JPS59128916A - Combustion chamber for side-valve-type diesel engine - Google Patents

Abstract

PURPOSE:To make a required compression ratio securable and the efficiency of ignition improvable, by making up an auxiliary combustion chamber with a wall part being projectingly installed in an upper peripheral edge of the valve face of a side-valve-type suction valve or an exhaust valve. CONSTITUTION:Suction and exhaust ports 7 and suction and exhaust valves 3 are installed in the side of a piston 1, while a wall part 3A is projectingly installed in position extending over the whole periphery of a valve face upper part of the valve head of this suction valve or exhaust valve 3, thus making up an auxiliary combustion chamber 8. At this wall part 3A, a hole or a notch is installed and thereby a subchamber nozzle hole 9 is formed thereat, while an escape part 10 for these suction and exhaust valves 3 of a cylinder head 6 turns to a cylinder form having a slightly larger inner diameter than an outer diameter of the valve face of these valves 3, and a fuel injection valve 4 is installed in this place. Thus, a required compression ratio is secured, while fuel and air are amply mixed by an injection flow out of the auxiliary combustion chamber and moreover, scavenging air becomes good and also ignitionability comes into a good state, so that the ignitionability is yet more improved through a temperature rise in the wall part.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion chamber for a side valve type diesel engine.

As shown in Fig. 1, the conventional side valve type internal combustion engine, in which the intake and exhaust valves 6 are provided on the side of the piston 2 that reciprocates within the cylinder 1, has a simple valve mechanism and is therefore easy to handle. It is known to have the advantage that it is simple and has a small number of parts, so the manufacturing cost is low, and there is also less noise generated from each moving part. When applied to the combustion chamber, the only way to ensure the compression ratio is to install the fuel injection valve 4 around the intake and exhaust valves 6, so the position of the fuel injection valve 4 is offset from the overall position of the combustion chamber 5. There are drawbacks.

Therefore, in direct injection type diesel engines, sufficient mixing of fuel and air is not achieved, resulting in deterioration of engine performance.In addition, in pre-chamber type diesel engines, the cylinder head 6 is Since escape is essential, there is a problem in that if a sub-combustion chamber is provided in the usual way, the compression ratio cannot be ensured.

This is because a gasoline engine has a low compression ratio, so the combustion chamber volume can be taken freely, whereas a diesel engine has a high compression ratio, so the combustion chamber volume is limited, causing the problems mentioned above. .

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a combustion chamber for a side valve type diesel engine that can solve the above-mentioned conventional problems, secure a sufficient compression ratio as a diesel engine, and provide good ignition performance and combustion performance. This is what I did.

That is, the combustion chamber of the site-knob type diesel engine of the present invention is such that, in the site-knob type diesel engine, the auxiliary combustion chamber is formed by a wall provided at the upper part of the valve face of the side-knob type intake valve or gas exhaust valve. It is characterized by the fact that it has been formed.

The present invention will be described in detail below with reference to the drawings, and the same parts in the conventional example and each embodiment shown in FIG. 1 are indicated by the same part numbers.

First, FIG. 2 is a longitudinal cross-sectional view of a main part of the combustion chamber of a side valve type tasel engine according to Example 1 of the present invention, and FIG. 3 is a plane cross-sectional view of a main part of FIG. 2. In this diesel engine,
As shown in FIGS. 2 and 3, an intake/exhaust boat 7 and an intake/exhaust valve 6 for opening/closing the intake/exhaust boat 7 are provided on the side of the cylinder 1 that reciprocates within the cylinder 1. By providing a wall portion 6A over the entire circumference of the upper part of the rev face of the valve umbrella 6, an auxiliary combustion chamber 8 is formed in the upper part of the intake and exhaust valve 6).

This wall portion 6A is provided with a hole or a notch shown in FIG. 2 to form a pre-chamber nozzle 9, and a relief portion 10 of the intake and exhaust valve 6 of the cylinder head 6 is provided with a hole or notch shown in FIG. It has a cylindrical shape with an inner diameter slightly larger than the outer diameter of the valve face, and a fuel injection valve 4 is provided opposite to this portion.

Next, FIG. 4 is a longitudinal cross-sectional view of a main part of a combustion chamber of a side-valve diesel engine according to a second embodiment of the present invention, and FIG. 5 is a plane cross-sectional view of a main part of FIG. A wall portion 6 as shown in FIGS. 4 and 5 is attached to a part of the upper part of the valve face.
A is provided to form an auxiliary combustion chamber 8, and a gap between this wall portion 6A and the cylinder head 6 is used as an auxiliary chamber injection port 9.

In addition, in both Examples 1 and 2 above, in order to keep the orientation of the sub-chamber nozzle 9 of the sub-combustion chamber 8 formed on the valve face of the intake valve or exhaust valve 6 constant, rotation of the intake valve or exhaust valve 6 was appropriately prevented. shall be provided.

As described above, in the present invention, the sub-combustion chamber 8 is formed by utilizing the relief part 10 provided in the cylinder head 6 during the lift of the intake valve or exhaust valve 6 and surrounding it with the wall part 6A provided on the valve face. Therefore, in the side valve type diesel engine to which the present invention is applied, it is possible to secure the compression ratio necessary for a diesel engine, and the fuel and air are sufficiently mixed by the jet flow from the auxiliary combustion chamber. In addition, the sub-combustion chamber is scavenged every time the intake valve or exhaust valve lifts.
There is an advantage that the ignitability is improved and the ignition performance is further improved because the temperature of the wall becomes higher when the sub-combustion chamber is provided above the exhaust valve.

The present invention is mainly applicable to cytono (lubric diesel engines).

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the main part around the combustion chamber of a conventional side-valve diesel engine, and FIG. 2 is a longitudinal cross-sectional view of the main part of the combustion chamber of the side-valve diesel engine in Example 1. 3 is a plan sectional view of the main part of FIG. 2, FIG. 4 is a longitudinal sectional view of the main part of the combustion chamber of the side valve type diesel engine in Embodiment 2 of the present invention, and FIG. 5 is a main part of the main part of FIG. 4. FIG. 6... Intake and exhaust valve, 6A... Wall, 5... Combustion chamber, 8
・・Sub-combustion chamber, 9・・Sub-chamber injection 1-1 Agent: Nobuo Ogawa, patent attorney - Ken Noguchi, patent attorney Teru, Patent attorney Kazuhiko Saishita No. 11" Figure 3

Claims (1)

[Claims] A combustion chamber for a side-valve diesel engine, characterized in that an auxiliary combustion chamber is formed by a wall provided at the upper part of a rev face of an intake valve or an exhaust valve of the side-valve type.