JPH0872779A - Power device of bicycle with prime mover - Google Patents

Abstract

PURPOSE: To provide a power device of a bicycle with a prime mover which can easily change over the manual traveling of the bicycle with the prime mover to the power traveling without weighing the pedaling with the driver's posture as it is, a simple structyre and low cost. CONSTITUTION: A hollow shaft concentric with a crankshaft is fit through a centrifugal type automatic clutch on the crankshaft 17 parallel to a rear wheel axle 13 to provide an input shaft 19 of a reduction gear 12 so that the speed of the crankshaft is reduced through a plurality of stages of gear train. An output shaft tube 25 rotatable to the rear wheel axle 13 fixed to a body is connected through a one-way clutch 27 to an output shaft gear 23 on the final stage of the reduction gear, and a driven sprocket 6 is mounted on the output shaft tube. A driven gear 33 for starting an engine is attached fixedly to the crankshft and a drive gear 34 is fit through a one-way clutch 35 on an intermediate shaft 21. Claw clutches formed between the output shaft gear and output shaft tube and a clutch bringing-together means 39 for turning on an off the claw clatches by a starter lever are provided.

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 a bicycle with a prime mover, which has an engine mounted on the body of a bicycle and is capable of manpower running and power running by the engine.

[0002]

2. Description of the Related Art In a motorized bicycle in which an engine is mounted on a bicycle body and can be driven by manpower or by power, the output of a high-speed rotating air-cooled 2-cycle gasoline engine is used as power for deceleration. Various types of structures have been proposed in the past, in which an engine and a speed reducer are combined into a unit to form a power unit, which is mounted on a bicycle body via a bracket or incorporated into a part of the body. The engine starting method for power running is also used to pull the grip of the recoil starter by hand,
A method is used in which the kick lever is stepped down with the foot or the pedal is pedaled while the bicycle is running to engage the clutch with the starter lever, and the gear train of the reducer is passed in reverse to rotate the engine crankshaft. There is.

[0003]

Although it is necessary to start the engine in order to drive a bicycle with a prime mover by power,
In the kick starter method and the recoil starter method, it is necessary to stop the bicycle, so that there is an inconvenience that the bicycle must be stopped once in order to switch to the power running during manual driving.

As a method for enabling switching during manpower running, a clutch is engaged by a starter lever to connect the rear wheel and the output shaft of the speed reducer, and the force (and coasting force) applied to the pedal is input from the rear wheel. However, a method is adopted in which the engine is started by rotating the crankshaft through the gear train of the speed reducer in reverse. In this method, since the gear train of the reduction gear is used as it is, the input human power is determined for traveling and the speed is inversely greatly increased, and the torque decreases and reaches the crankshaft. Therefore, the force applied to the pedal required to start the engine becomes large, and the pedal becomes heavy, which makes it difficult to start the engine.

For this reason, a method has been proposed in which a part of the reduction gear train is bypassed and only a part of the gears is used to reduce the speed increasing ratio (the number of teeth ratio) to start the engine. The problem is that the structure becomes complicated and the gear ratio cannot be freely selected. On the other hand, this type of motorized bicycle has a persistent need for a simple structure and low cost.

According to the present invention, the changeover of the bicycle with the prime mover to the power running during the manual driving can be easily executed while maintaining the driving posture without heavy pedal operation, and the bicycle with the prime mover has a simple structure and is inexpensive. The purpose is to provide a power plant of.

[0007]

A power unit for a motor-powered bicycle according to the present invention is a power unit for a motor-powered bicycle that is capable of human power travel by a pedal and power travel by an engine; one end is fixed to a body frame 1. The output shaft cylinder 25 is rotatably fitted to the rear wheel shaft 13 and is rotatably attached to the gear case 16 having the other end fixed to the vehicle body.
An engine 11 having a crankshaft 17 arranged parallel to the rear wheel shaft; and a hollow shaft housed in the gear case and externally rotatably fitted to the crankshaft and integrally formed with a gear. A gear train 23 connected to the output shaft cylinder rotatably fitted on the rear wheel shaft via a one-way claw clutch 27 is used as an output shaft gear, and a plurality of stages of gear trains connecting the gear trains A centrifugal automatic clutch 18 connecting the crankshaft of the engine and the input shaft of the speed reducer; a driven gear 33 for starting the engine fixedly mounted on the crankshaft; A drive gear 34 for engine starting which is externally fitted to the reduction shaft via a one-way clutch 35 and meshes with the driven gear; a claw clutch 37 provided between the gear of the output shaft of the reduction gear and the output shaft cylinder; Detachable claw clutch The driven sprocket 6 having a one-way claw clutch and the rear wheel hub 28 are fixed to the output shaft cylinder, and the engine is started by stepping on the pedal 4. .

[0008]

When driving manually, the driving torque generated by stepping on the pedal 4 is transmitted to the rear wheel 3 via the driving sprocket 5, the chain 7, the driven sprocket 6 and the output shaft cylinder 25, as in a general bicycle. The driving force by the human power is cut off by the one-way claw clutch 27 interposed between the output shaft cylinder 25 and the final stage output shaft gear 23, and is not transmitted to the speed reducer side. Conversely, the force applied from the rear wheel 3 side during coasting is cut off from the drive sprocket 5 side by the one-way claw clutch interposed in the driven sprocket 6, and also cut off from the speed reducer 12 side by the one-way claw clutch 27. To be done.

When the vehicle travels by power, the user depresses the pedal 4 to travel, pulls the starter lever 9 when there is inertia, operates the clutch shift 39, and connects the pawl clutch 37 to connect the output shaft cylinder 25 and the final stage. The output shaft gear 23 is connected. The rotational force (and inertia force) generated by stepping on the pedal 4 is transmitted from the output shaft cylinder 25 to the gear train via the pawl clutch 37, and drives the gear train from the opposite direction.

The rotational force is applied to the reduction shaft 2 at the stage next to the crank shaft 17.
1 (intermediate shaft) is transmitted to a coaxially fitted drive gear 34 for starting an engine via a one-way clutch 35, and a crankshaft 17 is rotated via a driven gear 33 for starting the engine to drive the engine 11 To start. At this time, the next-stage deceleration shaft 21 (intermediate shaft) also drives the input shaft 19, but it is blocked by the bearing 20 interposed between the input shaft 19 and the crankshaft 17, and the rotational force is not transmitted.

When the engine 11 starts, the crankshaft 17
However, the rotational force of the engine 11 is not transmitted to the intermediate shaft 21 because it is disengaged by the one-way clutch 35. When the engine 11 is started, the starter lever 9 is returned and the pawl clutch 37 is released. Throttle grip 8
When is turned to the acceleration side and the throttle valve is opened to increase the rotation speed of the engine 11, the centrifugal automatic clutch 18 works to connect to the speed reducer 12 side, and the rear wheel 3 is driven to be decelerated. At this time, the starting drive gear 34 is the starting driven gear 3
Although it rotates by 3, the one-way clutch 35 is in the idling direction and is disconnected from the intermediate shaft 21. If the engine is stopped, it will return to a state where it can be driven manually.

[0012]

Embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a schematic left side view of a bicycle equipped with a power unit of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. Since the body frame of this bicycle has substantially the same structure as that of a known general bicycle, detailed description thereof will be omitted and only essential parts will be described.

In FIGS. 1 and 2, 1 is a body frame of a bicycle, 2 is a rear hawk, 3 is a rear wheel, 4 is a pedal, 5 is a drive sprocket directly connected to a pedal crankshaft, and 6 is an output shaft cylinder 25 (FIG. 3). A driven sprocket having a one-way claw clutch fixedly attached to, a chain 7 wound from a drive sprocket 5 to a driven sprocket 6, 8 a throttle grip, 9 a starter lever, 10 an engine 11 and a speed reducer 12 It is a power unit.

FIG. 3 is a cross-sectional view of the main part of the power plant.
In FIG. 3, 13 is a rear wheel shaft fixed to the rear fork 2 by a positioning nut 14 and a stop nut 15, and 16
Is a gear case of the speed reducer 12 formed integrally with the crank case of the engine 11, 17 is a crank shaft of the engine 11, 18 is a centrifugal automatic clutch mounted on the crank shaft 17, and 19 is an outer rotor of the centrifugal automatic clutch 18. Is an input shaft of a hollow speed reducer having a small gear 19a formed on the outer peripheral surface thereof, which is integrally formed with the crankshaft 17 via a bearing 20.

Reference numeral 21 is an intermediate shaft integrally formed with a small gear 21a, 22 is an intermediate shaft gear fixed to the intermediate shaft 21 and meshing with the small gear 19a, and 23 is rotatably attached to the rear wheel shaft 13 via a bearing 24. The output shaft gear 25 is externally fitted and meshes with the small gear 21a.
An output shaft cylinder rotatably supported via 6, one end of which is connected to the driven sprocket 6, 27 is formed at one end of the output shaft cylinder 25 and a claw 23a provided at one end of the boss portion of the output shaft gear 23. It is a one-way pawl clutch formed by the inner pawl wheel 25a.

Reference numeral 28 is a rear wheel hub that is serration-coupled to the output shaft cylinder 25, and 29 is a strip-shaped spoke that connects the hub 28 and the rim of the rear wheel 3 in a funnel shape. The hub 28 also serves as an outer cylinder of the brake, and 30 is an expandable shoe of the brake. The gear case 16 has a bearing 31 at one end.
The rear wheel shaft 13 is rotatably fitted to and supported by the rear wheel shaft 13 via the bearing 32 on the output shaft cylinder 25, and the other end is fixed to the rear fork 2 by a mounting bracket (not shown). The rotation due to the driving reaction force of is stopped.

Reference numeral 33 is a starter driven gear fixedly mounted on the crankshaft 17, and 34 is a one-way clutch 35 via an intermediate shaft 2.
1 has a claw 36a on one side end face thereof, and has a claw 36a at its one end face, and is restricted in rotation by the boss portion of the output shaft gear 23, but is slidably mounted outside in the axial direction. Claw cylinder, 37 is a claw clutch formed by a claw 36a and a claw 25b provided on the side end surface of the output shaft cylinder 25, 38 is a compression spring for urging the claw clutch 37 to disengage, and 39 is a claw clutch 37. It is a clutch close to attach and detach.

The clutch shift 39 is used for the starter lever 9
(Fig. 1) Pulling the pin lever 40 causes the pin lever 4
0 rotates together with the fixed shaft 41, and the shaft 41 moves in the longitudinal direction by the groove cam 42a provided in the shaft guide 42 to rotate the plate lever 43. The plate lever 43 causes the claw cylinder 36 to compress the compression spring 38. The claw clutch 37 is attached and detached by pushing against.

The operation of the power plant configured as described above will be described. When driving manually, the driving torque generated by stepping on the pedal 4 is transmitted to the rear wheel 3 via the driving sprocket 5, the chain 7, the driven sprocket 6 and the output shaft cylinder 25, as in a general bicycle. The driving force by the human power is interrupted by the one-way claw clutch 27 interposed between the output shaft cylinder 25 and the output shaft gear 23 and is not transmitted to the speed reducer 12 side. The force input from the 3 side is cut off from the drive sprocket 5 side by the one-way claw clutch interposed in the driven sprocket 6, and the one-way claw clutch 27
Is cut off from the speed reducer 12 side.

When the vehicle travels by power, it travels by depressing the pedal 4 as in the case of manual travel, and when the coasting force is applied, the starter lever 9 is pulled to operate the clutch shift 39 to connect the pawl clutch 37. . The rotational force (and inertia force) generated by stepping on the pedal 4 is transmitted from the output shaft cylinder 25 to the output shaft gear 23 via the pawl clutch 37, and then the intermediate shaft 2
1, one-way clutch 35, drive gear 3 for starting the engine
4, the crankshaft 1 through the driven gear 33 for starting the engine
Rotate 7 to start the engine. At this time, reducer 1
The second intermediate shaft gear 22 and the input shaft 19 also rotate, but are disconnected from the crankshaft 17 by the bearing 20.

When the engine 11 starts, the crankshaft 17
However, the rotational force of the engine 11 is not transmitted to the intermediate shaft 21 because it is disengaged by the one-way clutch 35. When the engine 11 is started, the starter lever 9 is returned and the claw clutch 37 is released. When the throttle grip 8 is turned to the acceleration side to open the throttle valve to increase the rotation speed of the engine 11, the centrifugal automatic clutch 1
8 works to connect to the speed reducer 12 side and is decelerated to the rear wheel 3
Drive. At this time, the starting drive gear 34 is rotated by the starting driven gear 33, but the one-way clutch 35 is in the idling direction and is disconnected from the intermediate shaft 21. If the engine is stopped, it will return to a state where it can be driven manually.

[0022]

EFFECTS OF THE INVENTION In a power unit of the type directly connected to the rear wheel of a motorized bicycle, the engine can be easily started while the bicycle is manually driven, the structure is simple, the cost is low, and the deceleration of the speed reducer is slow. The force to depress the pedal can be reduced by using a gear having an appropriate force ratio for starting only, without being restricted by the ratio.

[Brief description of drawings]

FIG. 1 is a schematic left side view of a motorbike equipped with a power unit of the present invention.

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

FIG. 3 is a cross-sectional view of the main part of the power plant shown in FIGS.

[Explanation of symbols]

1 ... Body frame, 3 ... Rear wheel, 4 ... Pedal, 6 ... Followed sprocket, 11 ... Engine, 12 ... Reducer, 13 ... Rear wheel shaft, 16 ... Gear case, 17 ... Crank shaft, 18 ... Centrifugal automatic clutch, 19 ... Input shaft, 21 ... Intermediate shaft, 23
Output shaft gear, 25 ... Output shaft cylinder, 27 ... One-way claw clutch, 28 ... Rear wheel hap, 33 ... Starting driven gear, 34 ... Starting drive gear, 35 ... One-way clutch, 37 ... Claw clutch, 39 … Clutches.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuyuki Uenoyama, Kazuyuki Uenoyama, No. 1 Takamichi, Iwazuka-cho, Nakamura-ku, Nagoya, Aichi Mitsubishi Heavy Industries, Ltd. Nagoya Machinery Works (72) Kenji Yamazaki 399, Matsunagacho, Fukuyama-shi, Hiroshima No. 49 Stock Company Yamazaki Factory

Claims (1)

[Claims] 1. A power unit for a motorized bicycle, which is capable of manpowered travel by pedals and powered by an engine; a rear wheel axle (1) having one end fixed to a vehicle body frame (1).
3) an output shaft cylinder (25) rotatably fitted to the outside and rotatably attached to a gear case (16) having the other end fixed to the vehicle body; and a crank shaft (17) parallel to the rear wheel shaft. An input shaft (19), which is a hollow shaft housed in the gear case and rotatably fitted to the crank shaft and integrally formed with a gear,
A gear (2) connected via a one-way claw clutch (27) to the output shaft cylinder rotatably fitted on the rear wheel shaft.
3) is a gear of the output shaft, and a speed reducer (12) composed of a plurality of stages of gear trains connecting them; and a centrifugal automatic clutch (which connects the crank shaft of the engine and the input shaft of the speed reducer). 18) ;; a driven gear (33) fixed to the crankshaft for starting the engine; and an engine start that is externally fitted to the next stage reduction shaft via a one-way clutch (35) and meshes with the driven gear. Drive gear (34) for use with a claw clutch (3) provided between the output shaft gear of the reduction gear and the output shaft cylinder.
7) and a clutch shifter (3) for attaching and detaching the claw clutch
9) and a driven sprocket (6) having a one-way claw clutch and a rear wheel hub (2) on the output shaft cylinder.
A power unit for a motorized bicycle, characterized in that 8) is fixed, and the engine is started by stepping on the pedal (4).