JPH0480213B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for obtaining mechanical work from combustion gases in an internal combustion engine by a novel thermodynamic work cycle, and to a reciprocating internal combustion engine implementing this method.

As the expansion ratio of the internal combustion engine increases,
It is well known that greater amounts of energy can be extracted from the firing gases, increasing thermodynamic efficiency. Additionally, it has been found that increased compression results in increased power and fuel savings due to thermodynamic improvements. The goal for an efficient engine is to have a high compression ratio, start combustion at maximum compression, and then push the piston as far as possible to expand the gas.

Conventional engines have the same compression and expansion ratios, the former being limited by the octane rating of the fuel.
Furthermore, in these engines the exploded gas is only allowed to expand to its original volume before compression, so when the exhaust valve opens, it usually pushes the piston 4.92−
There is a pressure of 7.03 Kg/cm ³ resulting in energy loss.

Many attempts have been made to lengthen the expansion process to increase thermodynamic efficiency in internal combustion engines. An early design is described in U.S. Pat. No. 125,166, in which the engine expands the combustion gases to their original pressure before compression, but maintains maximum compression while pumping the charge. They lacked the means to transport and ignite it. In addition, the Atkinson cycle engine was considered to extend the expansion process, but
The mechanical complexity of this engine limited it to a single cylinder configuration.

A recent notable effort was disclosed in the Wishart institution described in US Pat. No. 3,408,811. In this engine, a large piston compresses the charge into a smaller cylinder that further compresses the charge, and then the charge is transferred into another small "combustion" cylinder, where the charge is further compressed. The charge was ignited and expanded to the full capacity of the smaller cylinder. The combusted gases were then transferred through a hole unobstructed by the piston into a larger cylinder where they were further expanded. This requires four cylinders with pistons performing two working strokes for each power stroke, thus making it an eight-stroke engine, with the mechanical and fluid friction inherent in such working strokes. The engine is also expensive to build due to its mechanical complexity.

Another attempt, shown in U.S. Pat. No. 4,174,683, involves keeping the inlet valve of the engine's working cylinder open for part of the compression stroke and then closing the valve to compress only a portion of the total charge. , which is then ignited to push the piston and expand the cylinder to its full volume. This process is extremely complex and requires a means of varying the position of the crankshaft axis and also varying the timing of the intake valve in response to load demands. moreover,
There is no means to increase compression or increase turbulence of the charge. Therefore, the four-stroke engine continues to operate with the inherent friction. Moreover, the full load operation of this engine is the same as for conventional engines;
Its improved properties are demonstrated only under partial load.

Other attempts have been made to extract more shaft work from the combustion gases using a similar method of introducing the firing gases into other cylinders after ignition to increase expansion, but the results seem to be the same. . Attempts have also been made to burn the charge in the inner half of the cylinders of a multi-cylinder engine and then direct exhaust from the ignition cylinder into the remaining half of the cylinders to extract additional shaft work. None of these attempts to date have been successful, and emissions are generally increased over conventional engines.

Rotary engines strive for the same advantages;
As an example, in the Wankel engine shown in U.S. Pat. No. 3,688,749, the charge is compressed in one chamber of a four-leaf rotor, ignited and expanded in the first chamber. It then enters a chamber on the downstream side through a duct and expands. The problem in this case is that the second expansion chamber is already half full with recompressed gas from the previous ignition;
This is due to large throttling losses during the transfer of the charge.

A reciprocating internal combustion engine according to the invention comprises a compression chamber in which an air charge is compressed, a power chamber in which combustion gases are ignited and expanded; a transfer manifold that communicates the compression chamber with the power chamber and transfers the compressed charge into the power chamber; an inlet valve to control the admission of air into the chamber for compression; an outlet valve to control the admission of the compressed charge from the compression chamber to the transfer manifold; and an outlet valve to control the admission of compressed charge from the compression chamber to the transfer manifold. an intake valve that controls entry into the chamber;
and exhaust valves for controlling the discharge of exhaust gas from the power chamber, these valves having a charge pressure such that the air charge is sustained within the transfer manifold and ignition is initiated at substantially maximum compression. a device timed to operate such that the fuel is introduced into the power room without an appreciable drop in the fuel, and further for mixing the fuel with an air charge to produce a combustible gas;
It is equipped with a combustible gas ignition device, a compression chamber,
The combustion chamber of the power chamber is sized relative to the exhaust capacity of the power chamber so that the exploded combustion gases can expand substantially beyond their original volume before compression.

The main advantages of the present invention over existing internal combustion engines are: For spark ignition engines, the compression ratio can be increased without the problem of abnormal combustion explosions;
For both spark-ignition and pressure-ignition engines, the expansion ratios are very high and there is very significant turbulence of the charge in the combustion chambers of both engines.

In the internal combustion engine according to the invention, the high compression ratio, the long expansion stroke and the increased charge turbulence increase the thermal efficiency at all loads and at the same time also provide a clean exhaust gas. These characteristics are enhanced by the extra power stroke that occurs per crankshaft revolution (as described below, the 4-cylinder and 8-cylinder
50 percent more for cylinder configurations and 33 percent more for three- and six-cylinder configurations), so operating at higher compression ratios means that even though the charge weight is reduced, the Almost the same power to weight ratio is guaranteed. Experimental data indicates that variations in compression ratio do not appreciably change the mechanical or volumetric efficiency of the engine. Therefore, the increase in thermal efficiency resulting from an increase in compression ratio is
Manifested by a corresponding increase in torque or mean effective pressure (mep), this power increase is an additional gain on top of the actual efficiency increase.

Next, embodiments of the present invention will be described with reference to the drawings.

The four-cylinder reciprocating internal combustion engine shown in FIG.
It is gasoline, diesel, gas, or mixed dual fuel, and has four cylinders 2 to 5, in which pistons 6 to 9 are arranged to reciprocate, respectively. The pistons 6-9 are connected to a common crankshaft 10 by means of connecting rods 11-14, respectively, as is conventional. Engine 1
is operated in a two-stroke cycle to produce three power strokes per revolution of crankshaft 10. For this purpose, one cylinder 5 constitutes a compression chamber and acts as a compressor, so that during operation of the engine the cylinder 5 is pre-pressurized to a high pressure with an air charge at atmospheric pressure or instead. The charged air charge is sucked in via the suction pipe 15 through the inlet control valve a.
During engine operation, the air charge is compressed inside the compression cylinder 5 by the associated piston 9, and the compressed charge is transferred from the outlet valve b to the high-pressure transfer manifold 16.
being pushed inside. The manifold 16 transfers the compressed charge to the three remaining (expansion) cylinders 2, 3,
It is made and arranged to be distributed into 4 parts. These cylinders 2 to 4 function as a power chamber and generate power for the engine.

The volume of each expansion cylinder 2, 3 and 4 combustion chamber is preferably only one-third as large as that of a conventional engine with the same compression ratio.
This is because the total volume of each combustion chamber should then not exceed the volume of the charge compressed by the compression piston, so that no expansion of the gas occurs before combustion occurs.

The engine 1 has a camshaft 20 which is driven at the same speed as the crankshaft so as to provide one working stroke per revolution to both the power piston and the compression piston, as will be explained below. It's summery.

The engine is operated as follows.

The intake valve i of each power cylinder is timed so that the charge begins to enter at approximately 40 degrees before top dead center (BTDC) (see Figure 5), and the exhaust valve is closed at approximately the same crank angle. The time will be adjusted. The compressed air charge in the transfer manifold 16 enters the combustion chamber of the cylinder to be ignited without an appreciable pressure drop and at high speed, while fuel may be simultaneously injected. In spark ignition engines, fuel can be injected after closing the intake valve. At about 10 degrees before top dead center, the intake valve closes and the fuel is ignited by a spark plug or automatic ignition. The charge is thus ignited at the point of maximum compression and the gas expands pushing the working cylinder beyond its original volume before compression.

When the intake valve opens about 40 degrees before top dead center, the piston has completed about 90.5 percent of its exhaust stroke and only 9.5 percent of the displacement, plus the small combustion chamber volume, is unoccupied by the piston. It remains. The air charge has a similar velocity to the rising piston, and virtually no expansion of the charge occurs before the piston reaches top dead center. The advancing piston moves forward at the point when the intake valve closes, i.e. approximately
10 Prevent the inflow of a charge volume larger than the combustion chamber volume before top dead center (the pressure in the combustion chamber is balanced with the pressure in the manifold). Combustion begins before top dead center for maximum efficiency. In this particular configuration, if the compression ratio is 16:1, the expansion ratio is 48:1.
become. Therefore, the gas expands to three times its original volume before compression. Alternatively, the first stage of compression takes place in the compression cylinder 5 and the charge with a volume slightly larger than the volume of the combustion chamber is transferred to the expansion cylinders 2, 3, 4.
and then a second stage of compression can be performed within these cylinders. The compression ratio is then determined by the ratio of the volume of the combustion chamber to the total displacement of a single compression cylinder.

The exhaust gases will be discharged via the exhaust manifold 21 and the scavenging will be very efficient. Traditional
In the case of a 4.2 liter 8 cylinder automobile engine, each piston takes up about the total cylinder volume on the exhaust stroke.
89.4% (displaced volume vs. total volume). Similar scavenging efficiencies are obtained with the engine according to the invention. For example, if intake valve i opens at 40 degrees before top dead center and exhaust valve closes at 40 degrees before top dead center, then
The piston stroke will be 90.54 percent complete. 90.54% displacement of 522.3cc (4.2 liter engine is the same) is 472.9cc. Dividing this by the total cylinder volume of the engine of the present invention yields 87.8 percent of the displaced (and scavenged) volume.

In Figure 12, an engine configuration similar to that shown in Figure 3 is shown, and the same parts have the same numbers b.
is attached. A protrusion 150 attached to the top of the piston 6b of the expansion cylinder closes the combustion chamber 151 at a position close to 40 degrees before top dead center when the piston rises during the exhaust stroke.
Close the opening. This arrangement allows the exhaust valve to remain open past top dead center, thereby allowing virtually all of the burned gases to be exhausted while simultaneously entering the combustion chamber through the charge, i.e., the intake valve. This facilitates cleaning of the exhaust gas by preventing it from entering the cylinder body. The protrusion 150 is located inside the combustion chamber opening, as shown in FIG.
52 may be fitted.

FIG. 14 is a diagram of the proposed valve timing that can be used in conjunction with the configuration shown in FIG. 12 to provide improved scavenging for all designs of the present invention. This operation is as follows. In the expansion cylinder (Fig. 12), the exhaust valve opens near the bottom dead center, and as the piston 6b rises, the burned gas is discharged to the exhaust valve e (not shown).
The intake valve opens approximately 40 degrees before top dead center.
Almost simultaneously, protrusion 150 closes and seals the outlet of combustion chamber 151. At this point (40 degrees before top dead center), the piston has completed 90% of its scavenging.
Therefore, the remaining travel is only 10%.
If the stroke of the piston is 10.16cm (4in),
The remaining stroke will be 1.016cm (4/10in). Therefore, the protrusion on the piston only needs to be 1.016 cm (4/10 inch) high to seal the combustion chamber opening when the intake valve opens at 40 degrees before top dead center. 14th
As shown, the exhaust valve can remain open well past top dead center.

In the valve timing diagram shown in FIG.
At 40 degrees before top dead center, the protrusion 150 of the piston 6b closes the combustion chamber opening 151 and at the same time fresh charge begins to enter the suction valve i. The piston continues to rise until it has virtually no clearance with the plane of the engine head, expelling virtually all of the discharged gas. While the crank rotates 40 degrees, the intake valve is open and the combustion chamber 151
A pressure balance occurs between the manifold 16b and the manifold 16b.
At 5-10 degrees before top dead center, the intake valve closes and fuel is injected and ignited at maximum compression for maximum efficiency. Shortly after top dead center, the exhaust valve e closes. The pressure of the gases being combusted first pushes against the top 150 of the piston and valve, expands, then enters the cylinder, and after the crank angle passes 40 degrees from top dead center, pushes the entire top of the piston and expands. The charge expands towards the piston over the entire length of the expansion stroke.

The compression ratio is obtained by dividing the displaced volume of a single compression cylinder by the total volume of all combustion chambers served by that compression cylinder. In the case of a 2 liter 4 cylinder engine, 500 c.c. is divided by 31.25 cc for a compression ratio of 16:1. The combustion chamber volume of this engine is 10.4 cc per cylinder, or 3
Only 31.25cc for one ignition cylinder.

Although the intake manifold 16 has to withstand high pressures, this does not increase the weight of the engine, since the volume of the intake charge passing through it is already partially or preferably completely compressed. This is because the volume is never larger than 1/16 to 1/8 of the volume passing through the malifold of a conventional engine. This small charge volume allows for a small internal manifold diameter.
The manifold 16 needs to be small enough to have sufficient velocity for the heavy charge to fill the expansion cylinders 2-4, but without appreciable pressure drop when filling one of the expansion cylinders. It must have sufficient volume. When the intake valve i to the power cylinder opens, the pressure in the combustion chamber and the pressure in the manifold balance.

If the amount of air charge introduced into the combustion chamber is small, the intake valve i can be made relatively small and light (the springs need to be light) and, in fact, can be enclosed without losing volumetric efficiency. can. Other means of tangential charging other than shrouds may also be used.

The intake valve is closed only for a short time (30 degrees or
40 degrees), which is approximately one-eighth the time (or crank angle) that a conventional male-cycle engine intake valve is normally open. However,
The volume of charge passing through the intake valve is only 1/48th of the volume passing through the intake valve of an O-cycle engine (3/3 of the already compressed normal charge), assuming a compression ratio of 16:1. 1). In a three or six cylinder engine, the volume entering the combustion chamber is only 1/32 of the volume passing through the intake valve of a conventional engine.

Fuel is injected directly into each of the expansion cylinders 2-4 or into individual inlet holes. The amount of fuel can be made proportional to the operating state of the engine by varying the effective stroke of the fuel pump, or by varying the opening time of the fuel injection nozzle fed from a constant pressure main, or can be made proportional by changing the flow rate through the.

Alternatively, a carburetor may be placed before the compression cylinder 5 and used to maintain the air-to-fuel ratio within stoichiometric ranges.

In the case of gas or spark-ignited types, the engine avoids wasting work by compressing more air than is necessary to maintain the stoichiometric ratio.
It is throttled near the atmospheric suction pipe 15 by a bow valve (not shown). Means for reducing or eliminating the required throttling in the case of spark ignition will be discussed below.

As far as compression ignition operation is concerned, the speed is alternatively controlled solely by the fuel proportion. Therefore, automatic control of the fuel-to-air ratio is not required and the throttling device is eliminated.

FIG. 2 shows a means of using an automatic one-way valve in the compression cylinder 5. Tongue-shaped valves 30 (inflow), 31
Although a (flow out) valve is shown, other types of valves such as slide valves, sleeve valves, etc. can be used.

3 and 12 show one means of actuating the power cylinder intake valve i for cylinder 2.
The speed of camshaft 20 is made equal to the speed of crankshaft 10 and is driven from the crankshaft by gear 22 of crankshaft and sprocket drive 23 shown in FIG. The large cams 24, 24b actuate push rods 25, 25b and swing arms 26, 26b to operate the intake valve i, which opens at about 40 degrees before top dead center and closes about 10 degrees before top dead center.

FIG. 4 shows that the cam 27 is connected to the push rod 28 and the swinging arm 29.
In the first design, the valve opens approximately at bottom dead center and opens at 40 degrees.
Close at 35 degrees before top dead center. As an alternative to this, the exhaust valves may be arranged in the 12th and 1st position for better scavenging if desired.
As shown in Figure 4, it may remain open past top dead center.

To facilitate starting of the engine, if desired, a rapid increase in the amount of compression can be achieved by temporarily blocking air intake to the expansion cylinder.
figure). The intake valves of the expansion cylinders 2, 3, 4 can be deactivated (there are several known methods for this, some of which will be described below). for example,
One-way blocking valve 3 in each branch of transfer manifold 16
2, 33, 34 (Figure 7) and close it. Alternatively, a slide valve may be placed between the transfer manifold and the cylinder inlet hole and closed. In addition, one direction 35, 36, 37 is placed between each expansion piston and the associated intake valve to allow unrestrained drawing of atmospheric air to each expansion piston during charging of the engine manifold with air. . Furthermore, a bypass passage 38 with a one-way valve 39 and a check valve 4 are provided to direct the pumped air into the manifold 16 to quickly increase the amount of compression.
If you want to attach 0 to the exhaust manifold 21, you can do it.

A second means of facilitating early starting is to open the valve leading from the compressed air reservoir to the cylinder, thereby supplying compressed air for instant ignition of the cylinder, or as described below. It can be used to turn the engine for starting. The air reservoir may be supplied with air by the air compressor deceleration brake described with respect to FIG. 11 or by any other method.

In order to produce efficient combustion that burns quickly,
The velocity of the compressed air in each manifold branch 17, 18, 19 should be high, and the charge velocity in the combustion chamber can reach the speed of sound. By adjusting the angle of the inlet hole relative to the cylinder diameter,
Alternatively, by using an enclosed intake valve, a strong vortex can be created in the combustion chamber.

This generated turbulence promotes combustion by mixing green and burnt gases at the flame front as they travel across the combustion chamber. This feature alone should make NO _x and HC emissions negligible and virtually eliminate CO emissions. The longer combustion time due to the extended expansion process should further reduce HC emissions to only a trace.

A similar four-cylinder engine 4 shown in FIG.
In 2, the same parts are shown with the same number with a suffix added, and in order to improve the scavenging efficiency, the expansion cylinder 2
Additional cylinder central exhaust holes 43, 44, 45 are provided in the walls of a, 3a, 4a, respectively. These exhaust holes are opened by the associated pistons 6a, 7a, 8a, respectively, at the lowest point of the piston stroke. When the exhaust hole is opened, the pressure in the cylinder can force a large amount of exhaust gas to the atmosphere.

Alternatively, a set of speed increasing gears 46 may be placed on the crankshaft 10a and engaged to move the scavenging blower 47, so that when the exhaust holes 43-45 are exposed by the respective pistons 6a-8a, can give you a breath of fresh air.
In this configuration, each power cylinder 2a, 3
The associated exhaust valves a, 4a are opened at about the same time as holes 43-45 are opened.

In the present invention, the exhaust valve is opened from before bottom dead center to approximately 40-45 degrees before top dead center, and the piston itself releases the appropriate gas.
90% of the air is exhausted (scavenged) through the exhaust valve. Therefore, if blower system 46-47 is added,
Only a small supply of fresh air is required to displace some of the burnt gases from the exhaust valve and dilute the remainder of the gases scavenged by the associated piston stroke.

These configurations will provide a cooler exhaust valve, allowing it to close sooner. It is thus envisaged that the air valve will be opened sooner and the expansion cylinder will be available for further compression of the charge if desired. For example, the compression takes place partly in the compression cylinder 5a,
The slightly larger charge is then further compressed by the expansion cylinders 2a-4a.

In an alternative configuration of either of the four cylinder engines described above, the single compression cylinder can be made double acting (not shown) while the basic operation of the engine remains the same. In this case, the compression cylinder compresses the air charge to a volume sufficient to feed three power cylinders at half to two-thirds of the normal charge volume, depending on the required expansion ratio.

It is also conceivable that a five-cylinder engine, one cylinder of which is a double-acting compression cylinder, feeds four expansion (power) cylinders, and the combustion chambers of these cylinders are half the volume of a conventional engine. This configuration produces four power strokes per revolution and the expansion ratio is twice the compression ratio.

Additionally, in an eight cylinder reciprocating engine any of the four cylinder configurations described above could be duplicated, or alternatively three compression cylinders could compress the air charge for the five power cylinders. In the former case, 6 power strokes occur per revolution, in the latter case 5 power strokes occur. In the latter case, the combustion chamber will be of 50 to 60 percent of its normal volume, depending on the desired expansion ratio.

In any of the engine configurations described above, the fuel for the engine may be gasoline, gas, or diesel, or the engine may be configured to operate on a mixture as a multifuel engine. In all cases, the amount of charge that explodes is small, so
The structure of the compression ignition engine can be made lighter, and its operation becomes even quieter.

9, the illustrated six cylinder internal combustion engine has two compression cylinders 68, 69 and four expansion (power) cylinders 70, 71, 72, 73.
and a common crankshaft 7 by connecting rods 75-80.
Associated pistons 103, 1 respectively connected to 4
04, 105, 106, 107, 108.

The operation of the engine with this arrangement is similar to that described above in the following respects. That is, air at atmospheric pressure or pressurized to a higher pressure passes through the inlet pipe 81, passes through the inflow control valves 113, 114, and enters the compression cylinders 68, 6.
9 and this air is compressed by outlet valves 84, 85 into a high pressure transfer manifold 82 which transfers the compressed charge to intake valves 109-
112 to the expansion cylinders 70-73. Therefore, each of the compression cylinders 68, 69 has 2
This will feed two expansion cylinders.

The combustion chamber of the expansion cylinder is preferably dimensioned to just half the volume of the cylinder of a conventional engine with a similar compression ratio, so that the expansion ratio is at least twice that of a conventional engine. . For example, 16:1
For a compression ratio of , the combustion chamber will be about one-fourth the volume of a conventional engine (half of the normal charge compressed to an even higher ratio) and the expansion ratio will be 32:1.

Each cylinder is a two-stroke cylinder and is scavenged by exhausting the burnt gases during the exhaust stroke of the piston. Therefore, virtually no air is used for scavenging. The working piston rises while exhausting exhaust gas through the exhaust manifold 83,
The related intake valves (109-112) have a charge of approximately 40
The associated exhaust valves (115-118) open to begin inflow at about 40 degrees before top dead center and close at about 40 degrees before top dead center. A good scavenging system, shown in Figures 12 and 14 and described in the description of the engine in Figure 1, will allow the exhaust valve to remain open past top dead center, while keeping the fresh charge and exhaust No mixing with gas occurs. The intake valve can have an envelope on one side that directs the air charge flow into a highly turbulent vortex as described above.
When the fuel is in progress or the intake valve is about 10
When it closes just before top dead center, it is immediately injected. When the intake valve closes, the charge is ignited by a spark plug or automatically. Volumetric efficiency is improved because the volume of the incoming air charge in selected embodiments is only 1/32nd that passing through the intake valve of a conventional engine. Each of the expansion cylinders 70-73 is thus given one power stroke per revolution, so a total of four power strokes per revolution are produced by a six-cylinder engine, which is greater than the power strokes of a conventional four-cycle eight-cylinder engine. equals number.

The valves of the power cylinder can be operated as shown in FIGS. 1, 3, and 6 or as shown in the apparatus in FIGS. 12 and 14. The compression cylinder can be constructed as shown in FIG. Preferably manifold 82 is insulated for compression ignition operation.

The air charge can be completely compressed by the compression cylinders 68, 69, or it is also conceivable that the compression takes place partly in the compression cylinders 68, 69 and then further compression in the expansion cylinders 70-73.

A three-cylinder engine configured to operate in the same manner as the six-cylinder engine described above is also conceivable.
In this case, one compression cylinder is provided which supplies the compressed air charge to the two expansion cylinders, thus producing two power strokes per revolution equal to the smoothness of a four-cylinder four-stroke engine. .
This arrangement is the same as shown in Figure 1, but
One power cylinder is removed and the firing chamber volume is ideally only half that of a conventional engine with the same compression ratio. Either of the designs shown in Figures 4 and 5 or the two systems shown in Figures 12 and 14 can be used for scavenging purposes.

Small throttling can be achieved in any spark ignition engine of the invention with multiple compression cylinders as shown below. Whenever the atmospheric pressure in the intake manifold drops appreciably below ambient pressure, eg, near half-throttling, the outlet of one or more compression cylinders is closed by a shut-off valve. The work done in compressing this trapped charge is recovered as the charge expands on the return stroke of the piston without any net induced pumping action by its cylinder.

In the spark ignition engine shown in FIG. 1, the throttle can be completely eliminated by slowing the injection of fuel into the combustion chamber and starting firing in the injected spray. The intense swirling motion of the gas ensures complete combustion of the extremely lean mixture.

The pumping work produced by throttling is significantly reduced and the pressure in the intake manifold 81 is reduced at all power loads, especially at one-third of maximum power and at no power, which is where most engine loads occur during typical vehicle operation. It remains almost constant over a range including load operation. This method can be used with any number of 4 cylinder or 3 cylinder configurations.

In FIG. 10, a six cylinder reciprocating internal engine is shown, with all cylinders 86-91 and associated pistons 119-124 operating in two cycles, each powered to a common crankshaft 98 via connecting rods 92-97. All cylinders are used to produce .

A feature of this engine is to prolong the expansion of the burnt gases for a longer period of time and to increase the turbulence of the charge with the calcination starting at maximum compression. When using gasoline, the engine can run at a higher compression ratio than normal.

In the case of this two-stroke design, scavenging of the cylinder is performed by reliable evacuation with virtually no loss of air charge or fuel during scavenging. The high expansion ratio, high compression ratio, and high charge turbulence result in a more fuel efficient engine and a higher power-to-weight ratio than an O-cycle engine.

This engine is roughly the same in construction as the four-stroke engine, but there are important differences. The firing chamber of each cylinder is preferably one-half to one-third of its normal size for the desired compression ratio and depending on the expansion ratio determined.
be made below. A camshaft (not shown) is meshed to rotate at the same speed as the crankshaft to open and close the injection inlet valves (125-130) and exhaust valves (131-136) once each revolution of the crankshaft. Compression occurs in one or more stages before the air charge enters the combustion chamber of the cylinder, and the intake manifold becomes a high pressure manifold. The fuel injector is
Fuel is injected directly into the combustion chamber, except for natural gas and propane. Efficient high pressure air compressor 99
is arranged between the air suction pipe 15 and the working cylinder.

Instead of the compressor 99, it is also conceivable to use an external source of compressed air, so that the engine can be operated on spent compressed air to further increase fuel economy.

The pressure ratio (nominal compression ratio) can be arbitrarily increased to equal or exceed the expansion ratio to obtain more power depending on load demand. This can be achieved by simply increasing the speed of the compressor.

One of the most important factors in the success of this design is to provide a compressor that produces both the pressure and air charge required for efficient operation, and such a suitable compressor is the subject of the present invention. is within the range of Three stages of radial compression are considered economical and ideal for compression ignition engines.

The operation and function of the six-cylinder engine shown in FIG. 10 are as follows.

Compressor 99 sucks air and connects it to the manifold.
Compress into 100. If the compressor pressure pulsations are large, a check valve 101 may be used. Manifold stock 100 includes a volume such that there is no appreciable drop in overall pressure as cylinders 86-91 are sequentially loaded. When the crank is turned, the working piston rises approximately 40 degrees before top dead center (see valve diagrams in Figures 5 and 14) and gas is exhausted when the piston has moved almost to the end of the cylinder. This forces 90 percent of the burned gases out of the exhaust valve (into the exhaust manifold 137), which opens as the piston begins its exhaust stroke. At that time, the piston is approximately 40 degrees before top dead center. The intake valve then opens and as the 90% completed piston continues its stroke, a dose of compressed air charge is delivered to the valve (surrounded by the valve).
Enter through. Fuel is injected at the same time (or as soon as the intake valve is closed). High air pressure, sustained flow, and small charge volume (approximately 32
(1:1 to 1:48) guarantees high volumetric efficiency. The intake valve then closes about 10 degrees before top dead center and the mixture is ignited. Thus, firing begins at maximum compression, but the air charge has at least 2 to 3 times the expansion of a corresponding O-cycle engine. If the combustion chamber is made to half its normal volume, the expansion ratio will be twice the compression ratio, and a combustion chamber of one-third the normal volume will triple the expansion ratio. If the compression ratio is 16:1, the expansion ratio is either 32:1 or 48:1.
It becomes something. If desired, scavenging can be improved using the scavenging schemes shown in FIGS. 12 and 14. In this system, the mouth of the combustion chamber is closed approximately 40 degrees before top dead center, the exhaust valve is held in between past top dead center, and the intake valve is opened when firing is prevented.
This method is best described in the explanation of the engine shown in Figure 1.

Although the air charge used is reduced, the increments of fuel used are correspondingly smaller. The farther the gas pushes against the piston and expands, the more work is done on the piston, the more complete the combustion, and the cooler the exhaust gases. Conventional diesel engines draw in almost 100 percent excess air at full load;
Turbulence and lack of time prevent complete mixing of oxygen and fuel. In the engine of the present invention, as described above, the restricted air enters in the tangential direction, so the fuel and
A thorough mixing of the air charge is obtained, which, together with extended expansion, results in complete combustion and, of course, allows the density of the air to be increased to a level deemed effective.

Alternatively, a single stage compression, for example 8:1, can be performed in the compressor 99, as in other designs, and the charge can be received and further compressed in the expansion cylinder.

It is also conceivable that the reciprocating internal combustion engine according to the invention has only one compression cylinder for use in supplying a single expansion (power) cylinder, ie it is a two-cylinder engine. In this case, the expansion cylinder has a larger volume than the compression cylinder.

A higher compression ratio than usual can be utilized in the gasoline engine of the present invention for the following reasons. The charge that is compressed outside the hot combustion cylinder is inherently cooler (less power is required to compress this cooler charge), so the temperature of the final gas at peak pressure is correspondingly lower. descend. High charge turbulence causes mixing of burned and unburned gases at the flame front, thus greatly increasing the flame speed so that the flame front can reach the final gas before the pressure wave arrives. become. The very small size of the combustion chamber (1/4 to 1/6 of the normal size) allows for a very short flame path from the spark plug to the final gases, further ensuring that the flame front arrives earlier than the pressure wave. do. Furthermore, the greater expansion of the gas reduces the temperature of the exhaust valve in the region of the final gas, which reduces the chance of an abnormal explosion. This also lowers the peak pressure temperature. Since the compression takes place outside the combustion cylinder, the nominal time between the start of compression and peak pressure is less, which reduces the residence time for premature knock conditions to occur. Since the air charge has a very rapid swirl, combustion of the fuel occurs as the injection progresses, leaving no fuel in the final gas. In addition, the entire charge can be subjected to post-compression cooling to obtain a large boost when maximum power is required, such as during an aborted landing by an aircraft.

Pre-ignition is not a problem in this engine because the fuel residence time is less than the time required for pre-ignition to occur.

The power of a compression ignition engine operated in this operating cycle can be greatly increased by supercharging. The inlet pressure can be increased starting from a small pressure increase until the theoretical compression ratio equals the expansion ratio. Some locomotives are operated with a boost pressure of 3 atmospheres, yielding a theoretical compression ratio of 48:1 at a compression ratio of 12:1. To reduce _NOx emissions in compression ignition engines, intercooling or post-cooling is likely required along with high pressure boost.

The power of spark ignition engines can also be greatly increased by increasing the inlet air pressure as well.

Although the features of this cycle provide extremely high compression without abnormal explosions, post-cooling is required as the compression ratio approaches the expansion ratio.

This cycle produces combustion gases that expand to subatmospheric pressures under conditions such as those used in compression ignition engines at very light loads.
Additionally, the nominal compression ratio can be increased to equal the expansion ratio by increasing the boost pressure or by closing one or more of the expansion cylinders. This closure is accomplished by deactivating the intake and exhaust valves as well as the fuel injectors.

In the proposed scheme for a four-cylinder engine with an expansion ratio three times the compression ratio, one expansion cylinder can be closed to increase the compression ratio to half the expansion ratio. If the pressure at the exhaust valve remains negative under light load, the second expansion cylinder can be closed to create a compression ratio equal to the expansion ratio. In an eight cylinder engine, one cylinder can be closed at a time for fine control of the compression ratio.

In the scheme proposed for a six-cylinder engine, the expansion ratio is twice the compression ratio. Under very light loads in a compression ignition engine, one expansion cylinder can be closed to increase the compression ratio to two-thirds of the expansion ratio.
To equalize the compression and expansion ratios, the two expansion cylinders are closed. Since this engine uses very little fuel, aftercooling would probably not be necessary, and _NOx emissions per mile would not exceed limits.

Several ways of deactivating cylinder poppet valves are already known. In 1899, the Daimler automobile engine introduced such a system.
This was provided by removing unnecessary members between the cam follower and the valve push-up rod. This allowed the valve spring to hold the valve closed until the spring loaded intermediate member was released.

An electronic method of valve control was produced by Eaton and is used in some automotive engines. This approach allows the swing arm pivot support to be removed to deactivate the valve.
The system provides an electronic controller that senses the pressure in the exhaust manifold and can remove the required number of expansion cylinders when this pressure drops to or below atmospheric pressure.

When the cylinder valve is closed, the energy of compression is returned to the expanding shaft of the same gas. Even if some gas contained in a closed cylinder escapes, the pressure of this gas and the pressure journey of the surrounding atmosphere interact to create a balance such that there is no net loss of energy. No "flow work" is done during cylinder closure.

Or, alternatively, an engine in which the gas is expanded to a pressure below atmospheric pressure provides additional economies. The pressure sensor 102 of FIG. 9 is placed in the exhaust manifold and monitored. The amount of fuel is adjusted so that there is always a slight positive pressure in the exhaust manifold. This system works particularly well on constant load, constant speed engines.

In FIG. 11, additional fuel savings are possible by using an economizer constructed as an air compressor deceleration brake in the engine described above.
The six-cylinder engine shown is similar to the engine shown in FIG. 9, and like parts are designated by like numbers with the suffix a. The air reduction brake has a compressor 138 connected to the vehicle's drive shaft or geared to the engine to store energy generated during braking or downhill travel. Energy is used to supply compressed air to the power cylinders via transfer manifold 82a. Such an economizer can be connected to an air reservoir 139 so that while the pressure of the air in this reservoir is high enough to be used in the power cylinder, the engine's compressor is Since the clutch is disengaged, no compression work is required from the compressor. Relief valve 140
prevents excessive build-up of pressure in the air reservoir. One-way valve 141 allows air from the tank 139 to be transferred to the tank 139 when the pressure in the tank is higher than the pressure in the transfer manifold 82a. In the case of an engine structure with compression cylinders, each compression cylinder is
During operation of the manifold, the inlet valve can be shut off and inoperative so that no net work is done by the compressor until the pressure in the manifold falls below the operating level. Several ways of deactivating cylinder valves are known and have already been mentioned.

Operating the engine on this air supply improves the engine's net mean effective pressure (NMEP) for increased power and greater efficiency per unit of fuel.

This feature results in energy savings, especially in heavy transport and in regions with many slopes. For example, an engine producing 100 horsepower uses 5.77 kg of air per minute. Therefore, if all the energy of the brake is consumed by the saving device,
A 10, 20 or even 30 minute supply of compressed air can be stored in
It is collected and stored while stopped and while moving downhill. When the pressure in the tank falls below the level desired for effective operation, the solenoids reactivate the compression cylinder valves and these valves (in conjunction with the turbocharger if necessary) deliver the required air charge. Start compressing.

This economizer or an alternative suitable type of air pump may also be used to prevent excessive manifold pressure fluctuations in either design of the present invention, if desired.

If this air tank is used, the engine does not require a compression system to start, and as soon as the shaft turns enough to open one intake valve, the compressed air and fuel enter the engine instantly. ” is ignited for starting. moreover,
The compressed air is used to turn the engine for starting by opening a simple valve in the cylinder head, as is common in large diesel engines, thus eliminating the need for a starting motor.

In addition to the already described devices for facilitating cranking of the engine, the intake valve i or the bypass valve 35, 36, 37 remains open during the entire lowering stroke of the associated piston. then the intake valves etc. are closed, the exhaust valves are left closed, the piston begins its upstroke, fuel is added (if not premixed), and near the completion of the upstroke it is ignited, and the next The descent stroke becomes a power stroke.

In summary, the present invention relates to a method for extracting mechanical work from combustion gases in an internal combustion engine, and to a reciprocating internal combustion engine implementing this method. This method consists, at least in part, of compressing an air charge in an engine compressor and transferring and introducing the compressed charge into the power room at an acceptable level of charge pressure. transferring a predetermined amount of fuel to a power chamber without dripping; forming a combustible mixture in the predetermined amount of fuel; igniting the mixture at substantially maximum pressure inside the power chamber; and expanding the piston, which is operable within the chamber, significantly beyond its original volume prior to compression.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a cylinder block of a four-cylinder internal combustion engine according to the present invention, FIG. 2 is a partial sectional view of the compression cylinder of the engine, FIG. 3 is a partial sectional view of the intake valve of the engine, and FIG. 4 is a partial sectional view of the exhaust valve. 5 is a valve diagram of the engine; FIG. 6 is a sectional view of the power cylinder showing the sliding valve; FIG. 7 is a schematic plan view of a similar engine for a rapid compression configuration; FIG. is a cross-sectional view of the cylinder block of a modified four-cylinder engine,
9 is a cross-sectional view of a six-cylinder engine, FIG. 10 is a cross-sectional view of a six-cylinder engine with a separate compressor, FIG. 11 is a cross-sectional view of a six-cylinder engine with an economizer, and FIG. Fig. 13 is an enlarged view of the protrusion and combustion chamber of Fig. 12, and Fig. 14 is a partial cross-sectional view of a power cylinder having an intake valve with a protrusion on the top of the piston. It is a valve diagram. 1... Internal combustion engine; 2-5... Cylinder; 6-9
... Piston; 11-14 ... Connecting rod; 16 ...
Transfer manifold; 20...camshaft; 21...exhaust manifold; 26, 29...swing arm; 35-37
...One-way valve; 42...4 cylinder engine; 43-4
5...Exhaust hole; 47...Blower; 99...Compressor; 101...Check valve; 139...Air tank;
140...Relief valve.

Claims (1)

[Claims] 1. An internal combustion engine having at least one two-stroke power chamber in which combustion gases are ignited and expanded, a piston operable in each chamber, and a compressor for compressing an air charge. a method for obtaining mechanical work from combustion gases, comprising the steps of: compressing an air charge in said one compressor; a point at which the total combustion chamber volume of the power chamber is approximately equal to the volume of the air charge being transferred from the compressor at the time of the air charge transfer; further compressing the combustible mixture to a substantially maximum pressure within the power chamber; and substantially compressing the combustible mixture within the power chamber. igniting the combustion gas at maximum pressure; and expanding the combustion gas by pushing a piston to a volume considerably larger than the volume occupied by the compressed gas in the power chamber at atmospheric pressure. How to get a job. 2. The method of claim 1, wherein the fuel is mixed with an air charge to form a combustible mixture before entering the compression chamber. 3. A method as claimed in claim 1 in which the fuel is mixed with an air charge to form a combustible mixture before leaving the compression chamber and entering the rear power chamber. 4. The method of claim 1, wherein the fuel is mixed with an air charge in the power chamber to form a combustible mixture. 5 A compression chamber that compresses the air charge, a power chamber where combustion gas is ignited and expands, and a piston that can operate within each chamber, and that rotates a common crankshaft in response to the reciprocating motion of each piston. A piston connected to the crankshaft by an articulating linkage, and the compression chamber is in communication with the power chamber through which the compressed charge is transferred and enters the power chamber. a transfer manifold; an inlet valve for controlling the flow of air into the compression chamber for compression; an outlet valve for controlling the flow of compressed charge into the transfer manifold; and from the transfer manifold to the power chamber. an inlet valve for controlling the inflow of a compressed air charge from the power chamber, and an exhaust valve for controlling the discharge of exhaust air from the power chamber, the valves being arranged so that the air charge is initially is retained within a manifold and then opens the intake valve at a time when the power chamber piston is near top dead center and closes the exhaust valve at about the same time or later than opening the intake valve. a fuel mixing device for mixing the fuel with an air charge to form a combustible mixture; and an ignition device for igniting the combustible mixture. The ignition device is timed to ignite the combustible mixture when the power chamber piston reaches just before top dead center after the intake valve closes when the power chamber piston approaches top dead center. The compression chamber and the combustion chamber in the power chamber are sized relative to the displacement volume of the power chamber such that the exploding combustion gases can expand significantly more than the volume occupied at atmospheric pressure of the compressed gas in the power chamber. A reciprocating internal combustion engine characterized by a specified 6. A reciprocating internal combustion engine according to claim 5, wherein said fuel mixing device for mixing fuel with an air charge is connected to an air passage supplying an air charge to said compression chamber. 7. The reciprocating internal combustion engine of claim 5, wherein said fuel mixing device for mixing fuel with an air charge is connected between said outlet valve and said intake valve. 8. The reciprocating internal combustion engine of claim 5, wherein said fuel mixing device for mixing fuel with an air charge is connected directly to said power chamber. 9. The power chamber and the compression chamber are provided by two separate cylinders, each cylinder including a reciprocating piston, and the volume of the compression cylinder is smaller than the volume of the power cylinder. Institutions listed in Section 5. 10 A compression chamber that compresses the air charge, a power chamber where combustion gas is ignited and expanded, and an articulating linkage device that can operate within each chamber and rotates a common crankshaft in response to the reciprocating motion of each piston. a piston connected to the crankshaft by a transfer manifold communicating the compression chamber with the power chamber and through which a compressed charge is transferred into the power chamber; , an outlet valve controlling the flow of a compressed air charge into the transfer manifold;
an intake valve for controlling the flow of a compressed air charge from the transfer manifold into the power chamber, and an exhaust valve for controlling the discharge of exhaust air from the power chamber; A charge is initially held within the transfer manifold, and then the power chamber intake valve is opened at a time when the power chamber piston is near top dead center, and the exhaust valve is closed to the power chamber intake valve. a fuel mixing device timed to be introduced into the power chamber by closing at about the same time as opening or at a later time and further mixing the fuel with the air charge to create a combustible mixture; and an ignition device that ignites the combustible mixture, and the ignition device is configured to close the intake valve when the piston of the power chamber approaches top dead center, and then close the intake valve when the piston of the power chamber approaches top dead center. the combustion chambers in the compression chamber and the power chamber are timed to ignite the combustible mixture when a volume of the detonated combustion gases occupies the atmospheric pressure of the compressed gas in the power chamber; sized relative to the displacement of said power chamber for significantly greater expansion, and further comprising: an air reservoir and a connector duct communicating said air reservoir with said transfer manifold; a device for controlling the flow of air between A reciprocating internal combustion engine characterized in that it is capable of storing energy, receiving air from said transfer duct when desired, and supplying air to said transfer manifold when necessary for operation of the engine. 11. Internal combustion engine according to claim 10, wherein the device for mixing fuel with an air charge is connected to an air passage supplying an air charge to the compression chamber. 12. The internal combustion engine of claim 10, wherein said fuel mixing device for mixing fuel with an air charge is connected between said outlet valve and said intake valve. 13. The internal combustion engine of claim 10, wherein said fuel mixing device for mixing fuel with an air charge is connected directly to said power chamber.