JPH0796881A - Driving force auxiliary device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a driving force assisting device that can detect a load element on the pedal side and a vehicle speed element in a combined form and does not require a separate vehicle speed detecting means. A drive force assisting device for transmitting a drive force of a motor 22 to a drive force transmitting means for transmitting a drive force of a pedal force driving means to a drive wheel, and a drive force assisting device rotating in response to rotation of a drive wheel in a drive force assisting device. Movable piece 38 fitted to 35 and rotating together with the drive transmission member 35, displacement means 36d, 39 for displacing movable piece 38 according to the load on the pedal side by the pedal manual driving means, and movement of movable piece 38 Detecting means 42 for detecting
And a control means for controlling the drive force of the motor 22 based on the detection signal of the detection means 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force assisting device for assisting human power by equipping a vehicle driven by human power with a motor.

[0002]

2. Description of the Related Art This type of driving force assisting device has an example (Japanese Patent Laid-Open No. 4-100790) of controlling the output of an electric motor by detecting the load on the pedal side of a human power drive system. Used a potentiometer to detect changes in the relative angles of both ends of a torsion rod spring provided on the pedal shaft, or used a strain gauge to detect the load on the pedal side.

[0003]

[Problems to be solved] Control of a motor for human power assistance is
It is controlled not only by the load on the pedal side but also by the vehicle speed,
For example, when the vehicle speed exceeds a certain level, the control by the motor is stopped.

Therefore, a device for detecting the vehicle speed is required, and the potentiometer or the like for detecting the load cannot be used for detecting the vehicle speed, and a separate vehicle speed detecting means must be provided.

The present invention has been made in view of the above point, and the object thereof is to detect the load element and the rotational speed element on the pedal side in one place and to provide a vehicle speed detecting means separately. There is no driving force auxiliary device.

[0006]

In order to achieve the above object, the present invention assists the human power by transmitting the driving force of the motor to the drive transmission means for transmitting the driving force of the pedal human power drive means to the drive wheels. In the driving force assisting device, a movable piece that fits into a drive transmission member that rotates in response to rotation of a drive wheel and that rotates together with the drive transmission member, and the movable piece that moves in accordance with the load on the pedal side by the pedal manual drive means. The driving force assisting device is provided with a displacement means for displacing the piece, a detection means for detecting the movement of the movable piece, and a control means for controlling the driving force of the motor based on the detection signal of the detection means.

Since the movable piece rotates corresponding to the drive wheel and is displaced according to the load on the pedal side, the load element and the rotational speed element on the pedal side are detected by detecting the movement of this movable piece. It is possible to detect both of them in one place, and it is not necessary to separately provide a vehicle speed detecting means, so that the number of parts can be reduced and the assembling work can be simplified.

[0008]

EXAMPLES An example of the present invention shown in FIGS. 1 to 9 will be described below. FIG. 1 is a side view of a two-wheeled vehicle 1 using the driving force assisting device of this embodiment.

From the head pipe 2 to the rear wheels
A main frame 3 extends in a substantially straight line obliquely downward to the shaft supporting portion 10 and a seat post 5 is erected from the middle of the main frame 3 to an upper part.

A front wheel 9 is rotatably supported at the lower end of a front fork 8 rotatably supported by the head pipe 2, and a rear wheel 10 is rotatably supported at an axle case 21 mounted by a mounting bolt 25 at the rear end of the main frame 3. Has been done. The upper part of the front fork 8 is connected to the handle 11, and the seat 12 is provided on the upper end of the seat post 5.

A crankshaft case 14 is hung from a connecting portion of the mainframe 3 with the seatpost 5 via a bracket 13, and pedal arms 16 are provided at both ends of a crankshaft 15 protruding left and right from the crankshaft case 14. The ends are fitted and attached at right angles, and the pedal 17 is provided at the tip of the pedal arm 16 so as to project in the left-right direction, and constitutes a pedal crank as a whole.

A gear case 18 behind the crankshaft case 14
The drive shaft 19 extends through the cylindrical cover 20 and extends rearward, and is fitted into the axle case 21 of the rear wheel 10. A motor 22 is provided between the pedal cranks along the gear case 18. A cavity is formed inside the main frame 3, and a battery 23 and a control unit 24 are built in the cavity.

Human power drive system by pedal 17 and motor 22
The configuration of the motor drive system according to FIG. 2 will be described with reference to FIGS. A center boss 35 is rotatably fitted to the crankshaft 15 via a pole ratchet type one-way clutch 30 at the left and right center positions on the crankshaft 15 which is rotatably supported by the crankshaft case 14 via bearings 15a. Have been combined.

The center boss 35 has a large-diameter disk portion 35b at the left end of a fitting cylindrical portion 35a that is rotatably fitted to the crankshaft 15, and a ratchet cylindrical portion 35c on the left side of the large-diameter disk portion 35b.
, 5 spring recesses 35d on the right side at equal intervals
Are formed.

Ratchet teeth 35e are formed on the inner peripheral surface of the ratchet cylindrical portion 35c, and a ratchet pole 31e is formed between the ratchet teeth 35e and a pole ratchet case 15b formed on the crankshaft 15 inside thereof as shown in FIG. A biasing means 32 for biasing the ratchet pole 31 is interposed.

In FIG. 4, with respect to the counterclockwise rotation of the crankshaft 15 (rotation of the pedal 17 in the forward direction), the ratchet pole 31 engages with the ratchet teeth 35e and the center boss 35 is engaged.
However, with respect to the clockwise rotation of the crankshaft 15, the ratchet pole 31 displaces inwardly against the biasing means 32, gets over the ratchet teeth 35e, and does not engage with the crankshaft 15. Does not rotate and the driving force is not transmitted to the center boss 35. The one-way clutch 30 as described above is configured.

On the other hand, a drive bevel gear 36 is rotatably fitted to the center boss 35 on the outer periphery of the fitting cylindrical portion 35a of the center boss 35. 36a is formed, and the disk portion of the drive bevel gear 36 has five recesses of the center boss 35.
Five recesses 36b for accommodating the spring are formed corresponding to 35d. As shown in FIG. 5, the concave portion of the center boss 35
35d and the recess 36b of the drive bevel gear 36 are combined to form one cylindrical space, and springs 37 are respectively interposed in the five formed spaces.

Therefore, the rotation of the center boss 35 is transmitted to the drive bevel gear 36 via the spring 37, and the spring 37 elastically contracts according to the load state of the center boss 35 and the drive bevel gear 36 so that the two rotate relatively. It moves dynamically.

A plurality of ridges 35f are formed on the outer peripheral surface of the ratchet cylindrical portion 35c of the center boss 35 so as to be oriented in the axial direction, and a sensor ring which is a cylindrical movable piece is formed on the outer periphery of the ratchet cylindrical portion 35c. 38 is fitted in a groove on the inner periphery of the ridge 35f on the side of the center boss 35 so as to be slidable in the axial direction.

Therefore, the sensor ring 38 rotates integrally with the center boss 35 and can be displaced in the axial direction.

On the other hand, five projecting pieces 36c project in the left axial direction from a predetermined radial position of the disk portion of the drive bevel gear 36, and the sensor ring 38 is provided inside the five projecting pieces 36c.
Are coaxially close.

As shown in FIG. 6, a groove cam 36d is obliquely formed in the protruding piece 36c in the shape of an elongated hole, and a pin 39 protruding outward from the sensor ring 38 is provided in the groove cam 36d.
It is movably fitted to d.

Therefore, when there is a relative rotational displacement between the center boss 35 and the drive bevel gear 36, the pin 39 rotates integrally with the center boss 35, so that the pin 39 is guided by the groove cam 36d to move in the axial direction to move the sensor ring 38. Is displaced in the axial direction.

2 and 6 show the case where there is no load on the pedal side by a solid line, the sensor ring 38 and the pin 39 are located at the rightmost end, but the load is applied to the pedal side and the one-way clutch Center boss 35 through 30
When the spring 37 compresses the spring 37 and displaces the drive bevel gear 36 ahead, the pin 39 precedes the protrusion 36c (relatively displaced to the left side) in FIG.
2, i.e., to the axial left as shown in phantom in FIG. 6, causing the sensor ring 38 to extend to the left as shown in phantom in FIG.

[0025] The center boss 35 increases as the load on the pedal side increases.
Tends to move ahead of the drive bevel gear 36, the sensor ring 38 is displaced to the left more and more.

In the sensor ring 38, a plurality of protrusions 38b each having a mountain-shaped tip are projected in a ring shape from the fitting portion 38a of the center boss 35 to the ratchet cylindrical portion 35c to the left side. As shown in FIG. 7, the plurality of protrusions 38b are spaced apart from each other by a predetermined distance and their tips are triangular.

The sensor ring 38 has a fitting portion 38a with a protrusion 38a.
The compression spring is thicker inward than b and is between this step and the disc-shaped retainer fitting 40 that is integrally fitted to the crankshaft 15.
41 are installed. The compression spring 41 constantly urges the sensor ring 38 to the right side to eliminate hysteresis due to the clearance between the pin 39 integral with the sensor ring 38 and the groove cam 36d.

A hall sensor 42 having a detection point 42a at a predetermined axial position where the protrusion 38b of the sensor ring 38 is displaced is fixed to the front portion of the crankshaft case 14.

The detection point 42a is slightly left of the tip of the protrusion 38b when the sensor ring 38 is located at the right end,
Protrusion 38b as the sensor ring 38 is displaced to the left
It means that the triangular mountain of will be moved relatively to the hem. Therefore, the rate at which the hall sensor 42 detects the protrusion 38b of the rotating sensor ring 38 increases as the load on the pedal side increases and the sensor ring 38 is displaced to the left.

FIG. 8 shows a voltage signal waveform detected and output by the hall sensor 42. As shown in FIG. 7, the detection point 42a of the Hall sensor 42 with respect to the protrusion 38b of the sensor ring 38
FIG. 8 shows the output waveform of the hall sensor 42 when the relative position of is detected at each of the positions a, b, c and d in correspondence with each position.

Since the Hall sensor 42 does not detect the protrusion 38b at all at the position a, there is no high-level portion indicating the detection, and the ratio is 0%. At the position b where the sensor ring 38 is displaced to some extent, the protrusion 38b is not detected. When the tip portion is detected, the proportion of the high level portion becomes about 10%, and at the c position where the sensor ring 38 is further displaced, the proportion becomes about 45%, and the sensor ring 38 is displaced to some extent or more and the protrusion 38b.
The detection point 42a of the hall sensor 42 is located at the hem of the d
In terms of position, the proportion of high-level parts is 90%.

This output signal is used as it is as a duty signal for controlling the motor 22.

Next, the drive transmission means on the downstream side of the drive bevel gear 36 will be described. Drive bevel gear 36 has driven bevel gear 45 that meshes at a right angle with bearing 46
Is supported by and is fitted to the front end of the drive shaft 19.

As shown in FIG. 3, the drive shaft 19 passes through the inside of the cylindrical cover 20 and is fitted into the axle case 21, and the bevel gear 46 is fitted to the end portion thereof.
It is rotatably supported by. A rotating cylindrical shaft rotatably supported by a bearing 48 in the axle case 21.
49 is a needle bearing that is penetrated by a pivot 50 inside
A bevel gear 52, which is supported via 51 and is fitted to the rotary cylindrical shaft 49, is meshed with a bevel gear 46 which is fitted to the drive shaft 19.

A bearing 48 for supporting a rotating cylindrical shaft 49 is fitted on the right outer side of the bevel gear 52, and the outer side thereof is covered with a lid member.
A nut 54 is screwed onto the right end threaded portion of the pivot 50 that is covered with 53 and projects outward from the lid member 53 to prevent the bearing 48 from coming off. A wheel hub 55 of the rear wheel 10 is fitted in a spline groove on the left half of the rotating cylindrical shaft 49 and fixed by a nut 56. The rear wheel 10 is supported by the wheel hub 55 via the spokes 57.

The rear portion of the main frame 3 is divided into left and right frames 3a and 3b, and the right frame 3b is attached to the axle case 21 with mounting bolts 25, and the left frame
The rear end 3c of the frame 3a is formed by a flange 50a formed on the pivot shaft 50 by fitting the left end of the pivot shaft 50 by branching the rear end 3c into a fork shape and a nut 58 fitted on the left end screw part of the pivot shaft 50.
Are sandwiched between.

The above is the manual drive system, in which the driver pedals.
When the crankshaft 15 is driven to rotate by stepping on 17, the drive shaft 19 is rotated through the one-way clutch 30, the spring 37, and the bevel gears 36 and 45, and the rotating cylindrical shaft 49 is rotated together with the rear wheel 10 through the bevel gears 46 and 52. It can be run as a bicycle.

At this time, when the load is large such as when climbing a slope or when starting traveling, the proportion of the high level portion of the output waveform of the hall sensor 42 increases. Also, if the pedal is not depressed during driving, the rotation of the rear wheels 10
Bevel gear 45 and center boss 35 in front of 19
However, the one-way clutch 30 does not transmit it to the crankshaft 15 and the pedal 17, so that the user can travel with the same feeling as when riding a normal bicycle.

On the other hand, the hall sensor 42 is the center boss 35.
It means that the rotation of the vehicle is detected (that is, the rotation of the rear wheel 10), and the cycle in which the high-level part of the output waveform appears corresponds to the vehicle speed. Both elements and are included.

Next, the drive system by the motor 22 provided between the left and right pedal cranks behind the crankshaft 15 will be described. The gear case 18 bulges to the left from the portion that houses the upstream side of the drive shaft 19, and the motor 22 is fitted into the front opening of the bulging portion from the front.

A gear 60 is formed at the end of the drive shaft projecting to the rear of the motor 22, and a gear 61 meshes with the gear 60,
A gear 62a is formed on a rotary shaft 62 that integrally supports the gear 61, a gear 63 is meshed with the gear 62a, and a gear 64a is formed on a rotary shaft 64 that is integral with the gear 63 to form a reduction gear group. There is.

On the other hand, the gear 65 fitted to the drive shaft 19 via the one-way clutch 66 is the gear of the rotary shaft 64.
It meshes with 64a.

Therefore, when the motor 22 is driven, it is decelerated by the meshing of the reduction gears to rotate the gear 65, and further transmitted to the drive shaft 19 via the one-way clutch 66 to assist the rotational drive of the rear wheel 10 by human power. can do.

The one-way clutch 66 and the rear wheels 10
Is not transmitted to the gear 65, and the reduction gear group and the motor 22 do not become a resistance due to inertia while traveling.

The human power assist control by the motor 22 described above is performed based on the output signal of the hall sensor 42,
This motor drive circuit is shown in FIG.

The output of the Hall sensor 42 is input to the base terminal of a power transistor 71 having a grounded emitter through the amplifier 70, the collector terminal of the power transistor 71 is connected to one terminal of the motor 22, and the other terminal is a battery.
Connected to 23.

The output waveform of the hall sensor 42 is as shown in FIG. 8, and since the power transistor 71 conducts in the high level portion, the output signal of the hall sensor 42 directly controls the duty of the motor 22. Therefore, it is not necessary to separately provide an electric chopping control circuit or the like.

The duty control of the motor 22 is such that as the load on the pedal side increases, the proportion of the high level portion of the hall sensor 42 increases (the duty ratio increases).
The time for supplying electric power to the motor 22 is increased, the driving force of the motor 22 is increased, the assistance by the motor 22 is increased, and the burden on the driver is reduced.

Further, in this embodiment, the motor 22 is arranged at a position where the driving force of the motor 22 is transmitted to the drive shaft 19 on the downstream side of the drive transmission position by the spring 37, and self-feedback is possible. That is, when the motor output exceeds the pedal effort of a person, the motor 22 acts in a direction to return the relative displacement between the center boss 35 and the drive bevel gear 36, and as a result, the motor output is reduced.

On the other hand, the motor 22 is a control unit.
Although it is also controlled by 24, the vehicle speed is measured from the output signal of the hall sensor 42 (not shown), and the motor 22 is controlled based on the vehicle speed. For example, the motor 22 is stopped when the vehicle speed is a low speed equal to or lower than a certain value and when the vehicle speed is higher than the certain value to avoid a heavy load on the motor 22 or an unnecessary operation.

In the present embodiment, the vehicle speed detection used for such control can be detected at the same time by the mechanism such as the sensor ring 38 and the hall sensor 42. Therefore, it is not necessary to provide a separate vehicle speed detection device, the number of parts is reduced and the assembly is performed. It is possible to simplify the work, reduce the weight of the vehicle body, and reduce the cost.

The protrusion 38b of the sensor ring 38 of this embodiment
The tip has a triangular shape and the proportion of the mountain portion changes linearly as it goes to the tip, and the sensor ring 38
Since the groove cam 36d for guiding the movement of is a linear long hole, the output of the hall sensor 42 linearly changes with respect to the pedal effort as shown by the solid line A in FIG.

As shown in FIG. 11 (1), assuming that the tip of the protrusion of the sensor ring 138 has a shape Ia in which the two sides of the triangular shape are bulged outward, the output characteristics of the hall sensor 42 are as shown in FIG. As shown by an alternate long and short dash line I in FIG. 10, an upwardly convex curve can be shown so that the assisting force of the motor 22 can be large while the pedaling force is small.

On the contrary, when the shape of the tip of the protrusion of the sensor ring 238 is a shape IIa in which two sides of a triangle are recessed inward as shown in FIG. 11 (2), the output characteristic of the hall sensor 42 is shown in FIG. Shows a downwardly convex curve as shown by the chain double-dashed line II,
It is possible to increase the assisting force of the motor 22 as the pedal effort increases.

By changing the shape of the tip of the protrusion of the center ring as described above, the output characteristic of the hall sensor 42 can be changed, and the way in which the auxiliary force of the motor 22 acts can be easily changed.

Further, the output characteristic of the hall sensor 42 can be changed by changing the shape of the groove cam 36d provided on the projecting piece 36c of the drive bevel gear 36.

That is, in this embodiment, the groove cam 36d is formed in an obliquely straight line shape as shown in FIG.
The output characteristic of the Hall sensor 42 is also a straight line as shown by the solid line in Fig. 12, but as shown in Fig. 12 (1), the groove cam 136 should have a curved shape 136d with the same tilt direction. Then, while the displacement of the sensor ring 38 is increased while the pedaling force is small, the characteristic of the upward convex curve shown by the alternate long and short dash line I is shown in FIG. 10, and conversely, as shown in FIG. With the convex curved shape 236d, the displacement of the sensor ring 38 increases as the pedal effort increases, and the characteristic of the downward convex curve indicated by the chain double-dashed line II in FIG. 10 can be obtained.

By changing the shape of the groove cam in this way, the way in which the auxiliary force of the motor 22 acts can be easily changed.

The above embodiment is a shaft drive driven two-wheeled vehicle that is transmission-driven by the drive shaft 19, but the present invention is also applicable to a transmission-driven two-wheeled vehicle using a chain.

For example, the drive bevel gear 36 of the above embodiment
If the bevel gear 52 is used as a chain sprocket and the chain is bridged between the two, and the driving force from the motor 22 is decelerated and transmitted to the sprocket that meshes with the chain via the one-way clutch, the pedal on the upstream side of the drive bevel gear 36 The load and vehicle speed detection mechanism can be used as it is.

[0061]

According to claims 1 and 2 of the present invention, since the movable piece is rotated corresponding to the drive wheel and is displaceable according to the load on the pedal side, the movement of the movable piece is detected. This allows both the load element on the pedal side and the rotational speed element to be detected in one place, reducing the number of parts, simplifying the assembly work, and reducing the weight of the driving force assisting device. it can.

According to the third aspect, the movable piece is formed of a plurality of chevron portions, and the chevron portions are detected at a predetermined position orthogonal to the chevron portions, whereby a duty signal for directly controlling the motor can be generated. It is possible to simplify an electric circuit such as a control circuit.

Further, by changing the chevron shape of the movable piece, the characteristic of the duty signal of the detecting means with respect to the pedal effort can be easily changed, and the way of applying the assisting force of the motor can be easily changed.

[Brief description of drawings]

FIG. 1 is a side view of a motorcycle to which a driving force assisting device according to an embodiment of the present invention is applied.

FIG. 2 is a cross-sectional view showing a configuration of a first half portion of a drive system.

FIG. 3 is a cross-sectional view showing the configuration of the latter half of the drive system.

FIG. 4 is a sectional view showing a one-way clutch portion of a pole ratchet type.

FIG. 5 is a cross-sectional view showing a drive transmission portion by a spring.

FIG. 6 is a diagram showing a groove cam and a pin provided on a protrusion of a bevel gear.

FIG. 7 is a view showing a shape of a tip of a protrusion of a sensor ring.

FIG. 8 is a diagram showing an output waveform of a hall sensor.

FIG. 9 is a circuit diagram of a drive control system of a motor.

FIG. 10 is a diagram showing an output characteristic of a hall sensor with respect to a pedal effort.

FIG. 11 is a diagram showing a modification of the shape of the tip of the protrusion of the sensor ring.

FIG. 12 is a diagram showing a modification of the shape of the groove cam.

[Explanation of symbols]

1 ... Motorcycle, 2 ... Headpipe, 3 ... Mainframe,
5 ... Seat post, 8 ... Front fork, 9 ... Front wheel,
10 ... Rear wheel, 13 ... Bracket, 14 ... Crankshaft case, 15
… Crankshaft, 16… Pedal arm, 17… Pedal, 18… Gear case, 19… Drive shaft, 20… Cylindrical cover, 21
… Axle case, 22… Motor, 23… Battery, 24… Control unit, 25… Mounting bolt, 30… One-wait clutch, 31… Ratchet pole, 32… Biasing means, 35… Center boss, 36… Drive bevel gear, 37 ... spring,
38 ... Sensor ring, 39 ... Pin, 40 ... Press fitting, 41 ... Compression spring, 42 ... Hall sensor, 45, 46 ... Bevel gear, 47, 48 ... Bearing, 49 ... Rotating cylindrical shaft, 50 ... Axis,
51 ... Needle bearing, 52 ... Bevel gear, 53 ... Lid member, 54 ... Nut, 55 ... Wheel hub, 56 ... Nut, 57 ...
Spokes, 58 ... Nuts, 60, 61 ... Gears, 62 ... Rotating shafts, 63
… Gear, 64… Rotating shaft, 65… Gear, 66… One-way clutch, 70… Amplifier, 71… Power transistor, 136… Groove cam, 138… Sensor ring, 236… Groove cam, 238… Sensor ring.

Claims (3)

[Claims] 1. A drive force assisting device for assisting human power by transmitting drive force of a motor to drive drive means for transmitting drive force of pedal manual drive means to drive wheels, wherein drive transmission rotates in response to rotation of drive wheels. A movable piece that fits into a member and rotates together with the drive transmission member, a displacement means that displaces the movable piece according to a load on the pedal side by the pedal human-powered driving means, and a detection means that detects movement of the movable piece. And a control unit that controls the drive force of the motor based on a detection signal of the detection unit. 2. The displacement means for displacing the movable piece in the crankshaft direction is provided in a drive transmission means on the downstream side of a one-way clutch provided on the outer periphery of a crankshaft connected to a pedal. The driving force assisting device according to claim 1. 3. The movable piece is formed with a plurality of mountain-shaped portions that are annularly continuous, and the detection means detects the rotating annular mountain-shaped portion of the movable piece at a predetermined position orthogonal to the mountain-shaped portion, and detects the rotational axis direction. 2. The driving force assisting device according to claim 1, wherein the displacement amount is detected as a duty signal of a ratio of a mountain portion and a valley portion of the mountain portion of the movable piece and is output to the control means.