JPH04262023A - Multiple cylinder engine of motorcycle - Google Patents

Abstract

PURPOSE:To make an engine in a small size and improve assembling property of a generator driving system and a starter transmission mechanism by arranging the rotation transmission mechanism of a starter motor between both bearings of a middle shaft provided with a generator arranged on its one end. CONSTITUTION:An electric generator 36 arranged on the engine outer side end of a middle shaft 20 is superposed, by side view, on a deceleration large gear for driving the main shaft of a transmission. A bearing 20B which supports the engine inside end of the middle shaft 20 is held by a crank case, and a bearing 20A which supports the generator 36 side of the middle shaft 20 is held by a bearing holder 20C which is detachable on the crank case from the outer side of the engine, so that the middle shaft 20 can be inserted from the generator 36 side together with the bearing holder 20C. A sprocket 21 and a starter transmission mechanism which form the drive system of the generator 36 are arranged on the middle shaft 20 between both bearings 20A, 20B. Consequently, since a space between the bearing 20A, 20B can be effectively utilized, the engine is made in a small size and the assembling property of the generator drive system and the starter transmission mechanism can be improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-cylinder engine for a motorcycle in which an intermediate shaft and a transmission main shaft are arranged in parallel behind a horizontal crankshaft.

0002

BACKGROUND OF THE INVENTION In a multi-cylinder engine with a horizontal crankshaft, an intermediate shaft is provided parallel to the crankshaft in order to narrow the overall width of the engine, and the output of the travel drive system is taken from this intermediate shaft. has always existed.

[0003] In this case, a large-diameter gear shifting clutch is provided on the transmission main shaft of the traveling drive system, and it is necessary to transmit the rotation of the intermediate shaft to the reduction gear of this clutch. There was a problem in that the distance had to be increased, leading to an increase in the size of the engine.

[0004] Therefore, a configuration has been considered in which the rotation of the crankshaft is directly transmitted to the main shaft without going through an intermediate shaft. In this case, from the viewpoint of maintainability of the generator, it is desirable to have the engine outer end of the intermediate shaft protrude from the bearing and install the generator on this protruding end. It becomes necessary to make the bearing spacing as large as possible, which causes the problem that the engine becomes larger. Furthermore, the crankcase side that holds the intermediate shaft is required to have high rigidity and good workability.

[0005]

[Object of the Invention] The present invention was made in view of the above circumstances, and it is an object of the present invention to effectively utilize the space between the bearings in spite of the sufficiently large spacing between the bearings of the intermediate shaft, thereby reducing the size of the engine. It is an object of the present invention to provide a multi-cylinder engine for a motorcycle in which the generator drive system and starter transmission mechanism can be easily assembled, and the crankcase can have high rigidity and good workability. This is the purpose.

[0006]

According to the present invention, the object is to provide an intermediate shaft behind and above the horizontal crankshaft, a transmission main shaft behind the crankshaft and below the intermediate shaft, A generator disposed at the outer end of the engine is chain-driven by the crankshaft via a generator drive system, and the transmission main shaft is driven by the crankshaft through a reduction large gear provided at the outer end of the engine on the side opposite to the generator. The multi-cylinder engine for a motorcycle is driven by gears via a multi-cylinder engine, in which the generator overlaps the large reduction gear in a side view, and a bearing supporting an inner end of the engine of the intermediate shaft is held in a crankcase, A bearing supporting the generator side of the shaft is held in a bearing holder that can be attached to and detached from the crankcase from the outside of the engine, and the intermediate shaft can be inserted together with the bearing holder from the generator side, and the intermediate shaft is inserted between the two bearings. This is achieved by a multi-cylinder engine of a motorcycle characterized in that a sprocket forming the generator drive system and a starter transmission mechanism of the engine are disposed on the intermediate shaft.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram of a first embodiment of the present invention, FIG. 2 is a side view showing the arrangement of the respective axes, FIG. 3 is a sectional view taken along the line III--III, and FIG. 4 is a sectional view of the main part. In these figures, reference numeral 1 is a horizontally placed four-cylinder crankshaft, and 2 is a piston. Four pistons 2 are each connected to one crankshaft 1 via a connecting rod 3. 4
, 4 are a pair of camshafts, and these camshafts 4, 4 are driven by a gear 5 integrated with the crankshaft 1 via a timing chain 6. Reference numerals 7 and 8 denote a transmission main shaft and a sub-shaft forming a transmission, which are arranged in parallel behind the crankshaft 1.

The transmission main shaft 7 is provided with a known wet multi-disc transmission clutch 9 at one end (FIG. 3). This clutch 9
A large reduction gear 12 is attached to the casing 10 via a damper spring 11, and this gear 12 is driven by a drive gear 13 integrated with the crankshaft 1. The rotation of the main shaft 7 is transmitted to the subshaft 8 via a gear group provided on the main shaft 7 and the subshaft 8, and the rotation of the subshaft 8 is transmitted to the subshaft 8.
is transmitted to an axis 14 parallel to the . The rotation of this shaft 14 is transmitted via a bevel gear 16 to an output shaft 15 perpendicular to this shaft 14, and this output shaft 15 drives rear wheels (drive wheels) via a propeller shaft (not shown).

Reference numeral 20 denotes an intermediate shaft located behind the crankshaft 1 and above the main shaft 7. This intermediate shaft 20 has two bearings 20A and 2 toward the crankcase side as shown in
Supported by 0B. In other words, the crankcase is divided into upper and lower halves, and the two bearings 20A and 2 are mounted on two substantially vertical walls integrally formed with the upper half of the crankcase.
0B is retained.

The engine outer end of the intermediate shaft 20 is a bearing 20A.
It protrudes further, and a generator 36, which will be described later, is disposed at this protruding end. Between the bearings 20A and 20B on the intermediate shaft 20, a sprocket 21 and a damper 22 forming a generator drive system, as well as a gear 27 and a one-way clutch 28 which are a transmission mechanism of the starter motor are mounted. That is, the intermediate shaft 20
A member 23 connected by a spline having an involute tooth profile is mounted on the cylindrical portion 23A of this member 23.
A sprocket 21 is rotatably mounted on the top. One end of this sprocket 21, that is, the end opposite to the generator 36 described later, has an enlarged diameter, and this enlarged diameter part and the member 23
A rubber damper 2 in which rubber 24 is loaded radially between
2 is installed.

FIG. 5 is a sectional view taken along the line V--V showing this rubber damper 22. As shown in FIG. In other words, radial walls 21A and 23A are arranged alternately in the facing portion of the sprocket 21 and the member 23.
is formed, and a fan-shaped rubber 24 is loaded between these walls 21A and 23A. The sprocket 21 is driven by a sprocket 25 formed integrally with the crankshaft 1 via a chain 26.

The gear 27 is rotatably mounted on the intermediate shaft 20, and the gear 27 and the member 23 are connected by a one-way clutch 28. 29 is a starter motor, 30 is a small gear 3 of this starter motor 29
This is an idle gear interposed between the gear 1 and the gear 27.

A bearing 20B that supports the engine inner end of the intermediate shaft 20 is press-fitted and fixed in advance to a vertical wall integrally formed on the upper crankcase half of the vertically split crankcase. Further, a bearing 20A that supports the intermediate shaft 20 on the generator 36 side is held by a vertical wall integrally formed with the upper crankcase half via a bearing holder 20C. In other words, this bearing holder 20 is attached to the bearing 20A.
C and the intermediate shaft 20 are assembled in advance, and the intermediate shaft 20 can be inserted and removed by attaching and detaching this assembled body from the outside of the crankcase.

When assembling the intermediate shaft 20, the sprocket 21, damper 22, gear 27, one-way clutch 2
Mounting hole 20D of bearing 20A and bearing holder 20C.
In this state, insert the intermediate shaft 20 from the mounting hole 20D side of the bearing holder 20C so as to pass through these, and fit the tip into the bearing 20B. The holder 20C may be attached to the attachment hole 20D.

Reference numeral 35 denotes a generator case that is integrated with the crankcase. One end of the intermediate shaft 20 extends into the case 35, and an alternator 36 is loaded therein. That is, a stator 37 is fixed to the inner surface of the case 35, while a rotor 38, which is a heavy rotating body, is fixed to the intermediate shaft 20, and a ring-shaped rotor 38 is fixed to the surface perpendicular to the central axis of the rotor 38. Two slip rings 39 are buried. Brushes 40, 40 fixed to the case 35 are in sliding contact with the slip rings 39, 39. Reference numeral 41 denotes a cover that is placed on the case 35. Note that this generator 36 is shown in FIG.
As shown in the figure, it overlaps with the large deceleration gear 12 in side view.

In this embodiment, the rotation of the crankshaft 1 is transmitted to the sprocket 21 via the chain 26, and then to the intermediate shaft via the rubber damper 22 and member 23 located on the opposite side of the generator 36 with respect to the chain 26. 20 and further transmitted to the rotor 38. At this time, torque fluctuations in the crankshaft 1 due to intermittent explosions in each cylinder are absorbed by the chain 26 and the rubber damper 22, and the rotor 38 is rotated smoothly. Furthermore, when starting the engine, the rotation of the starter motor 29 is controlled by the idle gear 30 and the gear 27.
, one-way clutch 28, member 23, rubber damper 22
, sprocket 21, and chain 26 to the crankshaft 1, and when the engine starts, the sprocket 21
The rotation becomes faster than the rotation of the gear 27, and the one-way clutch 28 is disengaged.

In this embodiment, since the damper 22 is disposed on the opposite side of the generator 36 across the chain 26, the intermediate shaft 2
At zero, rotation is transmitted to a position far from the generator 36. Therefore, in addition to the damper 22, the damper effect due to the torsion of the intermediate shaft 20 itself can be effectively utilized, and the capacity of the damper 22 can be reduced, and the tamper 22 can be made unnecessary.

On the other hand, the output of the traveling drive system is transmitted directly from the drive gear 13 of the crankshaft 1 to the large reduction gear 12 without passing through the intermediate shaft 20, and is transmitted to the damper spring 11, clutch 9, main shaft 7, The power is transmitted to the rear wheels via the subshaft 8, shaft 14, and output shaft 15. In addition, in this embodiment, if the drive gear 13 is provided at a position other than both ends of the crankshaft 1, as shown in FIG. 3, the amount of lateral protrusion of the clutch 9 of the main shaft 7 will be reduced, and balance becomes better.

[0019]

Effects of the Invention As described above, when an intermediate shaft having a generator disposed at one end is supported on the crankcase side by two bearings, even if the spacing between both bearings is sufficiently wide, the The sprocket of the generator drive system as well as the gears and one-way clutch that are the rotational transmission mechanism of the starter motor are placed on the intermediate shaft between the bearings, so the space between both bearings can be used effectively and the engine Miniaturization becomes possible.

The main shaft of the transmission is gear-driven by the crankshaft, and the intermediate shaft located above the main shaft of the transmission is driven by the crankshaft through a chain, while the clutch and generator are distributed to the left and right. The main shaft of the transmission can be brought sufficiently close to the crankshaft, and the intermediate shaft can be arranged with sufficient space between the shaft centers so as not to interfere with the crankshaft. Therefore, the longitudinal and vertical dimensions of the engine can be further reduced.

Further, a bearing supporting the engine inner end of the intermediate shaft is held in the crankcase, a bearing on the generator side is held in a bearing holder, and a starter transmission mechanism is installed between the two walls of the crankcase that support these bearings. etc., insert the intermediate shaft from the generator side, and fix the bearing holder to the mounting hole in the wall, so there is no need to provide the crankcase with a split surface that crosses these bearings. Therefore, high rigidity of the crankcase and good workability can be obtained at the same time. The intermediate shaft can be assembled by supporting parts such as the sprocket and starter transmission mechanism held on the intermediate shaft from the opening on the split surface side of the half body that forms the crankcase, so even if the engine is downsized, assembly is easy. Improves sex.

[Brief explanation of the drawing]

[Fig. 1] Configuration diagram of a first embodiment according to the present invention

[Figure 2] Side view showing the arrangement of each axis

[Figure 3] Part III-I
II Line sectional view

[Figure 4] Cross-sectional view of main parts

[Fig. 5] A cross-sectional view taken along the line V-V showing this rubber damper 22.

[Explanation of symbols]

1 Crankshaft 7 Transmission main shaft 20 Intermediate shaft 20A, 20B Bearing 21 Sprocket 26 Chain 27 Gear 28 One-way clutch 36 Generator

Claims (1)

[Claims] [Claim 1] A power generation system comprising: an intermediate shaft disposed rearward and upwardly of a horizontal crankshaft; a transmission main shaft juxtaposed behind the crankshaft and below the intermediate shaft; and disposed at an outer end of the engine of the intermediate shaft. A motorcycle in which the engine is chain-driven by the crankshaft via a generator drive system, and the main shaft of the transmission is gear-driven by the crankshaft through a reduction gear provided at the outer end of the engine opposite to the generator. In the multi-cylinder engine, the generator overlaps the large reduction gear in a side view, and a bearing that supports the engine inner end of the intermediate shaft is held in the crankcase and supports the generator side of the intermediate shaft. A bearing is held in a bearing holder that is removable from the crankcase from the outside of the engine, and the intermediate shaft can be inserted together with the bearing holder from the generator side. A multi-cylinder engine for a motorcycle, characterized in that a sprocket forming a drive system and a starter transmission mechanism for the engine are arranged.