DE2423879A1 - TWO-STROKE COMBUSTION ENGINE - Google Patents

Description

May 16, 1974

Patent attorneys

Dlpf.-Jng. A. Cür.aotor _{p R}

Dr.-ing. ff, - .. ^ kddsy ^red " ³

Dr.-Ing. W. Sloc.'anair
8 Munich 22, Mjxirn / iiansir. 43 9 Z |. 9 ^ R 7 Q

DR. K. SCHUf-'ANN - DIPL -.- lNG. P. JAKOB

NISSAH MOTOR CO., LTD.

No. 2, Takara-machi, "Kanagavia-ku, Yokohama City, Japan

Second act-Brennkraf tmas chine

The invention relates to internal combustion engines for motor vehicles, in particular two-stroke internal combustion engines.

The air pollution from the toxic components of the exhaust gases from internal combustion engines has serious problems raised, and there have therefore been various attempts and developments carried out to the exhaust gases in question To clean motor vehicle internal combustion engines. The invention aims to create a two-stroke internal combustion engine, with which these problems can be solved.

409881/0791

In order to eliminate the toxic compounds such as carbon monoxide, hydrocarbons and nitrogen oxides in the exhaust gases of internal combustion engines or at least keep them to a minimum, it has already been proposed to burn the fuel with an addition of gas or an aqueous solution of hydrogen peroxide or liquid oxygen. The fuel is completely burned by an exothermic reaction between the fuel and the oxidizing agent, so that the combustion gases generated are free of hydrocarbons and carbon monoxides that result from incomplete combustion of the fuel. In addition, since the fuel is burned without nitrogen, no nitrogen oxides, such as nitrogen monoxide, are contained in the combustion gases. In the two-stroke internal combustion engine proposed according to the invention, such a nitrogen-free oxidation mixture is used, inter alia, for the combustion of the fuel, which generally consists of hydrocarbons. An extremely large proportion of heat generated by the exothermic reaction between the fuel and the water to ff peroxy d or the liquid oxygen, and which is achieved by such an exothermic reaction due to _de% r extremely high temperature, the mixture of fuel and oxidant takes not to be condensed before inflammation. Another not yet mentioned feature of the two-stroke internal combustion engine according to the invention consists in an arrangement in which the outlet of the internal combustion engine is closed when the piston of the internal combustion engine is in the region of the upper point, and in which the fuel and the oxidizing agent in the Combustion chamber can be injected immediately after the outlet is closed and immediately before the piston reaches top dead center. . .

The two-stroke internal combustion engine according to the invention can ent-

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409-88 1/079

be neither a piston engine nor a rotary piston engine. The terms "state of a minimum volume" and "state of a maximum volume ", hereinafter in connection with the combustion chamber of the internal combustion engine are used refer to states of the combustion chamber in which the Piston is at top or bottom dead center (OT or BDC) if it is a piston internal combustion engine, and on the states of the combustion chamber (or the working space) in which the rotary piston (or rotor) is in such a position is located, in which it produces a minimum or maximum volume of the combustion chamber or the working space.

The invention "insists that a combustion chamber with an outlet is provided; that a piston is movably mounted in the combustion chamber, which one in each cycle largest or smallest volume of the combustion chamber limiting position assumes that a fuel injection device is provided, which injects liquid fuel into the combustion chamber in a timed manner, as well as an oxidizing agent injection device, the timed a nitrogen-free oxidant in the combustion chamber injecting, wherein the timing of the injection of the oxidant with the fuel injection is synchronized so that a fuel-oxidizer mixture is generated in the combustion chamber that an ignition device is provided, which the mixture in terms of time • controlled ignited that a valve is provided for the timed opening and closing of the outlet is, as well as controls that cycle the fuel and oxidizer injectors and then actuate the igniter during a first stroke and actuate the valve to close the exhaust during a second

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^: To keep the stroke open, the fuel and oxidant injectors being actuated; immediately before the piston reaches the top dead center position with the smallest stroke volume, and the valve. is operated so that it is immediately in front of the outlet

; Actuation of the fuel and oxidant device closes.

Further features, advantages and details of the invention emerge from the following description of exemplary embodiments based on the drawing. Show in it:

Fig.l is a schematic representation of a two-stroke piston combustion engine chine according to the invention;

2 shows a pressure-volume diagram, which is based on the inventive Internal combustion engine can be achieved, and

3 shows a schematic representation of a two-stroke rotary piston internal combustion engine according to the invention.

The engine shown in Fig.l has a cylinder 10 and a reciprocable in the cylinder Pistons 12, through which a combustion chamber 14 is delimited between the upper piston crown and a cylinder head 16 which is arranged on the top of the cylinder 10. The piston 12 is in a known manner by means of a Piston pin 18, a connecting rod 20 and a crank pin 22 on a crankshaft 24, which are in a crankcase 26 is mounted, hinged. In the cylinder head 16 are a fuel injection nozzle 28 and an injection nozzle 30 for an oxidizing agent is arranged, which protrude into the combustion chamber 14. The fuel injector 28 is provided with a

40 9881/0791

Fuel feed pump 32 via a control device 34 in connection ^ which is used to control the injection times of the liquid fuel into the combustion chamber 14. The injection nozzle 30 is also connected via a control device 38 for controlling the delivery of the oxidizing agent to a feed pump 36 for the oxidizing agent. The feed pump 36 for the oxidizing agent conveys a nitrogen-free oxidizing mixture which is in a liquid state, such as, for example, liquid oxygen or an aqueous solution or hydrogen peroxide gas. The oxidation mixture is injected through the injection nozzle 30 into the combustion chamber 14 at times which are synchronized with the times of the fuel injection, so that a mixture of fuel (or hydrocarbon) and the liquid oxygen or the hydrogen peroxide gases in the liquid state each time in the combustion chamber 14 is generated when the fuel injector 28 and the oxidizer injector 30 are actuated during the intake stroke of the piston 12. A spark plug 40, which protrudes into the combustion chamber 14, is arranged in the cylinder head 16. The spark plug 40 forms part of an ignition system of the engine and is therefore connected in a manner known per se to an energy source via an ignition control device (not shown). The combustion chamber 14 opens via an outlet 42 into an exhaust system, and in the outlet of an exhaust valve 44 is arranged which 42 under the influence of a cam or other actuating means, not shown, which is driven by the crankshaft 24, opens the outlet and closes. While the outlet 42 is arranged in the cylinder head 16 in the illustrated embodiment, it should be mentioned that the invention also includes a two-stroke internal combustion engine, the outlet 42 * of which in a central part of the cylinder 10 into the combustion chamber

40988 1/0791
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opens, as shown in Figure 1 by dashed lines is indicated. In this embodiment, the piston 12 acts as a valve device and opens and closes the arranged in the cylinder 10 outlet 42 · when it is in the Cylinder 10 moved back and forth.

During the operation of the engine, the fuel and the nitrogen-free oxidation mixture that is supplied by the pumps 32 and 36 are conveyed by the control devices 34 and 38, at the same time through the nozzles 28 and 30 is injected into the combustion chamber 14 in a liquid or gaseous state when the piston is at top dead center approaches, which is shown with solid lines in Fig.1. It is evident that at this moment the outlet valve is held in a position in which it closes the outlet 42 when the nozzles 28 and 30 are actuated to reduce the fuel and the oxidation mixture injected into the combustion chamber 14. The fuel injected into the combustion chamber 14 and the injected Oxidation mixtures are atomized and mixed together, so that a flammable mixture is formed. Immediately before the piston 12 reaches top dead center, the spark plug releases 40 from an ignition spark and ignites the combustible mixture in the combustion chamber 14. In the combustion chamber 14 is thereby a high combustion gas pressure is generated by which the piston 12 is pushed down from its dead center position will. Immediately before the piston 12 reaches its bottom dead center, which is indicated by dashed lines in the Fig.l is drawn, the outlet valve 44 opens the outlet 42, so that the expanded in the combustion chamber 14 Combustion gases escape through outlet 42 into the open atmosphere. The engine repeats during its operation

409881/0791

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these injection, work and delivery strokes.

The injection, work and delivery strokes of the engine described above are shown in FIG. 2 in a pressure-volume diagram (pV diagram). If one looks at FIGS. 1 and 2 at the same time, then point A corresponds to the pV line a time at which the outlet valve 44 is actuated to close the outlet 42. The fuel injector and the oxidizing agent injector 30 is used to inject the fuel and the oxidizing agent into the combustion chamber 14 is actuated for a period beginning at point B and immediately after point A. lies. The spark plug 40 becomes a through point to ignite the mixture of fuel and oxidizing mixture C is ignited, and at this point the engine's power stroke begins. The injection of the fuel and the oxidation mixture is terminated at point D, which is near top dead center (TDC) of piston 12. The combustion gas pressure generated in this way in the combustion chamber 14 reaches its peak value at points E and from this point the combustion gases begin to expand. The piston 12 moves accordingly to the bottom dead center (UT), and before it reaches the bottom dead center, the exhaust valve 44 is actuated at point F to the outlet 42 to open. The point G denotes the position of the bottom dead center. With dashed lines is through the curve X the Compression stroke of a two-stroke internal combustion engine is shown.

Since the outlet valve 44 is operated near the top dead center of the piston 12 to close the outlet 42, as shown by point A of the pV curve, essentially none takes place during operation of the engine

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Compression stroke instead. The elimination of the compression stroke leads to a reduction in the amount caused by the combustion of the mixture achievable energy, but such a loss of energy is compensated for by the extremely large amount of heat generated by the exothermic reaction between the fuel and the hydrogen peroxide or liquid oxygen. For example, if hydrogen peroxide is used as an oxidizing agent, then the flame temperature reached by the reaction between the fuel and the hydrogen peroxide is above 2000 ° C. Obviously, such a large amount of heat is sufficient to achieve this the force necessary for driving the piston 12 without adiabatic compression of the combustion mixture is required. A comparison between the curves of the pV diagram of the motor according to the invention versus one conventional motor shows that the work that can be achieved with the motor according to the invention is significantly greater than that which can be achieved Work with a conventional engine is. Tests have shown that the work in the engine according to the invention is approximately 150 to 200% greater than the work that can be achieved with a conventional two-stroke engine.

All the advantages described above can also be achieved if the two-stroke piston internal combustion engine according to Fig.l existing features in a two-stroke rotary piston internal combustion engine can be used according to Fig.3. The two-stroke rotary piston internal combustion engine shown in FIG has a rotor housing 46 and a rotary piston or rotor 4 8, which is mounted in the rotor housing 46 around an eccentric shaft 50 is rotatably mounted. Combustion chambers are formed between the inner wall of the rotor housing 46 and the control edges of the rotor 4 8 or working spaces 52 formed by the apex of the

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Rotor 48 separated from each other s} .nd. In the rotor housing 46 two outlets 54 are provided which are conventional are arranged symmetrically with respect to an axis of the eccentric shaft 50. Two sets of fuel injectors protrude into the engine housing 46 56 and oxidant injectors 58 inside. Each of a fuel injector 56 and one The set formed oxidant injector 58 is so downstream in the direction of rotation 48 from the adjacent outlet 54 arranged so that the fuel and oxidizer injectors 56 and 58 are in a row that is substantially runs parallel to the eccentric shaft 50, or in a direction perpendicular to the plane of the drawing. The fuel injectors 56 are above a control device 62 for controlling the fuel delivery with a common fuel pump 60, and so are the oxidant injectors 58 via a control device 66 for controlling the oxidizing agent delivery with a common oxidizing agent delivery pump 64 in connection, similar to the case in the exemplary embodiment shown in FIG. Two spark plugs 68 extend into the rotor housing 46 and are downstream of the rotor 48 in the direction of rotation adjacent fuel and oxidizer injectors 56 and 58 arranged.

When the rotor 48 rotates in the rotor housing 46 around the eccentric shaft 50 during operation, so that one of the switches of the rotor 48 has passed one of the outlets 54 at a point in time which corresponds to point A of the vP curve in FIG corresponds to, as shown in Figure 3 with solid lines, then one of the fuel and oxidant injection nozzles 56 and 58 existing nozzle set actuated at point B of the pV curve according to Figure 2, so that the Fuel and the oxidizing agent in the working space 52

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are injected, which is located in front of the corresponding apex of the rotor 48 (this working space in the illustrated Embodiment in the upper right part of FIG. 3 is shown). Then, at a point in time corresponding to point C on the pV curve in FIG ignited to the mixture of the fuel and the oxidizer to ignite. The fuel and oxidizer injectors 56 and 58 stop injecting the fuel and the oxidant at point D on the pV curve. The rotor 48 rotating in the rotor housing 46 is driven so by the combustion gases caused by the exothermic Reaction between the fuel and the oxidizing agent arise. When the rotor 48 is indicated by the dash-dotted lines Lines drawn in Fig. 3 reached the rotational position at the end of the expansion stroke, which corresponds to the section E-F of the pV curve according to FIG. 2, then the apex of the rotor located at the front end of the working space 52 runs 48 via the other outlet 54, which consequently communicates with the corresponding working space 52 at a time comes, which corresponds to point F of the pV curve according to FIG. The exhaust gases located in the working space 52 escape therefore through the outlet 54 into the free atmosphere (in which case the outlet in the lower part of FIG. 3 is meant is). Then the fuel and oxidizer injectors 56 and 58 and then the spark plug 68 is actuated (which are shown in the lower part of FIG. 3), so that in this way the subsequent injection and working stroke can be carried out.

From the above description it can be seen that the essential advantages of the two-stroke internal combustion engine according to the invention consist in the fact that the exhaust gases from the engine are none

4Ü9881 / 0791
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contain toxic components and that the performance of the engine without increasing the size of the engine structure is significant is increased. From the point of view that hydrogen peroxides or liquid oxygen are easy and economical can be obtained from inexhaustible sources of the atmosphere, the internal combustion engine according to the invention also carries contributes to the fuel consumption by the motor vehicles and to alleviate the increasingly serious problem of the energy crisis.

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Claims (5)

Patent to sayings Two-stroke internal combustion engine, characterized in that a combustion chamber (14, 46) with a Outlet (42,42 ', 54) is provided that in the combustion chamber a piston (12) is movably mounted, which in each cycle has a largest or a smallest volume of the Combustion chamber limiting position assumes that a fuel injection device (28,56) is provided which Time-controlled injected liquid fuel into the combustion chamber, as well as an oxidant injection device (30,58), which in time control a nitrogen-free oxidizing agent in the combustion chamber injecting, wherein the timing of the injection of the oxidant with the fuel injection is synchronized so that a fuel-oxidizer mixture is generated in the combustion chamber that an ignition device (40,68) is provided, which the mixture timed ignited that a valve (44) for timed opening and closing of the outlet is provided, as well as control devices (34,38,62,66), which the fuel and oxidant injection devices cyclically and then actuate the ignition device during a first stroke and the valve to close the outlet to keep open during a second stroke, the fuel and oxidant injection - 12 409881/0791 devices are operated - immediately "before the Piston (12) the top dead center position with the smallest Stroke volume reached, and the valve is actuated such that it is the outlet immediately before actuation of the Seals fuel and oxidizer devices. 2. Two-stroke internal combustion engine according to claim 1, characterized in that the oxidizing agent liquid oxygen or hydrogen pero ^ yd. 3. Two-stroke internal combustion engine according to claim 1 or 2, characterized in that the hydrogen peroxide is gekennzei chnet in a liquid or gaseous state. 4. Two-stroke internal combustion engine according to one of claims 1 to 3, characterized in that the internal combustion engine is a piston engine. 5. Two-stroke internal combustion engine according to one of claims 1 to 3, characterized in that the Internal combustion engine is a rotary piston engine. "- 13 - 409881/0791