JPS58195018A - Internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent any reflux starting from a working chamber into a suction passage by ejecting a high speed stream during an interval from proximity of a time at which capacity of the working chamber in a suction stroke is maximum, to proximity of a time at which communication between the working chamber and the suction passage is shut off. CONSTITUTION:In a high load range, a pump throttle valve 12 and closing valve 16 are fully opened, while a pump passage 11 is opened by a suction cut-off valve 13 for a certain duration within an interval from proximity of the time when the capacity of a working chamber 3 in a suction stroke is maximum, namely, when a piston reaches a bottom dead center, to proximity of the time when communication between the working chamber 3 and the suction passage 6 is shut off, namely, when a suction valve 4 is closed. The suction air fed under pressure from a pump 10 is thus ejected at a high velocity from a nozzle 15.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internal combustion engine, and more specifically, from the vicinity of the time when the volume of the engine working chamber reaches its maximum during the intake stroke to the time when communication between the working chamber and the intake passage is cut off. In internal combustion engines, high-speed airflow is ejected from the pump for a certain period of time during the period of time, thereby preventing backflow from the engine working chamber to the intake passage and increasing volumetric efficiency, greatly reducing engine intake resistance loss. It relates to something that improves fuel efficiency.

In order to understand the present invention, first, the above-mentioned internal combustion engine designed to increase volumetric efficiency will be explained.

FIG. 1 shows an embodiment of an internal combustion engine according to the present invention, which is equipped with a pump 10 driven by an engine output shaft or the like.

The figure uses an electronically controlled fuel injection device as the fuel supply device, and a computer (not shown) that receives information detected by the air flow meter 8, engine speed, intake air temperature, etc. Fuel is supplied by controlling the opening time of the injection valve 9.

Reference numeral 7 indicates a throttle valve that throttles the intake air (by changing the density) to control the engine output, and 13 indicates an intake cutoff valve that is driven by decelerating the engine output shaft to, for example, 1/2 of the rotation.

Now, considering the high load range of the engine where throttle valve 7 is fully open,
Both the pump throttle valve 12 and the closing valve 16 are fully open or almost fully open, and the working chamber 3 (the space where intake air is sucked and compressed, fuel is combusted, and combustion gas is expanded and discharged) during the intake stroke. The intake cutoff valve is activated during the period from near the time when the volume reaches its maximum (bottom dead center position of the piston 1) to near the time when communication between the working chamber 3 and the intake passage 6 is cut off (when the intake valve 4 closes). 13 for a certain period of time pump passage 11
(the pump passage on the discharge side) is opened, and the intake air pressure-fed from the pump 10 is jetted out from the jetting part 15 at an extremely high speed (that is, the communication part 14 formed in the intake cutoff valve 13 is opened). When it communicates with the pump passage 11, compressed intake air is blown out from the spout part 15. - To make the drawing easier to understand, a cross section of the pump passage 11 near the intake cutoff valve 13 is drawn in Fig. 2. be).

This causes a backflow phenomenon in which the intake air that is once drawn into the working chamber 3 is pushed out to the intake passage 6 at the beginning of the compression stroke when the piston 1 rises (in the high load and low speed range where the flow velocity of the intake air flowing through the intake passage 6 is not large enough). (which is particularly likely to occur), thus increasing the volumetric efficiency of the engine.

That is, even if the closing timing of the intake valve 4 is set so as to obtain the maximum volumetric efficiency in the high-load, high-speed range of the engine, the volumetric efficiency in the high-load, low (medium) speed range of the engine will not be reduced.

The period during which compressed intake air is ejected from the ejection part 15 is a short period in terms of the engine output shaft angle, and therefore the pump 10
can be of small capacity, and strong turbulence is formed in the working chamber 3 by the high-speed airflow from the jetting part 15, making it possible to adopt a high compression ratio without causing knocking in the engine. The increase in torque and output due to pump 10
This considerably compensates for the loss in drive horsepower.

Here, the ejection part 15 is arranged at a position not far from the connection part between the working chamber 3 and the intake passage 6 (which corresponds to the intake valve seat part).

In the internal combustion engine described above, the fuel efficiency of the engine may deteriorate due to the drive horsepower loss of the pump 10 (due to the compression work of the intake air and the internal friction loss of the pump).

Therefore, if it is possible to reduce the intake resistance loss caused by controlling the engine output by throttling the intake air (by changing the density) in the low (medium) load range of the engine when the throttle valve 7 is sufficiently closed, the engine Since fuel efficiency is greatly improved in the low (medium) load range of Fuel efficiency improves (especially in the case of internal combustion engines for automobiles that frequently use low load ranges).

The present invention reduces the degree of throttling of intake air by the throttle valve, reduces intake resistance loss in the low (medium) load range of the engine, and even if the engine is used in the high load range, the engine as a whole This will improve the fuel efficiency of the engine, and will be explained below with reference to the drawings.

The auxiliary intake passage 18 that branches off from the intake passage 6 at the branching part 17 bypasses the closing valve 16 and communicates with the working chamber 3 of the engine.
The piston 1 is closed in the middle of the intake stroke (for example, at a point at which the engine output shaft angle is 80 degrees after the top dead center of the piston 1).

In the low (medium) load range of the engine, that is, at least in the low load range of the engine, the closing valve 16 is closed, and therefore, after the intake cutoff valve 13 closes the auxiliary intake passage 18, intake air is not drawn into the working chamber 3. .

Here, after the intake air cutoff valve 13 closes the auxiliary intake passage 18 during the intake stroke, no intake air is drawn into the working chamber 3, so from this point onwards the volume of the working chamber 3 reaches its maximum (the bottom dead center of the piston 1). Most of the negative work expended during the period up to (position) returns as positive work during the compression stroke when piston 1 rises again (piston 1 is pushed from the crank chamber side by atmospheric pressure), so most of it It is not a loss.

However, during the intake stroke, until the intake cutoff valve 13 closes the auxiliary intake passage 18, the intake air is drawn in while being throttled by the throttle valve 7, so intake resistance loss cannot be avoided. Since the intake of air into the working chamber 3 is cut off, the intake stroke is effectively short-term, and the intake stroke into the working chamber 3 is cut off.
When the same weight of intake air is taken in, the degree of throttling of the intake air by the throttle valve 7 may be small.

That is, the intake resistance loss in the low (medium) load range of the engine is significantly reduced, and thus, despite the drive horsepower loss of the pump 10, the fuel efficiency of the engine as a whole is improved.

Figure 3 shows a PV diagram (pressure-volume diagram) in the present invention.
It will be understood that the intake cutoff valve 13 closes the auxiliary intake passage 18 at the Vc point, thereby significantly reducing the intake resistance loss in the low (medium) load range of the engine.

In the low (medium) load range of the engine when the shutoff valve 16 is closed, the pump passage 11 (the pump passage on the suction side) is ) is closed (fully opened) by the pump throttle valve 12.
It goes without saying that you should do it.

Subsequently, when the throttle valve 7 is further opened to increase the load on the engine, the closing valve 16 begins to open and intake air is taken in throughout the entire intake stroke.

(In this case, the pump throttle valve 12 starts opening after the closing valve 16 starts opening.) In other words, it is the same as before.

The closing valve 16 is kept closed in the low (medium) load range of the engine, but in order to open and close it, it is desirable to mechanically link it with the throttle valve 7 (pump throttle valve 12 The same is true).

Note that if the ejection part 15 is unidirectional, it may not be possible to prevent the intake air from flowing back from the working chamber 3 over the entire circumference of the intake valve seat.

This is because there are parts where the high-speed airflow from the jetting part 15 does not flow sufficiently.As a countermeasure, as shown in Fig. 4, the wall surface near the intake valve seat is raised by an amount corresponding to the angle α, and the intake valve 4 is completely closed. In order to minimize the leakage cross-sectional area of this part at a slightly earlier stage, or to eject compressed intake air also to the part corresponding to angle α, compressed intake air is ejected in two directions as shown in Fig. 5. What is necessary is to provide a spouting part 15' that does this.

The embodiment shown in FIG. 6 has a throttle valve 7 disposed in the sub-intake passage 18 (the pump, pump passage, pump throttle valve, etc. are omitted).

In this case, it is preferable that the closing valve 16 is mechanically interlocked with the throttle valve 7, and since the intake passage 6 is not provided with a throttle valve, the closing valve 16 serves as a substitute for this valve.

Next, as a method of controlling the intake flow rate sucked into the pump 10 (the intake flow rate discharged by the pump 10), in addition to opening and closing the pump throttle valve 12 provided in the pump passage 11 (suction side), As shown in the figure, there is a method in which a pump throttle valve 12 is provided in the pump passage 11 (discharge side) and the valve is opened and closed.

That is, in the low (medium) load range of the engine when the shutoff valve (not shown) is closed, the pump throttle valve 12 is closed (fully opened), and the pump circulation valve 21 provided in the pump circulation passage 20 is closed.
This is done in such a way that it is fully opened.

As a result, the intake flow rate (discharge intake flow rate) of the pump 10 becomes 0, and the drive horsepower loss of the pump 10 also becomes almost 0.

In this case, the pump throttle valve 12 starts to open after the shutoff valve (both not shown) mechanically interlocked with the throttle valve starts to open, and the pump throttle valve 12 starts to open until the pump circulation valve 21 reaches the specified opening. After opening, it is preferable to quickly close it from the fully open state.

The pump circulation valve 21 includes a diaphragm device 22 that operates by sensing negative pressure downstream of a throttle valve (not shown), for example.
It is made to open and close by.

In FIG. 7, since the pressure in the pump passage 11 on the discharge side is atmospheric pressure or positive pressure, this can be guided to the downstream side of the throttle valve to promote atomization of the fuel.

This is shown in Figures 8 and 9.

First, in FIG. 8, 23 is a nozzle from which the intake air guided from the pump passage 11 (discharge side) in FIG. It appears to be atomized.

In this case, in an internal combustion engine having four working chambers, if two fuel injection valves 9 are provided as shown in the figure, fuel can be evenly distributed to each working chamber (normally, four fuel injection valves 9 are required). ).

Next, FIG. 9 shows an embodiment in which a carburetor is also used as the fuel supply device, and by jetting the intake air led from the pump passage 11 (discharge side) in FIG. 7 at a high speed from the nozzle 23, This is an attempt to re-atomize the liquid fuel adhering to the wall directly below the carburetor.

When the intake air is ejected from the nozzle 23 at a high velocity, it is first reduced to the ambient pressure, and then the pressure becomes lower than the ambient pressure due to its own velocity energy, and the fuel nozzle 24
It is possible to suck up fuel from the air and atomize it.

26 is the mound from which the fuel from the float chamber of the carburetor is spouted;
The engine's required mixture ratio is appropriate.

Incidentally, if the pump passage 11 (suction side) is connected between the throttle valve 7 and the ventori part 25 as shown by the two-dot chain line, the mound 26 can be omitted.

Since the present invention is configured as described above, it is possible to significantly reduce the intake resistance loss in the low (medium) load range of the engine, and even though the fuel consumption deteriorates in the high load range due to the drive horsepower loss of the pump. Overall, the fuel efficiency of the engine is improved.

Note that the present invention is similarly applicable to rotary piston engines.

[Brief explanation of the drawing]

Figures 1 and 6 are cross-sectional views of the internal combustion engine according to the present invention, Figure 2 is a cross-sectional view of the pump passage near the intake shutoff valve, and Figure 3 is the P-V
Figures 4, 5 and 8 are diagrams (schematically drawn plan views) of the internal combustion engine according to the invention, Figure 7 is a sectional view of the pump, Figure 9 is
The figure is a cross-sectional view of the carburetor, 1 is the piston, 2 is the cylinder,
3 is a working chamber, 4 is an intake valve, 5 is an exhaust valve, 6 is an intake passage,
7 is a throttle valve, 8 is an air flow meter, 9 is a fuel injection valve,
10 is a pump, 11 is a pump passage, 12 is a pump throttle valve,
13 is an intake cutoff valve, 14 is a communication part, 15 and 15' are jet parts, 16 is a closing valve, 17 is a branch part, 18 is a sub-intake passage,
19 is a closing part, 20 is a pump circulation passage, 21 is a pump circulation valve, 22 is a diaphragm device, 23 is a nozzle, 24 is a fuel nozzle, 25 is a venturi part, and 26 is a burial mound. Patent applicant Osamu Kitamura■

Claims (1)

[Claims] (1) Equipped with an intake passage that has a connection to the working chamber of the engine, and a jetting part formed at a position not too far upstream from this connection, and which throttles the intake air taken into the engine and outputs it. It is an internal combustion engine that controls the pump for a certain period of time from around the time when the volume of the working chamber of the engine reaches its maximum during the intake stroke to around the time when communication between this working chamber and the intake passage is cut off. In an internal combustion engine, the intake air is forced to be ejected from the ejection portion via an intake cutoff valve, and the intake passage is provided with a closing valve at a predetermined position, and the closing valve is closed at least in a low load region of the engine. Further, this closing valve is bypassed and the auxiliary intake passage leading to the working chamber is closed in the middle of the intake stroke by the intake shutoff valve, and when the closing valve is closed, the intake is shut off. An internal combustion engine characterized in that after the sub-intake passage of the valve is closed, intake air from the pump is not drawn into the working chamber.