JP2525403B2 - Starting device for motorcycle engine - Google Patents

Description

Description: [Object of the Invention] (Industrial field of application) The present invention relates to a starting device for a motorcycle engine that is started by a starter motor.

(Prior Art) An engine mounted on a motorcycle has a mission case, which is arranged almost at the center of a vehicle body and extends rearward from a crankcase connected to a cylinder. A crank shaft, a counter shaft, a drive shaft, a balancer shaft, and the like are mounted on the crank case and the transmission case, and a starter system and the like are arranged.

Generally, an independent transmission path is used in the starter system, so that space allocation to the power transmission system, the balancer drive system, etc. is difficult, and the momentum engine layout tends to be large. FIG. 3 is a system diagram showing an example of the layout, in which the rotation is transmitted from the output gear c of the starter motor b to the crankshaft a through the idle gear d and the one-way clutch e, and fixed to the crankshaft a on the one hand. The balancer drive gear f and the balancer driven gear g on the balancer shaft h are engaged to drive the balancer shaft h.

In this way, since the starter system and the balancer drive system are separately and independently arranged with the crankshaft a interposed therebetween, and the power transmission system of the main mechanism is arranged around the crankshaft a, the degree of freedom in design in terms of space is reduced. There was a problem that it was unavoidable because it was small and the layout was uniform.

(Problems to be Solved by the Invention) As described above, in the conventional starter, since the independent transmission path is used, the layout is unified due to the balance with other systems, and the crankcase and the mission case are increased in size. In view of the above problem, the present invention uses a shaft used in another system for a starter system to effectively use the space and to reduce the engine layout. A vehicle engine starting device is provided.

[Structure of Invention]

(Means for Solving the Problems) In accordance with the above object, a motorcycle engine starting device according to the present invention is an automatic vehicle equipped with an idle gear and a one-way clutch in a starter system for transmitting a driving force of a starter motor to a crankshaft. In a starter for a two-wheeled vehicle engine, a counter shaft 5 and a drive shaft 6 are arranged side by side in a mission chamber formed behind the crank shaft 4,
A balancer shaft 9 is provided above the counter shaft 5 and the counter shaft 5, and an idle gear 21 is provided above the counter shaft 5 and the drive shaft 6, respectively, and a starter type one-way clutch 22 that can be meshed with the idle gear 21 is provided on the balancer shaft 9. , The crank webs 1 and 3 which are axially mounted within the width of the opposing crank webs 13 and 13.
The balancer drive gear 14 is integrally formed on one of 3, 13 and the balancer drive gear 14, which is formed by meshing the balancer drive gear 14 with the balancer driven gear 17 that is integrally rotated with the balancer shaft 9, also serves as a part of the starter system. On the other hand, the shaft end of the balancer shaft 9 is terminated at a position retracted from the extension line of the primary drive gear 7.

(Action) In this motorcycle engine starting device, the starter type one-way clutch is pivotally supported on the balancer shaft that constitutes the balancer drive system, so not only can the shaft be omitted,
By combining the two systems into one, the space around the crankshaft can be saved, and the crankcase or mission case can be prevented from increasing in size.

The balancer shaft can be arranged above and behind the crankshaft, and the starter motor can be arranged on the upper part of the transmission case behind it. Easy to place on the starter system side. Further, the balancer drive gear can be integrally formed on one of the crank webs, and the balancer drive driven gear can be used as both the starter driven drive gear and the drive gear, and the cost can be reduced by omitting the functional parts.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a developed sectional view of a starter system of a motorcycle engine taken along the line AA in FIG. 2, and FIG. 2 is a side view of the same.

A transmission case 3 is connected to the rear of a crank case 2 following the cylinder 1, and a crank shaft 4, a counter shaft 5, and a drive shaft 6 which are sequentially arranged in parallel rearward are mounted therein. The counter shaft 5 and the drive shaft 6 are arranged side by side in the mission chamber behind the crankshaft 4. A primary drive gear 7 is fixed to the end of the crankshaft 4 and meshes with a primary driven gear 8 of the counter shaft 5. An open / close clutch is interposed between the primary driven gear 8 and the counter shaft 5, and a transmission gear is arranged between the counter shaft 5 and the drive shaft 6. In this way, the rotational driving force of the crankshaft 4 is output from the drive shaft 6 via the open / close clutch and the transmission gear, and a main power transmission system is formed.

Next, the balancer shaft 9 is mounted above and behind the crank shaft 4. The balancer shaft 9 is, as shown in FIG.
And above the counter shaft 5. 10 is a piston, 11
Is a connecting rod, 12 is a crank pin, 13 is a crank web, and a balancer drive gear 14 is provided on the outer periphery of one crank web 13 and meshes with a balancer driven gear 15. The balancer driven gear 15 is the balancer shaft 9 described above.
The spline 16 is fitted to rotate together. The balancer weight 17 is integrally molded on the side surface of the balancer driven gear 15,
Further, the balancer weight 18 is fixed to the end of the balancer shaft 9. Thus, a balancer drive system for transmitting the rotation of the crankshaft 4 to the balancer shaft 9 is constructed.

Further, a starter motor 19 is fixed to the upper surface of the mission case 3 behind the balancer shaft 9, and an output gear 20 thereof is provided so as to project into the mission case 3. In the mission case 3, a double-row idle gear that constitutes a reduction gear train
21 is mounted on the idle shaft, and the large gear 21a of the idle gear 21 meshes with the output gear 20 of the starter motor 19.

On the other hand, the balancer shaft 9 has a one-way clutch 22
The clutch input gear 23 of the one-way clutch 22 is meshed with the small gear 21b of the idle gear 21. The one-way clutch 22 is composed of an inner race 22a rotatably supported by the balancer shaft 9, an outer race 22b rotatably and integrally supported by the spline 16, and a wedge-fitting roller 22c interposed between the races. Thus, the clutch input gear 23 is integrally fixed to the inner race 22a of the one-way clutch 22.

When the engine of the motorcycle is started, the driving force of the starter motor 19 is driven by the starter system output gear 20, the idle gear 21, the one-way clutch 22 and the balancer shaft 9.
To drive the balancer drive gear 14 from the balancer driven gear 15 to rotate the crankshaft 4.

After the engine is started, the balancer shaft 9 of the balancer drive system is driven by the rotational driving force from the crankshaft 4, and the idle gear 21 and the starter motor 19 which are starter systems below the clutch input gear 23 are disengaged by the axis of the one-way clutch 22. Be separated.
As shown in FIG. 1, the balancer shaft 9 terminates at the position where the shaft end is retracted from the extension line of the primary drive gear 7, and does not obstruct the trajectory of the primary driven 8 meshing with the primary drive gear 7.

In this motorcycle engine starter, the idle gear one-way clutch 22 is mounted on the balancer shaft 9 to form a starter system, and the starter system and the balancer drive system can be used in common. Space around crankcase 2 and mission case 3 (crank chamber and mission chamber)
Can be reduced and the case can be prevented from increasing in size.

〔The invention's effect〕

As described above, the starting device for a motorcycle engine according to the present invention has a starter type one-way clutch mounted on a balancer shaft that constitutes a balancer drive system, and a balancer drive gear and a balancer driven gear of the balancer drive system. Since the balancer drive gear is integrally formed on one of the opposing crank webs, the structure can be shared with the starter system, so that functional parts can be shared and the number of gear parts can be reduced to reduce the cost. The system and the balancer system can be efficiently arranged in the same space around the crankshaft, and the crankcase and the mission case can be made compact and compact.

Also, the one-way clutch mounted on the balancer shaft is mounted within the width of the opposing crank webs, and the shaft end of the balancer shaft is terminated at a position retracted from the extension line of the primary drive gear. The balancer drive system is partly shared to achieve compactness, and even if the drive force transmission of the starter system and balancer drive system is performed on the primary drive gear side, the balancer shaft is the main power transmission mechanism from the primary drive gear. The main power transmission mechanism arranged around the crankshaft can be designed with a large degree of freedom in space without obstructing or obstructing the route, and it is possible to prevent uniform layout or increase in size. And so on.

[Brief description of drawings]

FIG. 1 is a developed sectional view taken along the line AA in FIG. 2 showing an embodiment of a starting device for a motorcycle engine according to the present invention,
FIG. 2 is a side view of the same, and FIG. 3 is a system diagram of a conventional engine starting system. 4 …… Crank shaft, 9 …… Balancer shaft, 14 …… Balancer drive gear, 15 …… Balancer driven gear, 19 …… Starter motor, 20 …… Output gear, 21 …… Idle gear,
22 …… One-way clutch.

Claims (1)

(57) [Claims] 1. A starter for a motorcycle engine having a starter system for transmitting a driving force of a starter motor to a crankshaft, comprising an idle gear and a one-way clutch. A counter is provided in a mission chamber formed behind the crankshaft 4. The shaft 5 and the drive shaft 6 are arranged side by side, the balancer shaft 9 is provided above the crank shaft 4 and the counter shaft 5, and the idle gear 21 is provided above the counter shaft 5 and the drive shaft 6, respectively. A meshable starter type one-way clutch 22 is mounted on the balancer shaft 9 within the width of the opposed crank webs 13 and 13, and a balancer drive gear 14 is integrally formed on one of the crank webs 13 and 13. The balancer drive system of the starter system is formed by meshing the balancer drive gear 14 with the balancer driven gear 17 that is rotationally integrated with the balancer shaft 9. On the other hand, a starter for a motorcycle engine, wherein the balancer shaft 9 also functions as a part and is terminated at a position where the shaft end of the balancer shaft 9 recedes from the extension line of the primary drive gear 7.