JPH04358984A - Power unit cooling structure of electric-motor two wheeler - Google Patents

Abstract

PURPOSE:To improve the service life in a power unit by having an electric motor sufficiently cooled by a running wind, in the power unit of an electric- motor two wheeler. CONSTITUTION:In the case where a power unit 17 of an electric-motor two wheeler 1 is pivotally supported on a body frame 2 free of vertical rocking motion, while it is made up of a power transmission 21, supporting a rear wheel on the rocking end, and an electric motor 20 being projectingly installed in this power transmission 21, three cooling fins 54, 63, 71 are formed on an outer surface of the motor 20.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power unit cooling structure for an electric two-wheeled vehicle.

0002

[Prior Art] The power unit of an electric two-wheeled vehicle includes:
It is equipped with a power transmission device that is pivotally supported on the vehicle body frame so as to be able to swing up and down and supports a rear wheel at its swinging end, and an electric motor that projects from this power transmission device, and that transmits the power of the electric motor to the above-mentioned power transmission device. There is one that transmits the information to the rear wheels via a device.

0003

By the way, the above-mentioned power transmission device is long in the front and back in order to support the rear wheels, and its outer surface is large. Therefore, the heat generated in this power transmission device during power transmission is sufficiently cooled by the running wind. However, since the electric motor has a small outer surface, there is a risk that the heat generated by driving the electric motor may not be sufficiently cooled down by the running wind, and in this case, the life of the power unit will be shortened.

0004

[Object of the Invention] This invention was made in view of the above-mentioned circumstances, and provides a power unit for an electric two-wheeled vehicle in which the electric motor is sufficiently cooled by the running wind.
The purpose of this is to improve the life of the power unit.

[0005]

[Means for Solving the Problems] To achieve the above object, the present invention is characterized by a power transmission system that is pivotally supported on a vehicle body frame so as to be able to swing up and down, and that supports a rear wheel at the swinging end. The present invention includes a device and an electric motor protruding from the power transmission device, the power of the electric motor is transmitted to the rear wheels via the power transmission device, and cooling fins are formed on the outer surface of the electric motor.

[0006]

[Operation] The operation of the above structure is as follows. A power unit 17 of the electric two-wheeled vehicle 1 is pivotally supported on the body frame 2 so as to be able to swing up and down, and is provided with a power transmission device 21 that supports a rear wheel 30 at its swinging end, and a power transmission device 21 that projects from the power transmission device 21. It is composed of an electric motor 20. Cooling fins 54, 63, and 71 are formed on the outer surface of the electric motor 20. By the way, since the electric motor 20 has a small outer surface, there is a possibility that the heat generated by driving the electric motor 20 will not be sufficiently cooled down by the running wind 53. However, by providing the cooling fins 54, 63, and 71 as described above, the electric motor 20 is sufficiently cooled.

[0007]

Embodiments Hereinafter, embodiments of the present invention will be explained with reference to the drawings. (First Embodiment) FIGS. 1 to 6 show a first embodiment. In the figure, reference numeral 1 indicates a scooter-type electric two-wheeled vehicle, and an arrow Fr in the figure indicates the front thereof. The above electric motorcycle 1
The vehicle body frame 2 has an underbone shape,
The body frame 2 includes a head pipe 3 located at its front end, a front frame 4 extending rearward and downward from the head pipe 3, and a front frame 4 extending rearward from the rear end of the front frame 4 substantially horizontally. It is composed of a horizontal frame 5 and a rear frame 6 that extends rearward and upward from the rear end of the horizontal frame 5 and then extends rearward substantially horizontally, and these are integrally molded from a resin material.

A steering shaft 8 is supported on the head pipe 3 so as to be freely steerable, and a steering knuckle 9 is attached to the lower end of the steering shaft 8. At the lower end of this steering knuckle 9, there are links 10 connected to each other.
A front wheel 12 is supported via a shock absorber 11 and a shock absorber 11 . Further, a handle 13 is attached to the upper end of the steering shaft 8.

In FIGS. 1 to 3 and 6, 17
is a power unit, and this power unit 17 is composed of an AC travel drive electric motor 20 and a power transmission device 21. The electric motor 20 has a casing 2 whose axis extends left and right.
It has 3. The output shaft 20a is inside this casing 23.
and a rotor 20b are integrally and rotatably supported, and a stator 20c is attached to the casing 23 in correspondence with the rotor 20b.

The power transmission device 21 has a long transmission case 22 in the front and rear, and this transmission case 22 has a left side case 22.
a and a right side case 22b, which are screwed together with bolts 22c. An input shaft 21a, an intermediate shaft 21b, and a rear axle 21c are supported at the rear of the transmission case 22, and these are connected to a gear group 21 for deceleration.
They are interlocked and connected to each other at d. The casing 23 projects from the front right side surface of the right case 22b, and is integrally molded. The output shaft 20a and the input shaft 21a are interlocked and connected to each other by a chain winding means 21e.

On the other hand, a bracket 25 made of sheet metal is screwed to the lower surface of the rear frame 6 midway in the front and rear directions with bolts 26. Support pieces 27, 27 protruding from the front part of the transmission case 22 and the upper surface of the casing 23 are pivoted to the bracket 25 by a pivot shaft 28. The rear part of the case 22 is vertically swingable. In addition, in particular, FIGS. 1 and 2
, and as shown in FIG. 5, the rear part of the transmission case 22 is supported by a shock absorber 29 at the rear part of the rear frame 6, and a rear wheel 30 is supported on the right protruding end of the rear axle 21c.

The power of the electric motor 20 is transmitted to the rear wheel 3 via the chain winding means 21e and the gear group 21d.
0, and the electric two-wheeled vehicle 1 is allowed to travel. During this traveling, the impact that the vehicle body receives from the road surface 31 is absorbed by the shock absorbers 11 and 29. Additionally, 32 is a rear fender, which is integrally molded on the lower surface of the rear frame 6 and prevents mud thrown up by the rear wheels 30 from heading toward the electric motor 20.

1 to 3, a storage box 33 is provided on the rear frame 6. As shown in FIGS. This storage box 33
The rear frame 6 is integrally molded with a resin material, thereby suppressing an increase in the number of parts. This storage box 33 has an opening 34 at its upper part, and a sheet 35 is supported on the storage box 33. The front end of this seat 35 is connected to the storage box 3.
The seat 35 is pivotally supported at the upper front end of the seat 3 by a pivot pin 36, and the rear part of the seat 35 is vertically movable around the pivot pin 36.

[0014] Then, by rotating the seat 35 downward as shown in the figure, the rider can sit down.
When rotated upward, the opening 34 is opened and small items such as a helmet can be taken in and out of the storage box 33. Further, when the seat 35 is rotated downward as described above, the opening 34 is closed by the seat 35, and in this state, the seat 35 is rotated downward.
A locking means 37 is provided for locking the storage box 33 to the storage box 33 side. Further, a pair of left and right side covers 38, 38 are provided which cover the rear frame 6 and the storage box 33 from the left and right sides, and these side covers are symmetrical.

1 to 4, a footrest floor 39 is provided on the horizontal frame 5 on which a rider seated on the seat 35 rests his/her feet. The battery 4 is placed along the bottom side of this footrest floor 39.
0 is provided, and this battery 40 is composed of four units 40a. The battery 40 is connected to the electric motor 20.
It is supported by the horizontal frame 5.

In this case, the horizontal frame 5 has a wide and flat main body 41, and the upper surface of the main body 41 serves as the footrest floor 39. Further, a pair of front and rear recesses 42 are formed in each side of the main body portion 41, respectively. The openings 43 of each of these recesses 42 are open toward each side of the main body 41, and are closed by cover plates 44 made of resin so as to be openable and closable. and,
Each unit 40a is inserted into and removed from each recess 42, and at this time, a heat insulating and cushioning material 45 made of styrene foam is interposed between each unit 40a and the inner surface of each recess 42.

The horizontal frame 5 of the vehicle body frame 2 has a box-shaped cross section, and therefore has a structure with sufficient strength. On the other hand, ribs 46 are formed on each side of the front frame 4 and the rear frame 6, thereby improving strength. In this way, a vehicle body frame 2 that is overall light and highly rigid is obtained. Furthermore, by integrating the storage box 33 into the rear frame 6 as described above, the strength of the vehicle body frame 2 is also improved.

In particular, as shown in FIG.
A pair of left and right grooves 47, 47 extending back and forth are formed on the lower surface of the holder, and these grooves 47 can be expanded elastically. A wire harness 48 is removably fitted into each groove 47, and this wire harness 48 is connected to the electric motor 20.
The electrical components including the battery 40 and the battery 40 are connected to each other.

In FIG. 1, the footrest floor 3
A leg shield 49 is provided to cover the legs of the rider placed on the rider 9 from the front. Also, this leg shield 49
covers the head pipe 3, the front frame 4, and the steering shaft 8. 1 and 4, an undercover 50 is provided to cover the lower surface of the horizontal frame 5. As shown in FIGS. In FIG. 4, 51 is a water drain hole.

In FIGS. 1 and 2, the rear frame 6
A main stand 52 is provided on the lower surface of the front end. The main stand 52 is biased by a spring so that it can select either an upwardly rotating posture shown by solid lines in the figure or a downwardly rotating posture shown by phantom lines. and,
If the electric two-wheeled vehicle 1 is placed in the upward rotational position, it is possible to run the electric two-wheeled vehicle 1, and if the electric two-wheeled vehicle 1 is placed in the downward rotational position, the electric two-wheeled vehicle 1 can be maintained in an independent state.

In the above structure, in order to cool the power unit 17 by the traveling wind 53, the following structure is used. That is, in FIGS. 1, 2, and 6, a plurality of cooling fins 54 are provided protruding from the front left side of the transmission case 22 and the right side of the casing 23, and each of these cooling fins 54 is arranged in a rearward upward direction. It is extending. When the electric two-wheeled vehicle 1 runs, the running wind 53 that has passed along the lower surface side of the horizontal frame 5 cools the power unit 17 as a whole, and in particular, a part of it passes between the cooling fins 54. It flows rearward and upward, particularly cooling the electric motor 20 sufficiently.

The following figures show second to seventh embodiments. It should be noted that the common reference numerals are given to the configurations and functions that these embodiments have in common with the first embodiment described above, and the explanation thereof will be omitted. (Second Embodiment) FIGS. 7 to 10 show a second embodiment. According to this, the horizontal frame 5 includes a wide and flat box-shaped main body 55 and a bolt 56 on the upper surface of the main body 55.
A cover plate 57 is detachably screwed to the cover plate 57. A recess 4 is provided on the upper surface of the main body 55.
2 is formed, and an opening 43 of this recess 42 is opened upward, and this opening 43 is closed by the cover plate 57.

Each side edge of the undercover 50 extends upward along the side surface of the main body portion 55 and fits into the side edge of the cover plate 57. In the above configuration, the cooling fins 54
extends substantially horizontally from front to back, and a plurality of cooling fins 63 extending from side to side are formed on the front portion of the transmission case 22 and the outer peripheral surface of the casing 23. Furthermore, air guide ducts 64, 64 are provided between the horizontal frame 5 and the left and right sides of the undercover 50, and the front end opening 65 thereof opens forward, and the rear end opening 66 opens forward. Each cooling fin 5
It is bent slightly towards the inside of the car body so that it faces 4,63.

In FIGS. 8 and 10, a cover body 67 made of sheet metal is provided to cover each of the front end openings 65, and this cover body 67 is supported by the horizontal frame 5. As shown in FIG. This cover body 67 covers each front end opening 65 from the front, from above, and from inside the vehicle body. The traveling wind 53 that bypasses the cover body 67 and is introduced into the air guide duct 64 through the front end opening 65 passes through the rear end opening 66 to each cooling fin 54,
63, thereby cooling the electric motor 20 particularly effectively. In addition, in this case, the front wheel 12
The cover body 6 prevents pebbles and mud thrown up by the cover body 6 from entering the air guide duct 64 through the front end opening 65.
7 prevents this.

(Third Embodiment) FIGS. 11 and 12 show a third embodiment. According to this, the cooling fins 54 extend approximately horizontally in the front and back, and cooling fins 63 are formed on the front portion of the transmission case 22 and the outer circumferential surface of the casing 23, as in the second embodiment. Each of the above cooling fins 54, 63
The front part of each group is covered by each side cover 38.

In side view, an air guide pipe 69 is attached to the left side cover 38 of the side covers 38 near the front of each of the cooling fins 54, 63. The running wind 53 is guided by the air guide pipe 69 and supplied to each of the cooling fins 54 and 63, so that the electric motor 20 in particular is sufficiently cooled. In the illustrated example, only the left side cover 38 is shown, and the air guide pipe 69 is provided only on this side cover 38, but the air guide pipe 69 may be provided on the right side cover 38 as well.

(Fourth Embodiment) FIGS. 13 to 15 show a fourth embodiment. According to this, a plurality of annular cooling fins 71 are formed on the outer peripheral surface of the casing 23 and extend in the circumferential direction. Further, an upper air guide plate 72 and a lower air guide plate 73 are provided to cover the rear half of the casing 23 from above and below, and these are screwed to a support portion 74 protruding from the casing 23 with bolts 75.

The upper air guide plate 72 and the lower air guide plate 73 are formed in an arc shape centered on the output shaft 20a. Also,
Each of these front edges 72a and 73a is connected to the casing 2.
It is bent away from 3 and has a bell mouth shape. On the other hand, the respective rear edges 72b and 73b face each other and are bent in a direction away from each other as they go rearward from here. Further, the rear edge 72b of the upper baffle plate 72
is slightly longer rearward than the rear edge 73b of the lower baffle plate 73, and a discharge slit 76 is formed between the two. The traveling wind 53 is guided by the upper wind guide plate 72 and the lower wind guide plate 73, passes between each cooling fin 71, passes through the discharge slit 76, and is discharged rearward. Thereby, the electric motor 20 in particular is effectively cooled.

(Fifth Embodiment) FIG. 16 shows a fifth embodiment. This basic configuration is the same as that of the fourth embodiment, so only the different configuration will be explained.
3 is a flat plate extending almost horizontally. Further, the rear part of the upper baffle plate 72 once extends substantially vertically downward, and the rear edge 72
b is bent toward the rear at an almost right angle.

(Sixth Embodiment) FIGS. 17 and 18 show a sixth embodiment. According to this, the front frame 4, the horizontal frame 5, and the rear frame 6 are all integrally molded from pipe material. Further, a front fork 78 is provided in place of the steering knuckle 9. The battery 40 is supported by the rear frame 6. The front part of the transmission case 22 is an extension case 8 extending toward the right side.
It has 0. An input shaft 81 is supported by this extension case 80, and a drive pulley 82 is attached to this input shaft 81. On the other hand, a rear axle 83 is supported at the rear part of the transmission case 22, and a driven pulley 84 is supported on this rear axle 83.
5 is wrapped around it.

Weight 8 rotating together with the drive pulley 82
6 is provided. When the electric motor 20 operates, the drive pulley 82 rotates, and centrifugal force is generated in the weight 86 due to this rotation. Then, in proportion to the magnitude of this centrifugal force, the pulley winding diameter of the driving pulley 82 increases, while the diameter of the driven pulley 8 increases.
The pulley winding diameter at No. 4 is made smaller. An electric motor 20 projects forward from the front surface of the extension case 80, and the output shaft 20a of the electric motor 20 and the input shaft 81 are connected by a bevel gear set 88. The cooling fins 54 on the front surface of the casing 23 extend left and right, and the cooling fins 63 on the outer peripheral surface of the casing 23 extend front and rear.

(Seventh Embodiment) FIGS. 19 and 20 show a seventh embodiment. Since this basic configuration is the same as that of the sixth embodiment, only the different configuration will be explained.The electric motor 20 is provided to protrude upward from the top surface of the extension case 80.

[0033]

According to the present invention, there is provided a power transmission device in which a power unit of an electric two-wheeled vehicle is pivotally supported on a vehicle body frame so as to be able to swing up and down, and a rear wheel is supported at the swinging end of the power unit, and this power transmission device. When configured with a motor that protrudes from the motor, cooling fins are formed on the outer surface of the motor, so although the outer surface of the motor is small, the heat generated by its drive can be sufficiently cooled down by the wind when the motor is running. However, by providing the cooling fins as described above, the electric motor is sufficiently cooled. Therefore,
The heat of the electric motor is prevented from having an adverse effect on the power unit, and the life of the power unit can be extended.

[Brief explanation of drawings]

FIG. 1 is a side view of a first embodiment.

FIG. 2 is a plan view of the first embodiment.

FIG. 3 is a sectional view taken along the line 3-3 in FIG. 1 in the first embodiment.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 1 in the first embodiment.

FIG. 5 is a sectional view taken along the line 5-5 in FIG. 1 in the first embodiment.

FIG. 6 is a plan sectional view of the power unit in the first embodiment.

FIG. 7 is a side view of the second embodiment.

FIG. 8 is a plan view of the second embodiment.

9 is a sectional view taken along the line 9-9 in FIG. 7 in the second embodiment; FIG.

10 is a view taken along arrow 10 in FIG. 7 in the second embodiment; FIG.

FIG. 11 is a side view of the third embodiment.

FIG. 12 is a plan view of the third embodiment.

FIG. 13 is a perspective view of the fourth embodiment.

FIG. 14 is a partial cross-sectional plan view of the fourth embodiment.

FIG. 15 is a side sectional view of the fourth embodiment.

FIG. 16 is a side sectional view of the fifth embodiment.

FIG. 17 is a side view of the sixth embodiment.

FIG. 18 is a plan sectional view of the sixth embodiment.

FIG. 19 is a side view of the seventh embodiment.

FIG. 20 is a plan sectional view of the seventh embodiment.

[Explanation of symbols]

1 Electric motorcycle 2 Vehicle body frame 17 Power unit 20 Electric motor 21 Power transmission device 30 Rear wheel 53 Driving wind 54 Cooling fins 63 Cooling fins 71 Cooling fins

Claims (1)

[Claims] Claim 1: A power transmission device that is pivotably supported on a vehicle body frame so as to be vertically swingable and that supports a rear wheel at its swinging end; and an electric motor that projects from this power transmission device; A power unit cooling structure for an electric two-wheeled vehicle, wherein power is transmitted to a rear wheel via the power transmission device, and cooling fins are formed on the outer surface of the electric motor.