JP3369747B2 - Electric bicycle - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor having both a human-powered driving unit and an electric-powered driving unit. The present invention relates to an electric bicycle that is driven and assists human driving force with the driving force of an electric motor. 2. Description of the Related Art Conventionally, such an electric bicycle is provided with a drive system using human power and a drive system using an electric motor in parallel as disclosed in Japanese Patent Application Laid-Open No. 4-35887 (B62M23 / 02). 2. Description of the Related Art There is known a device in which a driving force of a driving system by human power is detected to control an output of an electric motor. In this electric bicycle, a cylindrical shaft is fitted on the crankshaft of the pedal in order to detect the driving force of the driving system by human power, that is, the rotational torque of the pedal. Through a one-way clutch to a planetary gear mechanism, and further to a rear wheel by a drive shaft meshed with the planetary gear mechanism. One end of a torque detection lever is interposed in the planetary gear mechanism, and the other end is in contact with a second lever connected to a potentiometer. The second detection lever is returned by a return spring, and the second lever is rotated by an angle corresponding to the pedaling force of the pedal via the torque detection lever, and the amount of rotation is measured by a potentiometer, whereby the crankshaft is rotated. The torque applied to the motor is detected. [0004] Further, a rotational driving force from an electric motor is also transmitted to the cylindrical shaft via a one-way clutch and a planetary gear mechanism, and the driving force of the electric motor is changed according to the detected torque. Increase and reduce the burden of human power. [0005] However, in the conventional electric bicycle, since the torque applied to the crankshaft is detected, a loss of the power until the driving force is transmitted to the rear wheels is considered. However, there is a problem that the driving control is performed to be lower than the required rotational driving force of the electric motor, and the effect of assisting human power is low. Further, the torque is determined by the torque detection lever and the second
Since the detection is performed by the potentiometer via the lever, there is a possibility that a detection error may occur due to vibration. The present invention has been made in view of the above circumstances, and has as its object to provide a coil disposed around an axle of a wheel and a magnetic field whose area covering the coil changes according to torque generated in the wheel. By having a member and
It is an object of the present invention to provide an electric bicycle that accurately detects human torque with a simple configuration and drives an electric motor accurately in accordance with the detected torque. [0007] An electric bicycle according to a first aspect of the present invention includes a human-powered driving unit that rotates wheels by the pedaling force of a pedal, and an electric driving unit that rotates the wheels by driving an electric motor. In an electric bicycle that detects a torque generated in a wheel by the treading force and controls the rotational drive of the electric drive unit based on the detected torque, a coil provided around an axle of the wheel includes a coil that expands and contracts according to the torque. An elastic body, a rotating plate that rotates with the expansion and contraction of the elastic body, a magnetic member whose area covering the coil changes due to the rotation of the rotating plate, and the torque detected by a change in voltage of the coil. The magnetic member is supported by a pin extending from a casing fixed to the wheel, and is pivoted by a pin extending from the rotating plate. It is characterized by a sea urchin. In the electric bicycle of the present invention, when the user steps on the pedal, the pedaling force is applied from the pedal to the casing fixed to the wheel via the rotating plate and the elastic body, and to the wheel. introduce. At the time of starting, when the user depresses the pedal, the rotating plate attempts to rotate, but the wheels are likely to remain stationary, and torque is generated. The moving plate also rotates greatly. When the vehicle runs by inertia, the elastic body hardly contracts, and the rotating plate hardly rotates. When the vehicle is accelerated, the elastic body contracts by depressing the pedal, as in the case of starting, and the rotating plate rotates accordingly. Thus, the rotating plate rotates according to the magnitude of the manual torque. On the other hand, a coil is provided around the axle of the wheel, and a magnetic member is disposed near the coil. The magnetic member is pivotally supported by a pin extending from a casing fixed to the wheel, and is pivoted by a pin extending from the rotating plate. The movement changes the area that covers the coil. When the area of the magnetic member covering the coil increases, the inductance of the coil increases. In the opposite case, the inductance of the coil decreases. Then, the torque detector detects the torque based on the change in the voltage. Embodiments of the present invention will be described below with reference to the drawings. FIG. 7 is an overall perspective view of an electric bicycle according to the present invention, in which 1 is an electric bicycle main body. The electric bicycle body 1 is provided with an electric motor 8 to be described later, and the driving force of the electric motor 8 is changed according to the magnitude of the torque by human power so that the human power is assisted by the power of the electric motor 8 to travel. Has become. A front wheel 2, a rear wheel 3, a handlebar 13 and a saddle 21 are mounted on a frame 4 of the electric bicycle body 1.
The front wheel 2 is steered by a steering wheel 13. A disk-shaped casing 5 is provided on the rotation shaft of the rear wheel 3. The disc-shaped casing 5 includes a rotating casing 6 and a fixed casing 7 fixed to the electric bicycle main body 1, and the rotating casing 6 rotates integrally with the rear wheel 3. In addition, the disk-shaped casing 5
Has a built-in electric motor 8, which is driven when electric driving is required, and rotates the rotating casing 6 together with a human-powered driving unit 10 described later. The driving portion including the disc-shaped casing 5 is the electric driving unit 9. The human-powered drive unit 10 includes a pedal 11 and a chain 12, and when the user steps on the pedal 11, the chain
The rear wheel 3 is rotated via 12. In this embodiment, the chain 12 is a transmission member of human power. However, the present invention is not limited to this, and a chain, a rotating shaft, or the like may be used instead of the chain 12. Brake levers 14 and 15 are attached to both left and right ends of a steering wheel 13 for steering the front wheel 2, and brake devices 18 and 19 are provided for the front wheel 2 and the rear wheel 3, respectively. The brake devices 18 and 18 are connected by wires 16 and 17. The wires 16, 17 are pulled by pulling the brake levers 14, 15, and the wires 16, 17 are pulled.
17 allows the front and rear brake devices 18 and 19 to operate, respectively. A brake switch 20 is provided in the middle of the wires 16 and 17, and the mechanism is such that when the brake levers 14 and 15 are operated, the power supply to the electric motor 8 is stopped. A battery section 22 serving as a power supply for the electric motor 8 is mounted on the frame 4 on the rear wheel 3. This battery part 22
Is composed of a battery case 23 slidably attached to the frame 4 and a single rechargeable battery housed in the battery case 23. The power supply voltage is approximately 24
It is a bolt. Next, the disc-shaped casing 5 will be described with reference to FIG. FIG. 8 is a front view showing the structure of the board-like casing 5 shown in FIG. 7, and 7 in the figure is a stationary casing fixed to the electric bicycle main body. Fixed side casing 7
The control unit 24 includes a control board 24, a radiator plate 25, etc., an electric motor 8, a first pulley 27, a second pulley 28, and a final pulley 29.
Speed reduction mechanism 30 composed of two pulleys, a transmission belt connecting between each pulley of the speed reduction mechanism 30 and connecting the speed reduction mechanism 30 and the electric motor 8
31 are arranged. The last-stage pulley 29 is fixed to the rotating casing 6, and when the electric motor 8 rotates, the first pulley to the last-stage pulleys 27 to 29 transfer the transmission belt 31.
As a result, the rotation side casing 6 rotates together with the final-stage pulley 29 and is decelerated. In addition, a one-way clutch (not shown) is interposed in the smaller pulley of the second pulley 28 connected to the final-stage pulley 29, and the motor 8 is turned when a force from the pedal is applied. There is no, that is, the pedal is light. A pressing member is provided between the first pulley 27 and the second pulley 28 for adjusting the tension of a belt 31 connecting the two.
32, the rotating head of the pressing member 32 is a belt 31
Belt 31 by rolling inside and pushing it out
Has been expanded. An elongated hole is formed in a portion where the rotary shaft of the first pulley 27 is mounted, and an adjusting screw 33 is screwed into the elongated hole. The first pulley 27 is moved in the direction in which the transmission belt 31 is stretched, and is fixed by the adjustment screw 33 in that state. A chain sprocket 37 for transmitting the driving force from the chain to the rotating casing via a freewheel 38 is mounted on the rear wheel axle 39.
When the chain rotates in the reverse direction, the driving force from the chain is not transmitted to the rotating casing by the freewheel 38. Next, the structure of the last stage pulley 29 will be described in detail with reference to FIGS. FIG. 1 is a side sectional view showing the structure of the final stage pulley, and FIG. 2 is a front view thereof. Attached to the axle 39 of the final stage pulley 29 are springs 40, 40, which are elastic bodies, provided symmetrically to the axle 39 so as to be substantially tangential to the axle 39. One side of the springs 40, 40 is fixed to the final stage pulley 29, and the other side is openable and contractible. The spring 40 is covered by a cover 48 attached to the final stage pulley 29. Thereby, when a pedaling force is applied to the rear wheel, the force is easily received by a pressing member 43 described later. A pressure receiving member 41 having a convex shape in side view is in contact with the open side of the spring 40. The pressure receiving member 41 has a portion smaller than the diameter of the spring 40 and a larger portion, and the smaller portion is
The spring 40 is attached so that it goes into the inside 40 and a large part covers the spring 40. The pressure receiving member 41 is made of a slippery material such as iron or ceramics. The chain sprocket is provided around the axle 39.
A turning plate 42 that turns by the rotation of the 37 is provided. The turning plate 42 is provided with a pressing member 43 that presses the pressure receiving member 41 symmetrically with the axle 39 by the rotation of the chain sprocket 37. The pressing member 43 is also formed of a slippery material such as iron or ceramics as before. Further, a rubber plate 47 for preventing the pressing member 43 pressed by the bias of the spring 40 from being impacted is attached to a portion of the final stage pulley 29 opposite to the back surface of the surface of the pressing member 43 that contacts the pressure receiving member 41. It is. The turning plate 42 is inserted concentrically inside the final stage pulley 29, and when a torque is applied, the pressing member 42
43 rotates together with the final stage pulley 29 by pressing the spring 40. When the pressing member 43 presses the pressure receiving member 41, the pressing position is slightly shifted, so that a portion that contacts the pressure receiving member 41 has a curved surface. On the other hand, when the torque is lost, the rotating plate 42 returns to the original position due to the extension of the spring 40. The axle 39 has an annular bobbin of the torque detecting section 50.
51 is fitted outside. The bobbin 51 has a U-shaped cut surface, and is mounted on the fixed casing 7 with its opening facing the rotating casing 6. A coil 52 is wound around the bobbin 51. On the rotating casing 6 side, three substantially blue dragon-shaped movable pieces 55 are arranged at equal intervals in the circumferential direction so as to cover the coil 52 so as to face the coil 52. The movable piece 55 is formed of a magnetic material such as iron or ferrite.
The movable piece 55 is supported by a first pin 53 extending from the rotation plate 42 and a second pin 54 extending from the rotating casing 6, and is rotatable around the second pin 54. ing. FIGS. 3 and 4 are front views of the torque detector. FIG. 3 shows a state where no torque is applied.
Indicates the state in which the tokule has been added. First
The pins 53, 53, 53 and the second pins 54, 54, 54 are equally spaced around the bobbin 51. Movable pieces 55, 5 in the shape of a roughly blue dragon sword
In the vicinity of the base end of 5, 55, long holes 56, 56, 56 are respectively opened so as to be in a substantially tangential direction, and the long holes 56, 56, 56
First pins 53, 53, 53 are slidably fitted in the 56.
Further, the second pins 54, 54, 54 penetrate slightly on the distal end side from the long holes 56, 56, 56 of the movable pieces 55, 55, 55. The movable pieces 55, 55, 55 are pivotally supported by the second pins 54, 54, 54 such that the tip ends thereof are in a direction opposite to the direction of rotation of the rotating plate. Further, the width of the movable piece 55, 55, 55 on the tip side is substantially the same as the width of the bobbin 51. In such movable pieces 55, 55, 55,
When no torque is applied, as shown in FIG.
53, 53, 53 are at the ends of the long holes 56, 56, 56 on the second pin 54, 54, 54 side, and the tip of the movable pieces 55, 55, 55 is a coil.
52 is covered. At this time, the angle formed by the first pin 53 and the second pin 54 about the center point O of the bobbin 51 is θ
The area of the movable pieces 55, 55, 55 covering the coil 52 is the maximum. Therefore, the inductance of the coil 52 is large. On the other hand, when the torque is applied, as shown in FIG. 4, the first pins 53, 53, 53 are rotated with the rotation of the rotary plate, and the other side of the slots 56, 56, 56 is rotated. And the angle between the first pin 53 and the second pin 54 becomes θb (θa <θb). The distal ends of the movable pieces 55, 55, 55 are second pins 54, 54, 54.
, The area of the movable pieces 55, 55, 55 covering the coil 52 decreases in accordance with the torque. Therefore, the inductance of the coil 52 decreases. Next, the circuit of the torque detector will be described with reference to FIG. FIG. 5 is a circuit diagram of the detecting section according to the present invention. A pulse waveform described later is applied to the coil 51 from a microcomputer (hereinafter referred to as a microcomputer) provided in the control unit 26 (see FIG. 8).
The coil 51 outputs a pulse having a height corresponding to the area of the movable piece 55 covering the coil 51. The pulse output from the coil 51 is converted into a signal averaged by the DC conversion converter 60 and is provided to the amplifier 61, where it is amplified and input to the microcomputer. FIG. 6 is a waveform diagram at each point in the circuit shown in FIG. 5, where (A) is a point A on the input side of the coil and (B)
Shows the point B on the output side of the coil, and (C) shows the waveform of the pulse at the point C on the output side of the DC conversion converter (both refer to FIG. 5). A rectangular pulse voltage is applied to the coil as shown in FIG. When the movable piece covers such a coil, the inductance of the coil is large.
The pulse of the resistor whose voltage fluctuates by the coil is shown in FIG.
As shown in (B), the pulse height becomes a sawtooth wave (broken line) lower than the sawtooth wave shown by the solid line. On the other hand, when the area of the movable piece that covers the coil is reduced by applying a torque, the inductance of the coil is correspondingly reduced, and the pulse of the resistor whose voltage fluctuates by the coil is indicated by a broken line in FIG. From the displayed waveform to the waveform shown by the solid line. When the pulse heights are averaged by the DC converter, as shown in FIG. 6C, the level of the signal indicated by the broken line corresponds to the reduction in the area of the wave piece covering the coil. A higher level signal (solid line) is obtained. As described above, since the torque is detected based on the change in the voltage applied to the coil, the change in the torque is directly converted into an electric signal, and the torque can be detected with a simple configuration and with high accuracy. In this embodiment, the area of the movable piece that covers the coil is reduced according to the torque. However, the present invention is not limited to this, and the area that covers the coil according to the torque increases. Needless to say, this may be done. As described above in detail, in the electric bicycle according to the present invention, the coil disposed around the axle and the magnetic member whose area covering the coil changes according to the torque generated on the wheels. Since the torque is detected by the change in the inductance of the coil, the torque can be detected with a simple configuration and with high accuracy. Further, the torque can be detected in consideration of all weights applied to the wheels, and human power can be assisted by appropriate control. The magnetic member is supported by a pin extending from a casing fixed to the wheel, and is pivoted by a pin extending from the rotating plate. The present invention has an excellent effect that detection is prevented and a failure hardly occurs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view showing a configuration of a final stage pulley. FIG. 2 is a front view showing a configuration of a final stage pulley. FIG. 3 is a front view of a torque detector. FIG. 4 is a front view of a torque detector. FIG. 5 is a circuit diagram of a torque detector according to the present invention. FIG. 6 is a waveform chart at each point in the circuit shown in FIG. 4; FIG. 7 is an overall perspective view of the electric bicycle according to the present invention. FIG. 8 is a front view showing the configuration of the board-like casing shown in FIG. [Description of Signs] 6 Rotation side casing 7 Fixed side casing 29 Final stage pulley 39 Axle 40 Spring (elastic body) 50 Torque detection unit 51 Bobbin 52 Coil 53 First pin 54 Second pin 55 Movable piece 56 Slot

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-156361 (JP, A) JP-A-60-38631 (JP, A) JP-A-5-203509 (JP, A) JP-A-3-203 223635 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B62M 23/02 B60L 15/20 B60L 15/28 H02P 7/00 G01L 3/14

Claims (1)

(57) [Claim 1] A human-powered driving unit that rotates a wheel by a pedaling force of a pedal, and an electric driving unit that rotates the wheel by a driving of an electric motor, and is generated on the wheel by the pedaling force. An electric bicycle that detects torque and controls rotation of the electric drive unit based on the detected torque. A coil provided around an axle of the wheel, an elastic body that expands and contracts according to the torque, A rotating plate that rotates with expansion and contraction of the body, a magnetic member whose area covering the coil changes by the rotation of the rotating plate, and a torque detector that detects the torque by a change in voltage of the coil. , Said
The magnetic member extends from the casing fixed to the wheel
Pin supported by a pin,
Therefore, it is characterized by being pivoted.
Dynamic bicycle.