JPS5844218A - Internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve fuel consumption of an engine, by providing an intake air shut off valve closing a sub-intake passage, forcibly feeding intake air with a pump, jetting the intake air for a certain period through said intake air shut off valve and scavenging residual gas in a working chamber. CONSTITUTION:A closing valve 23 is provided in a prescribed position of an intake passage 8, communicated to a working chamber 4 of an internal-combustion engine, and intake air is throttled to control an output. While an intake air shut off valve 18, closing a sub-intake passage 17, is provided. At about a conversion point transferred from an exhaust stroke to an intake stroke, intake air, forciby fed by a pump 14, is jetted through the intake air shut off valve 18 to scavenge residual gas in the working chamber 4. In this way, fuel consumption of the engine can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internal combustion engine in which intake air is interrupted in the middle of the intake stroke in a low engine load range, and the degree of intake throttling is reduced to reduce intake resistance loss. The purpose is to improve the fuel efficiency of the engine.

In general, as a means to improve (improve) the fuel efficiency of an engine,
In addition to scavenging the residual gas in the working chamber of the engine, it also provides appropriate flow (vortex, swirling flow, turbulence, etc.) to the intake air taken into the engine, and furthermore, it scavenges the fuel supplied by a fuel supply device such as a carburetor. It is said that it is effective to promote the atomization of the particles.

In other words, in the low load range of the engine, the ratio of residual gas to fresh air is large, which makes combustion unstable, and the mixture ratio required by the engine needs to be much richer than the stoichiometric mixture ratio, which reduces fuel efficiency. becomes worse.

Therefore, it is clear that if the residual gas is sufficiently scavenged, fuel efficiency will be improved.

Also, if an appropriate flow is given to the intake air taken into the engine, vaporization of the fuel will be promoted and a high-quality air-fuel mixture will be formed.In particular, if a strong flow is given so that it remains even during the compression process of the engine, This scavenges air near the ignition plug, improving ignitability, increasing the flame propagation speed after the engine goes out, and improving fuel efficiency.

It goes without saying that promoting atomization of fuel supplied from a fuel supply device such as a carburetor is effective in improving fuel efficiency.

The present invention aims to achieve the above objects No. 6 This will be explained below with reference to the drawings.

FIG. 1 shows an embodiment of an internal combustion engine according to the present invention, which is equipped with a throttle valve 10 that controls the output by throttling intake air taken into the engine, and which is driven by the engine's output shaft, camshaft, and electric motor. A pump 14 is provided.

In order to understand the present invention, first, a mechanism for reducing intake resistance loss by interrupting intake air in the middle of the intake stroke in a low load range of the engine and reducing the degree of intake throttling of the engine will be explained.

The intake valve 5 is driven by a cam and is no different from a normal one (for example, it opens at 20 degrees before the top dead center of the piston 2 and closes at 50 degrees after the bottom dead center), but the intake valve 18 (in the figure, the engine The rotary valve (which uses a rotary valve that is driven at a speed of 1/4 of the rotation of the output shaft) is designed to close in the middle of the engine's intake stroke.

That is, the intake cutoff valve 18 closes the auxiliary intake passage 17 branched from the intake passage 8 at the branch portion 16 in the middle of the intake stroke (for example, at an output shaft angle of 70° after top dead center).

No. 7 In this case, the intake cutoff valve 18 may be opened at the same time as the intake valve 5, or may be opened earlier than the intake valve 5.

Adopting the latter case (for example, opening at 90 degrees before top dead center) has the advantage that the closing portion 19 of the intake cutoff valve 18 can be made smaller and the communication passage 20 can be made larger, as shown in FIG.

Now, considering a low load region of the engine where the throttle valve 10 of the carburetor 9 is fully closed, when the intake valve 5 opens and the intake shutoff valve 18 also opens and the intake stroke begins, intake air flows from the auxiliary intake passage 17 into the working chamber. 4
(the space formed by the cylinder head 1, piston 2, and cylinder 3), and in the middle of the intake stroke (for example, at an output shaft angle of 70° after top dead center), the intake cutoff valve 18 closes (the closing part 19 closes the sub-intake passage 17),
Inhalation of intake air is blocked (since the closing valve 23 is closed in the low load range, even if the intake valve 5 opens, no intake air is drawn therefrom).

Subsequently, the piston 2 descends to reach the bottom dead center, rises again, and enters the compression stroke, and the air-fuel mixture confined in the working chamber 4 is ignited by the ignition plug 7 and combusted.

Here, during the period from the time when the intake shutoff valve 18 closes (the piston position at that time) to the bottom dead center of the piston 2, no intake air is drawn into the working chamber 4 (the expansion of the intake air inside the working chamber 4). However, when the piston 2 rises from bottom dead center and returns to the point at which the intake shutoff valve 18 closed in the previous intake stroke (the piston position at that time), the piston 2 is moved by the atmosphere (from the crank chamber side). On the contrary, it is pushed back by that amount, so there is no intake resistance loss. are equal).

However, during the intake stroke until the intake cutoff valve 18 closes, the intake air is throttled by the throttle valve 10 and sucked into the working chamber 4, so intake resistance loss cannot be avoided, but the intake is cut off in the middle of the intake stroke. Since the valve 18 is closed, when the same intake air weight is taken in, the degree of throttling of the intake air by the throttle valve 10 may be small.

In this way, the intake stroke of the period is actually short (it is terminated midway through), and the degree of intake throttling by the throttle valve is small, so it is possible to significantly reduce intake resistance loss (this is due to fuel efficiency). (leading to improvement).

Note that the branch portion 16 may be set directly below the throttle valve 10, and the sub-intake passage 17 may be connected to a dedicated carburetor (of course, in either case, the sub-intake passage 17
(bypasses the closing valve 23 and communicates with the working chamber 4).

Next, when the throttle valve 10 is further opened to increase the load on the engine, the closing valve 23 begins to open, and intake air is also drawn into the working chamber 4 from the intake passage 8, and intake air is drawn throughout the entire intake stroke. It will be like that.

At this time, the throttle valve 10 is sufficiently open, so the intake resistance loss is small.

In other words, it remains the same as before.

In this case, the closure 23 is opened and closed mechanically by the throttle valve 10, or by a diaphragm device (not shown) activated by sensing negative pressure downstream of the throttle valve 10.

In the former case, after the throttle valve 10 opens to a predetermined opening degree, the N
o10 It is better to have the closing valve 23 start opening together with this (
full opening is done at the same time).

Further, the closing valve 23 may be a plate-shaped valve 24 that can be raised and lowered as shown by the two-dot chain line (a cylindrical valve is also conceivable).

Further, the auxiliary intake passage 17 may branch from the intake passage 8 at the branching portion 16 in the vertical direction as shown in the figure, or in the horizontal direction as shown in FIG.

In FIG. 3, reference numeral 26 denotes a sub-closing valve that allows all the fuel flowing through the intake passage 8 to flow into the sub-intake passage 17 when the closing valve 28 is closed, and is opened and closed at the same time as the closing valve 23 (sub-closing valve 26). If the stop valve 26 is installed, the stop valve 23 can be removed, but in this case the auxiliary stop valve 26 will be used in its place).

It is also conceivable that the closing valve 23 may be replaced by a secondary throttle valve 28 of a two-stage carburetor as shown in FIG.

That is, the intake passage 8 is connected to the secondary throttle valve 28, the auxiliary intake passage 17 is connected to the primary throttle valve 27, and the secondary throttle valve 2
No. 8 closes the intake passage 8 in the low load range of the engine, and the auxiliary intake passage 17 bypasses the secondary throttle valve 28 (that is, No. 11, ie, the closing valve) and communicates with the working chamber 4. .

The feature of the present invention is that, in an internal combustion engine in which intake resistance loss is reduced as described above, residual gas in the working chamber 4 is scavenged by a high-speed airflow of intake air pumped from the pump 14 (again, as shown in FIG. 1). explain).

That is, in the exhaust stroke of the engine, when most of the combustion gas is discharged from the exhaust valve 6 and the transition point (top dead center position of the piston 2) where the exhaust stroke changes to the intake stroke is near, the intake cutoff valve 18 Pump discharge side passage 1 that was closed
5 is opened (the communication passage 22 formed in the intake cutoff valve 18 communicates with the pump discharge side passage 15), and the intake air (air in this case) that is pressure-fed from the pump 14 passes through the intake cutoff valve 18.
(via the communication path 22), the liquid is violently ejected from the nozzle 21 into the working chamber 4 for a certain period of time.

As a result, the residual gas in the working chamber 4 can be sufficiently scavenged (at the same time, the backflow of the residual gas to the intake passage 8 is also prevented), so even a thin air-fuel mixture can be stably combusted, improving fuel efficiency.

In this case, a plurality of nozzles 21 may be formed to evenly scavenge the working chamber 4, and the jetting of intake air from the nozzle 21 may start slightly earlier than when the intake valve 5 opens.

Furthermore, since the injection of intake air from the nozzle port 21 does not make much sense after the exhaust valve 6 is closed, it is assumed that the intake air is ejected until close to the time when the exhaust valve 6 closes.

Note that in the (medium) high load region of the engine, the ratio of residual gas to fresh air is small, so the injection of intake air from the nozzle 21 may be stopped.

Next, it is often better to finely control the flow rate of the intake air sucked into the pump 14 (the discharge flow rate of the pump 14 ejected from the nozzle 21) in accordance with the intake air flow rate of the engine.

Possible methods for controlling the discharge flow rate of the pump 14 include installing a small throttle valve 12 mechanically interlocked with the throttle valve 10 in the air passage 11, or installing an air jet 13 as shown by the two-dot chain line. .

Also, as shown by the two-dot chain line, when the throttle valve 10 is at its minimum opening, the pump 14 draws in air only from the first intake hole a, and as the throttle valve No. 13 opens, air is also drawn from the second intake hole b. It is possible to do so.

The crank chamber has a sealed structure similar to a two-stroke engine, and the intake air is passed through an appropriate check valve to the intake cutoff valve 18.
(Communication path 22), this crank chamber can be used as a substitute for the pump 14.

FIG. 5 shows an attempt to create a strong flow of intake air (vortex, swirling flow, turbulence, etc.) using a high-speed airflow of intake air that is force-fed from a pump.

That is, in FIG. 5, combustion gas in the working chamber of the engine is exhausted during the exhaust stroke, and when the exhaust valve (not shown) is about to close (at this time, the intake valve 5 and the intake cutoff valve 1 are closed).
8 is already open), and the pump discharge side passage 15, which had been closed until now by the intake cutoff valve 18, is opened (the communication passage 2
9 communicates with each other), and intake air pressure-fed from a pump (not shown) passes through the intake cutoff valve 18 (via the communication path 29).
It is violently ejected from the nozzle 21 into the working chamber.

At this time, since the direction of the nozzle 21 is set to be eccentric with respect to the central axis of the cylinder, a strong flow of intake air (for example, a vortex) is formed in the working chamber by No. 14 (sub-intake passage). 17 and set accordingly to help create a flow of intake air).

In addition, the direction of the nozzle 21 is not directed directly toward the working chamber, and the direction of the intake passage 8 is
Even if it is set eccentric to the central axis (near the intake valve 5), a strong flow of intake air (for example, a vortex) is formed here, which flows into the working chamber and creates a new flow of intake air. to occur.

The flow of intake air formed in this way remains during the compression process, scavenging the vicinity of the ignition plug (not shown), improving ignitability, and increasing the flame propagation speed after ignition. Fuel efficiency will improve.

In the low load range when the shutoff valve 23 is closed, the intake cutoff valve 1
If intake air is newly drawn into the working chamber after 8 is closed, the intake resistance loss will not be reduced, so the injection of intake air from the nozzle 21 will end by the time the intake cutoff valve 18 closes (the auxiliary intake passage 17). It shall be.

In addition, if a stronger flow of intake air is required in the high load range (medium) where the shutoff valve 23 is open, a new pump discharge side passage 30 is installed as shown by the two-dot chain line, and the air is fed under pressure from the pump No. 15. It is preferable to eject the intake air from the nozzle 21 through the intake cutoff valve 18 (via another communication path 31) (for example, if the communication path 31 is etc.).

When the closing valve 23 is closed (fully closed), the solenoid valve 3
Needless to say, the pump discharge side passage 30 should be closed by the second valve or the like.

The present invention shown in FIG. 6 scavenges the residual gas in the working chamber and creates a strong flow of intake air.

That is, the communication passage 22 communicates with the pump discharge side passage 15 near the conversion point (top dead center position of the piston) where the exhaust stroke changes to the intake stroke, and the intake air that is pressure-fed from the pump is passed through the intake cutoff valve 18. is ejected from the nozzle 21 for a certain period of time to scavenge residual gas in the working chamber, and another communication passage 34 (not communicating with the communication passage 22) formed in the intake cutoff valve 18 is connected to the pump discharge side passage 33. When communicated, the intake air forced from the pump is ejected from the nozzle 21 into the working chamber via the intake cutoff valve 18, forming a strong flow of intake air.

This further improves the fuel efficiency of the engine.

The intake air may start blowing out from the nozzle 21 a little earlier than when the intake valve 5 opens, and the intake air may start blowing out from the nozzle 21 by the time when the intake cutoff valve 18 (sub-intake passage 17) closes. shall be terminated.

Note that the intake air that has passed through the pump discharge side passage 33 is blown out from the nozzle 21, but an independent nozzle is newly installed.
It may be made to eject from there.

Only by the communication path 22 (by removing the communication path 34), the sixth
FIG. 7 shows an embodiment that performs the same function as that shown in the figure.

That is, in FIG. 7, when the communication passage 22 communicates with the pump discharge side passage 35 near the transition point where the exhaust stroke changes to the intake stroke, intake air is ejected from the nozzle 21 via the intake cutoff valve 18 and the remaining air in the working chamber is In addition to scavenging gas, the communication passage 22
When the nozzle 2 comes to communicate with the pump discharge side passage 36,
The intake air blows out again from 1, forming a strong flow of intake air.

No. 17 In addition, if the communication path 34 is opened just before the communication path 22 formed in the intake cutoff valve 18 finishes closing in FIG. 6 (if the partition wall 37 is removed in FIG. (There is no longer a short period during which intake air stops blowing out.) This high-speed airflow scavenges the residual gas in the working chamber and creates a strong flow of intake air. .

In the present invention shown in FIG. 8, the atomization of the fuel is also promoted by the high-speed airflow of the intake air that is force-fed from the pump.

That is, in FIGS. 1 and 8, 38 is a nozzle from which the intake air fed under pressure from the pump 14 is ejected, and the liquid fuel adhering to the inner wall of the intake passage 8 leading from the carburetor 9 to the working chamber 4 is sucked by the fuel nozzle 39. (Due to the weight and inertia of the fuel particles, the fuel ejected from the carburetor 9 adheres particularly to the bottom 8' of the bend in the intake passage.) (often converted into liquid fuel).

The pressure of the intake air fed from the pump 14 is positive and No.
18 However, when the intake air is ejected from the nozzle 38 at high speed, it is first reduced to the ambient pressure, and then due to its own velocity energy, the pressure becomes lower than the ambient pressure, and the liquid fuel adhering to the inner wall of the intake passage. can be sucked up from the fuel nozzle 39 and atomized.

In order to further promote atomization of the fuel, a spiral groove may be formed in the fuel nozzle 39 or the nozzle 38 so that the fuel or intake air is ejected in a spiral motion.

If the fuel supply device is a fuel injection device, the pump 14
The high-speed airflow of intake air that is force-fed from the fuel injection valve (not shown) collides with the fuel injected by the fuel injection valve (not shown) to atomize the fuel.

As described above, according to the present invention shown in FIGS. 1 and 8, the fuel is atomized extremely well, so that vaporization is promoted and complete combustion is possible, thereby significantly improving (improving) fuel efficiency.

In Figs. 1 and 8, in order to further promote atomization of the fuel when starting the engine, the intake air fed under pressure from the pump 14 may be ejected only from the nozzle 38, or when the engine is warmed up. In a low load range where the rear throttle valve 10 is fully closed, the fuel flow rate is small and vaporization is active, so the intake air from the pump 14 may be ejected only from the injection port 21.

Also in FIGS. 5 to 7, the fuel supplied from the fuel supply device can be atomized in the same way.

In Fig. 8, the fuel sucked up from the fuel nozzle 39 and atomized by the high-speed airflow collides with the inner wall of the intake passage and adheres thereto, and may liquefy again. It is also effective to provide two sets of the nozzle 39 and nozzle 38 and install them so as to face each other.

That is, the atomized fuel particles ejected from the fuel nozzle 39 collide and mix with each other, and become carried by the air current.

This creates a homogeneous air-fuel mixture, further improving fuel efficiency.

In addition, in Fig. 1, an intake cutoff valve 1 is installed in the cylinder head 1.
8. If it is difficult to form or incorporate the shutoff valve 23, etc., cut the cylinder head 1 at the cut surface 25 as shown by the two-dot chain line.
As shown in FIG. 10, this divided part is made into a block 40 in which the intake cutoff valve 18, the closing valve 23, etc. are integrally formed and assembled in advance, and this block 40 is attached to the cylinder head 1 with bolts etc. It is best to assemble it with

As described above, the present invention includes a closing valve at a predetermined position in the intake passage leading to the working chamber of an internal combustion engine that throttles the intake air to control the output, and this closing valve is kept closed in the low load range of the engine. Further, the auxiliary intake passage that bypasses the closing valve and opens to a predetermined position of the intake passage upstream of the intake valve is provided with an intake cutoff valve that closes the auxiliary intake passage in the middle of the intake stroke. In an internal combustion engine, (1) the engine operates by blowing out the intake air, which is pumped under pressure by the pump, through an intake cutoff valve for a certain period of time from the vicinity of the transition point where the exhaust stroke changes to the intake stroke until the time when the exhaust valve closes; Scavenge the residual gas in the chamber, or (2) blow out the intake air that is pumped for a certain period of time from around the time when the exhaust valve closes through the intake cutoff valve, thereby creating a flow of intake air. as well as
In addition, when the shutoff valve is closed, the intake air pumped by the pump is not newly sucked into the working chamber after the intake shutoff valve is closed, and (3) the conversion point at which the exhaust stroke changes to the intake stroke is prevented. The intake air that is force-fed by the pump in the vicinity of the pump is ejected through the intake cut-off valve to scavenge residual gas in the working chamber, and even after the exhaust valve is closed, the intake air that is force-fed from the pump is passed through the intake cut-off valve for a certain period of time. A flow of the intake air is formed by blowing it out through the pump, and when the closing valve is closed, the intake air pressured by the pump is not newly sucked into the working chamber after the intake shutoff valve is closed. , (4) Furthermore, to each of (1) to (3), an action is added to atomize the fuel supplied by the fuel supply device by causing the high-speed airflow of the intake air pumped from the pump to collide with the fuel supplied by the fuel supply device. Therefore, the fuel efficiency of the engine can be significantly improved.

[Brief explanation of the drawing]

Figures 1, 2, 5, 6 to 10 are internal combustion engine No. 2 according to the present invention.
2. Cross-sectional views of the engine or its related devices, FIGS. 3 and 4 are diagrams of an internal combustion engine according to the present invention. 1 is a cylinder head, 2 is a piston, 3 is a cylinder, 4 is a working chamber, 5 is an intake valve, 6 is an exhaust valve, 7 is a spark plug,
8 is an intake passage, 9 is a carburetor, 10 is a throttle valve, 11 is an air passage, 12 is a small throttle valve, 13 is an air jet, 14 is a pump, 15, 30, 33, 35, 36 are pump discharge side passages,
16 is a branch part, 17 is a sub-intake passage, 18 is an intake cutoff valve,
19 is a closing part, 20, 22, 29, 31, and 34 are communicating passages, 21 is a spout, 23 and 24 are closing valves, 25 is a cutting surface, 2
6 is a sub-closing valve, 27 is a primary throttle valve, 28 is a secondary throttle valve,
32 is a solenoid valve, 37 is a partition, 38 is a nozzle, 39 is a fuel nozzle, 40 is a block, a is a first intake hole, b is a second intake hole, and 8' is the bottom of the bent part of the intake passage. Patent applicant Shuichi Kitamura

Claims (6)

[Claims] (1) A closing valve is provided at a predetermined position in the intake passage leading to the working chamber of the internal combustion engine, which controls the output by throttling the intake air taken into the engine, and this closing valve is kept closed during low load areas of the engine. Further, the auxiliary intake passage that bypasses the closing valve and opens to a predetermined position of the intake passage upstream of the intake valve is provided with an intake cutoff valve that closes the auxiliary intake passage in the middle of the intake stroke. In an internal combustion engine, the intake air that is pressure-fed by the pump for a certain period of time from the vicinity of the transition point where the exhaust stroke changes to the intake stroke until the time when the exhaust valve closes is blown out through the intake cutoff valve, and is then blown out into the working chamber. An internal combustion engine characterized by exhausting residual gas. (2) A closing valve is provided at a predetermined position in the intake passage leading to the working chamber of the internal combustion engine, which controls the output by throttling the intake air taken into the engine, and this closing valve is kept closed during low load areas of the engine. Further, an intake cutoff valve is provided in the sub-intake passage which bypasses the closing valve No. 2 and opens to a predetermined position of the intake passage upstream of the intake valve, which closes the sub-intake passage in the middle of the intake stroke. In an internal combustion engine,
The intake air that is force-fed by the pump for a certain period of time near the time when the exhaust valve closes is blown out through the intake cutoff valve, thereby forming a flow of intake air, and when the closing valve is closed, the intake air is cut off. An internal combustion engine characterized by a structure in which, after the valve is closed, the intake air pumped by the pump is not newly drawn into the working chamber. (3) A closing valve is provided at a predetermined position in the intake passage leading to the working chamber of the internal combustion engine, which controls the output by throttling the intake air drawn into the engine, and this closing valve is kept closed during low load areas of the engine. Further, the auxiliary intake passage that bypasses the closing valve and opens to a predetermined position of the intake passage upstream of the intake valve is provided with an intake cutoff valve that closes the auxiliary intake passage in the middle of the intake stroke. In an internal combustion engine, in the vicinity of the conversion point where the exhaust stroke changes to the intake stroke, the intake air that is force-fed from the pump is jetted out through the intake cutoff valve to scavenge the No. 3 residual gas in the working chamber, and the exhaust valve is closed. After that, a flow of intake air is formed by blowing out the intake air that is force-fed from the pump through the intake air cutoff valve for a certain period of time,
An internal combustion engine characterized in that, when the shutoff valve is closed, intake air that is force-fed by the pump is not newly sucked into the working chamber after the intake shutoff valve is closed. (4) Claim 3 states that the intake air pumped by the pump is continuously blown out from the vicinity of the transition point where the exhaust stroke changes to the intake stroke until a certain period of time after the exhaust valve is closed. internal combustion engine. (5) A patent claim in which the jetting of intake air pumped by the pump is temporarily stopped from the vicinity of the transition point where the exhaust stroke changes to the intake stroke until a certain period of time after the exhaust valve is closed. Internal combustion engine according to range 3. (6) A closing valve is provided at a predetermined position in the intake passage leading to the working chamber of the internal combustion engine, which controls the output by throttling the intake air taken into the engine, and this closing valve is kept closed during the low load range of the engine. Further, the sub-intake passage, which bypasses the closing valve and opens to a predetermined position in the intake passage upstream of the intake valve, is provided with an intake cutoff valve that closes the sub-intake passage in the middle of the intake stroke. In an internal combustion engine, the intake air that is pressure-fed by the pump for a certain period of time from the vicinity of the transition point where the exhaust stroke changes to the intake stroke until the time when the exhaust valve closes is blown out through the intake cutoff valve to reduce the amount of air remaining in the working chamber. An internal combustion engine characterized in that gas is exhausted, and furthermore, a high-speed airflow of intake air pressure-fed from the pump collides with fuel supplied by a fuel supply device to slightly sulfurize the fuel.