JP2007045339A - Power-assisted bicycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power-assisted bicycle capable of preventing a damage of a control unit or the like caused by an excessive current running therein, omitting any change of a fuse or the like, and allowing an occupant to easily grasp an abnormal state even when an electric load such as a light is in an abnormal state such as a short-circuit state. <P>SOLUTION: The power-assisted bicycle has an electric motor 8 for generating the auxiliary driving force to be added to the driving force by the man-power, a battery 12 to supply the power to the electric motor 8 and an electric load 4, an ON/OFF circuit 20 to turn ON/OFF the power supply to the electric load 4 from the battery 12, a voltage-dropping circuit 18 for dropping the voltage from the battery 12, a voltage detection unit 19 for detecting the voltage of the voltage-dropping circuit 18 connected to the electric load 4, and a control unit 10 for performing the control to stop the power supply to the electric load 4 by switching the ON/OFF circuit 20 to the OFF-state when the voltage detected by the voltage detection unit 19 is outside the predetermined range, and notifying that the electric load is in an abnormal state to the outside by a warning unit 21. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric bicycle having an electric load such as a light.

  2. Description of the Related Art An electric bicycle configured to be able to travel easily on a hill or the like by adding an auxiliary driving force generated by an electric motor to a human driving force generated by a person's stepping force from a pedal is known. Also in this electric bicycle, a light that illuminates the front and the like in the dark such as at night is provided as in a general bicycle.

  A general bicycle has a structure in which a dynamo (DC generator) roller is brought into contact with a front wheel tire, rim, hub, etc. and rotated to supply power to the light. As a result, the dynamo is also rotated, which increases the pedal load on the person. On the other hand, unlike an ordinary bicycle, an electric bicycle has a battery that is a power source for driving an electric motor. Therefore, by using this battery as a power source for the light, a person can operate when the light is turned on. To prevent the load from increasing.

  Further, in this type of electric bicycle, for example, torque due to a pedaling force of a person acting on a crankshaft via a pedal is detected by a pedaling force detection unit such as a torque sensor, and the above torque is detected by a control unit having a microcomputer or the like. When the motor is large, the auxiliary driving force from the electric motor is controlled so as to correspond to the torque. In addition, as a battery for supplying electric power to the electric motor and the light, generally, a secondary battery that can be charged and used repeatedly is used, and it is determined that the voltage of the battery has decreased to a predetermined voltage, The control unit performs determination of the power supply state and the like.

  By the way, the light may be short-circuited when the bulb breaks. In this case, when the light switch (on / off circuit) for turning on / off the light is directly connected to the light, an excessive current flows in the on / off circuit, the control unit, etc. As a result, these points may be damaged. In order to prevent such a problem, in the conventional electric bicycle, as shown in FIG. 7, as shown in FIG. 7, a fuse 53 is used as a protection circuit for preventing an excessive current from flowing between the light 51 and the on / off circuit 52. When an excessive current flows from the battery 55 made of a secondary battery to the on / off circuit 52, the control unit 54, etc., the energization circuit is interrupted by the fuse 53, and the on / off circuit 52 And the controller 54 and the like are prevented from being damaged. In FIG. 7, 56 is a main power switch for turning on / off the power supply from the battery 55 to the entire electric bicycle, and 57 is a light operation switch for manually turning on / off the on / off circuit 52. The light operation switch 57 that is manually operated is provided with an on / off circuit 52.

  In addition, as an electric bicycle provided with a protection circuit that copes with an excessive current flow, for example, Patent Document 1 and the like include a resistor that prevents an excessive current from flowing into a battery or the like to damage the battery or the like. A technique provided with current limiting means is disclosed.

Further, as schematically shown in FIG. 8, the light 51 is of a type that operates at a voltage lower than the voltage of the battery 55, and a step-down circuit 58 is assembled at the place where the light 51 is provided. Is already known (a technique in which the step-down circuit 58 is provided in the light 51 is disclosed in, for example, Patent Document 2).
JP-A-8-268376 JP 2004-243923 A

  However, according to the conventional electric bicycle as shown in FIG. 7 and FIG. 8, when the light 51 is blown and shorted, the fuse 53 is also blown, so that not only the light 51 but also the fuse 53 must be replaced. In addition, a lot of labor and time are required, and the replacement cost of the fuse 53 is also incurred. In addition, the light 51 is out of sphere when the light 51 is suddenly turned off when traveling at night or the like. It was difficult for the passenger to determine whether the fuse was blown, and it was difficult to grasp the necessity for the replacement work of the fuse 53. Further, when the fuse 53 is also blown, it is not lit only by replacing the light bulb of the light 51, so that the passenger may mistakenly think that the light 51 itself has failed.

  The present invention solves the above-mentioned problem, and even when an electric load such as a light becomes an abnormal state such as a short circuit, it can prevent damage due to excessive current flowing to the control unit and the like, and replace a fuse or the like. It is an object of the present invention to provide an electric bicycle that does not need to be performed and that allows a passenger to easily know an abnormal state of an electric load.

  In order to solve the above problems, an electric bicycle according to the present invention includes an electric motor that generates an auxiliary driving force to be added to the driving force by human power, an electric load such as a light, a battery that supplies power to the electric motor and the electric load, and a battery An on / off circuit for turning on / off the power supply to the electric load, a step-down circuit for lowering the voltage from the battery, a voltage detection circuit for detecting the voltage of the step-down circuit connected to the electric load, and this voltage detection circuit When the detected voltage is outside the predetermined range, the on / off circuit is switched to the OFF state to control power supply to the electric load, and warning means is used to indicate that the electric load is abnormal And a control means for notifying outside.

  In this configuration, when an electric load such as a light is short-circuited, the voltage of the step-down circuit connected to the electric load is reduced, and this voltage drop is detected by the voltage detection circuit. When the voltage goes out of the predetermined range, the on / off circuit is switched to the OFF state by the control means, and the power supply to the electric load is stopped. This prevents an excessive current from flowing even when the electrical load is short-circuited. As a result, it is possible to prevent an excessive current from flowing through the on / off circuit, the control means, and the like, thereby protecting the circuit. Further, since it is not necessary to replace the fuse or the like even when the electrical load is short-circuited, it is possible to save time and effort for replacing the fuse, and there is no cost for replacing the fuse. Moreover, it is not misunderstood that the light itself has failed even though the fuse is blown.

  Furthermore, if the electrical load such as a light is in an abnormal state, the warning means will notify the outside that the electrical load such as the light is in an abnormal state when the on / off circuit is turned on. A passenger or the like can easily know that the electric load is in an abnormal state, and safety is improved.

  Further, the present invention is characterized in that when the main power switch is switched to the ON state, the control means temporarily turns on the power supply from the battery to the electric load and determines the state of the electric load. .

  With this configuration, even when the electrical load is short-circuited when it is not in use, it will detect that the electrical load is abnormal when the main power switch is turned on even if it becomes abnormal. The passenger can be notified. As a result, even if the power supply to the electric load is not manually switched on by the passenger or the like, the abnormal state of the electric load is notified in advance when the passenger switches the main power switch to the ON state.

  As described above, according to the electric bicycle of the present invention, even when an electric load such as a light is short-circuited, the on / off circuit is switched to the OFF state by the control means, and the power supply to the electric load is stopped. It is possible to prevent an excessive current from flowing through the on / off circuit, the control means, the battery, and the like, and it is protected and the reliability is improved. Furthermore, since it is not necessary to use a fuse, it is possible to save time and effort for replacing the fuse, and it is possible to reduce the repair cost without incurring the replacement cost of the fuse. In addition, when an electrical load such as a light is in an abnormal state, if the on / off circuit is turned on, this abnormal state is notified to the outside, so that the electrical load such as a light is in an abnormal state. It is convenient for the passengers to know easily, improving safety.

  Further, when the main power switch is switched to the ON state, the power supply to the electric load is temporarily turned on, and the state of the electric load is determined, for example, a battery in a state where the electric load is not used. When an abnormal condition such as a short circuit occurs, the passenger is notified in advance that the electrical load is abnormal simply by turning on the main power switch of the electric bike. The electric load can be maintained in a good state, which is convenient and further improves safety.

Hereinafter, an electric bicycle according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, an electric bicycle according to the present invention includes a vehicle body 3 with front wheels 1 and rear wheels 2 rotatably attached thereto, and a headlight that lights a light bulb in a dark situation such as when driving at night. As a light (an example of an electric load) 4, a pedal 5 to which a manual driving force (stepping force) is applied is attached via a crank 6, and the crankshaft 7 is rotatably supported and supported Stepping force detector 9 such as an electric motor 8 that generates driving force, a driving sprocket (not shown) for auxiliary driving force output, a torque sensor that detects human driving force generated by the pedaling force of the person from the pedal 5, and various control operations A motor drive unit 11 provided with a control unit 10 that performs power supply, a battery 12 including a secondary battery that supplies power to the motor drive unit 11 and the light 4, and a human-powered drive force and an auxiliary drive. And it includes a driving force transmission mechanism composed of a chain 13 for transmitting a force to the rear wheel 2, and the operation display switch section 15 attached to the handle 14. Then, the control unit 10 of the motor drive unit 11 detects the pedaling force from the pedal 5 by the pedaling force detection unit 9, and outputs an auxiliary driving force from the driving sprocket in accordance with the pedaling force, and the human driving force and the auxiliary driving force. In combination with the rear wheel 2 via the chain 13 so that the rider can easily travel on a slope. In addition, although the control part 10 is comprised by the electric circuit containing a microcomputer, for example, it is not restricted to this.

  As shown in FIG. 2, the operation display switch unit 15 is connected to a main power switch 16 that starts power supply to each unit by the battery 12 and an on / off circuit 20 provided in the control unit 10. There are provided a light operation switch 17 for manually switching on / off, a warning unit 21 for notifying that the light bulb of the light 4 has been burned out, and the like. The light 4 is driven by a voltage lower than the voltage of the battery 12 (for example, 24V), for example, 6V. The controller 10 is connected to the light 4 to lower the voltage of the battery 12. A step-down circuit 18 is connected, and a voltage detector 19 for detecting the output side voltage of the step-down circuit 18 is provided. In this embodiment, the step-down circuit 18 and the voltage detection unit 19 are provided on the control board provided in the motor drive unit 11 together with the control unit 10.

  When the voltage detected by the voltage detection unit 19 is outside the predetermined range, the control unit 10 controls the on / off circuit 20 to be switched to the OFF state to stop the power supply to the light 4. Further, when the voltage detected by the voltage detection unit 19 is outside the predetermined range as described above, it is determined that the light 4 is abnormal and the warning lamp provided in the warning unit 21 is turned on (or An alarm buzzer may be provided to generate an alarm sound).

Specifically, the control unit 10 performs a control operation as shown in the flowchart of FIG.
First, in step S1, it is confirmed whether or not the light operation switch 17 is switched to the ON side. If the light operation switch 17 is in the OFF side, the process proceeds to step S2 and the on / off circuit 20 is turned off. Then, the light 4 is turned off.

  If it is determined in step S1 that the light operation switch 17 is on, the process proceeds to step S3 where the on / off circuit 20 is turned on. In step S4, it is detected whether the write output voltage, that is, the voltage of the step-down circuit 18 is not an abnormal voltage outside a predetermined range, for example, 1 V or less, or 10 V or more. That is, it is determined based on the voltage of the step-down circuit 18 whether the light bulb of the light 4 is out of bulb.

  Here, even if the light bulb provided in the light 4 is in a state where the bulb is out of sphere (a state in which a lighting part such as a filament is cut off), the light 4 is short-circuited with the case where the portion is disconnected. In some cases, it becomes a direct connection state. In the case of a disconnection (open) state, the electric circuit is opened and the resistance in the light 4 becomes infinite, so that the voltage of the step-down circuit 18 increases as shown in a simplified manner in FIG. At the same time, since it is in a disconnected state, no current flows as shown in FIG. On the other hand, when the inside of the light bulb of the light 4 is short-circuited and directly connected, the resistance at the light bulb portion is close to 0 as shown in FIG. Is lower than the lower limit voltage (for example, 1 V) of the predetermined range. For this reason, when the light output voltage, that is, the voltage of the step-down circuit 18 is an abnormal voltage outside a predetermined range, for example, 1 V or less, or 10 V or more, it is determined that the light bulb of the light 4 has been burned out. To do. However, although the light bulb of the light 4 is not cut off, the voltage may temporarily fluctuate due to the influence of external noise or the like, and the voltage of the step-down circuit 18 may be outside the predetermined range. In S6, the time during which the voltage continues outside the predetermined range is counted, and if the voltage continues for a predetermined time or longer (for example, 1 second), the light bulb of the light 4 is not affected by noise or the like. It is determined that the voltage of the step-down circuit 18 is out of the predetermined range due to disconnection or the like.

  In this case, as described above, when the light bulb of the light 4 is cut off and becomes a disconnected state, the current to the light 4 does not flow as shown in FIG. On the other hand, when the light bulb of the light 4 is turned off and short-circuited to be in a direct connection state, the resistance in the light 4 is in a state close to 0. Therefore, in the state as it is, FIG. As shown by the phantom line X, an excessive current flows between the battery 12 and the light 4, and in that case, the on / off circuit 20, the control unit 10, the battery 12, and the like may be damaged. .

  However, in the present invention, when the voltage of the step-down circuit 18 is outside the predetermined range, it is determined that the light 4 is abnormal, and the process proceeds to step S7, where the on / off circuit 20 is turned off. Therefore, even when the light bulb in the light 4 is short-circuited and becomes a direct connection state, when the resistance in the light 4 becomes close to 0 and the voltage of the step-down circuit 18 becomes lower than 1V (lower limit) When the voltage becomes lower than the voltage, the on / off circuit 20 is controlled to be in the OFF state. Therefore, as shown in a simplified manner in FIG. 5B, an excessive current is prevented from flowing through the on / off circuit 20 and the control unit 10.

  When the light bulb of the light 4 is out of bulb, as shown in FIG. 4A, the resistance in the light 4 becomes infinite and the voltage of the step-down circuit 18 rises. When the voltage detection unit 19 detects that the voltage is higher than the upper limit voltage (for example, 10 V) within a predetermined range, the on / off circuit 20 is controlled to be in the OFF state. Therefore, as shown in a simplified manner in FIG. 4B, an excessive current is prevented from flowing through the on / off circuit 20 and the control unit 10.

  As a result, an excessive current is prevented from flowing through the on / off circuit 20, the control unit 10, the battery 12, etc., and these components are also prevented from being damaged, and good reliability is maintained. Furthermore, since the fuses that have been provided conventionally are not used, it is possible to save time and labor for replacing the fuses, and there is no cost for replacing the fuses, so that the repair cost can be reduced.

  In Steps S4 to S7, if the voltage of the step-down circuit 18 is outside the predetermined range, the process proceeds from Step S7 to Step S8, where the warning lamp of the warning unit 21 is turned on (or an alarm sound is generated by the alarm buzzer). To inform the passenger that the light 4 is abnormal. The passenger can easily and quickly know the abnormality of the light 4 by looking at the lit warning portion 21.

  After that, when it is confirmed in step S4 that the voltage of the step-down circuit 18 is within a predetermined range, including after replacement with the normal light 4, the counted time is reset (step S4). S9), ready for the next time count.

  In addition to the above configuration, when the control operation of the control unit 10 detects that the main power switch 16 has been switched from the OFF state to the ON state at the start of the electric bicycle, as shown in FIG. In (Step S11), the power supply from the battery 12 to the light 4 is temporarily turned on (Step S12), and the same operations as in Steps S4 to S9 described above are performed (detected by the voltage detection unit 19). Whether or not the voltage of the step-down circuit 18 is outside the predetermined range. If the voltage is outside the predetermined range, the on / off circuit 17 is turned off and the warning lamp of the warning unit 21 is turned on). The state of the light 4 may be determined in advance.

  According to this configuration, even when the light 4 is not used and the light bulb is short-circuited due to vibration during driving or the like, the main power switch 16 is turned on in order to use the electric bicycle next time. At the time of switching to the ON state, it is possible to immediately detect that the light 4 is defective and notify the passenger in advance. According to this, before the light operation switch 17 is switched to the on state by a passenger or the like, the defective state of the light 4 is notified in advance. Therefore, since the light bulb of the light 4 can be replaced in advance at the place when the electric bicycle departs, maintenance can be performed in a good state, convenience is improved, and safety is further improved.

  In the above embodiment, the case where the electric load for detecting the abnormal (defective) state is the light 4 as the headlamp. However, the electric load is not limited to this, and the rear lamp is used. It can also be applied to the light. The light 4 can also be applied to LEDs other than light bulbs such as filament lamps and halogen lamps. Furthermore, as another application example of an electric load, for example, in a cold season such as winter, a heater for heating a handle grip or the like is provided as an electric load, and a defective state (for example, a part is disconnected) In other words, the ON / OFF circuit 17 provided in a part of the energization circuit may be controlled to be in an OFF state based on a voltage change with respect to the heater.

  Moreover, although the case where the warning lamp was used as the warning part 21 was described in the said embodiment, what emits a sound, such as a buzzer, may be used instead, or these may be combined.

  The present invention is particularly suitable for an electric bicycle having an electric load such as a light. However, the present invention is not limited to this, and can also be applied to various moving bodies that move while using a secondary battery.

Overall side view of an electric bicycle according to an embodiment of the present invention Simplified block diagram of the electric bicycle Flow chart showing the control operation of the control unit of the electric bicycle (A) And (b) is a figure which shows the change condition of a voltage and an electric current when the light bulb of the light of the same electric bicycle produces a broken piece and is in a disconnected state (A) And (b) is a figure which shows the change condition of a voltage and an electric current when the light bulb of the light of the same electric bicycle produces a short circuit and is in a short state The flowchart which shows the control action of the control part in the electric bicycle which concerns on other embodiment of this invention. Simplified block diagram of a conventional electric bicycle Simplified block diagram of other conventional electric bicycles

Explanation of symbols

4 Light (electric load)
8 Electric Motor 9 Treading Force Detection Unit 10 Control Unit 12 Battery (Secondary Battery)
16 Main power switch 17 Light operation switch 18 Step-down circuit 19 Voltage detection unit 20 On / off circuit 21 Warning unit

Claims (3)

An electric motor that generates an auxiliary driving force to be added to the driving force by human power, an electric load, a battery that supplies power to the electric motor and the electric load, and an on / off circuit that turns ON / OFF power supply from the battery to the electric load; A step-down circuit that lowers the voltage from the battery, a voltage detection circuit that detects the voltage of the step-down circuit connected to the electric load, and the on / off state when the voltage detected by the voltage detection circuit is outside a predetermined range An electric bicycle including a control unit that switches the circuit to an OFF state to stop power feeding to the electric load and notifies the outside using a warning unit that the electric load is abnormal. 2. The electric bicycle according to claim 1, wherein when the main power switch of the electric bicycle is switched to the ON state, the control means temporarily turns on the power supply from the battery to the electric load to determine the state of the electric load. The electric bicycle according to claim 1 or 2, wherein the electric load is a light.

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