JPH07145739A - Arranging structure around engine for two cycle engine - Google Patents

Abstract

PURPOSE:To provide an arranging structure for a two cycle engine having a compact structure. CONSTITUTION:A cylinder 3 is protruded upward from the front upper surface of a crank case 2. A reed valve 21 is arranged in an intake passage 20 connected to a carburetor 4 which is arranged behind the crank case 2 and the cylinder 3, and a self-starting motor 10 is interlockingly connected to a crank shaft 5 through a gear speed reducing device 9. The reed valve 21 and the gear speed reducing device 9 are arranged so that they may look as being superposed on each other viewing from the axial direction of the crank shaft 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a two-cycle engine,
In particular, the present invention relates to an arrangement structure around a two-cycle engine for a motorcycle.

[0002]

2. Description of the Related Art As a conventional two-cycle engine for a motorcycle, as shown in FIG. 3, a balancer shaft 7 is provided on an upper portion of a crankcase 2, and a starter motor 10 is arranged on a lower side. It was found that the balancer shaft 7 was arranged in the lower part of the crankcase 2 as shown in FIG. 4 and the starter motor 10 was arranged in front of the reduction gear unit 9.

[0003]

In the above arrangement, in the former one, the starter motor is necessarily arranged on the lower side. Then, the minimum ground clearance becomes lower than that of the same engine reference position, and the crankshaft cannot be lowered when trying to secure the minimum ground clearance that comes from the design conditions. On the other hand, in order to lower the center of gravity of the engine, it is necessary to lower the crankshaft position, which causes the contradictory problem that the ground clearance becomes low at the conventional starter motor position. In the latter case, there is a problem that the width in the front-rear direction is increased, which becomes an obstacle during mounting on the vehicle body. The present invention was created in order to solve the above-mentioned problems, and an object thereof is to provide a structure for disposing a two-cycle engine having a compact structure around the engine.

[0004]

In order to achieve the above object, in a structure for disposing a two-cycle engine around an engine of the present invention, a cylinder is provided so as to project upward from an upper surface of a front portion of a crankcase, and a crankcase is provided. In the arrangement structure around the engine of a two-cycle engine, a reed valve is arranged in an intake passage connecting a carburetor arranged in the rear of the cylinder and a starter motor is interlocked with the crankshaft via a gear reduction device. Provided is that the gear reduction device and the reed valve are arranged so as to overlap with each other when viewed in the direction of the crankshaft axis.

[0005]

By adopting the arrangement structure around the engine of the two-cycle engine configured as described above, unlike the conventional one as described above, the space efficiency of the two-cycle engine including the starter motor can be improved and the size can be reduced. Can be planned.

[0006]

EXAMPLES Examples will be described below with reference to the drawings. 1 and 2, 1 is a two-cycle engine,
The engine 1 has a crankcase 2, and the crankcase 2 integrally has a transmission case at its rear part. A cylinder 3 is projected from the upper surface of the front portion of the crankcase 2 toward the upper front, and a carburetor 4 is attached to the rear surface of the cylinder 3.
A crankshaft 5 whose axial center extends in the width direction is supported in the crankcase 2, and the crankshaft 5 is connected to a piston in the cylinder 3 by a connecting rod 6. A balancer shaft 7 is supported in the crankcase 2 in parallel with the crankshaft 5. The balancer shaft 7 has a balance weight 8.

On the other hand, a starter motor 10 is interlocked with the crankshaft 5 via a gear reduction device 9. This gear reduction device 9 includes an output gear 11 attached to a starter motor 10, an input gear 13 supported on a crankshaft 5 via a one-way clutch 12, and these output gears 11
And a plurality of reduction gears 14 interposed between the input gear 13 and the
(14 ₁ , 14 ₂ ) and these respective gears 11, 1
The axes of the shafts 3, 14 (14 ₁ , 14 ₂ ) respectively extend in the width direction. The one-way clutch 12 transmits power only from the gear reduction device 9 side to the crankshaft 5.
The balancer shaft 7 and the gear reduction device 9 are provided in the lower part and the upper part of the crankcase 2 behind the cylinder 3, respectively, and these are arranged side by side in the width direction. Reference numeral 15 is a flywheel magnet, which has a magnet rotor 16 rotating with the crankshaft 5 and a stator 17 attached to the crankcase 2 side. In addition, the magnet rotor 16
Is fastened to the driven side 18 of the one-way clutch 12.

A closing cover 2 having an opening 23 so as to cover the front surfaces of the gear reduction device 9 and the flywheel magneto 15 and the rear surface of the gear reduction device 9.
2 is provided, the opening 23 of which is closed by an opening / closing lid 24, and a plurality of reduction gears 14 (1
4 _1, 14 ₂₎ of the shaft of the reduction gear 14 ₁ to conduct connected to the output gear 11 of the cell motor 10 is supported by bearings formed in the lid 24 and the side rear portion of the closure cover 22. In order to assemble the reduction gear 14 ₁ thereof, other reduction gears 14 _{2 and the} like are assembled, the closing cover 22 is mounted, and then the reduction gears 14 ₁ are inserted from the openings 23 and assembled, and then the opening / closing lid is installed. 24 is closed. Of course, it is needless to say that the maintenance inspection can be performed by opening the opening / closing lid 24 or removing the closing cover 22. In addition, cell motor 1
0 is inserted and assembled in the closing cover 22, and the starter motor 10 is supported by a bearing portion formed in a part of the closing cover 22. Since it is configured as described above, it is possible to accurately secure the inter-shaft distance of the gear reduction device 9 and the like, and as a result, it is possible to reduce noise when the gear rotates and to prevent gear wear and the like.

A bracket 19 is provided on one surface of the starter motor 10 in the width direction, and the bracket 19 is provided.
The starter motor 10 is attached to the boss on the crankcase 2 side with a bolt. Further, the cylinder 3 and the crankcase 2 are fixed with a tightening bolt,
The starter motor 10 is arranged behind the cylinder at a predetermined distance so as to secure a space through which the tool 25 can pass. Therefore, it is not necessary to remove the starter motor 10 when attaching and detaching the cylinder 3 during maintenance and inspection. Further, a carburetor 4 is arranged on the rear surface of the cylinder 3, and the carburetor 4 and the intake passage 2 of the crankcase 2 are arranged.
0 is provided with a reed valve 21. The reed valve 21 is arranged on the rear side of the reduction gear 14 at a position where it overlaps when viewed from the axial direction of the crankshaft 2. Further, the starter motor 10 is arranged in the dead space above the reed valve 21. As a result, even if the displacement is large, a large capacity of the starter motor 10 can be easily attached, and the starter motor 10 is arranged at a position separated by the reed valve 21 as described above. If the starter motor 10 is held integrally with the gear reduction gear 9 as described above, the axial distance between the gear reduction gear 9 and other parts can be ensured with high accuracy, and as a result, noise during gear rotation can be reduced and at the same time, the gear It is possible to make the effect of not causing abrasion and the like more remarkable.

[0010]

As described above, since the gear reduction device and the reed valve are arranged so as to overlap each other when viewed from the plane perpendicular to the crankshaft, the engine surroundings including the starter motor can be improved. The layout structure can be made more space efficient and compact, and the starter motor can be placed avoiding the cylinder, so the cylinder can be installed and removed in a short time, and its maintenance and inspection is extremely easy. The effect is that it can be performed.

[Brief description of drawings]

FIG. 1 is a sectional view taken along the line II of FIG. 2 according to the embodiment of the present invention.

FIG. 2 is a schematic side view of an embodiment of the present invention.

FIG. 3 is a schematic view of a conventional example seen from a side surface.

FIG. 4 is a schematic view of a conventional example seen from a side surface.

[Explanation of symbols]

 1 2 cycle engine 2 crankcase 3 cylinder 4 carburetor 5 crankshaft 6 connecting rod 7 balancer shaft 9 gear reduction device 10 starter motor 14 reduction gear 20 adsorption passage 21 reed valve

Claims (1)

[Claims] 1. A gear reducer is provided on a crankshaft, while a cylinder is provided so as to project upward from an upper surface of a front portion of a crankcase, and a reed valve is arranged in an intake passage connecting a crankcase and a carburetor arranged behind the cylinder. In the arrangement structure around the engine of a two-cycle engine provided with a starter motor that is interlocked and connected via a gear, the gear reduction device and the reed valve are arranged so as to overlap with each other when viewed from the direction of the crankshaft axis. Arrangement structure around the engine.