JP3974979B2 - Auxiliary power control device for battery-assisted bicycle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power-assisted bicycle including a pedaling force detection unit that detects pedaling force by human power and an electric motor that can exhibit auxiliary power according to a detection value of the pedaling force detection unit. This relates to the auxiliary power control apparatus.
[0002]
[Prior art]
Conventionally, such a battery-assisted bicycle is already known, for example, in Japanese Patent Application Laid-Open No. 7-309283. In this battery-assisted bicycle, an assist ratio, which is a ratio of assist power by an electric motor to pedal force by human power, is set to, for example, 6 km / h. The operation of the electric motor is controlled by setting a value larger than 1 (for example, 3) in the following low speed range, and the assist ratio is set to, for example, 1 in the medium speed range exceeding 6 km / h, for example. To control.
[0003]
[Problems to be solved by the invention]
However, in the above-mentioned conventional one, the assist ratio is determined regardless of the pedaling force, so when a woman or an elderly person who has weak pedaling force rides and climbs a hill, a large auxiliary power cannot be obtained and the hill cannot be climbed. In addition, in the low and medium speed range, the occupant may feel uncomfortable because the auxiliary power varies depending on the speed even with the same pedal effort.
[0004]
The present invention has been made in view of the above circumstances, and it is possible to obtain auxiliary power corresponding to the pedaling force, and to make it possible to travel comfortably without changing the auxiliary power with the same pedaling force. An object is to provide an auxiliary power control device for an auxiliary bicycle.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect of the present invention is an electric assisting device comprising: a treading force detecting means for detecting a treading force by human power; and an electric motor capable of exhibiting auxiliary power in accordance with a detection value of the treading force detecting means. The bicycle includes a controller that controls the operation of the electric motor such that the assist ratio, which is the ratio of the auxiliary power by the electric motor to the pedaling force by human power, is changed according to the detection value of the pedaling force detection means. When the detected value of the means is equal to or greater than a set value, the assist ratio is set to 1, but when the value is less than the set value, the assist ratio is set to a value larger than 1 to control the operation of the electric motor.
[0006]
According to such a configuration, since the assist ratio changes according to the pedaling force, it is possible to obtain auxiliary power according to the pedaling force, and since the auxiliary power does not change with the same pedaling force, the vehicle travels without a sense of incongruity. Can do. In addition, although the auxiliary power is increased for a person with weak pedaling force, the auxiliary power is not increased unnecessarily for a person with strong pedaling force, and the auxiliary power does not change with the same pedaling force.
[0007]
According to the second aspect of the invention, in addition to the configuration of the invention described in claim 1 wherein, prior Symbol controller assist when the detected value of the pedal force detection means is equal to or greater than a large maximum set value than the set value By controlling the operation of the electric motor with a ratio smaller than 1, the resultant force, which is the sum of the treading force and the auxiliary power, is prevented from increasing unnecessarily, and the resultant force suitable for the bicycle is obtained. The auxiliary power can be adapted to the bicycle .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.
[0009]
1 to 6 show a first embodiment of the present invention. FIG. 1 is a side view of a battery-assisted bicycle, FIG. 2 is a longitudinal side view of a motor unit, and is a sectional view taken along line 2-2 in FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2, FIG. 4 is a block diagram showing the configuration of the control device for the electric motor, FIG. 5 is a diagram showing an assist ratio according to the pedaling force, and FIG. It is a figure which shows motive power and resultant force.
[0010]
First, in FIG. 1, a front fork 13 to the head pipe 12 at the front end of a body frame 11 provided in the motor-assisted bicycle is supported steerably, the front wheel W _F at the lower end of the front fork 13 is rotatably supported, a front fork 13 A bar handle 14 is provided at the upper end of the bar. A motor unit 16 having an electric motor 15 is provided at the lower part of the body frame 11. The motor unit 16 extends downward from the body frame 11 above the rear part of the motor unit 16 and extends substantially horizontally behind the motor unit 16. left issued, the rear wheel W _R is rotatably supported to the right pair of rear forks 17 ... between the left and right pair of stays 18 ... are provided between the rear portion of the two rear fork 17 ... and the vehicle body frame 11. Further, a seat 19 is mounted on the rear portion of the vehicle body frame 11 so that the vertical position can be adjusted, and a carrier 20 is fixedly disposed on the rear side of the seat 19.
[0011]
A crankshaft 22 having crank pedals 21 and 21 at both ends is rotatably supported by the motor unit 16, and can transmit power from the crankshaft 22 and can also act as auxiliary power from the electric motor 15. a sprocket 24, an endless chain 26 is wound on the driven sprocket 25 provided to the axle of the rear wheel W _R.
[0012]
A front basket 28 is attached to the head pipe 12 via a bracket 27. In addition, a battery storage case 29 disposed on the rear surface of the front basket 28 is also attached to the bracket 27, and a battery 30 for supplying electric power to the electric motor 15 is stored in the battery storage case 29 in a removable manner. The
[0013]
The operation of the electric motor 15 is controlled by a controller 31 fixedly supported on the lower side of the vehicle body frame 11 on the front side of the motor unit 16, and the controller 31 is electrically driven based on the pedaling force and the vehicle speed by the occupant. The operation of the motor 15 is controlled.
[0014]
Most of the body frame 11 is covered with a cover 32, and a main switch 33 for supplying electric power from the battery 30 to the controller 31 and the electric motor 15 is disposed on the cover 32.
[0015]
Referring to FIGS. 2 and 3 together, the casing 35 of the motor unit 16 is fixedly supported on the lower part of the vehicle body frame 11. A rotating cylinder 36 coupled to the drive sprocket 24 is rotatably supported via a ball bearing 37 on the right side (upper side in FIG. 3) of the casing 35, and the right end portion of the crankshaft 22 is The rotating cylinder 36 is supported via a needle bearing 38, and the left end portion of the crankshaft 22 is supported on the left side (lower side in FIG. 3) of the casing 35 via a ball bearing 39.
[0016]
The pedaling force applied by the crank pedals 21 and 21 at the left and right ends of the crankshaft 22 is transmitted from the crankshaft 22 to the drive sprocket 24 via the pedaling force transmission system 40. The output of the electric motor 15 attached to the casing 35 is transmitted to the drive sprocket 24 via the auxiliary power transmission system 41 so as to assist the pedaling force by the crank pedals 21 and 21.
[0017]
A pedaling force transmission system 40 for transmitting the power of the crankshaft 22 to the drive sprocket 24 includes a torsion bar 42 connected to the crankshaft 22 and a first one-way clutch 43 provided between the rotary cylinder 36 and the torsion bar 42. It consists of.
[0018]
The crankshaft 22 is provided with a slit 44 extending along the axis thereof, and the torsion bar 42 includes a columnar shaft portion 42a that is rotatably fitted in the slit 44, and a left end of the shaft portion 42. The arm portion 42b protruding from both sides from the upper end of FIG. 3 and the arm portion 42c protruding from the right end (lower end of FIG. 3) of the shaft portion 42a are attached to the slit 44. Therefore, the pedaling force can be transmitted to the other arm part 42c side while twisting and deforming the shaft part 42a according to the pedaling force input from the crankshaft 22 to the one arm part 42b.
[0019]
The first one-way clutch 43 is well known in the art, and when the crankshaft 22 is rotated forward by stepping on the crank pedals 21, 21, the pedaling force from the crankshaft 22 is applied to the torsion bar 42 and the first one-way clutch 43. Is transmitted to the drive sprocket 24 via the rotary cylinder 36. When the crankshaft 22 is reversed by stepping on the crank pedals 21, 21, the first one-way clutch 43 slips and the crankshaft 22 is reversely rotated. Permissible.
[0020]
A slider inner 45 is supported on the outer periphery of the crankshaft 22 so as not to rotate relative to the crankshaft and is relatively movable in the axial direction. The slider outer 46 rotates relative to the outer periphery of the slider inner 45 via a plurality of balls 47. It is supported freely.
[0021]
The slider inner 45 is cam-engaged with a clutch inner ring in the first one-way clutch 43, and an intermediate portion of a detection lever 48 supported so as to be swingable on the casing 35 is from a side opposite to the clutch inner ring. It abuts against the slider outer 46. On the other hand, a stroke sensor 49 which constitutes the pedal force detection means S _T together with the detection lever 48 is attached to the casing 35, the tip of the detection lever 48 to the detector 49a of the stroke sensor 49 is in contact. Further, a spring 50 is contracted between the detection lever 48 and the casing 35, and the detection lever 48 is elastically brought into contact with the slider outer 46 by the spring force of the spring 50. The slider outer 46 and the slider inner 45 are The first one-way clutch 43 is biased toward the inner ring side of the clutch.
[0022]
When the torsion bar 42 is twisted in response to a pedaling force input from the crank pedals 21, 21 to the crankshaft 22, the slider inner 45 moves along the axis of the crankshaft 22 against the spring force of the spring 50 in FIG. 3. The detection lever 48 slid downward and moved by the slider outer 46 moving together with the slider inner 45 swings, whereby the detector 49 a of the stroke sensor 49 is pressed. Stroke of the detector 49a, the amount of torsion of the torsion bar 42, that is, in proportion to the pedal force inputted from the crank pedals 21, 21, so that the depression force by the pedaling force detecting means S _T is detected.
[0023]
The auxiliary power transmission system 41 for transmitting the power of the electric motor 15 to the drive sprocket 24 includes a drive gear 52 fixed to the rotating shaft 15a of the electric motor 15, and one end of a first idle shaft 53 parallel to the rotating shaft 15a. A first intermediate gear 54 that is fixedly engaged with the drive gear 52, a second intermediate gear 55 that is provided integrally with the first idle shaft 53, and a third intermediate gear 56 that is engaged with the second intermediate gear 55. And a second idle shaft 57 disposed coaxially with the third intermediate gear 56, a second one-way clutch 58 provided between the third intermediate gear 56 and the second idle shaft 57, and the second idle shaft 57. And a driven gear 60 that is provided integrally with the rotating cylinder 36 to which the drive sprocket 24 is coupled and meshed with the fourth intermediate gear 59.
[0024]
In such an auxiliary power transmission system 41, the torque accompanying the operation of the electric motor 15 is decelerated and transmitted to the drive sprocket 24. When the operation of the electric motor 15 stops, the second one-way clutch 58 Due to the operation, the idling of the second idle shaft 57 is allowed, and the rotation of the drive sprocket 24 by the depression force of the crank pedals 21 and 21 is not hindered.
[0025]
4, the motor drive circuit 62 for driving the electric motor 15, which is controlled by the controller 31, to the controller 31, along with the detected value of the pedal force detection means S _T is input, vehicle speed detecting means S the detected value of _V is input, the controller 31 outputs a signal for controlling the operation of the electric motor 15 based on the detection value of the pedaling force detecting means S _T and vehicle speed detecting means S _V.
[0026]
By the way, the vehicle speed detecting means S _V detects the rotational speed of the electric motor 15 as representative of the bicycle speed in the power assist state by the electric motor 15, and as shown in FIGS. And an electromagnetic pickup coil type sensor 64. Thus, the reluctator 63 having the protrusion 63a on the outer periphery is fixed to the rotating shaft 15a of the electric motor 15, and the sensor 64 has a detection part 64a that can be close to and opposed to the protrusion 63a and is fixed to the casing 35. Is done.
[0027]
In the controller 31, the assist ratio is the ratio of the auxiliary power by the electric motor 15 relative to the pedal effort by human power (auxiliary power / pedaling force) have been previously set as shown in Figure 5, is detected by the pedaling force detecting means S _T pedal force There the case first set depression force T ₁ for example is 20kgf or less, when the depression force detected by the pedaling force detecting means S _T is the third set depression force T ₃ example 70kgf above is the assist ratio is "1", In a range that exceeds the first set pedaling force T ₁ and is less than the third set pedaling force T ₃ , the assist ratio larger than “1” is set to change according to the pedaling force.
[0028]
In addition, in the range where the first set pedal force T ₁ is exceeded and the third set pedal force T _{3 is} less, the assist ratio is such that the assist ratio becomes the peak value n _P , n _P ′ at the second set pedal force T ₂ or T ₂ ′. Is set. Here, the second set pedaling forces T ₂ and T ₂ ′ are arbitrarily set corresponding to the maximum pedaling force exerted by a person with weak pedaling force such as a woman or an elderly person. Further, the peak values n _P and n _P ′ of the assist ratio are such that the resultant force of the pedaling force and the assisting power becomes a resultant force when the assist ratio is “1” when the pedaling force by the person is a maximum value, for example 70 kgf, for example 140 kgf. N _P is, for example, “1.8” when T ₂ is 50 kgf, and n _P ′ is, for example, “3” when T ₂ ′ is 35 kgf. is there.
[0029]
By determining the assist ratio in this way, the resultant force of the pedal effort and the auxiliary power is as shown in FIG. That is, as shown by a broken line in FIG. 6, in the conventional device having a constant assist ratio, the resultant force also changes linearly as the auxiliary power changes linearly according to the pedaling force, whereas a predetermined pedaling force range ( In the present invention in which the assist ratio set to be larger than “1” in the range exceeding the first set pedal force T ₁ and less than the third set pedal force T ₃ ) is indicated by a solid line. Thus, auxiliary power and resultant force can be increased when necessary. At this time, when the pedal effort is in the range of T _{2 to} T ₃ , it is desirable that the resultant force line changes substantially constant as shown by the solid line in FIG. 6 or slightly rises to the right as shown by the chain line.
[0030]
Next, to explain the action of this first embodiment, when the detected value of the pedal force detection means S _T is first set depression force T ₁ below, when as well as the third set pedaling force T ₃ or more, the assist ratio "1 ”, The auxiliary power is controlled to the same level as in the past when driving in a normal driving state where it is not necessary to depress the crank pedals 21 and 21 with a large pedaling force, and at high speeds. It is possible to run the bicycle with appropriate power so as not to run. In addition, by controlling the operation of the electric motor 15 so that the auxiliary power is maximized when a person with weak pedaling force such as an elderly person or a woman exhibits the maximum pedaling force, even a person with weak pedaling force is the same as a person with strong pedaling force. Therefore, even a person with weak treading force can climb the slope easily. In addition, when the pedal effort is the same, the same auxiliary power can be obtained, and the vehicle can travel without a sense of incongruity.
[0031]
Figure 7 shows a second embodiment of the present invention, the detected value is less than the set value T _O pedaling force detecting means S _T, according to a major assist ratio than "1", for example depression force large It is set to gradually become smaller Te, the assist ratio is in the range of less great maximum set value T _M than the detection value set value T _O a is the set value T _O or is set to "1", further In the range where the detected value exceeds the maximum set value T _M , the assist ratio is set to gradually decrease from “1” as the pedal effort increases. Thus, the set value T _O is set to, for example, 60 kgf substantially corresponding to the weight of a normal person, and the maximum set value T _M is the maximum resultant force when the maximum pedaling force that can be exerted by a person is, for example, 70 kgf. That is, it is set to 70 kgf which is 1/2 of 140 kgf.
[0032]
In addition, the assist ratio is set so as to change according to the pedaling force within a range not exceeding the curve A, and the curve A is a sum of the pedaling force and the auxiliary power and the maximum pedaling force that a human can exert. Indicates the assist ratio with which the two match. That is, when the assist ratio is a, the treading force is T, and the maximum resultant force is 140 kgf, the curve A is represented by {a = (140−T) / T}.
[0033]
According to the second embodiment, a person with relatively weak pedaling force can obtain a large auxiliary power as the pedaling force is small, and any person can obtain a substantially equal resultant force. For those with relatively strong pedaling power, it is possible to obtain auxiliary power equivalent to the pedaling force so that the running speed does not increase unnecessarily, and for those with extremely strong pedaling power, it is smaller than the pedaling force. It is possible to obtain the resultant force suitable for the bicycle by avoiding the resultant force from being increased by making the electric motor 15 exhibit the auxiliary power, and the auxiliary power by the electric motor 15 can be adapted to the bicycle. . Moreover, the same auxiliary power can be obtained when the pedal effort is the same as in the first embodiment.
[0034]
In the second embodiment, the range detected value is less than the set value T _S pedaling force detecting means S _T, without changing linearly the assist ratio with respect to the pedal effort, the assist ratio at a specific depression force as shown by a chain line It is also possible to determine the assist ratio so that becomes large.
[0035]
FIG. 8 shows a first reference example. When the pedal effort is equal to or less than the first set pedal effort T ₁ , the assist ratio is set to “1”, and when the pedal effort is equal to or greater than the third preset pedal effort T ₃ , Although set to “3”, the assist ratio increases linearly according to the pedaling force in the range of “1” to “3” in the range exceeding the first setting pedaling force T ₁ and less than the third setting pedaling force T _3. Set to do.
[0036]
According to the first reference example, even a person with a large pedal effort can increase the assist ratio and obtain a large auxiliary power.
[0037]
As shown in FIG. 9 as a second reference example of the present invention, the assist ratio is set to “3” when the pedal effort is equal to or greater than the third set pedal effort T ₃ , but when the pedal effort is less than the third preset pedal effort T ₃ , the assist ratio is set. The ratio may be set so as to increase linearly in accordance with the pedal effort in the range of “1” to “3”.
[0038]
FIG. 10 shows a third reference example of the present invention, and the assist ratio is set according to the pedal effort and the vehicle speed. In FIG. 10, a line indicated by a dotted line indicates when the pedaling force is large, and a line indicated by a solid line indicates when the pedaling force is small. However, regardless of the magnitude of the pedaling force, the second set vehicle speed V ₂ (for example, 15 km / h) In the following low / medium speed range, the assist ratio is set to n (> 1), and in the high speed range exceeding the second set vehicle speed V ₂ , the assist ratio is set at the third set vehicle speed V ₃ (for example, 24 km / h). It is set to gradually decrease as the vehicle speed increases so as to be “0”. By being set to a "n" than thus assist ratio is "1", and it is possible to obtain a large assist power in any human, that Ki out to comfortably run a bicycle.
[0039]
However, if the assist ratio is set large when the pedaling force is large at low speed, there is a possibility that a large current flows and the battery is consumed quickly, or the electric motor 15 is overheated. Therefore, in the low speed range of the first set vehicle speed V ₁ (for example, 5 km / h) lower than the second set vehicle speed V ₂ , the assist ratio is set to “n” constant when the pedal force is small, whereas the pedal force is When the vehicle speed is large, the assist ratio is set so as to gradually decrease from “n” to “1” according to the decrease in the vehicle speed. As shown by the chain line in FIG. 10, the assist ratio according to the decrease in the vehicle speed in the low speed range. The reduction ratio of is set to increase as the pedal effort increases.
[0040]
According to this third reference example, it is possible not only to prevent battery consumption and overheating of the electric motor 15, but also to set the assist ratio relatively large at the start, thereby reducing the wobbling at the start. It is possible to solve the problem and make a smooth start. Further, even when the vehicle is stepped on with a strong force at the time of start, it is possible to prevent the auxiliary power from becoming excessive and prevent a sudden start.
[0041]
FIG. 11 shows a fourth reference example of the present invention, and the assist ratio is set on a three-dimensional map determined by the pedal effort and the vehicle speed. On this three-dimensional map, basically, when the pedal force is in the range from 0 kgf to 70 kgf, the assist ratio is fixed to “3” when the vehicle speed is 5 km / h or less, and the vehicle speed is 5 km / h, for example. When h exceeds 15 km / h, the assist ratio is determined to change linearly from “3” to “1”, and when the vehicle speed exceeds, for example, 15 km / h and 24 km / h, the assist ratio starts from “1”. It is determined to linearly change to “0”, but when the pedal effort is in a range of 35 kgf or more, for example, when the assist ratio is a, the pedal effort is T, and the maximum resultant force is 140 kgf, {a = (140−T ) / T} is set so as not to obtain an assist ratio exceeding a plane (plane indicated by a chain line), and if the pedaling force exceeds 70 kgf, the assist ratio is 0 become ".
[0042]
As in the fourth reference example , when the assist ratio is determined on a three-dimensional map determined by the pedaling force and the vehicle speed, the assist ratio can be smoothly changed in accordance with changes in the pedaling force and the vehicle speed. As a result, a linear feeling appears in the change of the motor, and good drivability can be obtained.
[0043]
Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.
[0044]
【The invention's effect】
As described above, according to the present invention, it is possible to obtain the assist power corresponding to the pedal effort by changing the assist ratio according to the pedal effort. Since the assist power does not change with the same pedal effort, the vehicle travels without a sense of incongruity. it is possible. In addition , the auxiliary power does not change with the same pedaling force in this way, and the auxiliary power is increased for people with weaker pedaling force, but the auxiliary power does not increase without darkness for those with strong pedaling force. be able to.
[0045]
According particularly to the second aspect of the present invention, it is possible to obtain a resultant force resultant force which is the sum of the Stepping force and assisting power is adapted to the bicycle avoids increases thoughtlessly.
[Brief description of the drawings]
FIG. 1 is a side view of a battery-assisted bicycle according to a first embodiment.
FIG. 2 is a vertical side view of the motor unit, and is a cross-sectional view taken along line 2-2 of FIG.
3 is a cross-sectional view taken along line 3-3 of FIG.
FIG. 4 is a block diagram illustrating a configuration of an electric motor control device.
FIG. 5 is a diagram illustrating an assist ratio according to a pedaling force.
FIG. 6 is a diagram showing auxiliary power and resultant force according to the pedal effort.
FIG. 7 is a diagram showing an assist ratio according to the pedal effort in the second embodiment.
FIG. 8 is a diagram showing an assist ratio according to a pedaling force in the first reference example.
FIG. 9 is a diagram illustrating an assist ratio according to a pedaling force in a second reference example.
FIG. 10 is a diagram illustrating an assist ratio according to a vehicle speed and a pedal effort in a third reference example.
FIG. 11 is a diagram showing an assist ratio according to a vehicle speed and a pedal effort in a fourth reference example.
[Explanation of symbols]
15 ... electric motor 31 ... controller S _T ... pedal force detecting means S _V ... vehicle speed detecting means

Claims (2)

A pedal force detection means for detecting a depression force by human power (S _T), the motor-assisted bicycle comprising an electric motor (15) capable of exhibiting auxiliary power in accordance with the detected value of the tread force detecting means (S _T), by human power A controller (31) for controlling the operation of the electric motor (15) by changing an assist ratio, which is a ratio of auxiliary power by the electric motor (15) to the pedaling force, according to a detection value of the pedaling force detection means (S _T ). wherein, said controller (31), when the detected value of the pedal force detection means (S _T) is equal to or more than a set value, the assist ratio as a value greater than 1 said assist ratio is less than but defined in 1, wherein the set value An auxiliary power control device for a battery-assisted bicycle, wherein the operation of the electric motor (15) is controlled. Before SL controller (31), the operation of the electric motor (15) is made smaller than 1 the assist ratio when the detected value of the pedal force detection means (S _T) is greater maximum set value or more than the set value 2. The auxiliary power control device for an electric bicycle according to claim 1, wherein the auxiliary power control device is controlled .

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