JP2001071983A - Power unit for electric bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent cutting of the cable of a motor during removal of a power unit and to prevent the cable from obstructing the assembly of spokes. SOLUTION: In this power unit, the cable 54 of a motor 3 is brought out via a connector 55 freely detachably connected to the outer end of the motor 3 along the cross direction of a vehicle. The connector 55 is provided with a retaining part 55b located between the outer end of an axle supporting end bracket 51 and an axle tightening nut 52 and allowing the axle 6 to pass therethrough. A holder 61 allowing the axle 6 to pass therethrough and held in engagement with the end bracket 51 is disposed between the retaining part 55b and the end bracket 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power unit for an electric bicycle in which a motor is provided in a hub of a front wheel and an axle is fastened to an axle supporting end bracket with a nut.

[0002]

2. Description of the Related Art Heretofore, as a power unit for an electric bicycle of this type, a power unit in which a hollow portion is formed in an axle of a front wheel, and a cable for supplying power to a motor is led outward through the hollow portion of the axle. is there. The cable led out of the power unit is routed along the front fork.
In order to remove this type of power unit from the front fork during maintenance, a connector provided in the middle of the cable is disconnected, the nut of the axle is loosened, and the power unit is removed from the end bracket for supporting the axle of the front fork.

[0003]

However, in the power unit for an electric bicycle constructed as described above, when the power unit is detached from the front fork, it is sometimes forgotten to disconnect the cable connector. If the power unit is removed from the front fork while the cable is connected, the cable may be forcibly pulled and cut. Also, when assembling the rim to the hub of the power unit via spokes, this cable must be held, for example, by a jig for spoke tensioning so that the cable derived from the axle does not become entangled with the spokes. However, there was also a problem that workability was reduced.

[0004] The present invention has been made to solve such a problem, and the motor cable is cut off when the power unit is removed from the front fork, and the cable becomes an obstacle when assembling the spokes. It is an object of the present invention to provide a power unit for an electric bicycle without any.

[0005]

In order to achieve this object, a power unit for an electric bicycle according to the present invention comprises a connector having a motor cable detachably connected to an outer end of the motor in a vehicle width direction. And this connector,
An axle is provided between the outer end of the axle support end bracket and the axle fastening nut, and a holding portion through which the axle penetrates is provided. A holder to be engaged and held is provided. According to the present invention, the axle can be removed from the end bracket by removing the connector from the motor and disengaging the holder located inside the vehicle body from the connector. Also, by removing the connector, it is possible to prevent the cable from being led out of the motor.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment An embodiment of a power unit for an electric bicycle according to the present invention will be described below in detail with reference to FIGS. FIG.
1 is a side view of a power unit for an electric bicycle according to the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. In these figures, what is indicated by reference numeral 1 is an electric bicycle power unit according to this embodiment. This power unit 1
Are attached to the shaft center of the front wheel (not shown) and attached to the front fork 2. Also, this power unit 1
Has a brushless DC motor 3 inside as shown in FIG.
And a planetary reduction gear 4 are arranged side by side in the vehicle width direction, and a hub 5 is rotatably provided so as to cover the motor 3 and the planetary reduction gear 4. The bicycle to which the power unit 1 is mounted has a conventionally well-known structure in which a rear wheel is driven via a chain or the like by depressing a pedal (not shown).

The motor 3 has a motor housing 7 to which an axle 6 located on the right side in FIG. 2 is mounted, a stator 8 fixed to the inner peripheral surface of the motor housing 7, and a bearing 9 on the shaft center of the motor housing 7. , 10 and a motor controller 12 housed in one end (the right end in FIG. 2) of the motor housing 7. The motor housing 7 is fixed to the support plate 13 to which the axle 6 is fixed, a disk-shaped front cover 15 fixed to the support plate 13 by fixing bolts 14, and fixed to the front cover 15 by fixing bolts 16. It is formed of a cylindrical housing body 17 and a disk-shaped end cover 18.
The support plate 13 is provided with a stopper 19 for preventing the motor housing 7 from rotating due to the reaction force of the motor 3 and the planetary reduction gear 4. As shown in FIG. 1, the stoppers 19 are formed at two places on the support plate 13 so as to engage with the front edge and the rear edge of the front fork 2. The axle 6 located on the right side in FIG. 2 is fixed to the support plate 13. The housing body 17
The stator 8 is fixed to the inner peripheral surface of the
The rotor 11 is supported by the end cover 5 and the end cover 18 via the bearings 9 and 10. The rotor 11 has a permanent magnet 20 fixed to the outer peripheral end, and the left end in FIG. 2 is connected to the planetary reduction gear 4. Further, an axle 21 located on the left side in FIG. 2 is attached to the end cover 18 via a planetary reduction gear 4 described later.

The planetary speed reducer 4 is a planetary roller speed reducer 2
2 and the planetary gear reducer 23 are connected in series in this order in the power transmission system so that the number of reduction stages is two. The planetary roller speed reducer 22 is connected to the rotor 11 of the motor 3.
A sun roller 24 joined by serrations to
Four planetary rollers 25 attached to the sun roller 24
A planetary roller supporting carrier 26 for supporting these planetary rollers 25 so that they can rotate and revolve freely;
5 comprises an outer peripheral ring 27 to which it is attached.
The carrier 26 integrally forms a sun gear 28 of the planetary gear reducer 23 at the shaft center. The outer ring 27
Are fixed to the outer peripheral portion of the end cover 18 of the motor housing 7 by fixing bolts 29. The fixing bolt 29 also fixes the planetary gear support carrier 30 of the later-described planetary gear reducer 23 to the end cover 18.

The planetary gear reducer 23 is provided with a sun gear 28 provided on a carrier 26 of the planetary roller reducer 22.
And three planetary gears 31 meshing with the sun gear 28
And the carrier 30 that rotatably supports the planetary gears 31 and the outer peripheral gear 3 meshed with the planetary gears 31.
2. The carrier 30 includes an annular plate 30a located closer to the planetary roller reducer 22 than the planetary gear 31, and a carrier body 30c coupled to the annular plate 30a via a planetary gear support shaft 30b. The axle 21 located on the left side in FIG. 2 is fixed to the carrier body 30c. The outer peripheral portion of the annular plate 30a is fixed to the end cover 18 of the motor housing 7 by the fixing bolt 29. The outer peripheral gear 3
Reference numeral 2 denotes an inner ring of the one-way clutch 33, which is connected to the hub 5 via the one-way clutch 33. The one-way clutch 33 has a structure in which the outer ring 33a is fixed to the hub 5 by a fixing bolt 34, and power is transmitted from the outer gear 32 to the hub 5 only.

The hub 5 has a cylindrical hub body 41 having a bottom and a flange 5a formed on the outer periphery for connecting a spoke (not shown), and a lid 42 screwed into an opening of the hub body 41. It is constituted by and. The hub of the hub body 41 is rotatably supported by the support plate 13 of the motor housing 7 by the bearing 43, and the shaft of the lid 42 is rotatably supported by the axle 21 via the bearing 44. ing. The outer ring 33a of the one-way clutch 33 is fixed to the lid 42, and a structure is employed in which power is transmitted from the planetary gear reducer 23.

The axle 21 located on the left side in FIG. 2 of the two axles 6 and 21 is provided with a nut 46 on an end bracket 45 of one fork member 2 a of the front fork 2.
Has been concluded. The end bracket 45 has a U-shaped groove 45a that opens downward in a vehicle-mounted state. The axle 21 is inserted through the groove 45a.
The nut 46 is tightened in a state where the end bracket 45 is sandwiched between the collar 47 and the holder 48 fitted to the bracket 47. The holder 48 is provided for holding the axle 21 on the end bracket 45 with the nut 46 loosened.
Are engaged from the outside.

The other axle 6 is fastened by a nut 52 to an end bracket 51 of a fork member 2b located on the right side in FIG. This end bracket 51
Is a U that opens downward at the lower end in the vehicle-mounted state.
A letter-shaped groove 53 is formed, and the lower end of the fork member 2b is welded to the upper end. The upper end to which the fork member 2b is welded is inclined so as to gradually extend outward in the vehicle width direction as it goes upward, and a circular shape for allowing the motor cable 54 to pass through a portion corresponding to the hollow portion of the fork member 2b. A hole 51a is formed. Circular hole 51 in the inclined part
The reason why a is provided is to allow the cable 54 extending from below to be inserted into the hollow portion of the fork member 2b without being bent significantly. As described above, the cable 54 is guided to the upper end of the front fork 2 through the hollow portion of the fork member 2b, and the leading end is connected to a battery, a main switch, a treading force detection sensor, and the like (not shown). By laying the cable 54 inside the fork member 2b, the cable 54 does not appear on the appearance of the front fork 2. The cable 54
Is connected to the motor 3 via a connector 55.
Connected to

The connector 55 has a female contact 57 which is detachably connected to a strip-shaped male contact 56 erected on the controller 12 of the motor 3. The controller 12 includes a Hall element (not shown) for detecting the rotation of the rotor 11 and an electronic component (not shown) for forming a motor drive circuit. ), So that the output of the motor 3 is controlled so as to be substantially proportional to the stepping force. The controller 12 is fixed to the front cover 15 of the motor housing 7 with fixing bolts 58. Note that a configuration may be employed in which the output of the motor 3 is increased or decreased by an artificial operation without depending on the pedaling force.

In this embodiment, the male contact 56 is
Four are formed so as to extend along the axial direction of the axle 6, and project through the rubber holding member 59 fitted to the lower end of the support plate 13 to the outside of the housing. . A concave portion 59a into which the tip of the connector 55 fits is formed in a portion of the holding member 59 through which the male contact 56 penetrates. The connector 55 is formed into an L-shaped cross section with a synthetic resin, and the female contact 57 and the cable 54 are integrally provided inside by insert molding. The distal end portion of the connecting portion 55a provided with the female contact 57 of the connector 55 is connected to the concave portion 59a of the holding member 59.
The axle 6 is inserted through a metal collar 60 into a holding portion 55b extending upward from the connection portion 55a. The collar 60 is also provided integrally with the connector 55 by insert molding. The axle 6 penetrating the holding portion 55b is inserted into the U-shaped groove 53 of the end bracket 51, and the nut 52 is inserted between the end bracket 51 and the holding portion 55b of the connector 55 with the holder 61 interposed therebetween. It is fastened to the end bracket 51 by tightening.

The holder 61 is a disk 6 on which the axle 6 is fitted.
1a and an engaging claw 61b projecting upward from the upper end of the disk 61a are integrally formed. The engaging claw 61b has a distal end bent so that the distal end faces the motor 3, and the distal end is engaged with the through hole 62 of the end bracket 51 from outside. By engaging the engaging claw 61b with the end bracket 51 in this manner, even if the nut 52 is loosened, as long as the engaging state of the engaging claw 61b is not released, the axle 6 can be moved through the end bracket 5 via the holder 61.
It is held at 1.

In FIG. 2, the connector 55 and the cable 54
A protection cover for protecting the connector 55 and the cable 54 is provided at a reference numeral 63 provided outside the box. This protective cover 63 is formed so as to surround the connector 55 and the cable 54 from the front and rear direction and the up and down direction and the side of the vehicle body, and has a lower part engaged with the nut 52 and an upper end part engaged with the fork member 2b. Let me.

To assemble the power unit 1 constructed as described above, the motor housing 7 is assembled with the stator 8, the rotor 11, the controller 12 and the like incorporated therein, and the planetary reduction gear 4 is assembled to the motor housing 7. This is performed by assembling the hub 5. Thereafter, the power unit 1 is attached to, for example, a jig for spoke extension, and a rim is attached to the hub 5 via the spokes. At this time, since the cable 54 is not led out of the motor 3, the cable 54 does not hinder the work. In order to mount the front wheel on which the power unit 1 is integrally mounted as described above to the front fork 2, first, the axles 6, 21 are connected to the U-shaped grooves 45 of the end brackets 45, 51.
a, 53 from below, and the engaging claws 48a, 61b of the holders 48, 61 fitted to the axles 6, 21 are engaged with the engaging holes 49, 62 of the end brackets 45, 51.
Next, the connecting portion 55a of the connector 55 is fitted into the concave portion 59a of the holding member 59 on the motor 3 side to connect the female contact 57 to the male contact 56, and the axle is attached to the collar 60 of the holding portion 55b. 6 through. Then, by tightening the nuts 46, 52 to both axles 6, 21,
The power unit 1 is mounted on the end brackets 45, 51. After tightening the nuts 46 and 52, the protection cover 63 is engaged with the nut 52 and the fork member 2b and attached.

In order to remove the front wheel from the front fork 2 for maintenance of the motor 3 or replacement of tires, the protective cover 63 is first pulled outward and removed, and then the nut 52 near the connector 55 is loosened. And remove the connector 55 from the motor 3 by pulling it outward. Then, the other nut 46 is loosened, and both holders 48 and 61 are moved outward from the front fork 2 to release the engagement states of the engagement claws 48a and 61b. After the engagement is released, the front axles 6 and 21 are disengaged downward from the end brackets 45 and 51 by lifting the front fork 2 upward, and the front wheel can be removed from the front fork 2.

Therefore, according to the power unit 1, the connector 55 is removed from the motor 3, and then the engagement state of the holder 61 located inside the vehicle body from the connector 55 is released. Since the power unit 1 can be detached from the front fork 2, the power unit 1 cannot be detached from the front fork 2 when the connector 55 is connected. That is, since one of the series of operations for removing the power unit 1 from the front fork 2 includes the work of removing the connector 55, the power unit 1 is always removed after the connector 55 is removed. As a result, cable 5
4 can be reliably prevented from being forcibly pulled and cut. In the embodiment described above, FIG.
The left axle 21 is also attached to the end bracket 4 by the holder 48.
5, the holder 48 may be omitted.

Second Embodiment Another embodiment of the power unit for an electric bicycle according to the present invention will be described in detail with reference to FIG. FIG. 3 is a side view showing another embodiment in which the shape of the connector is changed. In this figure, the same or equivalent members as those described with reference to FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof will be omitted. The connector 55 shown in FIG.
The fifth holding portion 55b is formed to extend upward from the fork member 2b behind the vehicle body in a side view. The cable 54 led out from the upper end of the connector 55 is wired along the outer surface of the fork member 2b in this embodiment. Even if the connector 55 is formed in this manner, the same effect as when the first embodiment is adopted can be obtained.

[0021]

As described above, according to the present invention, the axle can be removed from the end bracket by removing the connector from the motor and disengaging the holder located inside the vehicle body from the connector. Become like For this reason, the power unit cannot be removed from the end bracket unless the connector is removed, so that it is possible to reliably prevent the cable from being forcibly pulled when being removed from the vehicle body. Also, by removing the connector, the cable can be brought out of the motor, so that when the spoke is assembled to the hub, the cable does not become entangled with the spoke,
The workability of the work of assembling the spokes can be improved.

[Brief description of the drawings]

FIG. 1 is a side view of a power unit for an electric bicycle according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a side view showing another embodiment in which the shape of the connector is changed.

[Explanation of symbols]

3 ... motor, 5 ... hub, 6, 21 ... axle, 45, 51 ...
End bracket, 46, 52 nut, 54 cable, 55 connector 55b holding part, holder 6
1, 61b: engaging claw, 62: engaging hole.

Claims (1)

[Claims] 1. A power unit for an electric bicycle in which a driving motor is provided inside a hub of a front wheel and an axle is fastened to an axle supporting end bracket with a nut, wherein a cable of the motor is connected to an outer end of the motor in a vehicle width direction. Through a connector detachably connected to the
A holding portion is provided between the outer end of the end bracket and the nut and through which the axle penetrates, and between this holding portion and the end bracket, the axle penetrates and engages and holds the end bracket. A power unit for an electric bicycle, comprising a holder to be mounted.