JP3306302B2 - Electric car - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle which travels with human power and electric power.

[0002]

2. Description of the Related Art Conventionally, it is generally known that an electric vehicle of this type travels by rotating wheels by human driving power and electric driving force and using either driving force or both driving forces. However, if a heavy load is applied for a long time, for example, a steep climb, the temperature of a motor serving as a driving source of the electric driving force increases, and the motor may be burned out. To prevent this, a temperature sensor that detects the motor temperature is provided near the motor, and when the motor temperature exceeds a predetermined value, the power supply to the motor is stopped to prevent the motor from burning, and the power supply is continued until the temperature falls. In the meantime, the vehicle was driven only by human power.

However, in the electric vehicle having the above structure, the electric driving force is lost when the motor temperature is high. Therefore, when the vehicle is running only with the electric driving force, the driving force is lost. When the vehicle is running, the driving force is only human power, so the driving force is suddenly lost, and there is a danger of wobbling and falling, which is very dangerous.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a safe electric vehicle in which the vehicle is prevented from wobbling and falling.

[0005]

SUMMARY OF THE INVENTION The present invention comprises a manual driving force for rotating wheels by human power and an electric driving force for rotating wheels by driving a motor according to a driving signal from a control circuit. Provide a temperature sensor to detect the temperature,
The control circuit inputs a signal from the temperature sensor,
It is characterized in that control for reducing the output of the electric driving force is performed according to the temperature rise of the motor. When the motor temperature becomes equal to or higher than a first predetermined value, the driving force of the motor is reduced.

Further, the control circuit is characterized in that a plurality of predetermined values are provided for the motor temperature, and the magnitude of the electric driving force is changed according to each predetermined value.

The control circuit provides a second predetermined value smaller than the first predetermined value for the motor temperature, and when the motor temperature decreases from the first predetermined value to the second predetermined value, the control circuit determines the driving force of the motor. It is characterized by returning to.

Further, the control for reducing the electric driving force is performed by limiting a maximum value of a PWM duty.

When the vehicle is running with the electric driving force together with the electric driving force or only with the electric driving force, when the motor temperature rises, the driving force of the motor is lowered and output, thereby suppressing the rise in the motor temperature and sharply increasing the motor temperature. So that the electric driving force is not lost. Further, a first predetermined value is set for the motor temperature, and when the motor temperature reaches the first predetermined value, the driving force of the motor is reduced and output to, for example, 70%, 50%, etc., and the rise of the motor temperature is suppressed. At the same time, make sure that the electric driving force does not suddenly disappear.

A plurality of predetermined values are provided for the motor temperature. When the predetermined value is small, that is, when the temperature is low, for example, the electric driving force of 100% is reduced to 80%, and the predetermined value of the next largest value is set. Value, that is, when the temperature slightly increases, the electric driving force is reduced to 70%, and when the temperature is further increased, the electric driving force is reduced to 60%.
%. As described above, as the motor temperature increases, control is performed to decrease the electric driving force, so that the motor temperature is prevented from rising and the electric driving force is controlled so as not to be suddenly lost.

Then, a first predetermined value for stopping the electric driving force and a second predetermined value for operating the electric driving force again are provided, and these predetermined values are provided with hysteresis so that the electric driving is performed at the predetermined value. There is no frequent change of force.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS.

First, the overall structure of the electric bicycle will be described with reference to FIG.

1 is a head pipe 2 provided at a front part,
The main frame 1 is connected to a seat tube 4 provided below the saddle 3. The main frame 1 is provided with a pedal 5 that can be rotated by human power at a portion connected to the seat tube 4.

Reference numeral 6 denotes a front wheel which is linked to the movement of the steering wheel 7 and determines the running direction by operating the steering wheel 7. The front wheel 6 comprises a spoke 8, a rim 9, and a tire 10.

Reference numeral 11 denotes a rear wheel serving as a driving wheel.
The vehicle also includes a tire 12, a rim 13, spokes 14, and a drive unit 15 for driving the rear wheel 11.

Reference numeral 16 denotes a front sprocket which rotates with the rotation of the pedal 5. The front sprocket 16 includes a chain.
17 is engaged and the rotation of the front sprocket 16 is
After being provided on 15 axles, power is transmitted to the sprocket 50.

Reference numeral 18 denotes a battery serving as a power supply for a motor 24 described later, which contains a 24-volt NiCd battery.
The battery 18 is removable and can be charged indoors when charging.

Reference numeral 19 denotes a front basket, and reference numeral 20 denotes a stand for supporting a bicycle when the vehicle is stopped.

Reference numeral 21 denotes a headlight.

FIGS. 4 and 5 show the driving section 15 described above.
Shows a specific configuration.

Reference numeral 22 denotes a disk-shaped fixed casing fixedly attached to the main frame 1, and reference numeral 23 denotes a rotating casing that is coaxial with the fixed casing 22 and rotates outside the fixed casing 22. The fixed casing 22 and the rotating casing 23 together form a hub. The fixed casing 22 is made of a light alloy having a thickness of 2 mm.

Reference numeral 24 denotes a U-shaped annular rib provided on the outer periphery of the rotating casing 23. The annular rib 24 is fixed to the rotating casing 23 at a plurality of positions.
Spokes 14 are extended from 24 toward the rim 13 to which the tire 12 is attached. In addition, the annular rib 24
It is formed of a steel plate and has a thickness of 2.3 mm. The annular rib 24 is formed as a separate component from the rotating casing 23, and a force from the spokes 14 is applied to the annular rib 24, which is required to have a high strength. 23 is made of a material weaker than the annular rib 24 and is made thinner, and the material and the material thickness are changed. With this configuration, the driving unit
15 The overall weight can be reduced, and the cost can be reduced by changing the material.

Reference numeral 25 denotes a motor serving as a driving source, 26 denotes a rotor, and 27 denotes a stator. The motor 25 is mounted on the fixed casing 22, a portion of the motor 25 projecting from the rotating casing 23 is covered with a motor cover 28, and an output shaft 29 of the motor 25 is supported by bearings 30. ing.

Reference numeral 31 denotes a planetary roller reduction mechanism which is screwed to the fixed casing 22 and fitted to the holding portion 32. The planetary roller reduction mechanism 31 is arranged around the same axis as the output shaft 29. .

The structure of the planetary roller speed reduction mechanism 31 will be described.

Reference numeral 33 denotes a fixed wheel fixed to the holding portion 32 with screws. Four planetary rollers 34 are provided on the inner circle of the fixed wheel 33, and the outer circumference of the planetary roller 34 is It is arranged so as to be in contact with the inner periphery of the fixed wheel 33 and to be in contact with the output shaft 29 of the motor 25 inside. An output pin 35 is provided at the center of the planetary roller 34.
A needle bearing is provided between the needle bearing and the needle bearing.

When the output shaft 29 of the motor 25 rotates, the contacting planetary roller 34 starts rotating around the output pin 35 and contacts the fixed wheel 33. Start revolving around. This output pin 35
By taking out the rotating output from the motor 25, the output of the motor 25 can be taken out at a reduced speed.

Numeral 37 denotes a cylindrical support which has a bottom surface pivotally supported by the output pin 35 and penetrates the output shaft 29. The support 37 is provided between the output shaft 29 and the output shaft 29 via a bearing 38. Further, a distal end side is provided via a bearing 39.

Numeral 40 denotes a one-way clutch mounted on the outer periphery of the support member 37. The one-way clutch 40 prevents the force from the pedal 5 from being transmitted to the motor 25, and transmits the driving force of the motor 25 to the rotating casing. Acts to tell 23.

Reference numeral 41 denotes a first pulley mounted coaxially with the output shaft 29 via two bearings on the output shaft 29 and further via the one-way clutch 40. The first pulley 41 is made of rubber. Belt 42 is hung.

Reference numeral 43 denotes a second pulley on which the other end of the belt 42 is hung. The second pulley 43 is fixed to the rotating casing 23 by bolts 44. The inside of the second pulley 43 is hollow, and a torque detecting unit 57 described later is provided therein.

Reference numeral 45 denotes a tension pulley for adjusting the tension of the belt 42. The tension pulley 45 has a roller 47 attached to one end of a support 46, and a tension pulley 45 attached to the fixed casing 22 at the other end. A screw 48 is provided, the support 46 can swing around the part where the screw 48 is attached, the tension pulley 45 is fixed by tightening the other screw 49, and the belt 42 is pressed,
The tension of the belt 42 can be adjusted.

Reference numeral 50 denotes a control board incorporated in the fixed casing 23. The control board 50 is incorporated in a portion having no pulley. In addition to the microcomputer that controls the rotation of the motor 25 in accordance with the output result from the torque detection unit 57 described later, the control board 50 includes a driving circuit that performs PWM control of the motor 25 and a constant voltage for inputting a starting voltage to the microcomputer. It is equipped with a circuit and a torque detection circuit.

Reference numeral 51 denotes a rear sprocket on which the chain 17 is hung. The rear sprocket 51 is provided on an axle 52 via a bearing 53, and a one-way clutch 54 is provided.
It is attached to a rotating plate 58 to be described later.

Reference numeral 55 denotes a rotating cylinder provided on the axle 52 via a bearing 56. The rotating cylinder 55 is
It rotates with the rotation of.

Numeral 57 denotes a torque detector mounted near the second pulley 43 and the axle 52. The torque detector 57 detects a human-powered driving force transmitted through the chain 17, that is, a human-power torque. It is provided in.

The reference numeral 69 is attached near the motor 25,
A temperature sensor for detecting the temperature of the motor 25;
Uses a thermistor, a posistor, or the like.

First, the torque detector 57 will be described with reference to FIG.
An explanation will be given based on. FIG. 6 is a schematic diagram of the torque detector 57, and each will be described.

The turning plate 58 is concentric with the axle 52, and a pressing rod 59 and a conversion rod 60 are integrally formed in two opposing positions in the axial direction. The pressing rod 59 is formed in a column shape with a bell-shaped surface, and an elastic body, that is, a spring 61 is pressed by a curved portion of the bell shape. And the rotating plate
58 expands and contracts the spring 61, and the other end of the spring 61 is connected to the second pulley.
The second pulley 43 rotates while pressing the inner wall of 43. The conversion rod 60 is a rectangular body extending in the direction of the axle 29, and is formed diagonally so that the tip portion becomes shorter in the rotation direction.

A spring 61 pressed by the pressing rod 59
Has the other end in contact with a part of the rotation side casing 23, and the pressing rod is
59, the spring 61 is expanded and contracted to rotate the rotating casing 23. At this time, the rotating plate 58 rotates while slightly distorting the rotating casing 23 in accordance with the expansion and contraction of the expanded and contracted spring 61. Then, the turning plate 58 turns in response to the distortion caused by human power. At this time, the conversion rod 60 also rotates by a slight rotation of the rotation plate 58 at the same time, and the angled portion 63 that comes into contact with the inclined portion 62 by the inclined portion 62 formed at the tip of the conversion rod 60.
Is pushed to move in the axle 29 direction. A magnetic member, that is, a ferrite ring 64 is attached to the chevron 63, and the ring 64 moves as the chevron 63 moves. At the end of this ring 64 is a ring 64
A C-ring 65 and a spring 66 are provided for biasing toward the 58 side. Therefore, the ring 64 moves in the direction of the axle 29 by the amount of distortion of the rotating casing 23 and the rotating plate 36.

Numeral 67 denotes a magnetic detecting member, that is, a coil provided in the fixed casing 22 near the ring 64. The coil 67 converts a change in inductance due to the approach of the ring 64 into an electric signal. This output can be used to detect human-powered torque.

The members shown in FIG. 6 are collectively referred to as a torque detector 57. Here, the conversion rod 60, the chevron 63, the ring 64, and the coil 67 are referred to as a detection unit, and the degree of expansion and contraction of the elastic body can be detected by these. Also, conversion rod 6
0 and the chevron 63 together form a conversion member 68, which converts the expansion and contraction of the elastic body 61 in the rotational direction into movement in the axle 29 direction.

In the above configuration, ferrite is used for the ring 64, but the ring may be made of a conductive material such as aluminum. Further, although the elastic member is the spring 61, the elastic member may be rubber or the like, and the detecting portion may be configured using a scale capable of detecting expansion and contraction of the rubber. Further, the elastic body may be used as pressure-sensitive rubber, and the expanding / contracting pressure may be taken out as an electric signal.

Next, a power system diagram having the above configuration will be described with reference to FIG.

First, a manual drive system will be described. The manual power provided by the pedal 5 is transmitted to the rear sprocket 51 by the chain 17 and rotates the rear wheel 11 via the turning plate 58 and the spring 61. Next, the electric drive system will be described.The extent of expansion and contraction of the spring 61, that is, the rotational movement distance of the rotating plate 58 is converted into movement in the direction of the axle 29 by the conversion member 68,
The ring 64 moves along with the movement. The movement of the ring 64 is converted into a change in the inductance of the coil 67 and is input to the control board 50 as an electric signal. Control board
50 is incorporated in the fixed side casing 22. Then, a signal from the coil 67 and a signal from the temperature sensor 69 are input to the control board 50, and a drive signal is output so that the motor 25 rotates based on the signal. Then, the output of the motor 25 is reduced by the planetary roller reduction mechanism 31, and the rear wheel 11 rotates via the first pulley 41.

Next, the control circuit will be described with reference to FIG.

FIG. 1 shows a first embodiment of the present invention.
In the present embodiment, the motor is driven in accordance with the manual torque. However, the motor may be driven by applying the manual driving force and the electric driving force independently.

Reference numeral 70 denotes a control circuit for performing PWM control of the motor 25 by the drive switching element 71.
70 is driven with an output corresponding to the torque detected by the torque detecting section 57. For example, the motor driving force is set to be one-to-one with respect to the manual driving force. At this time, the control circuit 70
, A signal from the temperature sensor 69 is always input, and when the temperature of the motor 25 increases, the PWM duty is reduced to reduce the driving force and control so that the temperature does not increase.

Reference numeral 72 denotes a flywheel diode connected in parallel to the motor 25.

Reference numeral 73 denotes a drive switch connected between the control circuit 70 and the battery 18. The drive switch 73 is mounted at a place where the user can easily operate the switch. By turning on sometimes, assistance by the motor 25 becomes possible.

Next, the operation of the control circuit will be described.

When the driving switch 73 is turned on, the control circuit 70 operates in accordance with the torque detected by the torque detecting section 57 and the temperature of the temperature sensor 69, and the driving switching element 71 is driven by a signal output from the control circuit 70. Turns ON-OFF,
The rotation speed of the motor 25 is controlled.

Next, changes in the temperature and the duty of the motor 25 will be described with reference to FIG.

In this figure, in both the upper and lower figures, the horizontal axis is the time axis, the upper figure shows the change in the motor temperature, the lower figure shows the change in the maximum duty, and the control of the duty by the change in the motor temperature is shown.

First, when the vehicle starts traveling on level ground, the motor 25
The temperature gradually rises and stops rising at a certain temperature. Although the maximum value of the duty at this time is set to 100%, the motor 25 is driven with a duty of about 30% because the electric driving force is not required much because the ground is flat.
Next, when approaching a steep uphill, the motor 25 is driven at a duty of about 100%, which is almost the same as the maximum value, so that the temperature of the motor 25 rises. Then, when the uphill continues, the temperature of the motor 25 rises and rises above the T2 temperature among the preset temperatures of T1 and T2. Then, when the temperature of the motor 25 further rises and reaches T1, the maximum value of the duty for driving the motor 25 is reduced to 50%, and control is performed so that the temperature does not rise any more. At this time, the actual drive duty is 50%, and the temperature of the motor 25 decreases by reducing the maximum value of the duty. Eventually, it will be level and there will be no need for much electric drive,
Actually, when the drive duty becomes 30%, the temperature of the motor 25 further decreases. And another predetermined value T
When it reaches 2, the maximum value of the duty is returned to 100% again to drive. At this time, the actual drive duty is maintained at 30%. Then, the temperature of the motor 25 decreases and continues at a predetermined temperature.

As described above, the predetermined temperatures T1, T
2 has hysteresis, and the maximum value of the duty is set to 100% only when the temperature falls from T1 and reaches T2.
, The duty is not frequently changed at one temperature, and stable running and control can be performed.

In the embodiment described above, the output of the electric driving force is controlled to decrease in accordance with the temperature rise of the motor. Specifically, the maximum value of the PWM duty is decreased. In the case of an assist type bicycle, the set assist ratio may be reduced.

Next, the control of the second embodiment will be described with reference to FIG.

Since the second embodiment has the same circuit as the first embodiment, the description is omitted, and the change of the motor 25 temperature and the duty will be described with reference to FIG.

In this figure, as in the first embodiment, the horizontal axis is the time axis in both the upper and lower figures, the upper figure shows the change in the motor temperature, and the lower figure shows the change in the maximum duty. Is shown.

In this control circuit, T1, T2,
T3 and T4 and a plurality of set temperatures are determined in advance. And
The control circuit is set in advance so that the maximum value of the duty changes, for example, to 100%, 90%, 80%, 70%, and 60% depending on these predetermined temperatures.

When the vehicle starts running and continues on an uphill, the motor
The temperature rises and approaches a predetermined set temperature T4. The duty at this time is 100% when the maximum driving force is required
It is set to become. In the case of an uphill, a duty of approximately 100% is required, so that the temperature of the motor 25 rises. When the temperature reaches T4, the maximum value of the duty for driving the motor 25 is reduced to 90%. Even so, the uphill continues, the temperature does not decrease, the duty reaches 80% when it reaches the temperature of T3, 70% when it reaches T2, and 60% at T1.
The control is performed so that the maximum value of the duty is reduced as the temperature rises to prevent the temperature from rising. If the electric driving force becomes less necessary during traveling, the motor temperature decreases, so that the maximum value of the duty at the time of outputting the electric driving force is returned from 60% to 100% together with the temperature. In the embodiment, the duty is gradually reduced from 60% to 100%. However, the duty is maintained at 60% until the temperature reaches T4 from T1.
It may be returned at a stretch.

In the present embodiment, as in the first embodiment, the maximum value of the duty for driving the motor is changed when the temperature reaches a predetermined temperature. However, in the case of an assist bicycle, the assist ratio is reduced. Is also good.

As described above, when the motor temperature becomes equal to or higher than the first predetermined value, the driving force of the motor is reduced. Therefore, even if the motor temperature rises and the electric driving force decreases, the electric driving force becomes zero. Because it does not become stable, there is no wobble and stable running can be performed.

Further, a plurality of predetermined values are provided for the motor temperature,
Since the magnitude of the electric driving force is changed according to the predetermined value, in addition to the effects described above, the fine driving force can be changed, so that the motor can be prevented from rising in temperature and the vehicle can run without discomfort even if the driving force decreases.

Further, a second predetermined value smaller than the first predetermined value is provided, and when the motor temperature falls from the first predetermined value to the second predetermined value, the driving force of the motor is returned to the original value. Therefore, the change of the duty is not frequently repeated, and stable running control can be performed.

According to the present invention, since a signal from the temperature sensor is input and the output of the electric driving force is controlled to decrease according to the temperature rise of the motor, even if the motor temperature rises and the electric driving force decreases, the electric driving force is reduced. Since the force does not become zero, there is no wobble and stable running is possible. Further, when the motor temperature becomes equal to or higher than a first predetermined value, the motor driving force is reduced. Therefore, even if the motor temperature rises and the electric driving force decreases, the electric driving force does not become zero. There is no, and stable running is possible.

Further, a plurality of predetermined values are provided for the motor temperature,
Since the magnitude of the electric driving force is changed in accordance with the predetermined value, in addition to the above-described effects, the driving force can be finely changed, and the motor can be prevented from rising in temperature, and can travel without feeling uncomfortable even when the driving force decreases.

Further, a second predetermined value smaller than the first predetermined value is provided, and when the motor temperature decreases from the first predetermined value to the second predetermined value, the driving force of the motor is returned to the original value. Therefore, the change of the duty is not frequently repeated, and stable running control can be performed.

[Brief description of the drawings]

FIG. 1 shows a control circuit according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between motor temperature and motor control.

FIG. 3 is the same power system diagram.

FIG. 4 is a side sectional view of the driving unit.

FIG. 5 is a plan view of the driving unit.

FIG. 6 is a schematic view of the operation of the torque detector.

FIG. 7 is an overall configuration diagram of the same.

FIG. 8 is a diagram showing a relationship between motor temperature and motor control according to a second embodiment of the present invention.

[Explanation of symbols]

 11 Wheel 70 Control circuit 25 Motor 69 Temperature sensor

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroaki Sagara 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Toshihiro Matsumoto 2-5-2 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Inventor Yoshihiko Maeda 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (56) References JP-A-8-113186 (JP, A) Hei 6-144343 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B62M 23/02

Claims (5)

(57) [Claims] 1. A temperature sensor for detecting the temperature of a motor, comprising: a manual driving force for rotating wheels by human power; and an electric driving force for driving a motor to rotate wheels by a driving signal from a control circuit. The control circuit inputs a signal from the temperature sensor and responds to a rise in the temperature of the motor.
An electric vehicle characterized by performing control to reduce the output of an electric driving force . 2. The control circuit according to claim 1 , wherein
A signal is input, and the motor temperature is equal to or higher than a predetermined first predetermined value.
The motor's driving force is reduced when
The electric vehicle according to claim 1. 3. The electric vehicle according to claim 1, wherein the control circuit sets a plurality of predetermined values for the motor temperature, and changes the magnitude of the electric driving force according to the predetermined value. 4. The control circuit according to claim 1, wherein the control circuit is configured to control the first temperature to a motor temperature.
3. The electric vehicle according to claim 2 , wherein a second predetermined value smaller than the predetermined value is provided, and when the motor temperature decreases from the first predetermined value to the second predetermined value, the driving force of the motor is restored. Wherein the control of the electric driving force according to claim 1 Symbol mounting electric vehicle and performing the maximum value of the PWM duty.