DE2550480A1 - COMBUSTION ENGINE - Google Patents

Description

Patent assessor Hamburg, October 31, 1975

Dr. Gerhard Schupfner
German Texaco IG

TEXACO DEVELOPMENT CORPORATION 135 East 42nd Street New York, N.Y. 10017 U.S.A.

Internal combustion engine

The invention relates to an internal combustion engine, which consists of at least one cylinder, cylinder head and piston, which together form a combustion chamber. Valves are also provided for entering air into the combustion chamber, the cylinder walls serving as guides for the swirling air masses.

In internal combustion engines, it is desirable to achieve the highest possible degree of efficiency and thus a maximum power output with low specific consumption. To do this, it is necessary to enter the combustion sequence from to precisely control the combustion air until the burned gases are released into the ambient air. You have different ones Attempts have been made to prepare the intake air in a special way so that it can be used for subsequent combustion is particularly suitable. In these tests, swirling air currents were generated in the combustion chamber, which in the Technical jargon can be referred to as "stratified charge".

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Stratified charge operation in internal combustion engines is basically known. The advantages include the larger range of fuels that can be used and the higher degree of efficiency of the combustion process with a suitable fuel setting.

It is also known that according to / adjustment of the fuel and air supply, the air-polluting constituents of the exhaust gas, such as NO and CO, can be regulated. The harmful components can be reduced in such a way that that the legal requirements for an environmentally friendly motor vehicle operation are met.

It is also known in the piston surface of an internal combustion engine to mold a chamber and recess to improve the combustion process. Such a one Chamber serves not only as part of the combustion chamber, but also as a swirl device for air, which lead to the formation of a combustible mixture Combustion chamber is introduced.

According to US Pat. No. 3,094,974, it is known to use a turbulent air flow to generate and enrich with a corresponding amount of fuel to increase the efficiency. A particular Amount of fuel is injected into the combustion chamber and, at the same time, an air flow over a specially shaped one

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Inlet, which sets it in rotation, introduced. The vortex flow direction extends from the injector to the Spark plug and is determined by the walls of the combustion chamber.

In the cited publication it is pointed out that a recess in the piston prevents the turbulence of incoming air reinforced. The incoming air is initially through the intake valves swirled and then during the compression stroke by compressing the air in the combustion chamber and swirled even more strongly in the smaller piston chamber.

Although cavities in piston surfaces have been used in many cases for various purposes, so far it has not succeeded in achieving the desired uniform fuel consumption reach. So simple, cup-like piston cavities are known, the cylindrical walls and an opening to the piston surface point out. There are also spherical piston cavities

known. The purpose of these arrangements is to provide either a pre-combustion chamber or rapid swirl of air through the cup-shaped recess or the to accelerate the cylindrical combustion chamber.

The object of the present invention is, in an internal combustion engine with the lowest possible thermal and mechanical load on the piston, a maximum of swirling

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development of the air and the combustion gases to achieve a uniform and accelerated combustion of the entered To enable fuel mixing and thus the overall efficiency to improve the combustion process. In particular, the gas exchange between the piston cavity and the combustion chamber should can be improved by targeted vortex formation.

The solution is essentially that the intake air swirls during the intake stroke and flows into a piston cavity is introduced. The piston cavity is relatively flat and has a central axis that is substantially runs parallel to the piston axis. The piston cavity opens to the face of the piston in the combustion chamber.

The flat piston recess also acts as an injection chamber for receiving injected fuel from an injection nozzle and to increase the degree of turbulence in the air. Part of the opening of the piston bowl is covered by an overhanging, uneven piston lip covered towards the combustion chamber. The piston lip thus forms an obstacle to flow and is arranged essentially perpendicular to the central axis of the piston recess. As a result, when the piston goes down from top dead center during the work cycle, the combustion products are produced and thus also environmentally harmful components in the piston bowl are violently mixed with air. For mixing becomes Air from the combustion chamber and from the piston bowl

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Passing taken into the combustion chamber.

In the following the invention is described in more detail using an exemplary embodiment and by means of several drawings explained. Show it:

Pig. 1 shows a cross section through a cylinder unit with the piston according to the invention,

Fig. 2 is a side view of the engine described in the present invention;

3 shows a cross section through a cylinder unit accordingly Fig. 1, wherein the piston according to the invention is shown in a changed position,

Fig. 4- a cross section through a cylinder unit perpendicular to the cylinder axis, with the top of the piston shown in Fig. 1,

Fig. 5 cross section through the upper part of the cylinder unit 4 along the line CC. '

In the side view according to FIG. 2, the internal combustion engine is 10 as Beihenmoiror in a multi-cylinder design shown. By means of an injection pump 12, fuel is injected from a fuel tank 15 into the relevant cylinder.

The injection pump is normally operated via an accelerator pedal 11

ORIGINAL INSPECTED

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and thus the amount of fuel injected is controlled. Ambient air is drawn into the through inlet 13 and air filter 14 Sucked in combustion chamber. An exhaust manifold 16 directs the hot exhaust gases into a catalytic converter or muffler 17 before release to the atmosphere.

In FIG. 1, the engine block 22 is shown with a cylinder 21 and a piston 23. At the top of the piston 23 is located the piston surface 24 and at the lower end of the piston skirt 26. A piston rod 19 is over a piston pin 20 rotatably mounted in the piston 23. The connecting rod with the crankshaft 18 is on the opposite side tied together.

Each piston is usually with multiple compression and oil control rings 27 and 28 equipped. These rings are mounted in piston ring grooves parallel to each other and slidably. As a result, when the piston 23 goes up and down in the cylinder 21 a seal between the cylinder wall and piston shaft achieved.

The cylinder head 3I is sealed with a seal 29 the cylinder block 22 is fixed. 5, each cylinder is provided with at least one intake valve 32 and one exhaust valve 32 a equipped. About one or more camshafts are

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the valves are connected to one another in order to control the engine according to the respective work cycles.

Each cylinder is provided with an injection nozzle which can be unscrewed and which has an injection opening y \ - for feeding the fuel into the combustion chamber at a precisely predetermined point with regard to the position of the piston. The injection nozzle is connected to the injection pump 12 via line 36 in order to inject fuel into the combustion chamber during the compression stroke when the piston has reached the top dead center position.

In the cylinder head there is also the spark plug 37, the ignition electrodes of which are arranged in the immediate vicinity of the injection opening 3. This allows the ignition system to serve as an integral part of igniting a rich, ignitable fuel-air mixture. The ignitable fuel-air mixture is located in a precisely localized area, the air comes in _(from the combustion chamber 4-0 with the injected fuel in contact.

The turbulence of air when entering the combustion chamber will now be described in more detail with reference to FIG. A pre-swirling is already achieved by the special shape of the valve 32, ζ . B. achieved by flow guide surfaces.

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It then enters a piston recess 38 of the piston 23, wherein the axes of the piston recess and piston are preferably arranged concentrically to one another. As shown in Fig. 5, the piston 38 has a substantially cylindrical shape Walls and has a diameter D which is less than the piston diameter. The bottom 39 of the piston bowl is Executed flat and meets at the corner edge 43 on the cylindrical molded walls of the piston bowl 38.

At the opening of the piston recess to the combustion chamber is a overhanging part or a non-uniform piston lip attached, according to the invention, the piston bowl space segment-like covers. As a result, an almost closed annular space 44 is formed within the piston recess 38 (see FIG. 4). If air and / or combustion gases in the piston bowl 38 whirl around, they are pressed against the walls of the piston bowl. The gases are created by centrifugal force pressed radially outward and thereby pressed into the annular space 44, which is closed on three sides.

A more detailed description will now take place on the basis of FIG. A. At the beginning of the work cycle, the piston is at top dead center. The compression chamber 40 is shown enlarged in the figure. In fact, the combustion chamber 40 is in the top dead center position of the piston

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thin, disk-like chamber formed, which is immediately is located above the piston face 24.

When the work cycle begins, fuel is fed into the piston recess 38 by means of an injection nozzle 38. The liquid fuel is absorbed by the swirling air masses and thereby a rich fuel-air mixture is produced in a locally limited area in the immediate vicinity of the injection. As soon as this rich mixture reaches the spark plug 37 , it is ignited. The resulting flame front is d _f ann quickly migrate through the annular space 44, accompanied by hot, expanding combustion gases.

To accommodate these expanding, static masses, is the upper section 42 of the inner annular space 44 is aerodynamically shaped (see FIG. 5). The top wall 42 is opposite the piston end face inclined, with it to the huldenzentrum increases. The partially closed piston bowl thus becomes the main mass of the swirling gases in the closed one Pick up part of the annulus.

To ensure complete and rapid burning of the remaining to achieve a thin fuel mixture in the cylinder, the expanding flame front will advance to the center of the piston bowl 38 and thereby also through the opening 43 reach the piston recess. For a clockwise

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Gas mixture swirling through the piston annulus 44, the annulus becomes larger on the route from A to B and smaller on the route from B to A. If the piston 23 now goes down from top dead center during the work cycle, part of the swirling air mass in the vicinity of the opening 43 will escape from the piston recess 38. The flame front swirling clockwise in the piston bowl and the hot combustion gas will move up and reach the combustion chamber through the opening 4-3. To improve this process, the inner edges of the piston lip 35 are designed so that they form an increasing widening from the center of the bowl to the opening 33 hi. This expansion can be achieved by any shape, the opening 43 being designed with an essentially cylindrical wall.

For example, the diameter of the opening 43 can be selected in this way that it allows. the opening 43 entirely within a segment of the wall 42 to be inserted. Likewise, how shown in figure 4 and 5, the flow between combustion chamber 40 and ■ annular space 44 are supported by that the opening 43 is arranged so that an edge in the immediate vicinity of the piston recess 38 below lies. In principle, however, the size and the position of the opening 43 can be varied as desired in order to achieve the desired mixing and to achieve combustion sequence.

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In order to regulate the timing of the mixing and combustion of the fuel-air charge, the opening 43 is also provided an upper and lower control edge 46 and 47 are provided. The lower control edge 47 is provided with a strong tear-off as shown to create an upright wall to form, which lead and control the gas exchange from trough 38 can.

During the compression stroke, the piston is moved to top dead center with the inlet and outlet valves 32, 32a closed. The compression of the previously introduced vortex air drives considerable amounts of air into the piston bowl 38 and increases it thereby the swirl speed.

Immediately before and during the reaching of the top dead center a predetermined amount of fuel is introduced from the injection nozzle 33 into the piston bowl space 38. Included the direction of injection is coordinated with the vortex flow. As already described, the injected fuel is form a localized, relatively rich fuel-air mixture which, when swept past the spark plug 37 is ignited. The spark plug is supplied with energy precisely at this point in the work cycle.

In the work cycle that now follows, the piston 23 will move out of top dead center and the flame front in the annular space 44

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circulate. This allows at the same time some of the hot, expanding gases and the air in trough space 38, exit the trough and escape into the expanding combustion chamber 40. At the same time, the The flame front continues its propagation movement in hollow 38 and the combustion in said trough is maintained by the remaining gas mixture and also by free air flowing through it at the same time. As a result, the inflamed mixture is through opening 43 in the manner flow that an improved mixing of the fuel, combustion products and free air in chamber 40 is achieved.

The result is a faster and more uniform combustion and subsequently also a more economical and cleaner, more environmentally friendly operation.

Claims (10)

October 31, 1975 T 75 054 D - Ί 3 -
Claims \ 1.jCombustion engine, consisting of at least a cylinder, cylinder head and piston, which together form a combustion chamber, and valves for input of air into the combustion chamber, the cylinder walls acting as guides for the swirling air masses serve, characterized in that an inlet space (44) is formed in the piston (23), into the air-fuel via a narrow passage opening (43) mixture is entered, the narrow passage opening (43) eccentric to the piston center axis is arranged seen the direction of movement of the piston. 2. Internal combustion engine according to claim 1, characterized in that that in the cylinder head (31) a fuel injection nozzle (36) with an outlet (34) is arranged, which on the The passage opening (43) for the injection of fuel into the annular space (44) is aligned so that the swirling Air flow is processed to produce an ignitable fuel-air mixture, and that A spark plug (37) for igniting the fuel-air mixture is arranged in the combustion chamber (40). ORIOiNAL INSPECTED 609825 / Ub44 b b c y \ , Ί 3. internal combustion engine according to claim 1 or 2, characterized in that the axis of the substantially cylindrically shaped Annular space (4A) runs parallel to the piston center axis. 4-. Internal combustion engine according to one of the preceding Claims, characterized in that the annular space (44-) is essentially is arranged concentrically to the piston center axis. 5 · Internal combustion engine according to one of the preceding Claims, characterized in that the annular space (44-) in one Plane is arranged which is substantially perpendicular to the piston center axis. 6. Internal combustion engine according to one of the preceding claims, characterized ,, that the narrow passage opening (4-3) essentially consists of a circular passage opening consists. ÖfilSIKAL JNSPECTED 609826/0644 - " ^r 5 - 7 · Internal combustion engine according to one of the preceding Claims, characterized in that the passage opening (4-3) has a diameter D, which is less than half the diameter of the annular space ice (4-4) ". 8. Internal combustion engine according to one of the preceding claims, characterized in that that at least one edge of the passage opening (43) with is adjacent to a wall of the annulus (44). 9. Internal combustion engine according to one of the preceding claims, characterized in that that the annular space (44) is substantially cylindrical and communicates with the passage opening (43), wherein the passage opening (43) is arranged eccentrically to the annular space (44). 10. Internal combustion engine / according to one of the preceding claims, characterized in that the Delimitation of the annular space (44) to the compression space (40) made by a sickle-shaped circular disk element which is made up of two congruent sections, the first section being an enlarging one Cross-sectional area and the second portion has a decreasing cross-sectional area. ORIGINAL INSPECTED 60982b / ubhk e e r s e 11 e