JPH08142966A - Power assist tricycle - Google Patents

Abstract

PURPOSE: To improve the traveling stability by arranging an intermediate shaft between a pedal shaft and rear wheel axles parallel thereto, and transmitting the stepping force of a pedal and the driving force of a motor to right and left rear wheels through this intermediate shaft to enable the driving of both wheels with a simple structure. CONSTITUTION: An intermediate shaft 33 is arranged between a pedal shaft 40 and axles 30a of rear wheels 30 parallel to the axles 30a, 30a, and the stepping force of a pedal 42 and the driving force of a motor 51 are transmitted to right and left rear axles 30,30 through this intermediate shaft 33. The traveling position can be stabilized more compared with the single wheel driving. Because the intermediate shaft 33 is arranged between the pedal shaft 40 and the axle 30a of the rear wheel 30, special one-way clutch or differential device can be dispensed with to allow the simple structure, and the manufacturing and assembling works can be facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power assisted three-wheeled bicycle in which an auxiliary driving force corresponding to the pedaling force of a pedal is supplied to a rear wheel by a motor.

[0002]

2. Description of the Related Art A large pedaling force is required when riding a bicycle, for example, on an uphill road, in a headwind, or while carrying a load. In order to reduce such a burden during running, a power assisted three-wheeled bicycle equipped with a power assist unit that gives an auxiliary driving force according to the pedaling force of the pedal has been proposed (for example, Japanese Patent Laid-Open No. 6-21179). reference). This power assist unit is composed of a motor that rotationally drives the rear wheels, a battery that supplies power to the motor, and a controller that controls the driving force of the motor according to the torque applied to the pedal and the vehicle speed.

Further, in the above-mentioned conventional publication, a one-wheel drive system is proposed in which the pedaling force of a pedal is transmitted to a rear wheel on one side via a chain and the driving force of a motor is transmitted to the rear wheel via a transmission gear. Has been done.

[0004]

However, in the case of the one-wheel drive system of the above-mentioned conventional publication, the running stability is not at a level that can be sufficiently satisfied, and there is a demand to further improve the running stability.

In order to improve the running stability, it is conceivable to adopt a two-wheel drive system in which the pedal effort and the motor drive force are transmitted to both rear wheels. In this case, left,
If the right rear wheel is attached to both ends of a single common axle, turning performance will deteriorate. Therefore, the left and right axles will be separate and independent, and the left and right axles will be a special one-way clutch or differential device. Therefore, there is a concern that the structure becomes complicated and manufacturing and assembling become difficult.

The present invention has been made in view of the above conventional circumstances, and an object of the present invention is to provide a power assisted three-wheeled bicycle capable of driving two wheels with a simple structure and improving traveling stability.

[0007]

According to a first aspect of the present invention, there is provided a vehicle body frame which pivotally supports a front wheel at a front end portion and a pair of left and right rear wheels at a rear end portion, and the rear wheel mounted on the vehicle body frame. A motor that rotates, a battery that supplies power to the motor,
In a power assisted three-wheeled bicycle including a power assist unit including a controller that controls the driving force of the motor according to the pedal effort, an intermediate shaft is arranged between the pedal shaft and the rear wheel shaft in parallel with the both shafts. However, the pedaling force of the pedal and the driving force of the motor are transmitted to the left and right rear wheels via the intermediate shaft.

The invention according to claim 2 is characterized in that the output shaft of the motor is arranged in parallel with the intermediate shaft, and the output shaft and the intermediate shaft are connected via a one-way clutch. Is characterized in that the output shaft of the motor is arranged coaxially with the intermediate shaft, and the output shaft and the intermediate shaft are connected via a one-way clutch.

[0009]

According to the power assisted three-wheeled bicycle of the present invention, the pedaling force and the motor driving force are transmitted to both the left and right rear wheels via the intermediate shaft, so that the running posture is stabilized as compared with the one-wheel drive. Can be planned. Further, since the intermediate shaft is arranged between the pedal shaft and the rear wheel shaft, it is not necessary to use a special one-way clutch or a differential device, and the structure is simple, and the manufacturing and assembling operations are easy.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 9 are views for explaining a power-assisted three-wheeled bicycle according to an embodiment of the invention of claims 1 and 2, and FIGS. 1 and 2 are a side view and a plan view of the power-assisted three-wheeled bicycle, respectively. 3 and 4 are a plan view and a cross-sectional side view, respectively, showing the rear part of the vehicle body frame, FIG. 5 is a schematic configuration diagram showing the rear wheel drive part, FIG. 6 is a cross-sectional side view showing the swing part of the front frame, and FIG. 6 is a sectional view taken along the line VI-VI in FIG. 6, and FIG. 8 is a block configuration diagram showing the operation.

In the figure, reference numeral 1 is a power-assisted three-wheeled bicycle of this embodiment, and a body frame 2 of the three-wheeled bicycle 1.
Connects a rear end portion 4a of a front frame 4 extending obliquely downward and rearward from the head pipe 3 to a rear frame 5 so that the rear frame 5 can swing, and a saddle 6a on which an occupant is seated is seated at a substantially central portion in the longitudinal direction of the front frame 4. Of the structure in which the seat tube 6 mounted with is installed upright, and the seat tube 6 and the front frame 4 are
The rear part is connected by a reinforcing frame 7.

A steering shaft 8a of a front fork 8 is pivotally supported by the head pipe 3, a front wheel 9 is pivotally supported at a lower end of the front fork 8, and a handle 10 is fixedly secured at an upper end thereof. Furthermore, the front fork 8
A front basket 11 is attached to this via a bracket.

The rear frame 5 includes a lower frame 15 having a generally U-shape in a plan view and an upper frame 16 having a generally U-shape in a plan view and arranged in parallel thereabove. Connected with, and the left and right sides of the upper frame 16 are bent and formed in a downward V shape to integrally form the bearing portion 16a. A reinforcing plate 18 extending in the vehicle width direction is bridged and joined to the lower frame 15, and two reinforcing plates 19, 19 extending in the vehicle body front-rear direction are bridged and joined to the upper frame 16. .

A rear basket 20 is mounted on the upper surface of the rear frame 5, and the rear basket 20 is bolted and fixed to the upper frame 16. A wide opening 20b is formed in the bottom wall 20a of the rear basket 20, and an opening / closing lid 25 is attached to the front edge of the opening 20b via a hinge 25a so as to be openable and closable. A grip 26 is pivotally attached to the opening / closing lid 25, and the grip 26 is stored in a storage portion 25b recessed in the opening / closing lid 25 so as to be flush with the opening / closing lid 25. This can improve workability when performing maintenance on the battery 52 and the controller 53. A lock key 27 for locking the opening / closing lid 25 is attached to prevent theft,
Prevents mischief.

As shown in FIGS. 6 and 7, a swing shaft 22 is fixed to the rear end portion 4a of the front frame 4 through a pair of brackets 21 and 21. Both ends 22a of the swing shaft 22 are cylindrical, and the central portion 22b is a square prism. Both ends 22a are rotatably supported by the reinforcing plate 18 via bearings 18a. Further, a bearing pipe 23 in the shape of a rectangular tube fixed to the reinforcing plate 18 is mounted on the swing shaft 22.
A Nyquid rubber 24 is disposed between the shaft 3 and the swing shaft 22. As a result, the front frame 4 is swingable to the left and right, and is returned to the original vertical position by the elastic force of the Nyquid rubber 24.

Rear wheels 3 are provided on the left and right outer portions of the rear frame 5.
0, 30 are provided, and the axle 30a of the rear wheel 30 is pivotally supported by the left and right bearing portions 16a of the upper frame 16 and the bearing portion of the lower frame 15, respectively.

Further, as shown in FIG.
A driven sprocket 32 is coupled to the inner end of a with a one-way clutch 31 interposed therebetween. An intermediate shaft 33 is arranged in front of both axles 30a in parallel with the axles 30a, and the intermediate shaft 33 is rotatably supported by the lower frame 15 via a bearing (not shown). The drive sprockets 34 and 35 are provided on both ends of the intermediate shaft 33, respectively.
And the driven sprockets 32, 3 are connected to each other through chains 37, 37.
It is connected to 2. A motor sprocket 38 is connected to the intermediate shaft 33 with a one-way clutch 39 interposed.

A boss 4b is formed at the base of the seat tube 6 of the front frame 4. A pedal shaft 40 is rotatably inserted in the boss portion 4b, and pedals 42 are attached to both ends of the pedal shaft 40 via cranks 41. This pedal shaft 40 has a drive sprocket 4
3, the sprocket 43 is fixed to the driven sprocket 3 of the intermediate shaft 33 via the pedal chain 44.
6, the sprocket 36 is connected to the intermediate shaft 33 via a one-way clutch 90. Here, the present embodiment has a structure in which the rotational force from the pedal 42 is simultaneously transmitted to the left and right rear wheels 30 via the intermediate shaft 33. Therefore, the one-way clutch 31 must absorb the rotational difference between the two wheels during turning. Becomes

A power assist unit 50 of this embodiment is arranged on the vehicle body frame 2. The power assist unit 50 includes a motor 5 for rotating both rear wheels 30.
1 and two batteries 5 for supplying power to the motor 51
2 and a controller 53 that controls the driving force of the motor 51. A torque sensor 54 and a vehicle speed sensor 55 are connected to the controller 53.

The torque sensor 54 detects the phase difference between the pedal shaft 40 and the chain sprocket 43 by elastic deformation of an elastic member (not shown) interposed between the pedal shaft 40 and the chain sprocket 43, and the detected value is detected. Is output to the controller 53. The vehicle speed sensor 55 is configured to detect the number of rotations of the rear wheel 30 and output the detected value to the controller 53.

The motor 51 is arranged in front of the upper frame 16 below the rear basket 20, and is mounted on a generally U-shaped support frame 56 formed integrally with the upper frame 16 so as to interpose a bracket (not shown). It is fixed. Further, the motor 51 is located at the center portion in the vehicle width direction such that the output shaft 51a of the motor 51 is parallel to the intermediate shaft 33, thereby preventing the foot from interfering during pedaling. The output shaft 5 of the motor 51
A sprocket 57 is fixed to 1a, and the sprocket 57 is connected to the motor sprocket 38 of the intermediate shaft 33 via a chain 58.

The battery 52 is housed in a rectangular parallelepiped battery box 60.
V battery, which is connected in series. The battery box 60 is laterally arranged in the rear frame 5 below the rear basket 20, and faces the outside from the opening 20b of the bottom wall 20a of the rear basket 20.

The battery box 60 is mounted on the left and right support frames 17a, 17a which are bridged between the front and rear reinforcing frames 17 of the rear frame 5 and joined.
Further, side frames 17b are bridged and joined to the left and right side portions between the front and rear reinforcing frames 17, respectively,
The side frame 17b and the reinforcing frames 17 described above.
The battery box 60 is surrounded by. As a result, the battery box 60 is restricted from moving in the front-rear direction and the left-right direction, and can be attached and detached only in the upward direction.

The controller 53 is arranged at the rear end of the front frame 4 so as to cover the upper surface of the front frame 4, so that the controller 53 utilizes the surface area of the front frame 4.
Promotes heat dissipation. The controller 53 determines the magnitude of the torque (pedaling force) generated in the pedal 42 from the detection value of the torque sensor 54, the vehicle speed from the detection value of the vehicle speed sensor 55, and the auxiliary driving force based on the built-in map. However, the battery 52 is configured to supply a current corresponding to the auxiliary driving force from the battery 52 to the motor 51. This auxiliary driving force is 1 for 1 pedaling force of the occupant.
Is set below, and the vehicle speed is, for example, 15 km / h.
It is set such that it becomes gradually smaller from the point when it exceeds 24 km and becomes zero when it reaches 24 Km / h.

Further, although not shown, a main switch for operating the power assist unit, an outlet for charging the battery, a warning lamp for displaying a battery voltage drop and a system abnormality of the controller are arranged around the battery box 60. There is.

Next, the function and effect of this embodiment will be described. The power assist unit 50 of the present embodiment supplies a larger auxiliary driving force as the pedal effort of the occupant is larger when the vehicle speed is a predetermined value (for example, 15 km / h) or less, and the speed is increased when the speed exceeds the predetermined value. The auxiliary driving force is decreased as it rises, and when the speed exceeds the maximum value (for example, 24 Km / h), the auxiliary driving force is made zero. In this way, labor can be reduced when climbing uphill, headwinds, loading luggage, and starting. The above-mentioned one-way clutches transmit the rotational force from the pedal shaft / motor shaft side to the rear wheel side, but do not transmit the rotational force in the opposite direction.

In this embodiment, the axles 3 of the rear wheels 30 are both.
0a and the pedal shaft 40, an intermediate shaft 33 is arranged, and the rotational force of the pedal shaft 40 is transferred to the intermediate shaft 3 via a chain 44.
3 is transmitted to the left and right rear wheels 30 by the chain 37, and the driving force of the motor 51 is transmitted from the intermediate shaft 33 to the rear wheels 3
Since it is transmitted to 0 through the chain 58, the traveling posture can be stabilized by driving both wheels, and the operability of the handle 10 can be improved.

Further, in this embodiment, the power from the pedal 42 and the driving force from the motor 51 are supplied to the left via the intermediate shaft 33.
It has a simple structure in which it is transmitted to the right rear wheel 30, 30. Therefore, manufacturing and assembling work can be easily performed, and cost can be reduced.

In the above embodiment, the intermediate shaft 33 and the rear wheels 30 are connected to each other via the chains 58 and 37, but the present invention is not limited to this. For example, an endless belt, a gear or the like may be connected. You may.

9 to 12 are views for explaining a power assisted tricycle according to an embodiment of the present invention. In FIG. 9, the same reference numerals as those in FIGS. 3 to 5 designate the same or corresponding parts. Show.

In this embodiment, an intermediate shaft 80 is arranged in front of both rear wheels 30, and a chain 44 from a pedal shaft 40 is connected to a sprocket 36 of the intermediate shaft 80. It is similar to the example. Further, the controller 53 of the present embodiment is arranged on the front side of the battery 52 of the front frame 4, and the motor 51 is arranged on one side of the lower frame 15.

The output shaft 51a of the motor 51 is connected to one end 80a of the intermediate shaft 80 via a one-way clutch 81 so as to be coaxial therewith. A sprocket 82 is coupled to one end 80a of the intermediate shaft 80, which is the transmission pipe 30a on the right side when viewed from the front.
Is connected to the sprocket 32 of FIG.

The transmission pipe 30a is connected to the right rear wheel shaft 30b via a one-way clutch 31, and the right rear wheel shaft 30b is supported by the upper frame 16 via a bearing 30c and a support shaft 72a.

A sprocket 85 is connected to the other end of the intermediate shaft 80 via a one-way clutch 84, which is connected via a chain 86 to the left rear wheel shaft 30.
It is connected to a sprocket 87 connected to d. The left rear wheel shaft 30d is supported by the upper frame 16 via a bearing 30c and a support shaft 72b.

A tensioner mechanism 70 for absorbing the expansion of the chains 44, 86, 83 is arranged between the intermediate shaft 80 and the rear wheel shafts 30b, 30d. The tensioner mechanism 70 includes support pipes 88a, 8a on the intermediate shaft 80.
8b, the end portions of the support pipes 88a, 88b are inserted into the long holes 71a formed at the front end of the swing arm 71, and the rear end of the swing arm 71 is connected to the support shafts 72a, 72.
It has a structure in which it is bolted and fixed to b. The pipes 88a and 88b can be moved back and forth by an adjusting bolt 73, and the swing arm 71 is supported by a support shaft 72.
It can swing up and down around a and 72b.

According to this embodiment, since the pedaling force and the motor driving force are transmitted to the left and right rear wheels 30 via the intermediate shaft 80, it is possible to obtain the effect of improving the running stability as in the above embodiments. Further, in the present embodiment, the output shaft 51 of the motor 51 is
Since a is coaxially connected to the intermediate shaft 80, the sprockets 38 and 57 and the chain 58 as in the above embodiment can be eliminated, and the number of parts can be reduced accordingly.

Further, in this embodiment, the extension of the chains 86 and 83 can be absorbed by advancing the support pipes 88a and 88b by the adjusting bolt 73, and the support shafts 72a and 72a can be absorbed.
The extension of the chain 44 can be absorbed by loosening the fixing nut 72b of 72b and swinging the swing arm 71 downward.

[0038]

As described above, according to the power assisted three-wheeled bicycle of the present invention, the intermediate shaft is arranged in parallel between the pedal shaft and the rear wheel shaft, and the pedaling force of the pedal is provided through the intermediate shaft. Also, since the driving force of the motor is transmitted to the left and right rear wheels, it is possible to improve running stability and simplify the structure around the rear wheel shaft.

[Brief description of drawings]

FIG. 1 is a side view for explaining a power-assisted tricycle according to an embodiment of the present invention.

FIG. 2 is a plan view of the tricycle according to the embodiment.

FIG. 3 is a plan view of a rear portion of the tricycle according to the embodiment.

FIG. 4 is a partial cross-sectional side view of a rear portion of the tricycle according to the embodiment.

FIG. 5 is a schematic configuration diagram showing a rear wheel drive mechanism of the above-described three-wheeled bicycle.

FIG. 6 is a cross-sectional side view showing a swinging portion of the front frame of the tricycle according to the embodiment.

7 is a sectional view taken along line VII-VII of FIG. 6 showing the swinging portion.

FIG. 8 is a block diagram of a power assist unit of the tricycle according to the embodiment.

FIG. 9 is a plan view showing a power-assisted tricycle according to an embodiment of the present invention.

FIG. 10 is a partial cross-sectional side view of the tricycle according to the embodiment.

FIG. 11 is a schematic configuration diagram showing a rear wheel drive mechanism of the above-described three-wheeled bicycle.

FIG. 12 is a schematic view (cross-sectional view taken along the line XII-XII of FIG. 11) showing the chain tension adjusting mechanism of the above-described three-wheeled bicycle.

[Explanation of symbols]

 1 power assisted three-wheeled bicycle 2 vehicle body frame 9 front end 30 rear wheels 30a axle 33,80 intermediate shaft 40 pedal shaft 42 pedal 50 power assist unit 51 motor 52 battery 53 controller

Claims (3)

[Claims] 1. A vehicle body frame that pivotally supports a front wheel at a front end portion and a pair of left and right rear wheels at a rear end portion, a motor mounted on the vehicle body frame and rotationally driving the rear wheel, and a power source for the motor. In a power-assisted three-wheeled bicycle including a battery to be supplied and a power assist unit including a controller that controls a driving force of the motor according to a pedaling force, an intermediate portion between a pedal shaft and a rear wheel shaft in parallel with the both shafts. A power-assisted three-wheel bicycle characterized in that a shaft is provided, and the pedaling force of the pedal and the driving force of the motor are transmitted to the left and right rear wheels via the intermediate shaft. 2. The power-assisted three-wheeled bicycle according to claim 1, wherein the output shaft of the motor is arranged in parallel with the intermediate shaft, and the output shaft and the intermediate shaft are connected via a one-way clutch. 3. The power assisted three-wheeled bicycle according to claim 1, wherein the output shaft of the motor is arranged coaxially with the intermediate shaft, and the output shaft and the intermediate shaft are connected via a one-way clutch.