JP2003164012A - Drive device for vehicle with assist power - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive device for a vehicle with assist power capable of improving efficiency in assembly. <P>SOLUTION: The drive device for a vehicle with an assist power comprises a rotary drum which rotates together with a wheel with the axle of the wheel as a center, and a transmission, motor, and reducer mechanism built in the rotary drum, so that the wheel is driven by an electric driving force of a motor in addition to a human power. It is provided with a torque detecting part which detects the magnitude of a human driving force at a human driving part which rotates and drives the rotary drum by a human power, and a motor control unit that drives the motor based on the detected value of the torque detecting part. The motor control unit is fitted to a coil that constitutes the torque detecting part. <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 used in a vehicle with auxiliary power such as an electrically assisted bicycle, an electric motorcycle, or an electric vehicle that uses a motor as auxiliary power.

[0002]

2. Description of the Related Art Conventionally, as a vehicle with auxiliary power, a stationary casing that constitutes a hub of the wheel together with a rotating casing that rotates together with the wheel around an axle of the wheel and a rotating casing provided at a position facing the rotating casing. A casing, a transmission that is provided around the axle in the hub and is capable of switching a gear ratio, and a motor that rotationally drives the rotating casing, and the motor is provided so as to surround the outer periphery of the transmission. There is an electric car that has
00-43780 (B62M23 / 02)). In this electric vehicle, a torque sensor that detects the magnitude of the human-powered driving force is provided in parallel with the motor, and the motor is driven based on the change in the inductance detected by the torque sensor to rotate the rear wheels. I have to.

The torque sensor is composed of a core formed of a magnetostrictive element and a coil portion arranged on the outer circumference of the core, and is arranged in parallel with the motor around the outer circumference of the transmission. A control board for driving the motor based on the detection value of the torque sensor is fixed to a side surface of a fixed casing of the motor. Then, electric power is supplied to the motor through a power cord connected to the control board.

[0004]

Since the drive portion of such an electric vehicle is compact, it can be made compact and lightweight. However, since the torque sensor and the control board are handled as separate parts, there is a problem that the assembling work becomes complicated.

In view of the above circumstances, it is an object of the present invention to provide a drive device for a vehicle with auxiliary power, which can improve the efficiency of assembly work.

[0006]

A drive device for a vehicle with auxiliary power according to the present invention comprises a rotary drum which rotates together with the wheel around an axle of the wheel, a transmission incorporated in the rotary drum,
A driving device for a vehicle equipped with a motor and a speed reducer, which drives the wheels by electric driving force by a motor in addition to human driving force by human power, and rotationally drives the rotating drum by human power. A torque detection unit that detects the magnitude of the human-powered driving force of the human-powered driving unit and a motor control unit that drives the motor based on the detection value of the torque detection unit are provided, and the motor control unit controls the torque. It is characterized in that it is attached to a coil portion which constitutes the detection portion.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A drive system for a vehicle with auxiliary power of the present invention will be described below with reference to the accompanying drawings.

As an auxiliary power vehicle according to one embodiment of the present invention, there is an electrically assisted bicycle as shown in FIG. 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 driving device 12 includes a transmission 19 for changing a gear ratio inside a rotary drum 18 that rotates together with a rear wheel 9 around an axle 10, and the rotation. A motor 20 for rotationally driving the drum 18 and a speed reducer mechanism 21 are provided in parallel. In the present embodiment, the axle 10 is divided into a first wheel axle 10a and a second wheel axle 10b, and the transmission 19 is attached 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 block the entrance 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.

A torque detector 25 is arranged between the transmission 19 and the motor 20. As the torque detection unit 25, for example, a sliding member 26 provided on the outer periphery of the transmission 19 so as to be slidable in the axial direction, and the sliding member 26.
Mounted on the rotary drum 18b by a bolt 30 while being supported on the outer periphery of the transmission 19 by a bearing 29 and a spring 28 for biasing the sliding member 26 toward the rear sprocket 17 side. And a torque sensor 32 including a sensor support member 31
Of the two motor cases 33a and 33b of the motor 20, the motor case 33 can be configured to include a coil 34 and a coil portion 36 including a coil bobbin 35 that is attached to one motor case 33b. The torque detection unit 25 converts a change in inductance due to the movement of the detection rod 27 into an electric signal. That is, the human-powered torque of the human-powered driving unit 11 that drives the rear wheels 9 by human power is converted into an electric signal. This electric signal is transmitted to the motor control unit 38 housed in the substrate case 37 integrally formed with the coil bobbin 35. The substrate case 3
7 stores a large electric component to be housed in a side wall recess S in which a part of the side wall of the motor case 33b is recessed inside the motor 20 so as to be arranged on the outermost periphery while avoiding the coil end of the rotor winding. I am trying. By accommodating the large-sized component provided in the board case 37 in the side wall recess S of the motor case 33b, the width dimension in the axle direction can be reduced. The motor control unit 38 is attached to a substrate case 37 integrally formed with the coil bobbin 35 of the coil unit 36, and also includes a control substrate 39 and the control substrate 3
The motor 20 is driven based on the detection value of the torque detection unit 25, which is composed of electric parts attached to the motor 9, such as a large-sized capacitor 40 and FET, and small-sized resistors and diodes. In addition, this control board 39
There is a power cord 4 for supplying power from the battery 13.
1 is inserted into a notched portion 42 of a part of the second wheel axle 10b, and is then connected along a notched portion 43 of the outer wall of the motor case 33. In addition, in order to prevent the power cord 41 from being damaged by the contact between the power cord 41 and the rotary drum 18b, it is preferable to provide a protection means for protecting the power cord 41. As the protection means, a member that covers the power cord 41 can be fitted into the cutout portions 42 and 43.
Since the number of parts is increased, for example, the outer wall of the substrate case 37 can be an outer peripheral wall 37a extending to the outer periphery of the power cord 41.

The motor 20 includes a motor case 33a,
33b, a rotor including a rotor core 52, a rotor winding 53, and a commutator 54, which are incorporated in the outer peripheral portion of a motor shaft 51, and a stator 55 and a carbon brush 56 arranged in the motor case 33b. ing. 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, which is fitted in a recess formed in one end 51a of the motor shaft 51. In addition, the rotary drum 18a 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.

In FIG. 3, 59 is a collar for holding the outer ring of the bearing 57 which is the pilot bearing, and 60 is a bearing for supporting the motor case 33a.
The rotor winding 53 is wound around the rotor core 52. Magnets 61 forming four poles are fixed to the stator 55 at equal intervals. Further, the carbon brush 56 is arranged at a position of 90 ° so that the substrate case 37 for accommodating the motor control section 38 is accommodated by recessing the side portion of the motor case 33b.

As the speed reducer mechanism 21, a planetary gear speed reducer or a planetary roller speed reducer can be used.
In this embodiment, a planetary gear reducer is used.
The speed reducer mechanism 21 includes the other end portion 51 of the motor shaft 51.
b, and three planet gears 63 rotatably coupled to the side of the motor case 33a.
And an internal gear 65 arranged via the ratchet gear 64 of the rotary drum 18a.
The planet gear 63 has a large gear 63 a meshing with the sun gear 62 and the internal gear 65.
It consists of a small gear 63b that meshes with. The ratchet gear 64 shuts off the human-powered driving force and the power of the motor 20 when the rotational speed of the rear wheel 9 becomes faster than the rotation of the rotary drum 18 by human power.

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 in the direction in which the ratchet gear 64 is hooked, that is, in the present embodiment, the ratchet gear 64 is viewed from the motor shaft 51.
It is connected in the direction of the right-hand thread. This ratchet gear 6
The inner diameter of 4 extends circumferentially on the side of the internal gear 65, and this portion is joined to the stepped portion of the internal gear 65, so that the inner diameter of the ratchet gear 64 and the internal gear 65 are inlayed and centered. Is possible. Also, the second wheel axle 10b centered on the inner ring of the bearing 23 fitted to the inner circumference of the rotary drum 18a.
Is connected to the planet gear 63
By holding a, the step portion formed on the second wheel axle 10b and the annular projection formed on the motor case 33a are fitted to each other, the center of the planet gear 63 and the internal gear 65 are Can be easily matched with the center.

Regarding the drive unit according to the present embodiment, first, the transmission of the power of the human power 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 rear sprocket 17 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 changed by the transmission 19 set to the gear ratio instructed by the user, and then the rotary drum 18 is rotated while the spring 28 constituting the torque sensor 32 is contracted. Then, the rear wheel 9 can be rotated.

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

The change in the inductance detected by the coil 34 due to the displacement of the detection rod 27 of the torque sensor 32 is input to the microcomputer of the control board 39. Then, based on the signal value, the PW from the motor control unit 38
The motor 20 is driven by the M signal. The drive of the motor 20 is reduced by a planetary gear reduction mechanism, that is, a sun gear 62, a planet gear 63 and an internal gear 65, and rotates the rotating drum 18 via a ratchet gear 64 connected to the planet gear 63. Then, 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.

[0023]

As described above, according to the present invention,
Since the coil section is attached to the motor control section, the efficiency of the assembling work can be improved.

Further, since the board case and the coil bobbin are integrated, the cost can be reduced, and the lead wire coming out of the coil bobbin can be directly attached to the control board, so that the lead wire can be shortened, which simplifies the wire processing and reduces noise. The impact can be mitigated.

[Brief description of drawings]

FIG. 1 is a side view showing an electrically assisted bicycle using the vehicle drive device with auxiliary power of the present invention.

FIG. 2 is a cross-sectional view showing a vehicle drive device with auxiliary power according to an embodiment of the present invention.

3 is an exploded view of main parts of a transmission and a motor in the drive system 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 Reducer mechanism 25 Torque detector 30a, 30b Motor case 35 coil bobbin 36 coil 37 board case 37a outer peripheral wall 38 Motor control unit 39 control board 40 capacitors 41 power cord S Side wall recess

Claims (6)

[Claims] 1. A rotary drum that rotates together with the wheel around an axle of the wheel, and a transmission installed in the rotary drum.
A driving device for a vehicle equipped with a motor and a speed reducer, which drives the wheels by electric driving force by a motor in addition to human driving force by human power, and rotationally drives the rotating drum by human power. A torque detection unit that detects the magnitude of the human-powered driving force of the human-powered driving unit and a motor control unit that drives the motor based on the detection value of the torque detection unit are provided, and the motor control unit controls the torque. A drive device for a vehicle with auxiliary power, which is attached to a coil unit that constitutes a detection unit. 2. The drive device for a vehicle with auxiliary power according to claim 1, wherein the coil portion is attached to a motor case of the motor. 3. The drive device for a vehicle with auxiliary power according to claim 2, wherein the substrate case of the motor control unit and the coil bobbin of the coil unit are integrally formed. 4. The drive device for a vehicle with auxiliary power according to claim 3, wherein the substrate case is housed in a side wall recess of the motor case. 5. The vehicle with auxiliary power according to claim 1, further comprising a protection unit that protects a power cord connected to a control board of the motor control unit from contact with the rotary drum. Drive. 6. The drive device for a vehicle with auxiliary power according to claim 5, wherein the protection means is an outer peripheral wall of the substrate case.