JPH02551B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection multi-cylinder engine suitable as an automobile engine, and particularly relates to a fuel injection multi-cylinder engine suitable for use as an automobile engine. This invention relates to an engine that generates a high-speed vortex of intake air in a combustion chamber by a sub-intake air flow ejected from the sub-intake air flow, thereby stabilizing combustion at high speed in the subsequent combustion stroke.

Conventionally known electronically controlled fuel injection device, so-called
The FEI has a flowmeter in the intake passage and an electromagnetically actuated fuel injection valve that is controlled by the flowmeter's signal.
Furthermore, in order to finely adjust the air-fuel ratio in the idling operating range, a small intake passage bypassing the flow meter is provided, and an air valve for adjusting the flow rate is provided in the small intake passage.

This invention attempts to increase the flow velocity of the auxiliary intake air supplied from the auxiliary intake passage by using the airflow flowing through the small intake passage, thereby increasing the velocity of the intake air vortex in the combustion chamber. The present invention will be explained below with reference to illustrated embodiments. In the figure, reference numeral 1 denotes a four-stroke, four-cylinder automobile engine, and a combustion chamber 2 is formed by a cylinder 3, a cylinder head 4, and a piston (not shown) that reciprocates within the cylinder 3. Reference numeral 5 designates an intake passage leading into the combustion chamber 2 via an intake valve 6, 7 an exhaust passage leading into the combustion chamber 2 through an exhaust valve 8, and 9 an ignition plug.

The intake passage 5 is formed by a spacer 11 connected to the cylinder head 4, a manifold 12, and a flow meter 14 connected to this via a rubber tube 13. It consists of a branch road 5A and an upstream gathering road 5B where the branch roads 5A are gathered. 15 is a throttle valve that is manually operated by an accelerator pedal or other operator (not shown), and 16 is a fuel injection valve provided downstream thereof. The flow meter 14 is a conventionally known one, and includes an intake cylinder 14A and a rotary blade 14B pivotally supported by the intake cylinder 14A. When the amount of intake air passing through the intake cylinder 14A increases, the wind pressure causes the rotor blade to rotate. 14B is designed to rotate counterclockwise in the figure, and the rotation angle increases or decreases depending on the intake air flow rate.
A signal emitted according to the magnitude of the rotation angle of the rotating blade 14B is input to the computer C, and after being calculated, is taken out from there as an output signal. The output signal causes the fuel injection valve to open for a time corresponding to the intake flow rate to inject fuel, and the above configuration is not particularly different from the conventional EFI.

Reference numeral 17 denotes a sub-intake passage, one end of which opens directly into the combustion chamber 2 from the wall surface of the intake passage 5 near the intake valve 6, and the other end opens into the combustion chamber 2 through a branch pipe 17A and a communication passage 17B. The sub-intake passages 17 of the cylinders are in communication with each other. The communication passage 17B communicates with the intake passage 5 upstream of the rotary blade 14B through a small intake passage 18, and is opened to the atmosphere through an air cleaner (not shown). 19 is the small intake passage 18
This is an air valve that adjusts the flow rate of air flowing into the sub-intake passage 17 through the intake passage.

When the engine 1 starts, an amount of intake air flows into the intake passage 5 according to the opening degree of the throttle valve 15.
detects the flow rate and sends it to computer C. The computer C calculates the fuel injection amount and the opening time of the valve 16 corresponding to the injection amount in order to adjust the air-fuel ratio of the mixture to a predetermined value according to the intake flow rate.
6 and excite it. In this way, the fuel injected from the fuel injection valve 16 generates an air-fuel mixture with a desired air-fuel ratio, which flows into the combustion chamber 2 during the intake stroke when the intake valve 6 opens. The negative intake pressure in the intake passage 5 also acts on the auxiliary intake passage 17, which is connected to it, so that the auxiliary intake passage 17 contains air-fuel mixture from the intake passages of other cylinders and air from the small intake passage 18. Inflow.
These airflows become thin, high-speed sub-intake airflows and are ejected from the valve opening of the intake valve 6 into the combustion chamber 2 . As is clear from FIG. 2, the sub-intake passage 17 opens outward from the axis of the cylinder hole and downward toward the upper surface of the piston. Therefore, the air-fuel mixture in the combustion chamber 2 generates a high-speed vortex around the cylinder axis due to the sub-intake air flow. This vortex remains during the compression stroke and generates numerous minute turbulences within the combustion chamber 2. During the subsequent combustion stroke, the flame is ignited by the spark plug 9 and rapidly propagates into the combustion chamber 2, resulting in a high-speed and stable flame. combustion takes place. The air valve 19 adjusts the air-fuel ratio of the air-fuel mixture. When the opening degree is increased, the amount of air passing through the flow meter 14 decreases, and only the fuel supplied from the fuel injection valve 16 decreases, resulting in a lean air-fuel ratio. becomes. Conversely, if the opening degree is reduced, the air-fuel ratio becomes richer. Increasing the opening degree of the air valve 19 in this way makes the air-fuel ratio leaner, but since the air flow rate in the small intake passage 18 increases, the flow rate from the auxiliary intake passage 17 also increases, making the excess flow in the combustion chamber even more severe. encouraged.
In other words, smooth combustion can be obtained even at a lean air-fuel ratio.

As explained above, this invention opens one end of the sub-intake passage with a small cross-sectional area pointing into the combustion chamber on the intake passage wall near each combustion chamber of an injection-type multi-cylinder engine, and opens the other end of each sub-intake passage. Since they are communicated with each other and opened to the atmosphere via an air valve, the air-fuel mixture is allowed to flow into the combustion chamber from the intake passage of the other cylinder.
Air for air-fuel ratio correction can flow into the combustion chamber from the air valve.

Therefore, the air flowing in from the air valve can increase the sub-intake flow rate and suck out the air-fuel mixture from the sub-intake passages of other cylinders.
As a result, the intake air vortex within the combustion chamber can be further promoted and the amount of air-fuel mixture can be increased, resulting in stable combustion. Furthermore, since the configuration requires only a change in piping and no special equipment is required, there is little increase in cost. Furthermore, since the upstream end of the small intake passage is connected to the upstream side of the flow meter via an air valve and is open to the atmosphere, even the air-fuel mixture diluted by the air valve promotes excessive flow and smooth flow. Combustion is obtained.

In addition, when the engine is idling, the throttle valve 1
5 may be substantially fully closed, and a substantial portion of the intake air amount during idling operation may be supplied through the auxiliary intake passage. Gas can be reduced, and carbides that tend to accumulate near the throttle valve can be reduced.

[Brief explanation of drawings]

The drawings show an example of the implementation of the present invention, and FIG. 1 is a cross-sectional side view of a four-stroke, four-cylinder engine, and FIG.
The figure is a sectional view thereof. 14...Flowmeter, 17...Sub-intake passage, 18...
...Small intake passage, 19...Air valve.

Claims (1)

[Claims] 1. An intake passage 5 is formed by a branch passage 5a that is guided to a plurality of combustion chambers 2 and each has a throttle valve 15 that controls the amount of intake air, and a collection passage 5B that is formed by gathering these branches on the upstream side of the throttle valve 15. A fuel injection valve 16 is provided in each branch path 5A, and a flow meter 14 is provided in the convergence path 5B, and the fuel supply amount of the fuel injection valve 16 is controlled by a signal from the flow meter 14. In a fuel injection multi-cylinder engine, one end of each sub-intake passage 17 with a small cross-sectional area is opened on the wall surface of the intake passage near each combustion chamber so as to be directed into the combustion chamber, and the other ends are communicated with each other and the air flow rate is adjusted. An intake device for a fuel injection multi-cylinder engine which is connected to the upstream side of the flow meter 14 through an air valve 19 to open it to the atmosphere.