JP2002218726A - Motor and vehicle fitted with auxiliary motive power using the motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor whose weight can be reduced, even if the diameter of its rotor is made larger, and to provide a vehicle fitted with auxiliary motive power which uses that motor. SOLUTION: The rotor 42 of the motor 40 is composed of an internal ring 44 of a light member into which a shaft is inserted, and an external ring 45 which is made of a magnetic material and is press-fitted to the periphery of the internal ring 44. Besides, the rotor 42 for the motor 40 is fitted, via bearings 43 to an internal transmission 21 fitted to the axle 20 of a wheel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor suitable for use in a vehicle with an auxiliary power, such as an electrically assisted bicycle, and a vehicle with an auxiliary power using the motor.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Application Publication No. 2000-105155 (G01L 3/14) discloses this type of vehicle with auxiliary power.
Discloses a DC brushless motor provided with a rotor around an axle (internal transmission).

[0003]

By the way, in such a motor, when the diameter of the rotor is increased, a large torque can be obtained because the rotation diameter is increased. However, in general, the outer peripheral portion of a heavy laminated silicon steel plate is obtained. When the diameter of the rotor having the magnets disposed therein is increased, the weight of the motor increases, and when used in an electrically assisted bicycle or the like, there arises a problem that the load becomes large.

The present invention has been made in order to solve such problems, and it is an object of the present invention to provide a motor which can be reduced in weight even if the diameter of the rotor is increased, and a vehicle with auxiliary power using the motor. It is intended for.

[0005]

In order to achieve the above object, a rotor of a motor according to the present invention is formed of a light-weight member, an inner ring through which a shaft is inserted, and a magnetic material. And an outer ring press-fitted to the outer periphery of the inner ring.

[0006] Further, a convex portion protruding outward is formed on the outer periphery of the inner ring, and a concave portion into which the convex portion of the inner ring is press-fitted is formed on the inner periphery of the outer ring. Things.

[0007] Further, a flange is provided on the outer peripheral portion on one surface side of the inner ring, the flange having a cutout portion at a portion where the convex portion is formed.

The rotor of the motor according to the present invention is
A plurality of holes including holes having different shapes are formed inside.

Further, the hole having the different shape is formed so as to have the same volume as the other holes.

The vehicle with auxiliary power according to the invention of the present application is a human-powered drive unit for driving wheels by human power, a torque detection unit for detecting human-powered torque of this human-powered drive unit, and the wheels are driven by a motor and a speed reduction mechanism. An electric drive unit that drives the electric drive unit with a size corresponding to a value detected by the torque detection unit, wherein the vehicle is driven by an auxiliary power. According to another aspect of the present invention, a rotor of the motor described in the above (1) is attached.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described using an electric assist bicycle as an example.

First, the configuration of the entire electric power-assisted bicycle will be described with reference to FIG.

In this electric assist bicycle, a head pipe 1 provided at a front portion and a seat tube 3 to which a saddle 2 is attached are connected by a main frame 4, and the main frame 4 and the seat tube 3 are connected. A pedal 5 that rotates by human power is attached to the portion.

The head pipe 1 includes a head pipe 1
A steering wheel 6 and a front wheel 7 for determining a traveling direction by operating the steering wheel are attached so as to be connected to each other. In the drawing, only the rim 8 of the front wheel 7 and the tire 9 are shown, and the spokes are not shown.

A battery 11 serving as a power source for a motor and the like to be described later is mounted below the front car 10 mounted on the head pipe 1. The battery 11 is a 24-volt NiCd battery. I have. The battery 11 is housed in a battery case and can be removed, and can be removed and charged indoors when charging.

A front sprocket 12, which rotates together with the pedal 5, is mounted on the pedal 5. A chain 13 is mounted on the front sprocket 12, and the rotation of the front sprocket 12 is transmitted via the chain 13 to a rear wheel 14.
Is provided on an axle (not shown) and transmitted to a sprocket.

The rear wheel 14 serving as a driving wheel is composed of a tire 15, a rim 16, a spoke (not shown), and a driving unit 17 for driving the rear wheel 14. As will be described later, the drive unit 17 includes a torque detection unit (torque sensor) that detects human-powered torque transmitted via the chain 13, an electric drive unit including a motor and a reduction mechanism, and a detection value of the torque detection unit. And a brake circuit 1 that brakes the rear wheel 14 by operating a brake lever 18 attached to the handle 6 and a control circuit including a microcomputer that outputs a drive signal to the motor by inputting a signal.
9 is attached.

As described above, the rear wheel 14 is composed of two parts, a human-powered drive unit composed of the pedal 5, the front sprocket 12, the chain 13, the rear sprocket, and a transmission, and an electric drive unit composed of a motor and a speed reduction mechanism. It is driven by a drive unit, and can travel together with them.

Next, the driving unit 1 of the electric assist bicycle
7 will be described in detail with reference to FIG.

An axle 20 of the rear wheel 14 is provided with a built-in transmission 21 similar to that of a normal bicycle at a part of its longitudinal direction, and this transmission 21 is attached to a rear sprocket 22 by a one-way clutch (not shown). ), Power is transmitted only by rotation of the pedal 5 in one direction, and power transmission to the transmission 21 is interrupted when the pedal 5 is rotated in the reverse direction.

The internal transmission 21 is covered with a rotary casing 23 which forms a hub of the rear wheel 14 around the axle 20.
The rotating casing 23 is composed of two parts, one of which is a rotating casing 23a formed with two annular ribs 24a and 24b for attaching spokes on the outer periphery.
The other is a rotating casing 23b screwed and fixed to the annular rib 24b at a plurality of locations so as to close the opening of the rotating casing 23a.

A large gear 25 constituting the final stage of the speed reduction mechanism is screwed and fixed to the inside of the other rotary casing 23b so as to form a concentric circle with the axle 20 on the outside. Brake holder 26
A rotating piece 27 having a disk-shaped upright wall formed toward the outside of the rotating casing 23b is attached to the rotating piece 23 by screws, welding, or the like. A brake device 19 is provided for slidingly contacting the inner periphery of the rotary piece 27 to brake the rotation of the rotary casing 23. These rotating pieces 27
The brake device 19 is covered with a brake cover 28.

A cord 29 such as a power supply line and other signal lines from the battery 11 passes through the brake cover 28,
A part of the cover 31b of the fixed casing 31 that constitutes the electric drive unit 30 is inserted through a cutout portion, and is connected to a control board 33 in a board case 32 attached inside the cover 31b of the fixed casing 31. I have.

The fixed casing 31 includes a main body 31a for covering a DC brushless motor, which will be described later, and the control board 33.
And a cover 31b to which a large pulley 34 and the like constituting a speed reduction mechanism are attached by screws. The main body 31a is attached to the outer periphery of the transmission 21 via a bearing 35, and the lid 31b is fixed to a portion of the axle 20 where the transmission 21 is not provided, with a tubular portion 31c protruding outward.

A stator 41 constituting the DC brushless motor 40 is mounted on the inner surface of the main body 31a of the fixed casing 31, and the stator 41 is formed by winding a core around 18 slots. The stator 3 has a cover 3 of the fixed casing 31.
Power for generating a rotating magnetic field is supplied via a control board 33 in a board case 32 attached inside 1b.

On the inner peripheral side of the stator 41, a rotor 4
2 is rotatably provided on the outer periphery of the transmission 21 via two bearings 43, 43. The rotor 42 includes an inner ring 44 and an outer ring 45, which will be described in detail later. A plurality of magnets 46 forming magnetic poles are embedded in the outer periphery of the outer ring 45. A toothed small pulley 47 is attached so as to protrude toward the portion 31b.

In this embodiment, the stator 41
Although the DC brushless motor 40 including the motor and the rotor 42 is used, other types of motors such as a stepping motor may be used.

Small pulley 47 provided on the rotor 42
And a belt between the large pulley 34 attached to the inside of the lid 31b of the fixed casing 31 via the one-way clutch 36 and a tension pulley (not shown). Each of the pulleys and belts is toothed so that slippage does not occur. The output shaft of the large pulley 34 protrudes outside the lid 31b to form a small gear 37. The small gear 37 is configured to mesh with the large gear 25 mounted inside the rotary casing 23b. I have. Therefore, the rotation of the rotor 42 is controlled by the small pulley 47,
The speed is reduced via the large pulley 34, the one-way clutch 36, the small gear 37, and the large gear 25 and transmitted to the rotary casing 23b. The large gear 25 mounted inside the rotating casing 23b and the lid 31 of the fixed casing 31
b, the cylindrical portion 31 protruding outward from the b and fixed to the axle 20
A bearing 39 is provided between the outer periphery and the outer periphery c.

On the other hand, the rear sprocket 2 to which human power is transmitted
A sensor plate 51 for a torque sensor, which is located inside the rotary casing 23a and detects human torque, is fixed to the outer periphery of the transmission 21 on the second side. A packing 52 is attached to the periphery of the opening of the rotary casing 23a so as to be in sliding contact with the sensor plate 51 to take measures such as waterproofing and dustproofing.

Inside the sensor plate 51, there is provided a sensor case 54 attached to the outer periphery of the transmission 21 via a bearing 53 and fixed to the rotary casing 23a with screws. The case 54 is connected via a coil spring 55 interposed between a holding pin 51 a fixed to the sensor plate 51 and a storage portion 54 a provided in the sensor case 54. That is, when the manual driving force is transmitted from the transmission 21 to the sensor plate 51, the coil spring 55 is contracted by a contraction amount corresponding to the magnitude of the manual torque,
The rotary casing 23a is rotated via the sensor case 54.

Inside the sensor case 54, an arc-shaped aluminum ring 5 is slidably mounted on the outer periphery of a ring holder 56.
The ring 57 is attached to the pin 57 at several places on the outer periphery of the ring 57 by being fitted to the pin 58.
The coin spring 59 has an urging force in the direction of spreading.
Is inserted. Further, the ring 57 comes into contact with an inclined surface (not shown) formed on the ring holder 56, and the sensor plate 51 and the ring 57 are displaced in the rotation direction when human force is applied. ,
The ring 57 moves in the axle direction along the inclined surface of the ring holder 56 while rotating. A coil 60 connected to the control board 33 on which the control circuit is mounted is mounted on the ring
7, the displacement in the direction of the axle 20 is taken as a change in inductance. That is, the change in the inductance is taken into the control board 33 as an electric signal indicating the magnitude of the manual torque, and the motor 4 is controlled based on the signal value.
0 is controlled.

As described above, since the ring 57 whose displacement is changed according to the contraction of the coil spring 55, that is, the magnitude of the manpower torque is used, the inductance of the coil 60 can be changed according to the magnitude of the manpower torque. Can be output as an electric signal.

On the back side of the board case 32 in which the control board 33 is accommodated, a Hall element 49 for detecting a rotational position of the rotor 42 necessary for controlling the drive of the DC brushless motor 40 is provided with a rotor 42. Magnet 4
The detection signal of the Hall element 49 is input to a microcomputer mounted on the control board 33 to generate a motor control signal.

Next, the motor 4 will be described with reference to FIGS.
The configuration of the zero rotor 42 will be described in detail. In addition,
The same reference numerals as those in FIG. 1 indicate the same parts.

The rotor 42 of the motor 40 comprises an inner ring 44 and an outer ring 45 formed of separate members. The inner ring 44 is made of an aluminum alloy which is a lightweight member, and the outer ring 45 is made of laminated silicon. Consists of a steel plate.

As shown in FIG. 6 and the like, the inner ring 44 is provided with convex portions 44a at a plurality of locations on the outer periphery at regular intervals. The inner ring 44 has a thin portion between the outer peripheral portion and the inner peripheral portion except for a portion where the convex portion 44a is formed, and holes 44b to 44e are formed in the thin portion. One of the slots 4
Holes having the same volume as 4b and different shapes (large and small round holes 44c to 44e in the present embodiment) are formed.

With this configuration, in addition to the weight reduction by forming the inner ring 44 from an aluminum alloy which is a lightweight member, it is possible to further reduce the weight without impairing the strength.

Further, a flange 44f is formed on one outer peripheral portion of the inner ring 44, and a cutout 44g is formed in a portion where the convex portion 44a is formed.

In the outer ring 45, as shown in FIG.
5b are formed, and an iron plate 46 for a magnet is press-fitted into each hole 45b.

A concave portion 45c into which the convex portion 44a of the inner ring 44 is press-fitted is formed on the inner peripheral side of the outer ring 45, and the inner ring 44 and the outer ring 45 are respectively formed with the convex portion 44a and the concave portion 45c. And press-fitted to the portion where the flange 44f of the inner ring 44 is formed as shown in FIG. Accordingly, the rotor 42 can be easily assembled.

Further, at the time of the press-fitting, aluminum chips cut out from the projections 44a of the inner ring 44 formed of an aluminum alloy are discharged from the notches 44g. As described above, even when the flange portion 44f is formed, the chips coming out of the convex portion 44a at the time of press-fitting can be discharged from the notch portion 44g, so that the assembly is further simplified.

The magnetizing of the iron plate 46 of the rotor 42 is performed after all the press-fitting is performed.
4c is positioned and fixed to a magnetizing jig.
Also in this case, the holes 44c to 44e having different shapes are formed by effectively utilizing the holes 44b to 44e for weight reduction.
Positioning during magnetization can be easily performed. Further, since the holes 44c to 44e having different shapes are formed so as to have the same volume as the other holes 44b, good rotation balance can be obtained.

Next, power transmission of the electric assist bicycle configured as described above will be described.

First, transmission of the manual driving force will be described.

When a manual driving force is input from the pedal 5,
The front sprocket 12 fixed to the pedal 5 rotates, and the rear sprocket 22 rotates via the chain 13. When the rear sprocket 22 rotates, power is transmitted only in one direction by a one-way clutch (not shown).

When the power in the traveling direction is transmitted, the speed is shifted by the transmission 21 set to the gear ratio specified by the user, and then the rotating casing 23 (23a) is contracted while the spring 55 constituting the torque sensor is contracted. And the rear wheel 14 can be rotated.

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

The change in inductance detected by the coil 60 due to the displacement of the ring 57 of the torque sensor is input to the microcomputer of the control board 33 as an electric signal. A signal is output to the drive circuit of the motor 40 based on the signal value, and the polarity of the stator 41 is changed by turning on and off the FET in the drive circuit to generate a rotating magnetic field.
This causes the rotor 42 to rotate, and the motor 40 to rotate. The rotational driving force of the motor 40 includes a small pulley 47, a large pulley 34, a one-way clutch 36, a small gear 37, and a large gear 2.
The rotation of the rotary casing 23 (23b) is reduced by the speed reduction mechanism composed of the rear wheel 5, and the rear wheel 14 is rotated.

As described above, the manual driving force and the electric driving force are combined by the rotary casings 23 (23a, 23b) to drive the rear wheel 14, so that the driving force corresponding to the user's pressing force on the pedal 5 is determined. The electric driving force is applied, and the vehicle can travel easily even on a slope.

In this embodiment, the axle 2 of the rear wheel 14
Bearing 43 on the internal transmission 21 mounted on the
, The rotor 42 of the motor 40 is attached, the internal transmission 21 of the axle 20 is effectively used as the shaft of the motor 40, and the motor 40 itself is also reduced in weight by the above-described configuration. An electric assisted bicycle can be realized.

In the above embodiment, the case where the present invention is applied to an electric assist bicycle is shown. However, the present invention is effective when applied to a vehicle assisted by a motor such as an assist type electric wheelchair. Furthermore, since the weight of the motor itself can be reduced, it can be applied to various motors.

In the above-described embodiment, the rotor 42 of the motor 40 is constituted by the inner ring 44 and the outer ring 45 formed of separate members. However, even if a hole is formed inside the integral rotor, the weight can be reduced. Can be achieved.

Further, in the above-described embodiment, the case where the present invention is applied to the one in which the axle 20 is provided with the internal transmission 21 is shown, but the present invention is also applicable to the one in which the axle has no transmission.

[0054]

As described above, according to the present invention, the rotor of the motor is press-fitted into the outer ring of the inner ring formed of a lightweight member and having the shaft inserted therethrough, and formed of a magnetic material. With the configuration including the outer ring, the motor can be reduced in weight even if the diameter of the rotor is increased.

Further, a convex portion protruding outward is formed on the outer periphery of the inner ring, and a concave portion into which the convex portion of the inner ring is press-fitted is formed on the inner periphery of the outer ring. Assembly is simplified.

Further, since a flange having a cut-out portion at the portion where the convex portion is formed is formed on the outer peripheral portion of one side of the inner ring, even if the flange portion is formed, the flange portion comes out of the convex portion at the time of press-fitting. Since the chips can be ejected from the cutout, assembly is further simplified.

Further, the rotor of the motor according to the present invention is
Since a plurality of holes including holes with different shapes are formed on the inside, it is possible to reduce the weight, and by forming holes with different shapes by effectively utilizing the holes for weight reduction,
Positioning during magnetization and the like can be easily performed.

Furthermore, since the holes having the different shapes are formed so as to have the same volume as the other holes, a good rotational balance can be obtained.

Further, the vehicle with auxiliary power according to the present invention has a human-powered driving unit for driving the wheels by human power, a torque detection unit for detecting the human-powered torque of the human-powered driving unit, and the wheels driven by a motor and a speed reduction mechanism. An electric drive unit that drives the electric drive unit with a size corresponding to a value detected by the torque detection unit, wherein the vehicle is driven by an auxiliary power. By mounting the rotor of the motor described in the above, the axle is effectively used as the shaft of the motor, and the motor itself is reduced in weight by the above-described configuration, so that a lightweight and compact vehicle with auxiliary power can be realized.

[Brief description of the drawings]

FIG. 1 is an essential part cross-sectional view of a drive unit of an electric assist bicycle according to an embodiment of the present invention.

FIG. 2 is an exploded sectional view showing a rotor portion of a motor attached to the transmission of the embodiment.

FIG. 3 is an enlarged sectional view of a rotor portion of the motor.

FIG. 4 is a plan view of the rotor.

5 is a central sectional view of the rotor of FIG. 4; FIG.

FIG. 6 is a plan view of an inner ring of the rotor.

FIG. 7 is a plan view of an outer ring of the rotor.

FIG. 8 is a side view of the outer ring of the rotor.

FIG. 9 is a side view showing the overall configuration of the electric assist bicycle to which the present invention is applied.

[Explanation of symbols]

 Reference Signs List 5 pedal 11 battery 12 front sprocket 13 chain 14 rear wheel 17 drive unit 20 axle 21 internal transmission 22 rear sprocket 23, 23a, 23b rotary casing 25 large gear 30 electric drive unit 31 fixed casing 31a main unit 31b lid 31c cylinder Shape 32 Board case 33 Control board 34 Large pulley 35 Bearing 36 One-way clutch 37 Small gear 39 Bearing 40 DC brushless motor 41 Stator 42 Rotor 44 Inner ring 44a Convex part 44b-44e Hole 44f Flange part 44g Notch part 45 Outer ring 45a Magnetic pole part 45b Hole 45c Concave part 46 Magnet (iron plate) 47 Small pulley 49 Hall element 51 Sensor plate 51a Holding pin 53 Bearing 54 Sensor case 54a Storage part 55 Coil spring 5 6 Ring holder 57 Ring 60 Coil

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seishi Yamaguchi 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Kazuhisa Matsumoto 2-chome Keihanhondori, Moriguchi-shi, Osaka No.5 Sanyo Electric Co., Ltd. F term (reference)

Claims (6)

[Claims] 1. The motor according to claim 1, wherein the rotor includes an inner ring formed of a lightweight member and through which a shaft is inserted, and an outer ring formed of a magnetic material and pressed into an outer periphery of the inner ring. 2. An outer periphery of the inner ring is formed with a convex portion protruding outward, and an inner periphery of the outer ring is formed with a concave portion into which the convex portion of the inner ring is press-fitted. The motor according to claim 1. 3. The motor according to claim 2, wherein a flange having a cutout in a portion where the projection is formed is formed on an outer peripheral portion on one surface of the inner ring. 4. The motor according to claim 1, wherein the rotor is formed with a plurality of holes including holes having different shapes inside. 5. The motor according to claim 4, wherein the holes having different shapes are formed so as to have the same volume as other holes. 6. A human-powered drive unit for driving wheels by human power, a torque detection unit for detecting human-powered torque of the human-powered drive unit, and an electric drive unit for driving the wheels by a motor and a speed reduction mechanism, wherein the torque 6. A vehicle with auxiliary power which drives the electric drive unit with a size corresponding to a detection value of a detection unit, wherein the vehicle is provided with an axle of the wheel via a bearing. A vehicle with auxiliary power, wherein the rotor of the motor according to any one of the preceding claims is attached.