STEP-PISTON INTERNAL COMBUSTION ENGINE WITH WORKING AND SERVICE CYLINDERS Technical field to which the invention belonas According to the International Patent Classification (IPC), the invention can be classifie as follows : -F 02 B 25/04-Engines with ports in cylinder head and in cylinder wall close to the bottom dead centre -F 02 B 19/00-Engines with pre-combustion chambers -F 02 B 21/00-Engines with air antechambers -F 02 F 1/00-Cylinders -F 02 B 3/00-Pistons -F 02 C 9/00-Machines or engines with oscillating piston Technical problem The technical problem to be solved with this invention lies in the structural design of the cylinder, piston, and distribution system of an internal combustion engine that is to enable : -manufacture of universal engines with high output and efficiency; -reduce the engine size ; -reduce the fuel consumption; -increase the engine output; -provide additional combustion of ignited mixture ; -release of cooler gases into the environment.

Technoloqical development The development of internal combustion engines is characterised by the output increase, better utilisation of materials, and increasing requirements concerning safety of operation, engine durability, fuel economy, as well as reduction in environmental pollution.

Better output, lower fuel consumption and cleaner exhaust are achieved by increasing the engine efficiency i. e. the fuel economy. To do this, it is necessary to substantially increase the pressure and temperature in the engine. This, however, brings us to the mechanical and thermal material endurance limit rather quickly.

The most heavily strained engine elements are at highest risk : valves, piston rings, piston face, cylinder head, exhaust ports, turbine blades etc. Unreasonable

increase of temperature and pressure can literally cause a normal engine to explode.

Until now, several types of internal combustion engines have been designed with linear oscillation or rotation piston movement. Each of these engine designs has its advantages and disadvantages.

All internal combustion engines, both Otto and Diesel, have some elements in common. The design of such elements depends on the rotation speed of the crankshaft (fast, medium, and slow engines), number of strokes (2-stroke, 4- stroke) and whether they have crossheads or not.

The cylinder is a static and the piston is a moving engine element. The working substance pressure and the piston inertia force exert effect on the piston.

The ignited mixture of fuel and air spreads as a fireball and exerts effect on the piston.

In all current engines, the exhaust gases are displaced by the piston.

In 2-stroke engines the working substance is exchanged through exhaust and inlet ports. These ports are located along the circumference of the lower cylinder section. They are opened and closed by the piston, and there are no valves or camshaft to control valves. When exhaust gases are pressed out, 1/4 ... 1/3 of the inlet air volume escapes through the exhaust. The gases are pressed out by the air, so the air and the gases mix together, and the air trapped in the cylinder of a 2-stroke engine is not so pure like in a 4-stroke engine where exhaust gases are being pressed out by the piston.

The combustible mixture in a 4-stroke Otto engine is created during the intake and compression strokes, i. e. during two strokes, or one cycle. 4-stroke engines require a special device with valves for opening and closing the ports for the exchange of the working substance.

A 4-stroke engine features the following strokes : 1St STROKE : intake-Exhaust valve is closed. The piston is moving upwards, drawing in a mixture of petrol and air through an open intake valve.

The valve closes immediately afterwards.

2 STROKE : compression-Exhaust and intake valves are closed. Moving upwards, the piston compresses the mixture in the combustion chamber, and owing to the heat caused by the compression, fuel droplets turn into gases.

3d STROKE : expansion-Both valves remain closed. A spark from the spark plug ignites the compressed mixture. Combusted gases expand and press the piston downwards. At the end of the stroke, the exhaust valve opens.

4th STROKE : exhaust-Intake valve is closed. Moving upwards, the piston presses the combustion remains out through the open exhaust valve. At the end of the stroke, the intake valve opens and the exhaust valve closes. The whole cycle begins again with the first stroke.

Theoretically, it is assumed that the valves open when the piston is at the top/bottom dead centre. However, in practice the open times overlap. The exhaust valve opens even before the piston reaches the bottom dead centre and it only closes some time after the piston remains at the top dead centre. The same, only vice versa, applies to the opening of the intake valve. This means that at the moment of overlapping, both valves are open at the same time. The stability of intake and exhaust gases actually improves the filling of the cylinder with fresh mixture and the emptying (exhaust) of the exhaust gases.

The lingering exhaust gases reduce the volume of the working substance that can be taken into the cylinder. Besides, the intake of a 4-stroke engine requires a vacuum in order that the surrounding pressure may press air into the cylinder. In a 2-stroke engine cylinder, more exhaust gases linger on than in a 4- stroke engine, so that the volumetric rate of 2-stroke engines is lower than that of 4-stroke engines. This applies to the suction engines and the charge engines. The volumetric rate is also affected, beside the temperature and the quantity of the lingering gases, by the flow resistance in intake and exhaust ports. The higher the temperature of the cylinders and of the parts along which the mixture i. e. air flows, the higher the temperature of the combustible mixture, that is air in the cylinder.

Since density decreases with the increase of temperature, the cylinder will hold less combustible mixture or air. The lingering gases have a similar effect. The more lingering gases there are and the higher their temperature, the hotter the combustible mixture or air, resulting in even lower density. In a 4-stroke engine, there are lingering gases only in the compression chamber.

In the development of engines the combustion chamber was constantly reduced to achieve compression value of 9-9.5, because of maximum thermal

efficiency. However, this caused an increase in the temperatures and, consequently, dissociation, that is the emission of carbon monoxide that is hazardous to health. So, the compression was lowered to 8, which reduced the thermal efficiency and increased the fuel costs. Consequently, new designs were developed to reduce the emission of carbon-monoxide yet retain the high compression. This was achieved by dividing the combustion chamber. The smaller chamber (pre-combustion chamber) serves to hold the rich combustible mixture to be ignited by a spark plug. The other chamber, with larger volume holds lean mixture that in a normal Otto engine could not be ignited. The pressure that occurs during the combustion in the pre-combustion chamber squirts flame into the larger chamber with lean mixture that quickly ignites and combusts. In this, the carbon-monoxide from the pre-combustion chamber that resulted from dissociation also burns up (multiple internal combustion engines). Because of additional devices, the manufacture of such engines is more expensive, and their consumption is somewhat higher than that of normal engines.

Mitsubishi's GDI (Gasoline Direct Injection) engine, just like a Diesel, intakes pure air through its intake valves. The fuel is injected directly into the cylinders, constituting a combustible mixture with compressed air. The mixture does not ignite of itself, though, because the pressure and temperature are still not high enough, but with a spark plug like in any normal Otto engine. To be able to ignite the mixture, there has to be a stochiometric ratio of air and petrol. The GDI- engine has pistons with"noses"that feature a groove on one side. The air-petrol mixture is whirls along the groove and is directed to the spark plug. The combustion quality is added to by a very high compression of 12 : 1 that makes possible the high specific output of such engines. Compared to a normal petrol fuelled engine, the GDI-engine has 35% lower consumption and 90% lower content of toxic nitrogen oxides and Carbon monoxide. The cloud of combustible mixture is pushed by the curved nose of the piston directly towards the spark plug, which makes it easier to ignite. This way, stable combustion is achieved with a relatively small quantity of fuel.

Description of the solution to the technical problem A step-piston internal combustion engine with working and service cylinders is a volumetric machine for continuous transformation of energy of the working substance into mechanical work.

The enclosed drawings that constitute an integral part of the invention's description illustrate the design and help to explain the basic principes of the invention.

Fig. 1-the step-piston internal combustion engine with working and service cylinders Fig. 2-the revolution graph of engine operation-working cylinder Fig. 3-the revolution graph of engine operation-service cylinder Fig. 4-step-piston internal combustion engine with working and service cylinders, working stages The step-piston internal combustion engine with working and service cylinders includes : spark plug (1), exhaust port (2), non-return valve (3), working cylinder (4), service (vacuum) cylinder (5), intake port (6), overflow port (7) and piston (8).

The volume of the engine cylinder is divided into two chambers, working (4) and service (5), in the form of a letter T turned upside down.

The piston (8) is in the form of a letter T turned upside down. At the top and bottom of the piston there are piston rings that separate the working chamber from the service chamber.

The essential thing about the cylinder and piston design is that the vacuum created in the service cylinder by the piston movement draws combustion gases from the working cylinder with over-pressure and to create vacuum in there for a better air and fuel supply.

Compared to the already available solutions, the invention lacks a cylinder cover.

This is how the step-piston internal combustion engine with working and service cylinders works : 1. With the ignition of fresh mixture there is over-pressure in the working cylinder (4) and the working piston (8) is pushed towards the low position until the crankshaft reaches 160° cycle, creating vacuum in the service cylinder (5).

2. While the crankshaft turns from 160° to 170°, the piston opens the overflow port (7), and owing to the vacuum created in the service cylinder (5) the combusted mixture in the working cylinder (4) is drawn to the service cylinder (5) through the overflow port (7).

3. While the crankshaft turns from 170° to 180°, fresh mixture is drawn in through the intake port (6) into the working cylinder (4), and simultaneously, the combusted mixture is further drawn from the working cylinder (4) to the service cylinder (5) through the overflow port (7).

4. While the crankshaft turns from 180° to 190°, fresh mixture is drawn in through the intake port (6) into the working cylinder (4), and simultaneously, some of the combusted mixture returns to the working cylinder (4) from the service cylinder (5) through the overflow port (7), whereas most of the combusted mixture from the service cylinder (5) is released through the exhaust port (2) and the open non-return valve (3) into the environment.

5. While the crankshaft turns from 190° to 200°, some of the combusted mixtures is further drawn from the service cylinder (5) to the working cylinder (4) through the overflow port (7), with continued release of the combusted mixture from the service cylinder (5) through the exhaust port (2) and the non-return valve (3) into the environment.

6. While the crankshaft is turning from 200° to 360°, the mixture is compressed and the combusted mixture from the service cylinder (5) is released through the exhaust port (2) and the non-return valve (3) into the environment.

The engine revolving graph (fig. 2) for the working cylinder shows the following strokes : 1. expansion 355°-157.50° 2. exhaust 157.50°-170° 3. intake 170°-180° 4. compression 180°-335° The engine revolving graph (fig. 2) for the service shows the following strokes : 1. vacuum ignition 0°-157.50° 2. intake of combusted mixture 157.50°-180° 3. exhaust of combusted mixture180°-360° 4. return of combusted mixture into the working cylinder 180°-202.50° The application of the invention and its exploitation will : -reduce the engine size ; -reduce the consumption ; -increase the engine output ; -provide additional combustion of the combusted mixture ;

-release cooler gases into the environment and reduce the emission of carbon- monoxide ; -enable its use in high compression industrial techniques.