JPH055423A - Two-cycle v-type internal combustion engine having exhaust valve - Google Patents

Abstract

PURPOSE:To provide a two-cycle V-type internal combustion engine with exhaust valves securing durability and reliability and facilitating connection of an exhaust pipe by off-setting cylinders in the axial direction of a crank shaft and, making exhaust paths of the cylinders and the axis of the crank shaft cross nearly perpendicularly, as viewed from above the respective cylinders, and extending them in the same direction. CONSTITUTION:Cylinders in V-form are off-set in the axial direction of a crank shaft, and make exhaust paths of the cylinders and the axis of the crank shaft cross nearly perpendicularly, as viewed from above the respective cylinders, and extend them in the same direction. Exhaust valves changing exhaust timing are provided at the upper ends of the exhaust paths of the respective cylinders on the side of an exhaust port. The exhaust valve of one cylinder is disposed on the inside of the V and the exhaust valve of the other cylinder is disposed on the outside of the V, and both valves are disposed on the front side of the respective cylinders.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-cycle V equipped with an exhaust valve in which a crankshaft is arranged at a right angle to a vehicle traveling direction.
Type internal combustion engine.

[0002]

2. Description of the Related Art A two-cycle V-type internal combustion engine in which a crankshaft is arranged at a right angle to a vehicle traveling direction is disclosed, for example, in Japanese Utility Model Application No. 56-14.
It is known as shown in No. 4544. In such a V-type internal combustion engine, the exhaust passages extending from the respective cylinders forming the V-shape are in opposite directions when viewed from above the cylinders. The reason is that if they are extended in the same direction, the exhaust pipe connected to the exhaust passage protruding into the V-shaped space may be obstructed by one of the cylinders, which may make connection difficult.

On the other hand, in a normal two-cycle internal combustion engine, it is often taken into consideration that the side pressure of the piston in the explosion stroke does not affect the exhaust port of the cylinder. The reason is that the cylinder wall on the side where the exhaust port exists due to the exhaust port opening to the cylinder wall has an insufficient side pressure receiving area and the side pressure becomes excessive. Therefore, when the engine is rotating in the right direction, an exhaust port is provided on the right side of the cylinder.

[0004]

However, when the exhaust passages of the respective cylinders extend in the opposite directions when viewed from above the cylinders as in the prior art, for example, the rotation direction of the crankshaft is set to the right rotation. Even if the exhaust port of one cylinder is prevented from being subjected to the lateral pressure, the other cylinder still has the lateral pressure applied to the exhaust port side.

If the lateral pressure received on the exhaust port side is within the limit, such a structure can be adopted, but in the two-cycle internal combustion engine in which the exhaust timing can be changed in order to improve the output, At high speeds, the exhaust port is opened wide to accelerate the exhaust timing, so there is a problem in that the area for receiving the lateral pressure is insufficient, resulting in a significant disadvantage.

The present invention has been made in view of the above problems of the prior art, and its object is to offset the cylinder in the axial direction of the crankshaft,
An exhaust valve that ensures durability and reliability and facilitates exhaust pipe connection by making the exhaust passages of each cylinder substantially orthogonal to the axis of the crankshaft when viewed from above each cylinder and extending in the same direction. It is intended to provide a two-cycle V-type internal combustion engine equipped with.

[0007]

In order to achieve the above object, a two-cycle V-type internal combustion engine provided with an exhaust valve according to the present invention is arranged such that a cylinder forming a V-shape is offset in the axial direction of a crankshaft, Exhaust gas in which the exhaust passage of each cylinder is made substantially orthogonal to the axis of the crankshaft when viewed from above each cylinder and extends in the same direction, and the exhaust timing is changed to the upper edge of the exhaust passage of each cylinder on the exhaust port side. A valve is provided, the exhaust valve of one cylinder is arranged inside the V-shape, and the exhaust valve of the other cylinder is arranged outside the V-shape.
Each exhaust valve is arranged on the front side of the cylinder.

[0008]

Operation: 2 equipped with the exhaust valve configured as described above
Since it is a cycle V type internal combustion engine, the exhaust passage of each cylinder is made substantially orthogonal to the axis of the crankshaft as viewed from above each cylinder and extends in the same direction, and the exhaust passage side of the exhaust passage of each cylinder is provided. Since the exhaust valve for changing the exhaust timing is provided at the upper edge, the side pressure of the piston is less likely to be applied to each exhaust port side during the operation of the internal combustion engine.

Further, since the front and rear cylinders are offset from each other in the axial direction of the crankshaft and the exhaust passage extends from the exhaust port of this cylinder substantially orthogonal to the axis of the crankshaft, the exhaust passages are the same. When the exhaust pipe is connected to the exhaust passage projecting into the V-shaped space even if it is extended in the direction, the other cylinders do not get in the way.

Further, since the exhaust valve is disposed on the front side of the cylinder, it is sufficiently cooled by the traveling wind while the vehicle is traveling.

[0011]

Embodiments of the present invention will be described with reference to the accompanying drawings. In the figure, reference numerals 1 and 2 denote cylinders of a two-cycle V-type internal combustion engine, and the cylinders are arranged so as to face each other in a V shape.
Then, the cylinder block 3 of each cylinder 1,2
Pistons 5 and 6 are arranged at 4 so as to be vertically movable.

Further, the cylinder blocks 3 and 4 have scavenging passages 7 and 8 for communicating the respective crank chambers and combustion chambers.
The exhaust passages 9 and 10 for discharging the combustion gas and the intake passage (not shown) are formed.

On the inner walls of the exhaust passages 9 and 10, exhaust valves 11 and 12 which are rotating shafts are rotatably arranged. Both end shaft portions 11a, 12 of the exhaust valves 11, 12
a is rotatably provided on the cylinder blocks 3 and 4 via bearings 13 and 14.

As is apparent from FIG. 2, the exhaust valves 11 and 12 are formed in a substantially zigzag shape, and a part of the exhaust valves 11 and 12 exposed in the exhaust passages 9 and 10 are exhaust passages 9 and 10. Notches are formed so as to be smoothly continuous with the inner surface of 10, and the notch portions 11b and 12b are part of the inner surfaces of the exhaust passages 9 and 10.

In FIG. 2, the fixed pulley A is attached to the shaft end 11a of the exhaust valve 11 located on the right side, that is, the front side, and the shaft end 12a of the exhaust valve 12 located on the left side, that is, the rear side. Is provided with a fixing pulley B, which are connected by a pair of wires 15 and 16, respectively, and rotate in conjunction with each other in the same direction. The driving member 17 is fastened and fixed to the shaft end portion 11a of the exhaust valve 11 by a tightening bolt 18, and one end of a pair of driving wires 19 and 20 is engaged with the driving member 17 and the other end thereof is engaged. The unit is connected to the servo motor 21. Since the rotation angle of this servo motor 21 is controlled according to the rotation speed of the engine, this servo motor 2
The exhaust valves 11 and 12 are interlocked and rotated according to the rotation angle of 1.

As is apparent from FIGS. 1 and 2, the axis L of the crankshaft is perpendicular to the vehicle traveling direction with respect to the cylinder 1 located forward of the vehicle traveling direction. The cylinders 1 and 2 forming a V-shape are offset from each other by X in the direction of the axis L of the crankshaft. Also, each of the cylinders 1,
The exhaust passages 9 and 10 of No. 2 extend in the same direction in a direction substantially orthogonal to the axis L of the crankshaft when viewed from above each cylinder. Further, the exhaust valve 12 of the cylinder 2 is arranged inside the V-shape, and the exhaust valve 11 of the cylinder 1 is arranged outside the V-shape.
Are arranged in front of the cylinders 1 and 2.

In the structure of the above embodiment, since the exhaust passages 9 and 10 of the cylinders 1 and 2 extend in the same direction when viewed from above the cylinders respectively, during operation of the internal combustion engine, By selecting the rotation direction of the crankshaft (right rotation R in the case of the embodiment), the lateral pressure of the piston is hardly applied to each exhaust port side. Also, front and rear cylinders 1,
2 are offset from each other in the axial direction of the crankshaft, and the exhaust passages 9 and 10 extend from the exhaust port of this cylinder substantially orthogonal to the axial line of the crankshaft, so that the exhaust passages extend in the same direction. When the exhaust pipe is connected to the exhaust passage 10 that projects into the V-shaped space even if it is taken out, the other cylinders 1 do not get in the way. Further, the exhaust valves 11 and 12 are the cylinders 1,
Since it is disposed on the front side of the vehicle 2, it is sufficiently cooled by the traveling wind while the vehicle is traveling.

[0018]

In the two-cycle V-type internal combustion engine equipped with the exhaust valve according to the present invention, the exhaust passage of each cylinder is made substantially orthogonal to the axis of the crankshaft and extends in the same direction when viewed from above each cylinder. Since an exhaust valve for changing the exhaust timing is provided at the upper edge of the exhaust passage of each cylinder on the exhaust port side, the side pressure of the piston may be applied to each exhaust port side during operation of the internal combustion engine. As a result, the durability and reliability of the 2-cycle V-type internal combustion engine with an exhaust valve can be improved.

Further, since the front and rear cylinders are offset from each other in the axial direction of the crankshaft and the exhaust passage extends from the exhaust port of this cylinder substantially orthogonal to the axis of the crankshaft, the exhaust passages are the same. When the exhaust pipe is connected to the exhaust passage that extends in the direction and projects into the V-shaped space, other cylinders do not get in the way and the exhaust pipe can be connected very easily.

Further, since the exhaust valve is arranged on the front side of the cylinder, it is sufficiently cooled by the running wind while the vehicle is running. Therefore, the cooling failure around the exhaust port due to the provision of the exhaust valve is prevented. It can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a two-cycle internal combustion engine according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of FIG.

[Explanation of symbols]

 1, 2 cylinders 9, 10 Exhaust passage 11, 12 Exhaust valve L Crankshaft axis X Offset

Claims (1)

Claim: What is claimed is: 1. In a two-cycle V-type internal combustion engine having an exhaust valve in which a crankshaft is arranged at right angles to a vehicle traveling direction, a cylinder forming a V-shape is offset in the axial direction of the crankshaft. Then, the exhaust passages of the respective cylinders are made substantially orthogonal to the axis of the crankshaft as viewed from above the respective cylinders and extend in the same direction, and the exhaust passages of the exhaust passages of the respective cylinders are
An exhaust valve for changing the exhaust timing is provided on the upper edge of the cylinder side, the exhaust valve of one cylinder is arranged inside the V-shape, and the exhaust valve of the other cylinder is arranged outside the V-shape, and each exhaust valve A two-cycle V-type internal combustion engine having an exhaust valve, characterized in that the engine is arranged in front of the cylinder.