JPS6316573B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an engine arrangement structure for a motorcycle, etc., in which a motorcycle transmission and auxiliary machinery are arranged in a compact manner. Especially for motorcycles, it is desirable to make maximum use of the limited frame space and arrange equipment as compactly as possible. Fig. 1 shows a schematic right side view of an engine in a conventional general motorcycle, and Fig. 2 shows a schematic plan view of the same. Main shaft 4 equipped with driven multi-speed gears
and a countershaft 5 having a gear train that meshes with the transmission gear of the main shaft are arranged on a substantially horizontal plane A, and a sprocket is attached to the countershaft 5 to drive the rear wheels by a chain, or Alternatively, a bevel gear may be used to drive the propeller shaft 6 in the right angle direction as shown in the figure to transmit power to the rear wheels. The above drive system is further equipped with a generator 7 and a starting motor 8, but in motorcycles, the overall width of the engine section is kept as narrow as possible, the bank angle when driving around curves is given a margin, and the leg space is saved. In order to make it wider, the generator 7 is not installed on the same axis as the crankshaft 2, but is placed on the rear left side of the engine 1, and the shaft 7a of the generator 7 and the crankshaft 2 are connected to the sprocket 9.
a, 9a and a chain 9b. Here, in the space on the right side of the generator 7, a large-diameter primary reduction driven gear and a Since the upper part of the case housing the clutch 3 protrudes, there is a narrow gap between the case and the carburetor 12.The starting motor 8 is placed behind the generator 7 to avoid this, and is driven by a pinion 8b attached to the shaft 8a of the starting motor 8. The gear 7b of the generator 7 is decelerated through the idling gear 9, and the shaft 7a of the generator 7 is driven through a one-way clutch interposed between the gear 7b and the shaft 7a of the generator 7. ing. Therefore, when starting the engine 1, starting the starting motor 8 rotates the shaft 7a of the generator 7 via the idling gear 9, and further rotates the crankshaft 2 via the sprockets 9a, 9a and chain 9b. When the engine 1 starts, the one-way clutch acts to cut off rotation from the engine 1 side to the starting motor 8, while the generator 7 is driven by the rotation of the crankshaft 2 and generates electricity. In contrast to the above-mentioned publicly known arrangement structure for starting the engine of a motorcycle, motorcycles are required to be more compact.Firstly, in order to make the main frame 10 more compact, the aforementioned arrangement in which the starting motor 8 is disposed behind the generator 7 is required. Left side mounting hanger 1 in mounting hangers 11a and 11b of engine 1
1a is obstructed by the starting motor 8, making installation difficult. Further, in accordance with the above-mentioned direction of compactness, the engine 1 is desired to be shortened not only in width from side to side but also in length l from front to back. The present invention aims to make motorcycles more compact, and the main shaft of the drive system was conventionally arranged almost parallel to each other on a plane formed by the crankshaft and the countershaft. The generator and starting motor are placed below the plane formed by the shaft and countershaft, so that the plane connecting the tops of the clutch, main shaft, and countershaft cases forms approximately one plane, and the generator and starting motor are placed on the plane. The present invention provides a motorcycle engine in which a mounting space for left and right hangers of the engine is secured, and the front-rear length of the engine is shortened by providing the two hangers facing each other and parallel to the crankshaft. The present invention will be described below with reference to FIGS. 3 and 4 showing one embodiment. Fig. 3 shows a schematic right side view of the engine of the present motorcycle, and Fig. 4 shows a schematic plan view thereof. A main shaft 4' disposed above and equipped with a multi-stage transmission gear driven from the crankshaft 2' via a clutch 3' is disposed below the plane A'. In this way, at the rear of the engine 1', the surfaces connecting the tops of the cases of the clutch 3', main shaft 4', and countershaft 5' form approximately one plane B'. As before, the generator 7' is placed on the plane B' at the rear left side of the engine 1' in parallel with the crankshaft 2'. On this one plane B', by moving the main shaft 4' downward, the protrusion of the upper part of the case housing the large-diameter clutch 3' is no longer present, and the gap with the carburetor 12' is wide, so the starting motor 8' can be mounted opposite to the right side of the generator 7'. In this arrangement, the shaft 7a' and crankshaft 2' of the generator 7' are connected to the sprockets 9a', 9a' and the chain 9.
The starting motor 8' and the generator 7' are connected by a transmission means such as a gear 7b for a one-way clutch via an idling gear 9' by a pinion 8b' attached to a shaft 8a' of the starting motor 8'. ' is decelerated and driven, and gear 7b' and shaft 7 of generator 7' are
A' is connected by transmission means such as driving a shaft 7a' of a generator 7' via a one-way clutch interposed between the generator 7' and the generator 7'. The operation of the starting system in the engine of the present invention having the above-mentioned structure is completely the same as that of the conventional engine, so a description thereof will be omitted. As described above, in the present invention, by arranging the main shaft 4' below the plane formed by the crankshaft 2' and the countershaft 5', the uppermost part of the main shaft 4' to which multi-speed change gears are mounted is arranged. Since the gap between the upper case B' and the carburetor 12' is widened and the generator 7' and starting motor 8' can be installed parallel to and facing the crankshaft 2', the hanger 11a on which the engine 1' is mounted is ', 11b' can be mounted with a wide span at ideal positions on the main frame 10' in terms of rigidity without being obstructed by the starting motor 8' on both the left and right sides, making it possible to make the main frame 10' more compact and rigid. . Further, by arranging the generator 7' and the starting motor 8' on the left and right sides, the left-right weight balance of the engine of a vehicle, such as a two-wheeled vehicle, can be improved as much as possible, as shown in the table below.

[Table] Furthermore, the distances 2', 4' between the crankshaft 2' and the main shaft 4' and the distances 4', 5' between the main shaft 4' and the countershaft 5' are the same distances 2, 4 of the conventional engine 1. 4 and 5, the longitudinal length l' of this engine is shorter than the longitudinal length l of the conventional engine.As a result, the rear axle pivot of the vehicle is moved forward, and the rear fork length can be increased, and the length of the vehicle The center of gravity moves forward, which has the effect of improving the left-right weight balance of the engine as well as ride comfort.

[Brief explanation of the drawing]

FIG. 1 is a schematic right side view of the engine of a conventional general motorcycle, FIG. 2 is a schematic plan view of the same, FIGS. 3 and 4 show an embodiment of the present invention, and FIG. Fig. 4 shows a schematic right side view of the engine, and Fig. 4 shows a schematic plan view thereof. 1,1'...engine, 2,2'...crankshaft, 3,3'...clutch, 4,4'...mainshaft, 5,5'...countershaft, 7,7'...generator, 8,8' ...Starting motor, 10... Main frame, 11a, 11b... Mounting hanger.

Claims (1)

[Claims] 1 A transmission device consisting of an engine crankshaft, a main shaft equipped with a multi-stage transmission gear driven from the crankshaft via a clutch, and a countershaft having a gear train that meshes with the transmission gear of the main shaft. In the motorcycle engine, the uppermost surface of the case housing the transmission is formed into a substantially flat surface, and a generator and a starting motor are provided on the flat surface facing each other and parallel to the crankshaft, A motorcycle engine characterized in that a starting motor, a generator, and a crankshaft are connected by a transmission means.