automatically energizes the electromagnetic solenoid 23. As a result, the generator 1 assumes the non-generating state to lighten a pedaling load.

In the foregoing embodiments, the generator 1 is switchable between the generating state and non-generating state by connecting and disconnecting the magnet M to/from the hub barrel 8. This switching structure is variable in many ways as shown in Fig. 7 through 9, for example.

Fig. 7 shows one such switch mechanism 20 for switching between the generating state and non-generating state. In the generating state, the coil C supported on the hub spindle 10 is connected thereto to be rotatable relative to the magnet M rotatable with the hub barrel 8. In the non-generating state, the coil C is disconnected from the hub spindle 10 to be rotatable with the magnet M due to the magnetic force of the magnet M.

With a switch mechanism 20 as shown in Fig. 8, switching is made between the generating state in which the magnet M and coil C are spaced a small distance from each other so that power is generated by relative -10rotation between the magnet M and coil C, and the non-generating state in which the magnet M and coil C are spaced a large distance from each other so that the magnet M and coil C are relatively rotatable in a light way with the magnetic force of the magnet M applying a reduced resistance to rotation of the coil C. The switching between the generating state and non-generating state is effected by an electric motor 19b which turns a screw shaft 19a meshed with the support 9 of the coil C to screwfeed the coil C.

A switch mechanism 20 as shown in Fig. 9 includes a magnetism blocking element 18 for switching between the generating state and nongenerating state. In the generating state, the magnetism blocking element 18 is retracted from a position between the magnet M and coil C to allow the magnetic force of the magnet M to act on the coil C to generate power with relative rotation between the magnet M and coil C. In the non- generating state, the magnetism blocking element 18 lies in the position between the magnet M and coil C so that the magnet M and coil C are relatively rotatable in a light way with the magnetic force of the magnet M applying a reduced resistance to rotation of the coil C.

Preferably, the load of driving the generator is totally eliminated when electric power is not needed. However, the switch mechanism 20 shown in Fig. 8 or 9 may be employed to partially reduce, instead of totally eliminating, the load of driving the generator when electric power is not needed. Thus, the generator 1 may be used also for controlling purposes, thereby dispensing with the controlling generator shown in Fig. 4. The driving load of the time requiring no electric power may be reduced to 20% or less of the driving load of the time requiring electric power.

The present invention is applicable also to electric systems having a generator disposed in varied locations, such as outside the hub. Further, the present invention is applicable not only to an electric system for supplying power to a head light or a radio, but to electric systems for supplying power to varied lamps such as a tail light or signal lights o r to varied non-lighting devices other than the radio.

Claims

A control apparatus for controlling a generator in an electric system of a bicycle, the generator being switchable between a generating state for performing a generating function and a non-generating state for stopping or suppressing the generating function, said apparatus comprising detecting means for detecting a necessity to supply power to an operating device in said electric system, and generator control means operable on a result of detection by said detecting means to place said generator selectively in a generating state and in a non-generating state.
2. A control apparatus as claimed in claim 1, wherein said operating device is a head light.
3. A control apparatus as claimed in claim 1 or 2, wherein said electric system further includes an auxiliary power source for supplying power to said generator control means in particular.
4. A control apparatus as claimed in claim 3, wherein said auxiliary power source is a battery.
5. A control apparatus as claimed in claim 3, wherein said auxiliary power source is a solar battery, said solar battery acting also as the detecting means for detecting ambient light and transmitting a detection result to said generator control means.
6. A control apparatus as claimed in claim 3, wherein said auxiliary power source is a second generator for constantly generating power during a run of the bicycle.
7. A control apparatus as claimed in any one of claims 1 to 4 or 6, wherein said detecting means is a light sensor for detecting ambient light.
8. A control apparatus as claimed in any one of claims 1 to 4 or 6, wherein said operating device is a radio, and said detecting means is a radio power source switch.
9. A control apparatus as claimed in any preceding claim, wherein said generator includes a coil and a magnet for generating an electric current, and said generator control means includes a switch mechanism for switching said coil and said magnet between a state capable of relative movement and a state incapable of relative movement.
10. A control apparatus as claimed in any of claims 1 to 8, wherein said generator includes a coil and a magnet for generating an electric current, and said generator control means includes a switch mechanism for selectively inserting a magnetism blocking element between said coil and said magnet.
11. A control apparatus as claimed in any one of claims 1 to 8, wherein said generator includes a coil and a magnet for generating an electric current, and said generator control means includes a switch mechanism for selectively varying a distance between said coil and said magnet. -
12. A control apparatus for controlling a generator in an electric system of a bicycle, substantially as described herein with reference to any one of Figures 1,3 or 6 and to any one of Figures 2,7,8 or 9 or to Figures 4 and 5 of the accompanying drawings.