JP3159391B2 - Power transmission device for motorcycle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a power transmission device automatic two <br/>-wheel vehicle Ru vehicle der small.

[0002]

2. Description of the Related Art In a motorcycle or the like, the rotation of an engine crankshaft is decelerated via an input shaft and an intermediate shaft and transmitted to an output shaft. However because they are automatic two-wheel vehicle dimensions is limited smaller, as the engine is small it is desirable. Therefore, the present applicant first arranges the intermediate shaft above the straight line in the vehicle longitudinal direction connecting the crankshaft and the input shaft, and arranges the output shaft below, that is, arranges the intermediate shaft and the output shaft substantially up and down, the proposed power transmission device of an automatic two-wheeled vehicle which is adapted to reduce the longitudinal dimension.

[0003]

However, in such a power transmission device, since the output shaft is disposed below the straight line, the engine may swell downward and the minimum ground clearance may be reduced. Particularly, an engine mounting portion is often provided in a lower portion of the engine, and the minimum ground clearance is further reduced in such a structure.

[0004]

[Summary of the order to solve the above problems the present invention, the input shaft rotation of the crankshaft of the engine, that is decelerated through the intermediate shaft transmitted to the output shaft of the automatic two-wheeled vehicle power transmission device in the plane connecting the crank shaft and with said input shaft disposed parallel ground and substantially, the above the plane intermediate shaft, and place the output shaft, the crank in the plane than the intermediate shaft the output shaft It is located near the axis, and the engine mounting part is below the plane and above the lower end of the case.
It is characterized in that it is arranged on the side .

[0005]

[ Function ] A plane connecting the crankshaft and the input shaft is substantially flat with the ground.
Since the engine is arranged in a row and the intermediate shaft and the output shaft are arranged above the plane , the engine does not swell downward. Therefore, even if the engine mounting portion is provided below the plane, a sufficient minimum ground clearance can be ensured.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. The outline of the motorcycle will be described with reference to FIG.

This motorcycle is a foldable small motorcycle. In the figure, reference numeral 1 denotes a rear frame composed of a pair of left and right frame members 2, 2, and 3 denotes a rearward movable member with respect to the rear frame 1. 1 shows a main frame including a pair of left and right frame members 4 and 4.

A front fork 6 is provided at a front portion of the vehicle body to support a front wheel 7 with the front fork 6, and a handle holder 8 which can be folded rearward is provided above a front portion of the vehicle body. A handlebar 9 is provided at the upper end.

A rear wheel 13 is provided at a rear portion of the rear frame 1 via an axle 12, and an engine E is disposed below the rear frame 1 (a support structure of the engine E will be described later). A fuel tank 15 is disposed between the frame members 4 and 4, and a seat 17 is disposed above the frame members 4 and 4 via links 16 that can be folded forward.

Next, the power transmission device will be described in detail below. 2 is a left side view of the engine, FIG. 3 is a longitudinal sectional view thereof, FIG. 4 is a right side view thereof, FIG. 5 is an internal development view of the engine, FIG. FIG.

The engine E is mounted on the rear frame 1 via mounting portions A and B as shown in FIG.

In the figure, reference numeral 20 denotes a crankcase, which comprises a left case 21 and a right case 22. Inside the crankcase 20, a crankshaft 23, an input shaft 24, an intermediate shaft 25, and an output shaft 26 are arranged in parallel. And rotatably arranged.

A cylinder 28 is provided on the upper part of the crankcase 20, and a piston 29 is slidably provided in the cylinder 28. The piston 29 and the crankshaft 2
3 are connected by a connecting rod 30.

At the right end of the crankshaft 23, a mounting portion 31 is provided.
And the inner end of the flywheel 32 is fitted to the outer periphery of the mounting portion 31. ACG3 is inside the flywheel 32.
3 and a bolt 3 is provided on the side of the flywheel 32.
4 and the fan 35 is mounted.

A worm wheel 38 is formed on the left side of the ACG 33 of the crankshaft 23, and the worm wheel 38 is meshed with a worm 40 of a rotating shaft 39. The rotary shaft 39 drives an oil pump P provided in front of the crankcase 20.
9a and a large-diameter portion 39b, and the small-diameter portion 39a and the large-diameter portion 39b are connected by engaging the concave and convex portions 39c and 39d.

A variable pulley 41 is provided on the left side of the crankshaft 23. The variable pulley 41 has a dish-shaped fixed face 41a fitted on the end of the crankshaft 23, and a crankshaft facing the fixed face 41a. 23, and a dish-shaped movable face 41b slidably provided in the axial direction. The movable face 41b is attached to the crankshaft 23 so as to be parallel and slidable with respect to the axis, and a plurality of weight rollers 42 are provided on the back surface on the movable face 41b side.
Back plate and a lamp plate 44 provided to cover it
Hold with.

The lamp plate 44 is held in a fixed position by a sleeve 45 and a nut 46, and a spring (not shown) is disposed between the lamp plate 44 and the movable face 41b to keep the movable face 41b constant. It is urged toward the fixed face 41a.

On the other hand, a variable pulley 48 is provided at the left end of the input shaft 24, and the variable pulley 48 is slidably and rotatably mounted on the input shaft 24 with a dish-shaped fixed face 48 a fixed to the input shaft 24. The movable face 48b is freely provided.

The movable face 48b has a fan 48c.
And a spring 50 is provided between the movable face 48b and the spring receiver 49 to constantly bias the movable face 48b toward the fixed face 48a.

A V-belt 52 is mounted between the variable pulley 48 and the variable pulley 41, and a starting clutch 54 is provided on the input shaft 24 at a position more distal than the variable pulley 48.

A gear 24a is provided at the right end of the input shaft 24,
The gear 24a meshes with a gear 25a provided on the intermediate shaft 25. A gear 25b is provided on the right side of the gear 25a of the intermediate shaft 25, and the gear 25b meshes with a gear 26a of the output shaft 26. A pulley 26b is provided at the right end of the output shaft 26, and a V-belt or a chain (not shown) is mounted between the pulley 26b and a pulley (not shown) provided on the axle of the rear wheel 13.

As shown in FIG. 3, the plane connecting the crankshaft 23 and the input shaft 24, which is indicated by a straight line L in the vehicle longitudinal direction connecting the crankshaft 23 and the input shaft 24, is the ground shown in FIG.
It is arranged substantially parallel to the plane G. The intermediate shaft 25 and the output shaft 26 are disposed above a flat surface substantially parallel to the ground G. Further, the engine mounting portion A is provided below the plane above the power transmission member connecting the crankshaft 23 and the input shaft 24, that is, within the vertical width of the pulleys 41 and 48 housed in the crankcase 20. As shown in FIG. 3, the crankcase 20 is provided below the straight line L.
The engine mounting portion A is provided above the bottom surface (lower end) of the engine.

On the other hand, a bolt 58 is provided on the left side of the engine E.
The left engine cover 60 is mounted via..., And a chamber S1 is formed inside the cover 60. A right engine cover 62 is mounted on the right side of the engine E via bolts 61. A chamber S2 is formed in the cover 62. A number of openings 62a are formed in the right engine cover 62 so as to correspond to the fans 35 (see FIG. 5), and an IG coil 64 is formed above the right engine cover 62 as shown in FIGS. The CDI unit 65 is mounted. A bulging portion 67 bulging forward is formed at the front of the right engine cover 62, and the bulging portion 67 surrounds the oil pump P.

On the other hand, the left case 21 of the crankcase 20
2 and 5, a cooling air inlet 70 and a cooling air inlet 71 are formed, and as shown in FIG.
The left case 21 has a rib 21 at a position below the outlet 71.
a is formed. Therefore, together with the crankshaft 23, the fan 3
5, the cooling air taken into the right engine cover 62 from the opening 62a of the right engine cover 62 flows into the chamber S1 from the intake port 70 as shown by the arrow, and
c, flows through the chamber S1, and cools each member in the chamber S1. The cooling air flows from the outlet 71 to the left case 21.
Out of the case, flows under the left case 21, and further
a flows out backward.

As described above, in the present embodiment, the crankshaft 23
The intermediate shaft 25 and the output shaft 26 are arranged above a plane connecting the shaft and the input shaft 24, and within the upper and lower widths of the pulleys 41 and 48 housed in the crankcase 20 and below the straight line L in FIG. Since the engine mounting portion A is provided above the bottom surface of the crankcase 20 (specifically, this mounting portion A protrudes below the left case 21), the front and rear length of the engine E is ensured while securing the minimum ground clearance. Can be shortened.

FIG. 8 shows a longitudinal section of a flywheel mounting portion according to another embodiment. In this embodiment, a concave portion 31a facing inward is formed in the mounting portion 31, and the inner end of the flywheel 32 is formed in the concave portion 31a. It is fitted and fixed with a tubular member 80 and a nut 81.

[0027]

According to the present invention as described above, according to the present invention, the input shaft rotation of a crankshaft of an engine, a power transmission device of automatic two-wheeled vehicle that transmitted to the output shaft at a reduced speed via the intermediate shaft, wherein The plane connecting the crankshaft and the input shaft is the ground
Substantially arranged parallel to the intermediate shaft above the plane, and place the output shaft, placing the output shaft to the crankshaft toward the said plane than the intermediate shaft, the engine mounting portion, below the plane In addition, since it is arranged above the lower end of the case , the engine does not swell downward. Therefore, even with a structure in which the engine mounting portion is provided below the plane, a sufficient minimum ground clearance can be secured, and the longitudinal length of the engine can be shortened.

[Brief description of the drawings]

FIG. 1 is a side view of a motorcycle as an example of an embodiment.

FIG. 2 is a left side view of the engine.

FIG. 3 is a longitudinal sectional view of the engine.

FIG. 4 is a right side view of the engine.

FIG. 5 is an internal development view of the engine.

6 is a view taken in the direction of arrow 6 in FIG. 4;

FIG. 7 is a view taken in the direction of arrow 7 in FIG. 4;

FIG. 8 is a longitudinal sectional view of a flywheel mounting portion according to another embodiment.

[Explanation of symbols]

23 ... crankshaft, 24 ... input shaft, 25 ... intermediate shaft, 26
... output shaft, A, B ... engine mounting part, G ... ground, L ... straight line showing a plane connecting the crankshaft and the input shaft.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B62M 7/02 B60K 17/04 F16H 7/12

Claims (1)

(57) [Claims] 1. An engine according to claim 1, wherein the rotation of the crankshaft of the engine is an input shaft,
In dynamic <br/> force transmission apparatus of the automatic two-wheeled vehicle that transmitted to the output shaft at a reduced speed via the intermediate shaft, ground plane connecting said input shaft and said crankshaft and Ryakutaira
And arranged in rows, the above the plane intermediate shaft, and an output shaft arranged to place the output shaft to the crankshaft toward the said plane than the intermediate shaft, the engine mounting portion than said plane below And case
The lower end disposed above power transmission device of the automatic two-wheeled vehicle, characterized in that.