JP2003165482A - Vehicle driving device with assist power - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle driving device with an assist power capable of realizing the running restricted in the generation of noise. <P>SOLUTION: This vehicle driving device with an assist power has a man power driving part (a), a motor b for giving the assist electric driving power, a planet gear c formed by connecting a sun gear, an internal gear, a large gear and a small gear to each other, and this vehicle driving force with assist power is provided with an epicycle reduction gear mechanism for transmitting the electric driving force from the motor to wheels. At least the peripheral part of the large gear of the planet gear is made of the synthetic resin, and at least the peripheral part of the small gear is made of metal. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle drive device with auxiliary power. More specifically, the present invention relates to a drive device for a vehicle with auxiliary power that can travel with low noise.

[0002]

2. Description of the Related Art Conventionally, in an electrically assisted bicycle or the like, a drive device for a vehicle with auxiliary power, which includes both a human power drive unit and a motor, has been used.

In the conventional vehicle drive device with auxiliary power, a human power drive unit for driving wheels by human power, a torque detection unit for detecting a human power torque of the human power drive unit, and a magnitude of the human power torque detected by the torque detection unit. Accordingly, a motor for giving an auxiliary electric drive force to the wheels, a planetary gear reduction mechanism for transmitting the electric drive force from the motor to the wheels, and an electric drive force for acting only in one rotation direction of the wheels. It has a ratchet mechanism.

The planetary gear speed reduction mechanism includes a sun gear fixed to the motor shaft of the motor, an internal gear composed of an internal gear rotatably provided near the center of the wheel, a large gear and an internal gear meshing with the sun gear. It is composed of a planet gear to which a meshing small gear is connected. And these are formed of all metals to maintain strength.

Further, the ratchet mechanism is provided with at least one ratchet pawl provided on the outer periphery of the internal gear and a ratchet pawl provided near the center of the wheel so that the electric driving force engages with the ratchet pawl only in the direction of driving the wheel. And a ratchet gear having teeth.

With this configuration, the human-powered drive unit rotates the wheels by the human-powered drive force transmitted via the pedal and the chain, and at the same time, the torque detection unit detects the human-powered torque. On the other hand, the motor generates an auxiliary electric driving force according to the magnitude of the detected human torque,
The electric driving force is transmitted to the planetary gear reduction mechanism.

The electric driving force is transmitted to the ratchet mechanism while being decelerated by the planetary gear reduction mechanism, and is transmitted to the wheels as an auxiliary power of the human driving force.

Further, the ratchet gear shuts off the rotation of the wheel and the power of the motor when the rotation speed of the wheel becomes faster than the rotation of the rotating drum fixed near the center of the wheel by the motor.

[0009]

Conventionally, in order to increase the strength, the entire planet gear is made of metal such as steel, so that the noise is large. On the other hand, in order to reduce the noise, the entire planet gear is made of synthetic resin. If it is manufactured by the above method, there is a problem that the structure is enlarged in order to increase the strength.

Further, since the internal gear is made of metal such as steel in order to increase the strength, there is a problem that a sound of meshing between the metals is generated during driving.

The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a drive device for a vehicle with an auxiliary power, which can reduce the size of the drive device and travel with low noise.

[0012]

A vehicle drive device with auxiliary power according to the present invention comprises: (a) a human-powered driving unit for driving wheels by human power; and (b) a human-powered driving force by the human power. A motor for giving an electric driving force, (c) an internal gear consisting of a sun gear fixed to the motor shaft of the motor, an internal gear rotatably provided near the center of the wheel,
A vehicle drive with auxiliary power, which has a planetary gear in which a large gear meshing with the sun gear and a small gear meshing with the internal gear are coupled, and a planetary gear reduction mechanism for transmitting electric driving force from the motor to the wheels The apparatus is characterized in that at least an outer peripheral portion of the large gear of the planet gear is made of synthetic resin, and at least an outer peripheral portion of the small gear is made of metal.

The synthetic resin is preferably a polyacetal or polyamide resin.

At least one ratchet pawl provided on the outer periphery of the internal gear and ratchet teeth fixed to the vicinity of the center of the wheel and meshing with the ratchet pawl only in the direction in which the electric driving force drives the wheel. A ratchet mechanism having a ratchet gear is preferably provided, and at least an outer peripheral portion of the internal gear is preferably made of synthetic resin.

The synthetic resin is preferably a polyacetal or a polyamide resin.

It is preferable that the large gear and the small gear of the planet gear are fixed to each other by screwing.

The sun gear is preferably made of metal.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a drive system for a vehicle with auxiliary power of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a side view of an electrically assisted bicycle equipped with a drive device that is an embodiment of a drive device for a vehicle with auxiliary power of the present invention, FIG. 2 is a cross-sectional explanatory view of the drive device of FIG. 1, and FIG. 4 is an exploded sectional view of the planetary gear reduction mechanism of FIG. 4, FIG. 4 is an explanatory view showing a planar arrangement of main parts of the planetary gear reduction mechanism of FIG. 2, and FIG.
6 is a plan view showing a state in which the internal gear and the ratchet gear of FIG. 6 are meshed with each other, FIG. 6 is a sectional view taken along line VI-VI of FIG. 5, and FIG. 7 is an exploded sectional view of the planetary gear of FIG.

An electric power assisted bicycle as shown in FIG. 1 is an example of a vehicle with auxiliary power according to one embodiment of the present invention. This bicycle has a seat tube 6 for supporting a handle 1, a front wheel 4 connected via a head pipe 2 and a front fork 3 connected to the handle 1, and a saddle 5 provided below the head pipe 2. A main frame 7 connected to the seat tube 6
Rear wheel 9 connected to the rear of the vehicle via a chain stay 8
And a human-powered driving unit 11 which is arranged between the portion where the main frame 7 and the seat tube 6 are connected to each other and the axle 10 of the rear wheel 9, and which can rotate the rear wheel 9 by human power, and the rear wheel 9. A drive device 12 (see FIG. 2) for driving, and a motor 20 described later that is built in the drive device 12.
And a battery 13 serving as a power source of the. The human power drive unit 11 includes a pedal 14, a chain 15, and front and rear sprockets 16 and 17 (see FIG. 2).

As shown in FIGS. 1 to 3, the drive unit 12 has a transmission 19 inside the rotary drum 18 that rotates together with the rear wheel 9 around the axle 10 and is capable of changing the gear ratio. A motor 20 that rotationally drives the rotary drum 18.
A planetary gear speed reduction mechanism 21 is provided in parallel. In the present embodiment, the axle 10 is the first wheel axle 10a.
And a second wheel axle 10b, and the transmission 19 is assembled to the first wheel axle 10a.

The rotary drum 18 is composed of two parts. The rotary drum 18b for mounting the spokes 22 of the rear wheel 9 and the bearing 2 on the second wheel axle 10b.
3 and a rotary drum 18a fixed by bolts 24 at a plurality of positions so as to close the opening of the rotary drum 18b.

The transmission 19 is, for example, an interior 3
A gear transmission can be used. This transmission 19 has
The rear sprocket 17 is a one-way clutch (not shown).
Are connected via. Power is transmitted only in one direction of the pedal 14, and when the pedal 14 is rotated in the reverse direction, power transmission to the transmission 19 is cut off.

Between the transmission 19 and the motor 20,
A torque detection unit 25 for detecting a manual torque applied to the transmission 19 is arranged. The torque detector 25 is not particularly limited in the present invention, and a conventionally known one can be used.

A motor control section 38 is provided inside the motor case 33 which is composed of two parts, the motor cases 33a and 33b. In the motor control unit 38, a power cord 41 for supplying power from the battery 13 is inserted into a cutout portion 42 of a part of the second wheel axle 10b, and then a part of the outer wall of the motor case 33 is inserted. Notched portion 43
It is wired along.

The motor shaft 51 is rotatably supported by press-fitting the first wheel axle 10a into an inner ring of a bearing 57 such as a ball bearing or an angular ball bearing fitted in a recess formed at one end thereof. In addition, the rotating drum 1
8a is rotatably supported by a bearing 23 fitted to the outer periphery of the second wheel axle 10b. The motor case 33a is connected to the end of the second wheel axle 10b by a bolt 58. As a result, the second wheel axle 10b supports the motor case 33a and also supports the rotary drum 18a that houses the planet gear 63 and the ratchet gear 64 that transmit the output of the motor 20 described later.

The planetary gear speed reduction mechanism 21 of the present embodiment is
As shown in FIGS. 2-4 and 7, the motor shaft 5
1, a sun gear 62 formed on the other end of the motor 1, three planet gears 63 rotatably coupled to the side of the motor case 33a, and an internal gear arranged via a ratchet gear 64 of the rotary drum 18a. And 65. The planet gear 63 is composed of a large gear 63 a meshing with the sun gear 62 and a small gear 63 b meshing with the internal gear 65.

As shown in FIG. 7, the planet gear 63 is rotatably supported on the side portion of the motor case 33a by screwing between a mounting bolt 75 and a bearing metal 76.

Further, the ratchet mechanism 71, as shown in FIGS. 4 to 6, has at least one ratchet pawl 72 provided on the outer periphery of the internal gear 65 and a direction for driving the rear wheel 9 (see FIG. 5). And a ratchet gear 64 having ratchet teeth 73 that mesh with the ratchet pawl 72 only in the direction of arrow A). Ratchet claw 72
Are constantly urged in the outward direction of the internal gear 65 by elastic means such as a spring (not shown).

The ratchet gear 64 cuts off the rotation of the wheels and the power of the motor 20 when the rotation speed of the rear wheels 9 becomes faster than the rotation of the rotary drum 18 by the motor 20. .

Outer diameter threaded portion 66 of the ratchet gear 64
The screw 67 that is formed on the rotary drum 18a is coupled to the screw 67 by a rotational driving force of the motor shaft 51. That is, the outer diameter threaded portion 66 and the threaded portion 67 are tightened in the driving direction of the motor shaft 51 or the direction in which the ratchet pawl 72 of the ratchet gear 64 is engaged. In the present embodiment, the ratchet gear 64 is viewed from the motor shaft 51. , Are coupled in the direction of the right hand screw.

The internal gear 65 of this embodiment is
Since at least the outer peripheral portion is made of synthetic resin, a noise generated by the internal gear 65 made of metal is smaller, a loud noise is not generated, and comfortable traveling can be provided.

When the internal gear 65 is made of synthetic resin, it can suppress the noise generated more than metal materials, but more preferably synthetic resin such as polyacetal or polyamide resin in which glass fiber or carbon fiber is compounded. If used, the strength can be increased, and it is particularly preferable in terms of thinning. Further, the internal gear 65 is
If at least the outer peripheral portion that comes into contact with the ratchet pawl 72 is made of synthetic resin, the noise reduction effect can be achieved.
If the entire internal gear 65 is made of synthetic resin, the noise can be reduced and the production is facilitated by integral molding.

In this embodiment, since at least the outer peripheral portion of the large gear 63a of the planet gear 63 is made of synthetic resin and at least the outer peripheral portion of the small gear 63b is made of metal, the torque applied to the teeth is Small gear 63
In the case of a, the noise reduction effect of the synthetic resin can be obtained. On the other hand, the small gear 63 with a large torque applied to the teeth
Since the rigidity can be improved in b by using a metal material such as steel, carbon steel, or chrome molybdenum steel, the thickness of the small gear 63b can be reduced. As a result, not only the planetary gear reduction mechanism 21 but also the entire drive device can be made thin and compact.

The large gear 63a of the planet gear 63 can obtain a noise reduction effect higher than that of a metal material by being made of a synthetic resin, but more preferably, a polyacetal or polyamide resin in which glass fiber or carbon fiber is compounded. If a synthetic resin such as is used, the strength can be increased, and it is particularly preferable in terms of thinning. Further, the large gear 63a can produce a noise reduction effect if at least the outer peripheral portion in contact with the sun gear 62 made of metal is made of synthetic resin, but if the whole large gear 63a is made of synthetic resin, higher noise can be achieved. The reduction effect can be achieved, and the integral molding facilitates manufacturing.

The rigidity of the small gear 63b can be improved if at least the outer peripheral portion in contact with the internal gear 65 is made of a metal material. However, if the entire small gear 63b is made of a metal material, the rigidity is further improved. In addition, the integral molding facilitates manufacturing.

As shown in FIG. 7, the planet gear 6
The dissimilar materials may be coupled between the large gear 63a and the small gear 63b of No. 3 by any coupling method.
If you fix it with 4 etc., it is easy to attach and detach,
Easy repair and replacement of parts.

Further, in this embodiment, since the sun gear 51 which applies a large torque to the teeth is made of a metal material having high rigidity, the strength is improved and a thinner sun gear can be adopted.

Next, regarding the drive unit according to the present embodiment, first, the transmission of the power of the human-powered drive force will be described.

When a manual driving force is input from the pedal 14, the front sprocket 16 fixed to the pedal 14 rotates, and the rear sprocket 17 rotates via the chain 15. When the sprocket 17 is rotated after that, power is transmitted only in one direction by a ratchet (not shown).

When the power in the traveling direction is transmitted, the speed is changed by the transmission 19 set to the gear ratio designated by the user, and then the rotary drum 18 can be rotated and the rear wheels 9 can be rotated.

Next, the power transmission of the electric driving force will be described.

First of all, the torque detecting section 25 is operated by the transmission 1
The human torque applied to 9 is detected. Then, under the control of the torque detection unit 25, the motor 20 is driven according to the magnitude of the detected human torque. The drive of the motor 20 is
A planetary gear speed reduction mechanism, that is, a sun gear 62, a planet gear 63, and an internal gear 65 reduce the speed, and the rotating drum 18 is rotated via a ratchet gear 64 connected to the planet gear 63. And
The rear wheel 9 rotates.

As described above, the human driving force and the electric driving force are combined by the rotary drum 18 to drive the rear wheel 9.

[0044]

According to the present invention, the internal gear that comes into contact with the ratchet pawl is made of synthetic resin.
It is possible to reduce noise.

Further, by making the planetary gear small gear from a metal material, the thickness of the small gear can be reduced, and the apparatus can be miniaturized.

[Brief description of drawings]

FIG. 1 is a side view of an electrically assisted bicycle equipped with a drive device that is an embodiment of a drive device for a vehicle with auxiliary power of the present invention.

FIG. 2 is a cross-sectional explanatory view of the drive device of FIG.

3 is an exploded cross-sectional view of the planetary gear reduction mechanism of FIG.

FIG. 4 is an explanatory diagram showing a planar arrangement of main parts of the planetary gear speed reduction mechanism of FIG. 2.

5 is a plan view showing a state where the internal gear and the ratchet gear of FIG. 4 are meshed with each other.

6 is a sectional view taken along line VI-VI of FIG.

7 is an exploded cross-sectional view of the planetary gear of FIG.

[Explanation of symbols]

4 front wheels 9 rear wheels 10 axles 10a first wheel axle 10b second wheel axle 11 Human power drive 12 Drive 18, 18a, 18b rotating drum 19 transmission 20 motor 21 Planetary gear reduction mechanism 25 Torque detector 62 sun gear 63 Planet Gear 64 ratchet gear

Claims (6)

[Claims] 1. A human-powered driving unit for driving a wheel by human power, (b) a motor for giving an auxiliary electric driving force in addition to the human-powered driving power by human power, and (c) a motor shaft of the motor. A sun gear fixed to the wheel, an internal gear consisting of an internal gear rotatably provided near the center of the wheel,
A vehicle drive with auxiliary power, which has a planetary gear in which a large gear meshing with the sun gear and a small gear meshing with the internal gear are coupled, and a planetary gear reduction mechanism for transmitting electric driving force from the motor to the wheels An apparatus for driving a vehicle with auxiliary power, wherein at least an outer peripheral portion of a large gear of the planet gear is made of synthetic resin and at least an outer peripheral portion of the small gear is made of metal. 2. The drive device for a vehicle with auxiliary power according to claim 1, wherein the synthetic resin is polyacetal or polyamide resin. 3. At least one ratchet pawl provided on the outer circumference of the internal gear, and ratchet teeth fixed to the vicinity of the center of the wheel and meshing with the ratchet pawl only in the direction in which the electric driving force drives the wheel. A ratchet mechanism having a ratchet gear having the above, wherein at least an outer peripheral portion of the internal gear is made of synthetic resin. 4. The drive device for a vehicle with auxiliary power according to claim 3, wherein the synthetic resin is polyacetal or polyamide resin. 5. The large gear and the small gear of the planet gear are fixed to each other by screwing.
3. A vehicle drive device with auxiliary power according to item 3 or 4. 6. The drive device for a vehicle with auxiliary power according to claim 1, 2, 3, 4, or 5, wherein the sun gear is made of metal.