JPH08127386A - Bicycle with electric motor - Google Patents

Abstract

PURPOSE: To save power consumption by generating torque, corresponding to a difference from virtual torque necessary for walking a bicycle body of excepting a fixed load from the body total unit, in an electric motor, and reducing an input. CONSTITUTION: A drive system by an electric motor 36 is switched to a walking mode by a walk discriminating means 60 when walked a bicycle body, to generate torque necessary for walking a body total unit. Drive torque T of an input drive system is detected by a torque detector 52, and in accordance with changing this detected drive torque T, a current supplied to the electric motor 36 from a battery 39 is changed by a controller 42, to generate in the electric motor 36 torque corresponding to a difference from virtual torque necessary for walking the body of excepting a fixed load from the body total unit. Thus, by sharing the necessary torque by an input, power consumption of the electric motor 36 can be saved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle equipped with an electric motor in which a drive system driven by human power and a drive system driven by an electric motor are provided side by side, and the drive force of the electric motor assists the drive force driven by human power.

[0002]

2. Description of the Related Art A bicycle equipped with an electric motor in which a driving system driven by human power and a driving system driven by electric motor are provided side by side to assist the driving force driven by human power with the driving force of the electric motor is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-74491. Are disclosed in US Pat. This electric motor-equipped bicycle detects the pedaling force input from the foot pedal and increases the driving force of the electric motor to reduce the human power load when the human power load is large. In this bicycle with an electric motor, since the electric motor is driven according to the pedaling force, the pedaling force is not transmitted from the pedal when the vehicle is pushed by hand to travel, so that the driving force of the electric motor is not generated. However, since this bicycle is equipped with batteries and motors, it is a heavy burden to run by hand.

In order to solve this problem, the applicant of the present invention has proposed a bicycle with an electric motor disclosed in Japanese Patent Laid-Open No. 4-358988. This electric motor-equipped bicycle has a push-walking determination means that determines the walking state while pushing the vehicle body by hand, and a controller that controls the electric motor to a push-walking speed that is slightly slower than the normal walking speed of a human in the push-walking state. Is equipped with.

[0004]

However, in the bicycle with an electric motor disclosed in Japanese Patent Laid-Open No. 4-358988,
Even if it is not pushed by human power, the drive torque of the electric motor is generated to the extent that the vehicle can run by itself if it is supported so as not to fall down. In this case, there is an advantage that the user only has to support the vehicle body, but since the driving torque is large, a large current is required, the power consumption becomes large, and the battery mounted to drive the electric motor is large. There was a problem that the discharge of was fast.

In addition, in the bicycle with an electric motor of this publication, the user walks while pushing the handle, but since the handle is provided at a high position, for example, he / she gets over a step on a road or a wheel stop on a bicycle parking lot. At the time, or when pushing up the inclined surface of the pedestrian bridge, the user had to swing the arm high and lift the front wheel, which required a large amount of physical strength. This kind of operation is disadvantageous in that this type of bicycle, which has an electric motor and a battery mounted therein and becomes heavy, requires particularly strong arm strength.

Further, in the bicycle with an electric motor of this publication, a switch for setting the drive system by the electric motor to the walking mode is provided on the steering wheel or saddle (hereinafter also referred to as a seat as appropriate). Here, when a switch is provided on the steering wheel, the wiring connecting the switch and the controller must be arranged along the steering wheel and the frame of the vehicle body.
This wiring is swung or twisted. There is a possibility that the wiring may be damaged by such a twisting force or by being caught by other parts during swinging. Also, if a switch is provided on the saddle, it takes time to support the handle after the switch is activated, so the pushing and walking motion becomes unstable, so, for example, grasp the handle with one hand and use the saddle or seat with one hand. It is desirable to have a tube, etc., but in this case more physical strength is required to lift the front wheel.

The present invention has been made in consideration of the above circumstances, and it is a first object of the present invention to provide a bicycle with an electric motor capable of saving power consumption. A second object of the present invention is to provide a bicycle with an electric motor that can easily apply an upward force to a front wheel without a large arm force. Further, a third object of the present invention is to provide a bicycle with an electric motor that avoids damage to the wiring of the switch set to the push-walk mode.

[0008]

In order to solve the above problems, in the invention according to claim 1, a drive system by human power and a drive system by an electric motor are provided side by side, and the drive power of the electric motor is used for human power. In a bicycle with an electric motor adapted to assist the driving force of the vehicle, when the vehicle is pushed and walked, the drive system by the electric motor is switched to the pushing-walking mode, and the torque required for pushing the entire vehicle It is characterized in that the electric motor is caused to generate a torque corresponding to a difference from a virtual torque required to walk the vehicle body by removing a constant load from the whole, thereby reducing human power.

According to the second aspect of the invention, a head tube that rotatably holds the front wheel and the handle, a seat tube to which a seat is attached, and the head tube and the seat tube are connected. And a connection part, and a grip that can be gripped by a user when pushing the vehicle body is provided on the head tube side of the connection part. Further, in the invention according to claim 3, a switch for switching the drive system by the electric motor to the push-walk mode is provided in the grip, and wiring to the switch is inserted into the grip or the surface of the grip. It is characterized by being buried in.

[0010]

According to the first aspect of the present invention, when the vehicle body is pushed and walked, the drive system by the electric motor is switched to the push and walk mode. Then, in the push-walk mode, a torque corresponding to the difference between the torque required to walk the entire vehicle body and the virtual torque required to walk the vehicle body that is obtained by removing a constant load from the entire vehicle body is set. It is generated in the electric motor. In other words, instead of causing the electric motor to bear all the force required to push and walk the entire vehicle body, the vehicle body for which the constant load is removed (for example,
A normal bicycle not equipped with an electric motor) does not have to bear the weight necessary to walk while walking, and the electric motor does not have to bear the weight. Therefore, the electric motor is caused to bear the load corresponding to a constant load (for example, the weight equivalent to the electric motor or the battery), and the drive torque to be generated in the electric motor can be reduced. Therefore, the required current is reduced, the power consumption can be saved, and the consumption of the battery mounted for driving the electric motor can be reduced.

According to the second aspect of the invention, a grip is provided on the head tube side of the connecting portion for rotatably holding the head tube and the seat tube, and the grip is provided by the user when pushing and walking the vehicle body. I try to grab. Therefore, the position where the user grips is lower than that of the steering wheel, and for example, when overcoming a step on a road or a wheel stop on a bicycle parking lot or pushing up a slope of a pedestrian bridge, an upward force is applied to the front wheel even if there is not a large amount of physical strength. It will be easier.

Further, in the invention according to claim 3, a switch is provided in the grip to switch the drive system by the electric motor to the walking mode, and the wiring to the switch is inserted into the grip or embedded in the surface of the grip. Therefore, the wiring is not swung or twisted, and there is no possibility of damaging the wiring due to a twisting force or being caught by another component when swinging. In addition, since the vehicle body can be supported by holding the grip after the switch is activated, the pushing and walking motion does not become unstable, and it is easy to apply upward force to the front wheels as described above. is there.

[0013]

【Example】

(1) First Example A. Configuration of Embodiments Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is a side view showing a partial cross section of a bicycle with an electric motor according to the first embodiment. In the figure, reference numeral 10 indicates a main tube (connecting portion), and a head tube 11 is fixed to the front portion of the main tube 10. A handle stem 12 is inserted into the head tube 11 so as to be rotatable around the axis of the head tube 11. A pair of left and right front forks 16 are fixed to the lower portion of the handle stem 12, and front wheels 14 are rotatably attached to the front forks 16. A handlebar 18 extending in the left-right direction is fixed to the upper portion of the handle stem 12.

The main tube 10 extends obliquely downward and rearward from the front portion, and a seat tube 22 and one rear tube 26 are fixed to the rear end thereof. The seat tube 22 supports the seat post 19 to which the saddle 20 is fixed. A pair of chain stays 27 is fixed to the rear tube 26, and the chain stay 27 and the seat tube 22 are connected by a pair of left and right seat stays 24. As illustrated, the seat tube 22, the seat stay 24, the rear tube 26, and the chain stay 27 have a substantially triangular shape so that the user can support the weight of the vehicle when he / she gets on the vehicle. A rear wheel 28 is rotatably attached to a connecting portion between the seat stay 24 and the chain stay 27.

A power unit 34 is attached below the seat tube 22. This power unit 3
Reference numeral 4 is a unit of a drive system by human power, a drive system by an electric motor, and a combination mechanism of both, and a crankshaft 33 is attached to the case, and cranks 32 are provided at both ends of the crankshaft 33. It is fixed.
A foot pedal 31 is attached to each of the cranks 32. Reference numeral 36 indicates an electric motor.

A casing 41 is fixed to the lower portion of the main tube 10. A controller 42 is provided inside the casing 41. The electric motor 36 is supplied with a driving current from a rechargeable battery 39. The batteries 39 are housed in upper and lower two tiers in an inner box, the inner box is further housed in an outer box, and the outer box is arranged between the seat tube 22 and the rear wheel 28. It is supported by 22, the seat stay 24, and the rear tube 26. The battery 39 supplies a current to the electric motor 36, and the controller 42 increases or decreases this current.

The circuit for driving the electric motor 36 is shown in FIG.
Is shown in. In this figure, reference numeral 54 is a battery 39.
Shows a main key switch interposed between the controller 42 and the controller 42. When the main key switch 54 is turned off, the electric motor 36 is not driven at all, and the bicycle with the electric motor is propelled only by human power.
As the electric motor 36, for example, a permanent magnet type DC motor or a series winding DC motor can be used. Further, the controller 42 is preferably a chopper type controller that changes the on / off time ratio (duty ratio) of the DC voltage according to the torque.

Further, a grip 49 consisting of a U-shaped pipe is attached to the upper portion of the main tube 10, that is, in the vicinity of the head tube 11, and when the user pushes and walks the vehicle body, the handlebar 18 is held by the user with one hand. Grab
The grip 49 is designed to be gripped with the other hand. As a result, the position gripped by the user is lower than that of the steering wheel 18, and, for example, when overcoming a step on a road or a wheel stop on a bicycle parking lot or pushing up an inclined surface of a pedestrian bridge, the front wheel 14 can be turned upward even if there is no great strength. It becomes easy to give power.

This grip 49 has a grip switch 5
0 is provided. The grip switch 50 is the wiring 5
The controller 42 is connected to the controller 42 through 1 and switches the controller 42 to the walking mode as described later. Here, the wiring 51 is the grip 49.
Is inserted inside. As a result, the wiring 51 is swung or twisted as the other members move,
Damage is avoided. Further, the wiring 51 may be embedded in the surface of the grip 49. A cover 89 (shown by phantom lines) that covers the main tube 10 and the like is attached to the body of the bicycle with an electric motor, and the grip 49 projects upward from the cover 89 shown by phantom lines so that the user can You can grab this.

As shown in FIG. 2, the rotation of the crankshaft 33 when the user depresses the foot pedal 31, is transmitted to the drive sprocket 44 via the one-way clutch 30. This rotation is transmitted to the rear wheel 28 via the chain 37 and the free wheel 29, and the rear wheel 28 rotates to propel the bicycle with the electric motor.

On the other hand, when the electric motor 36 is driven, the rotation of the rotor is reduced by the speed reducer 40 and the one-way clutch 3.
8 is transmitted to the drive sprocket 44, which also causes the rear wheel 28 to rotate. As the speed reducer 40, for example, a planetary roller mechanism is preferable from the viewpoint of quietness and space saving. In this way, the bicycle with the electric motor includes the drive system by the human power transmitted by the crankshaft 33 and the drive system by the electric motor 36.

Here, the driving force of the electric motor 36 is controlled by the driving force of human power, that is, the stepping force of the foot pedal 31. Specifically, a torque detector 52 is provided in the middle of a drive system driven by human power, the drive torque T of the drive system driven by human power is detected by the torque detector 52, and the controller is operated according to the increase / decrease in the detected drive torque T. At 42, the current supplied from the battery 39 to the electric motor 36 may be increased or decreased. This makes it possible to increase the driving force of the electric motor when the burden of human power is large and reduce the burden of human power.
Further, when there is no pedaling force from the foot pedal 31, the controller 42 does not drive the electric motor 36. That is, this electric motor-equipped bicycle is not assisted by the electric motor 36 when the propulsive force by human power is not working.

Further, in this bicycle with an electric motor,
When pushing the vehicle body by hand, the drive system by the electric motor is switched to the pushing-walking mode. Therefore, in addition to the drive system described above, a push-walking determination means 60 for determining the push-walking state is provided. FIG. 3 shows the configuration of the push-walking determining means 60.
The push-walking determination means 60 determines that the push-walking is performed when the following three conditions are satisfied. The driving torque T due to human power is 0. The vehicle speed V is a certain speed V ₀ or more in the forward direction. The grip switch 50 is pressed.

Under the above conditions, the drive torque T is compared with the comparator 6
When the torque T is zero, the comparator 62 is turned on. The condition is that the vehicle speed V at the time of forward movement is detected by the speed sensor 64 (FIG. 1) provided on the front wheels 14 or the rear wheels 28, and this vehicle speed V is set at the constant speed V
It is determined by comparing with ₀ (preferably about 1 to 2 km / h) by the comparator 68, and if V ₀ or more, the comparator 68 is turned on. Furthermore, the conditions are grip switch 50
Is determined by. Here, the grip switch 50 may be turned on by continuing to push with a hand, and turned off when the pushing force is weakened. Alternatively, if the push switch is pushed once and turned on, it is turned off unless it is pushed again. You may not want to become.

The comparator 62, the comparator 68, and the grip switch 50 are connected to the AND circuit 72, and the comparator 6
2. When all the signals of the comparator 68 and the grip switch 50 are turned on, the AND circuit 72 determines that the walking state is in progress and outputs an ON signal. This puts the electric motorized bicycle in a push-walk mode.

The output signal of the AND circuit 72 is input to the push-walking controller 42A. The controller 42A is provided so as to share a part of the controller 42 described above. The operation of the push-walking controller 42A will be described later.

In this embodiment, a release switch 74 for releasing the push-walk mode when the brake is applied even during the push-walk state is provided in the brake lever portion of the handle (see FIG. 1). This switch 74 has a contact 74A interposed between the power source and the input terminal of the AND circuit 72.
Can be opened and closed, and contact 7 when the brake is applied.
4A is opened and the AND circuit 72 outputs an OFF signal.
At this time, the push-walk mode is released and the drive of the electric motor 36 is stopped.

B. Operation of the Embodiment Next, the operation of the bicycle with the electric motor of this embodiment will be described. Since the operation in the normal traveling mode has already been described, it will be omitted here and only the operation in the push-walk mode will be described.

First, when pushing the vehicle body, the driving torque T is 0 because there is no input from the foot pedal 31.
kg · m. Although the rear wheel 28 rotates, the chain 37 and the drive sprocket 44 do not rotate because of the free wheel 29. Therefore, the comparator 62 is turned on. Further, the speed sensor 64 (FIG. 1) provided on the front wheels 14 or the rear wheels 28 detects the vehicle speed V during forward movement, and when the vehicle speed V exceeds a certain speed V ₀ (preferably about 1 to 2 km / h), comparison is made. The device 68 is turned on. Further, the user manually pushes the grip switch 50 to turn it on. In this way, all the above conditions 1 to 4 are satisfied, and the AND circuit 72 outputs an ON signal. That is, the bicycle with the electric motor is in the walking mode. As described above, in the push-walk mode, the user holds the handle 18 with one hand and the grip 49 with the other hand to run the vehicle body.

The output signal of the AND circuit 72 is input to the controller for push walking 42A. Controller 4
2A applies a current to the electric motor 36, and controls the rotational torque of the electric motor 36 so as to assist the user in pushing the bicycle, although the bicycle equipped with the electric motor cannot run by itself. By this, the vehicle body moves at a constant speed V ₁ (for example, 2 to 3 km / h).

Specifically, as shown in FIG. 5 (B), the torque T ₁ required to push and walk the entire vehicle body and the amount of the vehicle body obtained by removing a constant load from the entire vehicle body A torque ΔT corresponding to the difference from the required virtual torque T ₂ is generated in the electric motor 36 to reduce human power. That is,
The electric motor 36 does not bear all the force required to walk the entire vehicle body, but the vehicle body without a certain load (for example, a normal bicycle without an electric motor).
The electric motor 36 does not have to bear the weight necessary to walk while pushing the electric vehicle, but the electric motor 36 does.

Therefore, the torque ΔT corresponding to a constant load (for example, the weight corresponding to an electric motor or a battery)
Only the electric motor is burdened, and the drive torque to be generated in the electric motor can be reduced.
Therefore, the required current is reduced, the power consumption can be saved, and the battery 39 mounted to drive the electric motor 36 is used.
It is also possible to reduce the consumption of. From the user's side, it is possible to push and walk an electric motor-equipped bicycle with a force that pushes a normal bicycle. It should be noted that the virtual torque T ₂ is calculated and obtained from the force required at that time by pushing an ordinary bicycle in advance.

The driving torque ΔT that the electric motor 36 bears differs depending on the gradient of the road surface on which the user walks. That is, when the slope of the road surface is small, as shown in FIG. 5A, the difference between the resistance F ₁ when the bicycle equipped with the electric motor travels and the resistance F ₂ when the ordinary bicycle travels is small. On the other hand, when the slope of the road surface is large, the difference between the resistances F ₁ and F ₂ is large as shown in FIG. 6 (A). When the same walking speed V ₁ is taken, the difference between the resistance F ₁ and the resistance F ₂ in this case appears in the torque difference ΔT (T ₁ −T ₂ ). Therefore, the larger the gradient of the road surface, the larger the motor torque must be. Here, since the motor torque is proportional to the motor current, the controller 42A must increase the current passed through the motor 36 (see FIGS. 5 and 6B).

Therefore, it is preferable that the controller 42A be connected to the tilt sensor 91 shown in FIG. Although the inclination sensor 91 is fixed to the main tube 10 in the illustrated example, the inclination sensor 91 is not limited to this, and may be provided anywhere on the vehicle body, for example, attached to the casing 41. When the gradient measured by the tilt sensor 91 is large, the controller 42A increases the current flowing through the motor 36, and when the gradient is small, the current flowing through the motor 36 is decreased.

To release the push-walk mode, the grip switch 50 is operated to turn it off or the handle 1
The brake attached to 8 should be operated. When the grip switch 50 is turned off, the AND circuit 72
Is turned off, the controller 42A stops energizing the electric motor 36, and the rotation of the electric motor 36 stops. As a result, the vehicle body can be moved only by human power. When the brake is operated, the contact 74 is opened and the AND circuit 72 outputs an OFF signal. Then, the rotation of the electric motor 36 is stopped, and unless the user moves it forward, the vehicle is stopped by the braking by the brake.

In the above example, there are three conditions: the driving torque T due to human power is 0, the vehicle speed V is a certain speed V ₀ or more in the forward direction, and the grip switch 50 is pressed. Although it is determined that the mode is the push-walking mode when all the conditions are satisfied, it is also possible not to determine any of the conditions. In this case, even when the vehicle speed V is 0, that is, when the vehicle is stopped, it is possible to enter the push walking mode by pressing the grip switch 50 without stepping on the foot pedal 31. Further, as shown in FIG. 1, the comparator timer 68A to delay the ON signal 68 is provided, fixed time velocity V from equal to or higher than a predetermined speed V ₀ t ₀
This signal may be input to the AND circuit 72 when is passed. In this way, the push-walking determination means 60
It is possible to make various modifications.

(2) Second Embodiment FIG. 4 is a side view showing a second embodiment of the bicycle with the electric motor according to the present invention. In the first embodiment shown in FIG. 1,
Although the grip 49 was projected upward from the cover 89 shown by the phantom line, in the second embodiment, by forming the hole 91 in the cover 90 that covers the main tube 10 and the like,
A grip 49 is provided on the cover 90 itself.

[0038]

As described above, according to the first aspect of the invention, the electric motor is not caused to bear all the force necessary for pushing the entire vehicle body, but the constant load is removed. The electric motor does not bear the weight necessary for walking while walking a minute car body (for example, a normal bicycle without an electric motor), but the human body bears the weight. Therefore, the electric motor is caused to bear the load corresponding to a constant load (for example, the weight equivalent to the electric motor or the battery), and the drive torque to be generated in the electric motor can be reduced. Therefore, the required current is reduced, the power consumption can be saved, and the consumption of the battery mounted for driving the electric motor can be reduced.

According to the second aspect of the invention, a grip is provided on the head tube side of the connecting portion for connecting the head tube and the seat tube so that the user grips the grip when pushing the vehicle body. There is. Therefore, the position where the user grips is lower than that of the steering wheel, and for example, when overcoming a step on a road or a wheel stop on a bicycle parking lot or pushing up a slope of a pedestrian bridge, an upward force is applied to the front wheel even if there is not a large amount of physical strength. It will be easier. Further, in the invention according to claim 3, since a switch for switching the driving system by the electric motor to the walking mode is provided in the grip and the wiring to the switch is inserted into the grip or embedded in the surface of the grip. The wiring is not swung or twisted, and there is no possibility of damaging the wiring due to the twisting force or being caught by other parts when swinging. Further, since the vehicle body can be supported by gripping the grip after the switch is activated, the pushing-walking operation is stable, and it is easy to apply the upward force to the front wheels as described above.

[Brief description of drawings]

FIG. 1 is a side view showing a partial cross section of a bicycle with an electric motor according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a power transmission system of the bicycle equipped with the electric motor.

FIG. 3 is a circuit diagram showing push-walking determination means used for push-walking of the electric motor-equipped bicycle.

FIG. 4 is a side view showing a second embodiment of the bicycle with an electric motor.

FIG. 5 is a graph for obtaining a driving torque when pushing the electric motor-equipped bicycle of the embodiment on a road surface having a small slope.

FIG. 6 is a graph for obtaining a driving torque when pushing the electric motor-equipped bicycle of the embodiment on a road surface having a large slope.

[Explanation of symbols]

10 main tube (connection part), 12 head tube, 22 seat tube, 31 foot pedal, 32
Crank, 36 electric motor, 39 battery, 42A
Controller, 49 grips, 50 grip switches, 51 wiring.

Claims (3)

[Claims] 1. A bicycle equipped with an electric motor in which a drive system driven by human power and a drive system driven by electric motor are provided side by side to assist the drive force driven by human power by the drive force of the electric motor, when the vehicle body is pushed and walked. The difference between the torque required to walk the entire vehicle body by pushing the electric motor drive system to the walking mode and the virtual torque required to walk the vehicle body by removing a constant load from the entire vehicle body. A bicycle equipped with an electric motor, characterized in that the electric motor is caused to generate a torque corresponding to the above to reduce human power. 2. A head tube that rotatably holds a front wheel and a handle, a seat tube to which a seat is attached, and a connecting portion that connects the head tube and the seat tube. The bicycle with an electric motor according to claim 1, wherein a grip that can be grasped by a user when pushing the vehicle body is provided on the head tube side. 3. The grip is provided with a switch for switching the drive system by the electric motor to the push-walk mode, and wiring to the switch is inserted into the grip or embedded in the surface of the grip. A bicycle with an electric motor according to claim 2.