JPH0986475A - Auxiliary power assisted bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control an assist ratio with auxiliary power, and grasp the magnitude of a pedal stepping force and auxiliary power. SOLUTION: A resultant force device 55 is formed to have an output rotation member 65, a resultant force rotation member 80 rotationally integrated and freely movable in an axial direction through a ball spline 93, a pedal stepping force transmission member 56. Also, the resultant force device 55 has an auxiliary power transmission member 61, a pedal stepping force transmission torque cam 99 for causing the action of a thrust component proportional to a pedal stepping force, and an auxiliary power transmission torque cam 100 for transmitting auxiliary power and concurrently causing the action of a thrust component. Furthermore, the device 55 has coil springs 102L and 102R for keeping a neutral position E, a position sensor 106 for detecting a travel direction and a travel variable, cam rollers 97R and 97L having a control device for detecting a strength difference between two thrust components, controlling the output of an electric motor 31, keeping the cams 99 and 100 freely rotatable and having rotational center axes orthogonal with a crankshaft 11, and cam grooves 95R and 95L.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary power assisted bicycle in which an electric motor is mounted on the body of a bicycle and the auxiliary power assists the pedaling force to facilitate uphill running and running while receiving a headwind. Regarding

[0002]

2. Description of the Related Art Such an auxiliary power assisted bicycle is provided with a resultant force device which combines a pedaling force applied to a crankshaft and an auxiliary power of an electric motor and outputs the resultant force to a drive wheel side. As the resultant force device, a planetary gear device, a differential device, and the like have been widely used from the past.

When the pedal effort and the auxiliary power are combined by the resultant force device, the assist ratio by the auxiliary power, that is, the ratio of the pedal effort and the auxiliary power is always constant, preferably the assist ratio is always 1: 1. Therefore, it is necessary to control the output of the electric motor so that the pedaling feeling becomes natural and the riding feeling of the auxiliary power assisted bicycle is kept good. And special care must be taken so that the auxiliary power does not exceed the pedal effort in any case.

In the conventional assisted power assisted bicycle, the pedaling force is detected by a dedicated detecting means (torque sensor or the like), and the signal is input to a control device (small CPU or the like), which controls the pedaling force. In accordance with the above, the current supplied to the electric motor is controlled to set the assist ratio to 1: 1 or an arbitrary ratio.

[0005]

However, the accuracy of the detection means for detecting the pedaling force, the output characteristics of the electric motor with respect to the current value, the friction loss of the resultant device, and the like are slightly different from one another. If these small differences are accumulated, the assist ratio easily changes.

Therefore, in order to accurately set the assist ratio to 1: 1 or an arbitrary ratio, not only the accuracy of the pedal depression force detecting means, but also the output characteristics of the electric motor, friction loss of the resultant device, etc. are strictly checked. However, it is necessary to check the output of the electric motor again after assembling all of them, and by adopting such an assembling method, a large increase in cost and a decrease in productivity are inevitable.

Moreover, even if the assist ratio is 1: 1 under the condition that the battery is correctly charged in a new vehicle, if the battery is overcharged and the output of the electric motor is improved, or the running-in operation is performed. If the friction loss of the resultant device is reduced later and the output of the electric motor is relatively improved, the assist power may exceed the pedal effort, so the assist ratio is not necessarily 1: 1.

[0008] If the auxiliary power exceeds the pedal effort, not only will the driving feeling of the auxiliary power assisted bicycle be unnatural, but also an accelerating force unexpected for the occupant will be brought about. It is necessary to set the output of the above to be small so that the auxiliary power does not exceed the pedal effort even when the battery is overcharged or the friction loss of the resultant device is reduced.

However, if the output of the electric motor is set to a small value in advance in case the battery is overcharged or the friction loss of the power unit is reduced, it is possible to reduce the friction loss of the power unit when the battery is properly charged. When the vehicle is large, the output of the electric motor becomes too low, and the assist ratio cannot be maintained at 1: 1.
When the voltage of the battery is decreasing, the output of the electric motor is further weakened, and the assist ratio is further reduced.

Further, since the planetary gear device and the differential device used as the conventional force combiner have a large friction loss and cannot follow a minute torque fluctuation, it is difficult to accurately determine the assist ratio also in this respect.

The present invention has been made in order to solve such a problem, and the auxiliary power that can easily control the assist ratio by the auxiliary power of the electric motor accurately to 1: 1 or an arbitrary ratio. The purpose is to provide an assisted bicycle.

Another object of the present invention related to this is to make it possible to more accurately grasp the magnitudes of the pedal effort and the auxiliary power applied to the resultant device.

And another object of the present invention is to:
To improve the durability of the force combiner by changing the material of each part without disassembling and assembling the force combiner, and to effectively use the dead space inside the force combiner to prevent the size increase of the force combiner. is there.

[0014]

In order to achieve the above object, an auxiliary power assisted bicycle according to the present invention has a crankshaft rotatably driven by pedaling force and an auxiliary power as described in claim 1. An electric motor that is generated and a force combiner that combines the pedal effort and the auxiliary power and outputs the resultant force to the drive wheel side are provided. An output rotary member that transmits the resultant force of the auxiliary power, a resultant rotary member that is provided integrally with the output rotary member via a ball spline so as to be rotatable and axially movable, and a pedal that transmits the pedal effort to the resultant rotary member. A pedaling force transmitting member, an auxiliary power transmitting member for transmitting auxiliary power to the resultant rotating member, and a pedaling force transmitted from the pedaling force transmitting member to the resultant rotating member at the same time as the pedal. When a pedal stepping force transmission torque cam that applies a thrust component force having a strength proportional to the pedaling force from one side of the resultant force rotating member along the axial direction of the crankshaft, and the auxiliary power from the auxiliary power transmitting member is transmitted to the resultant force rotating member. At the same time, an auxiliary power transmission torque cam that applies a thrust component force having a strength proportional to the auxiliary power from the other side of the resultant force rotating member along the axial direction of the crankshaft, and a device that keeps the resultant force rotating member in a neutral position in the axial movement range Biasing means, movement detection means (position sensor) for detecting the movement direction and movement amount from the neutral position of the resultant force rotating member that moves in the axial direction by receiving the two thrust component forces, and input from the movement detection means And a controller for controlling the output of the electric motor so that the strength difference between the two thrust components is detected based on And a cam roller whose rotation center axis is orthogonal to the crankshaft and which is provided rotatably between the pedal depression force transmission member and the auxiliary power transmission torque member, and the resultant rotation member. And a cam groove formed in a spiral direction with which the cam roller is engaged.

In the auxiliary power assist type bicycle according to the present invention, as described in claim 2, a shaft supporting surface provided on the pedal effort transmitting member and a shaft supporting surface provided on the auxiliary power transmitting member. Are arranged so as to be separated from each other in the axial direction of the crankshaft, and the resultant rotary member is rotatably supported by straddling between the two shaft supporting surfaces.

Further, in the auxiliary power assisted bicycle according to the present invention, as described in claim 3, the resultant rotary member is formed so that the ball spline constituent portion and the cam constituent portion are separate bodies. The ball spline component and the cam component are assembled by screw fastening.

In the auxiliary power assisted bicycle according to the present invention, as described in claim 4, the ball spline forming portion of the resultant rotating member and the screw fastening portion of the cam forming portion are connected to the shaft of the pedal depression force transmitting member. It was provided on the outer circumference of the supporting surface.

[0018]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a left side view of an auxiliary power assisted bicycle according to the present invention.

This auxiliary power assisted bicycle 1 is provided with a body frame 2 made of, for example, a metal tube, and a front fork 4 supporting a front wheel 3 is provided on a front head of the body frame 2 with a handlebar 5 and a basket 6. The rear wheel 7 is pivotally supported on the rear portion of the body frame 2, and the saddle 8 is mounted on the upper center of the body frame 2.
Is installed.

At the lower center of the body frame 2, an auxiliary power assist device 10 having an electric motor built therein is mounted. A crank shaft 11 extending in the vehicle width direction is rotatably supported by the auxiliary power assist device 10.
A crank 12L and a crank 12R are rotatably and integrally fixed to both ends of the pedal 11, and pedals 13 are rotatably provided at the tips of the cranks 12L and 12R, respectively.

A drive sprocket 15 located on the right side of the auxiliary power assist device 10 is mounted on the crankshaft 11 between the drive sprocket 15 and the driven sprocket 16 provided on the rear wheel 7. Chain 17
Is wrapped around.

The crankshaft 11 is rotationally driven in the forward rotation direction indicated by the arrow A when an occupant seated on the saddle 8 depresses the pedal 13 with his / her foot.
Rotates in the same direction as the crankshaft 11, and this rotation is transmitted to the driven sprocket 16 by the chain 17 and the rear wheel 7
Is driven.

Further, a battery unit 20 for operating an electric motor incorporated in the auxiliary power assist device 10 is fixed to the front half of the vehicle body frame 2. This battery unit 20 includes, for example, a dozen small batteries 21.
And a charger (not shown) are sealed in the battery case 22. The auxiliary power assist device 10
At the upper part of the control device 23 for controlling the output of the electric motor
Is attached. The control device 23 is, for example, a small CPU.

FIG. 2 is a cross-sectional view of the auxiliary power assisting device 10, and FIG. 3 is a left side view of the auxiliary power assisting device 10 taken along the line III-III of FIG.

The casing 25 forming the outer shell of the auxiliary power assist device 10 is made of, for example, an aluminum alloy, and has a left side case 25L, a center case 25M and a right side case 25R as shown in FIG. The structure is fixed with bolts 26. Note that FIG. 3 shows a state in which the left side case 25L is removed.

The crankshaft 11 is rotatably supported by bearings 27 and 28 at the rear portion of the casing 25, and the cranks 12L and 12R have bolts 29 at both ends of the crankshaft 11 protruding left and right from the casing 25. Fixed by.

The above-mentioned electric motor is provided at the front of the casing 25.
31 are installed. The electric motor 31 generates auxiliary power, and its outer case 32 is fixed to the center case 25M by several bolts 33.

A main shaft 34 of the electric motor 31 is parallel to the crankshaft 11, and a drive shaft 37 is rotatably connected to a left end of the main shaft 34 via a tubular joint member 36 pivotally supported by a bearing 35. ing. The left end of the drive shaft 37 is supported by a bearing 38 provided on the left side case 25L side, and the drive shaft 37 is provided with a primary drive gear 40 so as to rotate integrally.

A first intermediate shaft 41 and a second intermediate shaft 42 are installed between the drive shaft 37 and the crank shaft 11. A primary driven gear 43 that meshes with the primary drive gear 40 is axially supported by a first intermediate shaft 41 via a one-way clutch 44, and a boss 45 of the primary driven gear 43 extends rightward and is provided on the center case 25M side. The bearing 46 is pivotally supported. The left end of the first intermediate shaft 41 is supported by a bearing 47 provided on the left side case 25L side, and a secondary drive gear 48 is rotatably integrated with the first intermediate shaft 41 between the bearing 47 and the primary driven gear 43. Has been.

A secondary driven gear 49 meshing with the secondary drive gear 48 is rotatably supported by a second intermediate shaft 42, and a tertiary drive gear 50 rotatably integrated with the secondary driven gear 49 is provided on the right side of the secondary driven gear 49. It is meshed with a tertiary driven gear 51 rotatably supported by the crankshaft 11.

As shown in FIG. 3, the drive shaft 37 and the primary drive gear 40 rotate in the rotational direction indicated by the arrow B, the primary driven gear 43 and the secondary drive gear 48 in the rotational direction C, and the secondary driven gear 49. The tertiary drive gear 50 rotates in the rotational direction D, and the tertiary driven gear 51 rotates in the rotational direction A of the crankshaft 11.

The one-way clutch 44 provided on the primary driven gear 43 transmits only the rotation of the primary driven gear 43 in the C direction to the first intermediate shaft 41 and the secondary drive gear 48.
When the rotation speed of the first intermediate shaft 41 and the secondary drive gear 48 exceeds the rotation speed of the primary driven gear 43, the one-way clutch 44 is disconnected and the first intermediate shaft 41 and the secondary drive gear 48 idle. It is supposed to do.

On the other hand, in the rear portion of the casing 25, a force combiner 55
Is installed. FIG. 4 is an enlarged transverse cross-sectional view of a portion of the resultant device. The resultant device 55 is provided coaxially with the crankshaft 11, and is configured as follows, for example.

First, a substantially cylindrical pedal depression force transmission member 56 is rotatably supported on the crankshaft 11 via a metal bearing 57. A diameter of the right end portion of the pedal effort transmission member 56 is enlarged to form a clutch housing 58, and a one-way clutch 59 is provided inside the clutch housing 58. The one-way clutch 59 transmits only the rotation of the crankshaft 11 in the normal direction A to the pedal depression force transmission member 56, and when the crankshaft 11 reversely rotates or the rotation speed of the pedal depression force transmission member 56 changes the rotation speed of the crankshaft 11. It is configured to disconnect the clutch when the value exceeds the limit. A cam roller holder 60, which extends cylindrically to the left, is integrally formed on the outer peripheral portion of the clutch housing 58.

Further, an auxiliary power transmission member 61 is rotatably mounted on the outer periphery of the left end portion of the pedal effort transmission member 56 while being axially restricted by a circlip 62. The auxiliary power transmission member 61 is integrally formed with a cam roller holder 63 extending rightward in a cylindrical shape, and the above-mentioned tertiary driven gear 51 is integrally provided on the outer periphery of the auxiliary power transmission member 61. Therefore, the tertiary driven gear 51
Rotation of the electric motor 31, that is, the auxiliary power of the electric motor 31
The rotation decelerated by 8,49,50 is directly transmitted to the auxiliary power transmission member 61.

On the other hand, an output rotary member 65 is rotatably supported near the right end of the crankshaft 11. The output rotating member 65 includes a disc-shaped output disc 66 and the output disc 66.
It is composed of three parts, a cylindrical output joint 67 and an output slider 68, which are sequentially connected to the left side of 66. These three parts 66 to 68 are concentrically positioned by knock pins 69 and 70, and are connected by screws 71. ing.

An output boss 73 is formed at the right end of the output disk 66, and a bearing 74 arranged in the output boss 73 rotatably supports the entire output rotary member 65 around the crankshaft 11. This output boss 73 is a casing 25 (right side case 25
R) protrudes to the outside, and the drive sprocket 15 described above is rotationally fixed integrally therewith by a connecting means such as a spline or a screw. A plurality of inner peripheral spline grooves 76 extending in the axial direction are formed on the inner periphery of the output joint 67 and the output slider 68 (see also FIG. 3).

The output rotary member 65 is prevented from moving in the axial direction by the circlip 77, and the circlip 78 mounted on the right end of the pedal depression force transmitting member 56 includes the output disc 66 and the output joint 67 of the output rotary member 65. Since it is sandwiched between and, the movement of the pedal effort transmission member 56 in the axial direction is also prevented. The pedal effort transmission member 56 and the output rotation member 65
The relative rotation between is free.

Then, the output disc 66 of the output rotating member 65.
A resultant force rotating member 80 is provided on the inner peripheral side of the output joint 67. The resultant force rotating member 80 includes a resultant housing 81 formed in a substantially cylindrical shape, and a cam sleeve similarly formed in a substantially cylindrical shape and fixed inside the resultant housing 81.
82 and an annular position sensor ring 83 fixed to the outside of the resultant housing 81. An annular groove 84 is formed on the outer periphery of the position sensor ring 83.

By the way, a cylindrical shaft support surface 86 is formed on the outer periphery of the clutch housing 58 of the pedal effort transmission member 56, and a cylindrical shaft support surface 87 is also formed on the outer periphery of the auxiliary power transmission member 61. Has been formed. These two bearing surfaces 86,87
Are located apart from each other in the axial direction of the crankshaft 11, and the resultant rotary member 80 is axially supported so as to straddle between the shaft supporting surfaces 86 and 87.

FIG. 5 is a view showing only the cam sleeve 82 with the resultant housing 81 removed from the resultant rotary member 80. As shown in this figure, a male screw 88 is formed on the right end of the cam sleeve 82, and this male screw 88 is used as a resultant housing.
Both parts 81, 82 are integrally fixed by being fastened to a female screw 89 (shown in FIG. 4) formed on the right end of the inner peripheral portion of 81. The cam sleeve 82 is screwed tightly until its right end abuts an inner flange 90 formed at the right end of the resultant housing 81. In addition, male screw 88 and female screw
89 is arranged so as to be located on the outer periphery of the shaft support surface 86 of the pedal effort transmission member 56. Also, these screw parts 88, 89
Is formed as a left-hand thread. On the other hand, the position sensor ring 83 is fixed to the outer side of the resultant housing 81 by fixing means such as press fitting or caulking.

The resultant housing 81 serves as the ball spline forming portion described in claim 3, and a plurality of outer peripheral spline grooves 91 extending in the axial direction are engraved on the outer periphery thereof (see also FIG. 3). Steel balls 92 are arranged between the spline groove 91 and the inner peripheral spline groove 76 of the output rotary member 65 to form a ball spline 93. With the ball spline 93, the resultant rotation member 80 is integrally rotated with the output rotation member 65, and is kept movable in the axial direction.

Further, the cam sleeve 82 of the resultant force rotating member 80 constitutes the cam forming portion described in claim 3. FIG.
As shown in, the cam sleeve 82 is formed with a pair of left and right cam grooves 95R, 95L extending in a V shape in the spiral direction.
The cam grooves 95R and 95L are formed, for example, in three sets at intervals of 120 ° in the circumferential direction of the cam sleeve 82, the cam grooves 95R are inclined in the left-hand screw direction, and the cam grooves 95L are formed in the right-hand screw direction. To be done. As shown in FIGS. 2 and 4, a center flange 96 that stands up inward is formed between the cam grooves 95R and 95L. The inner diameter of the center flange 96 is slightly larger than the outer diameter of the intermediate portion of the pedal effort transmission member 56.

On the other hand, the cam roller holder 60 formed on the pedal depression force transmission member 56 and the cam roller holder 63 formed on the auxiliary power transmission member 61 are provided on the outer peripheral surfaces thereof at intervals of 120 ° in the circumferential direction. 97R and 97L are provided. These cam rollers 97R and 97L are rotatably supported by the roller pin 98, and the rotation center axes of the cam rollers 97R and 97L (the axis of the roller pin 98) are orthogonal to the crankshaft 11.

The cam roller 97R on the pedal depression force transmitting member 56 side is engaged with the cam groove 95R of the cam sleeve 82 to form the pedal depression force transmitting torque cam 99, and the cam roller 97L on the auxiliary power transmitting member 61 side is changed to the cam sleeve 82. The cam groove 95
The auxiliary power transmission torque cam 100 is configured by being engaged in L. The diameters of the cam rollers 97R and 97L are such that the cam rollers 97R and 97L can freely roll in the cam grooves 95R and 95L.
Moreover, the size of the cam grooves 95R and 95L is set so as not to rattle in the width direction.

The pedal tread force transmission torque cam 99 applies the pedal tread force P as indicated by a vector in FIG. 5 when the pedal tread force transmission member 56 receives the rotation of the crankshaft 11 (pedal tread force) and rotates in the A direction. Force rotating member 80 (cam sleeve 82)
At the same time, the thrust component force p having a strength proportional to the pedal effort P is generated, and the thrust component force p presses the cam sleeve 82 to one side, for example, to the left.

Further, the auxiliary power transmission torque cam 100 has the auxiliary power transmission member 61 receiving the auxiliary power of the electric motor 31 and
When rotating in the direction, the auxiliary power M is transmitted to the cam sleeve 82, and at the same time, a thrust component force m having a strength proportional to the auxiliary power M is generated, and the thrust component force m causes the cam sleeve 82 to move to the other side. For example, pressing to the right.

Further, a pair of left and right coil springs 102R and 102L are provided on the inner peripheral sides of the pedal depression force transmission torque cam 99 and the auxiliary power transmission torque cam 100. These coil springs 102R, 102L serve as the biasing means described in claim 1, and the coil spring 102R on the right side.
Is mounted between the center flange 96 of the cam sleeve 82 and the clutch housing 58 of the pedal effort transmission member 56, and the left coil spring 102L is mounted between the center flange 96 and the auxiliary power transmission member 61. . The left and right coil springs 102R and 102L have the same shape and the same spring constant.

The clutch housing 58 and the auxiliary power transmission member 61 of the pedal effort transmission member 56 are immovable in the axial direction of the crankshaft 11, and the center flange 96 between them is movable in the axial direction of the crankshaft 11. , When the center flange 96 is pressed from the left and right sides by the two coil springs 102R and 102L having the uniform biasing force, the biasing forces are balanced at the position E where the lengths of both coil springs 102R and 102L are equal. The center flange 96 stops. This position E is a neutral position of the resultant force rotating member 80 (center flange 96).
It is set to be the midpoint of the range that can be moved in the axial direction of.

The resultant device 55 is constructed as described above. A disc-shaped sensor plate 103 is provided adjacent to the left side of the resultant device 55 so as to rotate integrally with the crankshaft 11, and the sensor plate 103 has a gear-shaped concave-convex shape 104 formed on the outer periphery thereof. There is. On the other hand, as shown in FIG. 3, a rotation speed sensor 105 is installed in the casing 25 (25M), and this rotation speed sensor 105 is mounted on the sensor plate.
103 The rotation speed of the crankshaft 11 is detected by reading the movement of the uneven shape 104 on the outer circumference.

A position sensor 106, which is also shown in FIG. 6, is provided below the force combiner 55. The position sensor 106 serves as the movement detecting means described in claim 1. Position sensor 106 has bolt 10
The miniature bearing 109, which is fixed to the lower surface of the casing 25 by 7 and is pivotally supported by the tip of the rotating arm 108 provided on the upper surface, is slidably fitted in the sensor groove 84 of the position sensor ring 83. ing.

When the resultant force rotating member 80 moves in the axial direction of the crankshaft 11, the position sensor ring 83 also moves in the axial direction together with the resultant force rotating member 80.
The rotation arm 108 of 6 rotates, and the movement direction and the movement amount from the neutral position E of the resultant rotation member 80 are detected.

The position sensor 106 is electrically connected to the control device 23 as shown in FIG. 7, and the moving direction and the moving amount of the resultant force rotating member 80 measured by the position sensor 106 are input to the control device 23. It has become so. The controller 23 is electrically connected to the battery unit 20, the electric motor 31, the rotational speed sensor 105 and other devices.

Next, the operation of the auxiliary power assist type bicycle 1 thus constructed will be described.

When the auxiliary power assisted bicycle 1 is running, the crankshaft 11 receives a pedaling force and rotates in the direction A, and the rotation of the crankshaft 11 is transmitted to the pedaling force transmitting member 56 via the one-way clutch 59 of the force combiner 55. Then, the pedal effort transmission member 56 is rotationally driven in the A direction. on the other hand,
The auxiliary power of the electric motor 31 is six gears 40, 43, 48, 49, 50, 5
The speed is reduced in three stages by 1 and transmitted to the auxiliary power transmission member 61, and the auxiliary power transmission member 61 is also rotationally driven in the A direction.

Pedal pedal force transmission member 56 and auxiliary power transmission member
The rotational force of 61 passes through the pedal depression force transmission torque cam 99 and the auxiliary power transmission torque cam 100, respectively, and the resultant force rotation member 80
And the resultant rotary member 80 rotates the output rotary member 65 in the A direction via the ball spline 93. The rotational force of the output rotary member 65 is the resultant force of the pedal effort and the auxiliary power, and the resultant force is output to the rear wheel 7 which is the drive wheel by the drive sprocket 15, the chain 17 and the driven sprocket 16. Therefore, the pedaling force is assisted by the auxiliary power of the electric motor 31, and the auxiliary power assisted bicycle 1 can be easily traveled even with a small pedaling force.

The pedal depression force transmission torque cam 99 and the auxiliary power transmission torque cam 100 transmit the rotational forces of the pedal depression force transmission member 56 and the auxiliary power transmission member 61 to the resultant force rotation member 80, and at the same time, as shown in FIG. Since two thrust component forces p and m having a strength proportional to the auxiliary power M are applied to (the cam sleeve 82 of) the resultant force rotating member 80 from both left and right sides, the resultant force rotating member 80 is left and right sides due to the thrust component forces p and m. Is pressed from.

When the assist ratio is 1: 1, that is, when the pedaling force P and the auxiliary power M are equal in intensity,
Since the strengths of the two thrust component forces p and m acting from both sides of the resultant force rotating member 80 are equalized and cancel each other out, as shown in FIGS. 4 and 8 (B), the resultant force rotating member 80 (center flange 96 The position of) is kept in the neutral position E.

However, when the assist ratio is not 1: 1, the strengths of the two thrust component forces p and m become unequal, so that the resultant force rotating member 80 presses the thrust component force p or m of the stronger one. Then, the crankshaft 11 is moved in the axial direction.
For example, if the pedaling force P is stronger than the auxiliary power M, the thrust component force p of the pedaling force P becomes stronger than the thrust component force m of the auxiliary power M, so that the resultant force rotating member 80 (center flange 96) has a thrust component force. It is pushed by p and moves to the left of the neutral position E as shown in FIG. 8 (A).

If the auxiliary power M is stronger than the pedaling force P, the thrust component force m of the auxiliary power M is stronger than the thrust component force p of the pedaling force P, so the resultant force rotating member 80.
The (center flange 96) is pressed by the thrust component m and moves to the right of the neutral position E as shown in FIG. 8 (C).

Then, the movement direction and the movement amount of the resultant rotary member 80 (center flange 96) from the neutral position E are read by the position sensor 106, and the data is inputted to the control device 23. The controller 23 is a position sensor
Based on the input from 106, the strength difference between the two thrust components p and m is detected, and the electric motor 31 is adjusted so that the difference becomes zero.
Control the output of. That is, when the resultant force rotating member 80 is moved to the left of the neutral position E as shown in FIG. 8 (A), the output of the electric motor 31 is improved, and the resultant force rotating member 80 is moved as shown in FIG. 8 (C). When moving to the right of the neutral position E, the output of the electric motor 31 is reduced. As a result, the resultant device 55
Is maintained in the state of FIG. 8 (B), and the assist ratio is always 1: 1
Kept in.

The assist ratio can be set not only to 1: 1 but also to an arbitrary ratio by making the controller 23 arbitrarily set the strength difference between the two thrust components p and m. For example, a pair of strength differences between two thrust component forces p and m
When set to 0.5, the auxiliary power M for the pedal effort P
Is halved.

It is also possible to continuously change the ratio of this intensity difference during traveling. For example, when the assist power assisted bicycle 1 is started, the assist ratio is set to 1: 1 which is the maximum ratio, and the assist ratio is reduced as the vehicle speed increases, so that the load of human power is reduced and the power consumption of the electric motor 31 is reduced. It can be largely omitted, and the amount of discharge of the battery unit 20 can be suppressed to greatly extend the traveling distance.

Further, the control device 23 uses the rotation speed sensor 105.
The vehicle speed is judged from the rotation speed of the crankshaft 11 input from the electric motor 31 when the vehicle speed exceeds a certain value.
Reduce the power supply to the vehicle or set it to 0 to prevent the vehicle speed from becoming excessive.

This auxiliary power assisted bicycle 1
Can also be driven only by the pedal effort without operating the electric motor 31. In this case, the entire force combiner 55 rotates in the A direction together with the drive sprocket 15 in response to the pedaling force, and the rotation of the drive sprocket 15 is transmitted to the rear wheel 7. At this time, the third driven gear 51 together with the resultant device 55.
Also rotates in the A direction, and the tertiary drive gear 50, the secondary driven gear 49, the secondary drive gear 48, and the first intermediate shaft 41 are reversely driven, but the one-way clutch 44 is disconnected, so that the primary driven gear 43 The primary drive gear 40 does not rotate, so that reverse driving of the electric motor 31 is prevented and the pedal effort is kept light.

As described above, the auxiliary power assist type bicycle 1
With this configuration, since the assist ratio is directly and mechanically detected at the part of the force combiner 55 where the pedal effort and the auxiliary power are combined, the assist ratio can be accurately calculated without error. For this reason, the pedal depression force applied to the crankshaft 11 is detected once, and the electric motor is adjusted accordingly.
There is no need to control the output of 31, and detection means such as a torque sensor for detecting the pedal effort is unnecessary.

Therefore, it is not necessary to consider the error of the pedal depression force detecting means, and the output ratio of the electric motor 31 is set because the assist ratio is set to 1: 1 or an arbitrary ratio by the net output of the electric motor 31. , The charge state of the battery unit 20, or the influence of the friction loss of the force combiner 55 before and after the break-in operation on the assist ratio can be completely ignored, and the assist ratio can be controlled accurately and easily. You can

Moreover, since the position sensor 106 only needs to read the strength difference between the thrust component forces p and m, which are significantly smaller than the absolute values of the pedal effort and the auxiliary power, the reading error of the position sensor 106 can be made very small. It is possible to control the assist ratio accurately.

Further, since the pedal depression force transmission torque cam 99 and the auxiliary power transmission torque cam 100 of the force combiner 55 are constituted by rollers, the resistance during operation is very small and the movement is smooth. Therefore, even if the ratio of the component force p of the pedaling force P and the component force m of the auxiliary power M slightly changes, the resultant force rotating member 80 can sensitively detect and follow this minute change in the ratio. Therefore, the assist ratio can be controlled more accurately. Since grease can be filled in the cam grooves 95R, 95L, the lubricity of both torque cams 99, 100 is greatly improved and the durability is also improved.

In addition to this, the resultant force rotating member of the resultant device 55.
80 is a bearing surface 86 of the pedal depression force transmission member 56 and a bearing surface of the auxiliary power transmission member 61, which are spaced apart in the axial direction of the crankshaft 11.
Since it is axially supported across 87, the resultant force rotating member
The core runout for the entire crankshaft 11 is minimized,
As a result, the shake of the position sensor ring 83 becomes very small. Therefore, the position of the resultant force rotating member 80 is accurately detected, and the magnitudes of the pedal effort and the auxiliary power applied to the resultant device 55 can be accurately grasped.

The resultant force rotating member 80 is constructed so that the resultant force housing 81, which is the ball spline constituent portion, and the cam sleeve 82, which is the cam constituent portion, are separate bodies. The material of the cam sleeve 82 is different, and the material suitable for each is selected, and the resultant device
The durability of 55 can be improved remarkably. Also, since both parts 81 and 82 are assembled by screw fastening, they can be easily disassembled, and
The material of each part can be changed without degrading 80) and assembling.

Since the female screw 89 of the resultant housing 81 and the male screw 88 of the cam sleeve 82 are formed as a left screw, the cam sleeve 82 is tightened in the resultant housing 81 when being rotationally driven in the A direction. . Therefore, the coupling between the resultant housing 81 and the cam sleeve 82 does not loosen during operation.

The screw fastening portions of the resultant force housing 81 and the cam sleeve 82 are arranged on the outer periphery of the shaft supporting surface 86 of the pedal effort transmitting member 56, whereby the dead space at the outer periphery of the clutch housing 58 of the pedal effort transmitting member 56. Can be effectively used, and the resultant device 55 can be prevented from becoming large.

By the way, in the resultant force device 55, for example, when there is a difference in the operability of the pedal depression force transmission torque cam 99 and the auxiliary power transmission torque cam 100, or when there is a difference in the spring constants of the left and right coil springs 102R and 102L. , It is possible that the neutral position E of the resultant rotary member 80 is slightly deviated and the assist ratio is changed. In that case, the neutral read value of the position sensor 106 is simply reset according to the deviated neutral position E. Since the ratio can be accurately returned to 1: 1, the maintainability is very good.

[0075]

As described above, the auxiliary power assisted bicycle according to the present invention has a crankshaft which is rotationally driven by pedaling force, an electric motor which generates auxiliary power,
The pedaling force and the auxiliary power are combined, and a resultant force device for outputting the resultant force to the driving wheel side is provided.
An output rotary member that is axially supported by the crankshaft and transmits the resultant force of the pedal depression force and auxiliary power to the drive wheel side, and a resultant rotation provided integrally with the output rotary member via a ball spline so as to be rotatable and axially movable. A member, a pedal depression force transmission member that transmits a pedal depression force to the resultant force rotation member, an auxiliary power transmission member that transmits auxiliary power to the resultant force rotation member, and a pedal depression force transmitted from the pedal depression force transmission member to the resultant force rotation member. At the same time, a pedal depression force transmission torque cam that applies a thrust component force having a strength proportional to the pedal depression force P from one side of the resultant rotation member along the axial direction of the crankshaft,
An auxiliary power transmission torque cam for transmitting the auxiliary power from the auxiliary power transmission member to the resultant force rotating member and at the same time causing a thrust component having a strength proportional to the auxiliary power to act from the other side of the resultant force rotating member along the axial direction of the crankshaft. And biasing means for keeping the resultant force rotating member at a neutral position in the axial movement range, and detecting the moving direction and the amount of movement from the neutral position of the resultant force rotating member that moves in the axial direction by receiving the two thrust component forces. Based on the input from the movement detecting means (position sensor) and the movement detecting means, the strength difference between the two thrust component forces is detected, and the output of the electric motor is adjusted so that the strength difference becomes 0 and an arbitrary strength difference. And a control device for controlling, wherein the pedal depression force transmission torque cam and the auxiliary power transmission torque cam are rotatable between the pedal depression force transmission member and the auxiliary power transmission member. A cam roller rotation center shaft provided perpendicular to the crankshaft, is formed in the helical direction to force the rotating member is characterized in that it has structure and a cam groove in which the cam roller is engaged.

According to this structure, since the assist ratio is directly and mechanically detected in the resultant device, the assist ratio can be accurately determined without error, and the net output of the electric motor can be used to determine the assist ratio. Since the ratio is set to 1: 1 or an arbitrary ratio, there is no influence on the assist ratio due to variations in the output characteristics of the electric motor, the state of charge of the battery unit, or changes in friction loss of the force combiner before and after running-in. It can be ignored and the assist ratio can be controlled accurately and easily.

Moreover, since the pedal depression force transmission torque cam and the auxiliary power transmission torque cam are of roller type, the resistance during operation of the pedal depression force transmission torque cam and the auxiliary power transmission torque cam can be made extremely small, whereby the assist ratio can be increased. It can be controlled more accurately.

In the auxiliary power assisted bicycle according to the present invention, the shaft supporting surface provided on the pedal effort transmitting member and the shaft supporting surface provided on the auxiliary power transmitting member are separated from each other in the axial direction of the crankshaft. Since the resultant rotary member is axially supported by straddling between the two shaft supporting surfaces,
The center runout of the entire resultant rotating member with respect to the crankshaft is minimized, and the position detection of the resultant rotating member becomes accurate. Therefore, it is possible to more accurately grasp the magnitudes of the pedal effort and the auxiliary power applied to the resultant device.

Further, in the auxiliary power assisted bicycle according to the present invention, the resultant force rotating member is formed such that the ball spline forming portion and the cam forming portion are separate bodies, and the ball spline forming portion and the cam forming portion are formed. Since the parts are assembled by screw fastening, it is possible to greatly improve the durability of the resultant device by making the materials of the ball spline forming part and the cam forming part different from each other and selecting a suitable material for each. Also, the ball spline component and the cam component are assembled by screw fastening, so disassembly is easy,
It is possible to change the material of each part without impairing the disassembling and assembling of the resultant device.

In the auxiliary power assisted bicycle according to the present invention, the ball spline forming portion of the resultant rotating member and the screw fastening portion of the cam forming portion are arranged on the outer periphery of the shaft supporting surface of the pedal depression force transmitting member. It is possible to effectively use the internal dead space, and prevent the resultant device from becoming large.

[Brief description of drawings]

FIG. 1 is a left side view of an auxiliary power assist type bicycle according to the present invention.

FIG. 2 is a cross-sectional view of an auxiliary power assist device showing an embodiment of the present invention.

3 is a left side view of the auxiliary power assist device taken along the line III-III of FIG.

FIG. 4 is an enlarged transverse cross-sectional view of the resultant device.

FIG. 5 is a view showing only the cam sleeve with the resultant housing removed from the resultant rotary member.

FIG. 6 is a plan view showing a position sensor.

FIG. 7 is a block diagram showing a control system of the auxiliary power assist device.

FIG. 8 is a vertical cross-sectional view showing an operating state of the force combiner, where (A) shows a case where the pedal effort is stronger than the auxiliary power, (B) shows a case where the pedal effort and the auxiliary power are equal, and (C). Indicates the case where the auxiliary power is stronger than the pedal effort.

[Explanation of symbols]

1 Auxiliary power assist type bicycle 3 Auxiliary power assist device 7 Rear wheel which is a driving wheel 11 Crankshaft 23 Control device 31 Electric motor 55 Combiner device 56 Pedal pedal force transmitting member 61 Auxiliary power transmitting member 65 Output rotating member 80 Combined rotating member 81 Combined force Combined force housing which is a ball spline forming part of the rotating member 82 Cam sleeve which is a cam forming part of the combining force rotating member 86 Shaft supporting surface provided on the pedal depression force transmitting member 87 Shaft supporting surface provided on the auxiliary power transmitting member 93 Ball spline 95R, 95L Cam groove 97R, 97L Cam roller 99 Pedal pedal force transmission torque cam 100 Auxiliary power transmission torque cam 102L, 102R Coil spring as biasing means 106 Position sensor as movement detecting means P Vector indicating pedal pedal force M Vector indicating auxiliary power p Pedal pedal force Vector m indicating the thrust component force with strength proportional to The neutral position of the vector E resultant rotary member showing a thrust component force having an intensity of Example

Claims (4)

[Claims] 1. A crankshaft 11, which is rotationally driven by a pedal effort, an electric motor 31 which generates auxiliary power, and a resultant force device 55 which combines the pedal effort and auxiliary power and outputs the resultant force to the drive wheel side. The output rotation member 65 that is supported by the crankshaft 11 and transmits the resultant force of the pedal depression force and the auxiliary power to the drive wheels, and the output rotation member 65 through the ball spline 93. A resultant force rotating member 80 provided integrally and movably in the axial direction, a pedal stepping force transmitting member 56 for transmitting a pedaling force to the resultant force rotating member 80, and an auxiliary power transmitting member 61 for transmitting auxiliary power to the resultant force rotating member 80. And the pedal effort from the pedal effort transmitting member 56 is transmitted to the resultant force rotating member 80, and at the same time the pedal effort P
Pedal force transmission torque cam 99 that exerts a thrust component p having a strength proportional to the above from one side of the resultant rotation member 80 along the axial direction of the crankshaft 11, and the auxiliary power transmission member 61.
Auxiliary power transmission torque cam for transmitting the auxiliary power from the resultant rotary member 80 to the resultant rotary member 80, and at the same time applying a thrust component m having strength proportional to the auxiliary power M from the other side of the resultant rotary member 80 along the axial direction of the crankshaft 11. 100 and the resultant rotation member 80
From the neutral position E of the resultant force rotating member 80 that moves in the axial direction by receiving biasing means (for example, coil springs 102L and 102R) that keeps the axial position in the neutral position E in the axial movement range. Of the thrust components p and m based on the input from the movement detecting means (for example, the position sensor 106) and the movement detecting means for detecting the movement direction and the movement amount of the two. 0 and a control device 23 for controlling the output of the electric motor 31 so as to obtain an arbitrary strength difference. Further, the pedal depression force transmission torque cam 99 and the auxiliary power transmission torque cam 100 are connected to the pedal depression force transmission member 56 and the auxiliary power transmission. Cam rollers 97R and 97L that are rotatably provided on the transmission member 61 and have a rotation center axis orthogonal to the crankshaft 11, and the cam rollers 97R and 97L that are formed in the resultant rotation member 80 in a spiral direction. Is the cam groove 95R,
An auxiliary power assist type bicycle characterized by being configured with 95L. 2. A shaft supporting surface provided on the pedal effort transmitting member 56.
86, and the shaft support surface 87 provided on the auxiliary power transmission member 61 is configured to be spaced apart in the axial direction of the crankshaft 11,
The auxiliary power assist type bicycle according to claim 1, wherein the resultant force rotating member 80 is rotatably supported by straddling the two shaft supporting surfaces 86, 87. 3. The resultant force rotating member 80 is formed so that the ball spline forming portion (resulting force housing 81) and the cam forming portion (cam sleeve 82) are separate bodies, and the ball spline forming portion and the cam forming portion. The auxiliary power assisted bicycle according to claim 1, wherein the parts are assembled by screw fastening. 4. The ball spline forming part (81) of the resultant force rotating member 80 and the screw fastening parts (male screw 88 and female screw 89) of the cam forming part (82) are attached to the shaft supporting surface 86 of the pedal depression force transmitting member 56.
The auxiliary power assisted bicycle according to claim 3, wherein the auxiliary power assisted bicycle is arranged on the outer circumference.