JPS61205359A - Internal-combustion engine - Google Patents

Abstract

PURPOSE:To produce two types of strong whirls and improve engine output ever so better, by setting up four valves each at both sides as sandwiching a longitudinal axis of a cross section in a cylinder head between, and setting two outer pieces on one side and two central pieces on the other down to each of suction valves. CONSTITUTION:Each four-piece of suction valves S1-S4 and exhaust valves E1-E4 are all installed in a cylinder head. And, each valve is disposed on a straight line at one side of a longitudinal axis d1, namely, at the right side as the exhaust valve E1, the suction valve S3, the suction valve S3 and the exhaust valve E4 in order from the upside as paralleling these four valves with the longitudinal axis d1. Likewise, at the other side of the longitudinal axis d1, namely, at the left side, four valves such as the suction valve S1, the exhaust valve E2, the exhaust valve E3 and the suction valve S4 are disposed on a straight line in order in parallel with the longitudinal axis d1. With a reciprocal action among each suction air inhaled each out of two outer suction valves S1 and S4 and two central suction valves S2 and S3, two types of strong whirls are producible inside a cylinder hole at a suction stroke, thus combustion is well improvable.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internal combustion engine having a cylinder having an oval cross section, and particularly to an internal combustion engine having a cylinder having an oval cross section.
This relates to the arrangement of exhaust valves.

The cylinder of an internal combustion engine usually has a circular cross section, and in a four-stroke engine, the intake valve and exhaust valve are arranged in the cylinder head that covers the end of the cylinder. In an internal combustion engine with a cylinder head, the intake and exhaust valves must be arranged within a circular outline of the cylinder cross section projected onto the cylinder head.
It was sometimes difficult to arrange the exhaust valves to ensure intake and exhaust port areas commensurate with the cylinder area and to improve intake and exhaust efficiency.

For this reason, the cross section of the cylinder is made into an oval shape with a long axis and a short axis, and a plurality of intake valves are arranged in one half of the short axis direction in a straight line along the long axis direction in the cylinder head. At the same time, it has been proposed to provide a plurality of exhaust valves in a straight line in the other half of the minor axis direction in correspondence with the intake valves. Institutions are shown.

However, on the other hand, in a normal internal combustion IJJ that has a cylinder with a circular cross section, the intake air inside the cylinder is controlled by selecting the intake boat shape, adopting a shroud valve, or considering the masking type combustion chamber shape. It is possible to actively form a swirl to improve combustion conditions, but in internal combustion engines that have cylinders with oval cross sections, the cylinder cross section is non-circular, so the suction flows through the suction port. It cannot be expected that the intake air will form a vortex within the plane cross section, which may be disadvantageous in terms of combustion.

Therefore, the present invention aims to generate a strong vortex in the intake air in the cylinder during the intake stroke even in an internal combustion engine having a cylinder with an oval cross section.

In order to achieve ``1 C'' and for this reason, in the present invention, in an internal combustion engine equipped with a cylinder having an elliptical cross section, the cylinder head has four cylinders on both sides of the long axis of the cross section. valves are arranged in a straight line parallel to the long axis, and of the four valves arranged on one side of the long axis, the central two valves and the four valves arranged on the other side. The outer two valves are used as intake valves.

According to the present invention, each of the intake valves arranged on the outside of the other side and the intake valve closer to the back of the two intake valves arranged in the center on the right side form a pair with each other, The intake air sucked into the cylinder through these two intake valves forms a pair and influences each other to generate a vortex flow. That is,
The intake air taken in through the outer intake valve flows while swirling along the cylinder wall surface portion with a large curvature that exists at the outer end of the long axis of the oval cross section, and flows from the central intake valve that is paired with this intake valve. The intake air is deflected toward the outer intake valve due to the influence of the flow, and as a result, the intake air from the pair of intake valves forms a strong unidirectional vortex within the cylinder.

IL fake Hereinafter, the present invention will be described with reference to an illustrated embodiment.

FIG. 1 is a plan view of a cylinder head of an internal combustion engine according to the present invention viewed from the cylinder side, and FIG. 2 is a longitudinal sectional view of the cylinder portion of the internal combustion engine, where 1 is a cylinder head and 2 is a cylinder block. Cylinder hole 3 in cylinder block 2
The cross section of the cylinder hole 3 has an oval shape with a major axis d1 and a minor axis d2, as shown by a in FIG. 1. Therefore, the piston 4 fitted in the cylinder hole 3 also has the same oval cross section.

As shown in FIG. 1, the cylinder head 1 includes four intake valves S1, S2, S3, and S4, and four exhaust valves E+,
E2, Es, and E4 are arranged, and these valves are arranged on one side of the long axis d1, that is, on the right side in the figure, from above: exhaust valve E1, intake valve S2, intake valve S3, and exhaust valve E4.
Four valves are arranged in a straight line parallel to the long axis d1 in this order, and on the other side of the long sleeve d1, that is, on the left side in the figure, there are four valves arranged in this order from above: intake valve S1, exhaust valve E2, exhaust valve E3, and intake valve S4. Similarly, the valves are arranged in a straight line parallel to the long axis d1. In other words, 4
Of these valves, the two in the center are intake valves, and the long axis d
The four valves arranged on the other side of the
The valve is the intake valve.

Each of these intake valves S and exhaust valves E opens and closes each valve port that communicates with each intake passage 5.5 and exhaust passage 6.6 provided in the cylinder head 1, respectively. As shown in FIG. 2, the intake passage 5 and the exhaust passage 6 are arranged at different angles in the vertical direction so that they do not interfere with each other. Each intake passage 5 and exhaust passage 6 are connected to a common intake pipe 7 and an exhaust pipe 8, respectively.

FIG. 3 shows the flow of intake air during the intake stroke in the above embodiment. When the intake valves S1 to S4 are opened during the intake stroke, intake air flows through the corresponding intake passages 5 as indicated by arrows A,
It is sucked into the cylinder hole 3 as shown by B, C, and D.

At this time, the intake air A taken in from the outer intake valve, for example, the intake valve S1, hits the cylindrical cylinder wall portion 9 with a large curvature at the longitudinal end of the cylinder hole 3, and goes around along the wall surface of the portion. This becomes a swirling flow, and the intake air B drawn into the cylinder hole 3 through the intake valve S2 is influenced by the swirling flow and is deflected toward the intake valve Sl as shown in the figure. As a result, the intake air A and the intake air B generate a strong vortex that swirls clockwise in the figure.

A similar interaction occurs between the intake air C taken in through the 7-air valve S3 and the intake air t taken in through the intake valve S4, and this part has a strong force that rotates counterclockwise as shown. A vortex is created.

As described above, in the present invention, in an internal combustion engine equipped with a cylinder having a long cross section, four valves are installed on each side of the cylinder head with the long sleeve of the cross section in between. Of the four valves arranged in a straight line parallel to the long axis and arranged on one side of the long axis, the two in the center and the other 41 valves arranged on the other side. Since the outer two of the valves il are used as the intake valves, the interaction between the intake air drawn from the outer intake valves and the intake air drawn from the center intake valve causes the air to flow inside the cylinder hole during the intake stroke. Two strong vortices are generated, which causes combustion to change. Furthermore, by stabilizing the direction of the intake air within the cylinder hole, the attenuation of the kinetic energy of the intake air is reduced, and the intake inertia effect can be fully utilized, thereby increasing the intake efficiency and improving the engine output.

[Brief explanation of drawings]

Fig. 1 is a plan view of the cylinder head of an internal combustion engine according to the present invention, viewed from the cylinder side, Fig. 2 is a longitudinal sectional view of the cylinder portion of the internal combustion engine, and Fig. 3 is a plan view showing the flow of intake air in the cylinder hole. It is a diagram. 1... Cylinder head, 2... Cylinder block,
3... Cylinder hole, 4... Piston, 5... Intake passage, 6... Exhaust passage, 7... Intake pipe, 8... Exhaust pipe, 9... Cylinder wall portion, S ...Intake valve, E.
・Exhaust valve.

Claims (1)

[Claims] In an internal combustion engine equipped with a cylinder having an oval cross section, four valves are disposed in a straight line parallel to the long axis of the cylinder head on both sides of the long axis of the cross section, and It is characterized in that the central two of the four valves arranged on one side of the long axis and the outer two of the other four valves arranged on the other side are used as intake valves. Internal combustion engine.