JPS5914608B2 - gasoline engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a gasoline engine which improves the combustion end and reduces the amount of unburned hydrocarbons and nitrogen oxides in exhaust gas, and which has a simple fuel supply system structure and is easy to manufacture. BRIEF DESCRIPTION OF THE DRAWINGS For the purpose of simplicity, the present invention will now be described with reference to the drawings.

In FIG. 1, 1 is a main combustion chamber (hereinafter simply referred to as the main chamber) facing the top surface of the piston.

), 2 is an auxiliary combustion chamber (hereinafter simply referred to as an auxiliary chamber) in which the torch flame is ejected into the main chamber 1 through an injection hole 3.

). The auxiliary chamber 2 is provided with an ignition plug 4 and a fuel injection valve 5.

The fuel injection valve 5 injects fuel at a constant amount regardless of the load.

Figure 2 is a diagram qualitatively showing the relationship between fuel flow rate (fuel flow rate per effective stroke of the piston) and load, and shows that the amount Q1 injected into the subchamber 2 out of the fuel flow rate under load is independent of the load. Indicates that it is constant.

6 is an intake pipe, I is an intake valve, and 8 is an exhaust pipe.

The intake pipe 6 is provided with a throttle valve 9 and a lean mixture supply device 10.

The throttle valve 9, unlike that in a normal engine, remains fully open throughout most of the load range G, and throttles the flow of the air-fuel mixture in the intake pipe only near idling.

FIG. 3 is a diagram showing the relationship between throttle valve opening and load. In this diagram, Lo is the idling load, and X is the section where the throttle valve performs its throttling action.

The rotation of the throttle valve 9 in the section X is performed via a mechanism that is linked to the depression of the speed pedal.

The lean mixture supply device 10 can be constructed as a simple carburetor or an injection pump.

If this device is configured as a carburetor, a so-called slow boat is unnecessary, and the flow rate of fuel passing through the main jet is controlled in accordance with the amount of depression of the 0-speed pedal.

A reactor 11 is provided on the exhaust pipe 8 to further reduce hydrocarbons in the exhaust gas, and a heat insulating liner 12 is provided to improve the function of this reactor.

The main fuel supply system that supplies the air-fuel mixture to the main chamber 1 through the intake pipe 6 provides a fuel flow rate of Q2 as shown in FIG. 2 mentioned above.

The heat flow rate Q is a value Ql depending on what is injected into the subchamber 2.
It is the sum of this and Q2.

The fuel flow rate Q2 in the main fuel supply system is O during idling.

In other words, the idling operation is performed in a state where only air is supplied to the main chamber 1 from the intake pipe 6.

The auxiliary chamber 2 is a first chamber in which idling operation is performed by itself.
It has a second function of generating a torch flame to combust a lean air-fuel mixture that cannot be ignited with a spark plug.

The formation of nitrogen oxides is significantly suppressed when the air-to-fuel ratio (hereinafter simply referred to as A/F) is high, such as 18 or higher.

In such an A/F, ignition using a spark plug cannot ensure ignition, but torch flame from the subchamber can.

The generation of nitrogen oxides can also be suppressed by lowering the A/F.

The combustion in the auxiliary chamber 2 may leave unburned gas (unburned phosphorus is later combusted in the main chamber 1).

Fuel injection into the X auxiliary chamber 2 is performed so as to obtain as rich a gas as possible for ignition by the ignition plug 4.

FIG. 4 is a drawing showing the A/F range M of the main chamber and the A/F range N of the auxiliary chamber on a drawing showing the A/F and the amount of nitrogen oxide produced.

Since the exhaust gas remains in the subchamber 2, this also serves to suppress the production of nitrogen oxides.

In order to allow the torch flame from the auxiliary chamber 2 to enter the main chamber 1 conveniently, the top surface 14 of the piston 13 has a recess that smoothly guides the torch flame.

The gasoline engine according to the present invention described above has the following features:
This makes the fuel supply system particularly simple and eliminates the generation or residual of air pollution.

[Brief explanation of the drawing]

Fig. 1 is a route map showing the configuration of a gasoline engine according to the present invention, Figs. 2 to 4 are graph diagrams for explaining what is shown in Fig. 1, and Fig. 2 mainly shows the relationship between fuel flow rate and load. Fig. 3 shows the relationship between the throttle valve opening 4 degrees and the load, and Fig. 4 shows the relationship between the A/F and the amount of nitrogen oxide produced in the main and sub-chambers. Shown in relation to the room. 1...Main room, 2...Sub-room, 3...
...Ejection port, 4... Spark plug, 5... Fuel injection valve, 6... Intake pipe, 9... Throttle valve, 10... ...Lean mixture supply device.

Claims (1)

[Claims] 1. The main combustion chamber is provided with a sub-combustion chamber that ejects a torch flame for ignition, and the sub-combustion chamber is provided with a fuel injection valve and a spark plug that always inject a fixed amount of fuel into the sub-chamber, The constant amount of fuel injected from the fuel injection valve is made to be as rich as possible for ignition by the ignition plug, and the main fuel supply system on the intake pipe side that supplies a lean mixture to the main combustion chamber is turned off during idling. Only air is supplied to the main combustion chamber, and the throttle valve installed in the intake pipe is Q-shaped so that the flow path in the intake pipe is throttled only near idling and remains fully open afterward. gasoline engine.