JPS59201927A - Charging unit for diesel engine - Google Patents

Abstract

PURPOSE:To enable to supply sufficient air to an auxiliary charging valve for its whole rotating area by forming a main charging manifold to supply air to a main suction valve with a chamber part and a branch pipe part for providing a branch pipe part to be connected through to the auxiliary charging valve inside the chamber part. CONSTITUTION:A Diesel engine main body 4 is of multi-cylinders, and air is supplied to each cylinder by a main charging valve 5 and an auxiliary charging valve 6. A main charging manifold 7 is formed by a chamber part 8 and a branch pipe 9, which is led to a main suction valve 5. Next to the branch pipe 9, in the center position, a branch pipe 10 to the auxiliary valve 6 is provided to lead to the chamber 8. In this way, a flow into a chamber 8 is slow and sufficient for branch flow to the branch pipe 10 to improve the volumetric efficiency and at the same time, the branch flow to the branch pipe 10 in the chamber 8 is not prevented even the rotation of the engine goes into the high speed area.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air supply system for an internal combustion engine, and more particularly to an air supply system for a diesel engine having an auxiliary air supply valve.

Diesel engines are equipped with two intake valves to improve volumetric efficiency.

The above-mentioned two-valve air supply valve includes one in which two valves of the same size are provided, and one in which a main and auxiliary air supply valve of different sizes are provided.

In conventional systems that use main and auxiliary air supply valves, one main air supply manifold is used, and the air is diverted to the auxiliary air supply valve in the middle of a branch pipe.

However, the conventional device described above has the following drawbacks.

It is difficult to divert the flow from the flow path flowing into the main air supply valve to the auxiliary air supply valve because it is obstructed by the flow to the main air supply valve. This branch flow is further inhibited in the high engine speed range, and there is a fear that it will not be possible to improve the volumetric efficiency.

SUMMARY OF THE INVENTION An object of the present invention is to provide an air supply system for a diesel engine that is capable of supplying sufficient air to an auxiliary air supply valve over the entire rotational range of the engine.

A feature of the present invention is that the flow is diverted from the chamber of the air intake manifold, where the flow is slow, to the auxiliary air intake valve, thereby achieving good volumetric efficiency over the entire rotation range of the engine. It becomes something.

This will be explained below using figures.

FIG. 1 is a schematic diagram showing a conventional two-valve air supply system.

In the conventional air supply system, the main air supply valve 1-\inflow flow Pl
prevents the branch flow P2 to the auxiliary air supply valve 2.

That is, when the flow of Pl is large (high speed), the divided flow P2
This makes it difficult for flows to branch into

In particular, when the engine rotates at high speeds, Pl becomes high speed.
Correspondingly, the inertial force of the flow also increases, and the branching into the branch P2 is inhibited.

The above-mentioned disadvantage arises because the flow is attempted to be diverted to the auxiliary air supply valve 2 in the branch pipe 3 where the flow rate is high.

In order to obtain a sufficient amount of branched flow, it is recommended to divide the flow at a point where the flow is slow.

The present invention, which improves the above drawbacks, will be explained below.

The diesel engine main body 4 has multiple cylinders, and air is supplied to each cylinder by a main air intake valve 5 and an auxiliary air intake valve 6. The auxiliary air supply valve 6 supplements the main air supply valve 5, and is also smaller than the main air supply valve 5.

The main air supply manifold 7 includes a chamber portion 8 and a branch pipe 9, and one branch pipe 9 communicates with the main air supply valve 5.

In the present invention, a branch pipe 10 to the auxiliary air supply valve 6 is provided at an intermediate position between adjacent branch pipes 9, and is connected to the chamber 8.

Since the present invention is configured as described above, it has the following effects.

Since the flow in the chamber 8 is gentle, the flow is sufficiently divided into the branch pipe 10, and an improvement in volumetric efficiency is reliably achieved.

Even if the engine is in a high rotation range, the flow within the chamber will not prevent the flow from being diverted to the branch pipe 10.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a conventional air supply device, and FIG. 2 is a schematic plan view showing an embodiment of the present invention. Agent: Patent Attorney Tsuji Sanbe

Claims (1)

[Claims] In a diesel engine having a main air intake valve and an auxiliary air intake valve, a main air intake manifold that supplies air to the main air intake valve is composed of a chamber portion and a branch pipe portion, and the auxiliary air supply is supplied to the chamber portion. An air supply system for a diesel engine, characterized in that it is provided with a second branch pipe section that communicates with an air valve.