EP0776423A1

EP0776423A1 - Two-stroke engine with spark ignition

Info

Publication number: EP0776423A1
Application number: EP95928040A
Authority: EP
Inventors: Stanislaw Jarnuszkiewicz; Sobieslaw Zasada
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-08-16
Filing date: 1995-08-16
Publication date: 1997-06-04
Anticipated expiration: 2015-08-16
Also published as: PL174629B1; WO1996005426A1; HUT76953A; CZ43197A3; ATE173055T1; EP0776423B1; PL304731A1; DE69505831D1

Abstract

In a two-stroke engine with ports controlled by the piston and with the air charge or a lean fuel-air mixture precompressed in the crankcase (11), the cylinder space is fed with a jet of rich fuel-exhaust gas mixture from the feed chamber (13) by means of a feed canal (14). The feed chamber (13) is formed by the inner space of the rotary distributor (A) closed by a rotary control element (16) driven by a non-slip transmission (17) from the engine crankshaft (10). The feed canal (14) ends at the cylinder wall with an opening situated between the upper edge of the exhaust port (4) and the position of the edge of the head of the piston (5) at the moment of ignition. The control element (16) has two openings, an inlet one (18) and an outlet one (19), spaced at the angle ( alpha ) and coupled in such a position that, while rotating, the inlet opening (18) meets the opening of the feed canal (14) during the engine power stroke, and the outlet opening (19) - during the compression stroke.

Description

Two-stroke engine w th spark ignition

Field of the invention

The subject matter of this invention is the two-stroke engine with spark ignition, in which the energy of exhaust gases produced during the engine operation is used to pre¬ pare the combustible charge.

Background of the invention

The main reason for the limited application of two-stroke engines, especially to mechanical vehicles, is toxicity of the exhaust gases they release. One of the design trends which improve operation of the two stroke engine consists in eliminating the outlet losses by supplying fuel to the cylinder space after the exhaust port has been closed, and controlling combustion by spacial qualitative differentia¬ tion of the fuel charge, which consists, among other things, in producing an enriched mixture in the spark plug zone. A method of producing such a laminar structure of the mixture is known, in which a gaseous charge containing fuel is introduced from a separate feed chamber to the air, or to a lean combustible mixture compressed by the piston in the cylinder space. The charge containing fuel consists of vaporized liquid fuel mixed with air or with exhaust gases; it is very rich m fuel, beyond the flammability limit. The fuel charge jet is introduced during the compression stroke through the feed canal leading from the feed chamber where the fuel charge is compressed to a pressure higher than that in the cylinder space at the moment of delivering the fuel charge. The feed canal is oriented towards the spark plug. Mutual mixing of the two charges results in the desired differentiation of the mixture, as regards its com¬ bustibility properties, in the engine cylinder space.

There are many engine designs in which the fuel charge is prepared in this manner. In the engine presented in speci¬ fication of the German patent No. DE 2 241 643, a piston compressor driven by a gear from the crankshaft, plays the role of the feed chamber. The compressor cylinder space is connected, via a suction canal, with a device spraying fuel into the drawn-in air, and with the engine cylinder space via a feed canal m which a non-return valve is mounted. The feed canal, positioned in the compressor cylinder wall, is uncovered when it meets the orifice in the piston pro¬ jection at the moment the compressed charge containing fuel should be introduced to the engine cylinder space.

Among the designs which use the energy of pressure and temperature of the exhaust gas to prepare the fuel charge, is the engine presented in the German journal VDI Bericht, appendix No. 1066 entitled "Direkte Gemischemblasung am 2-Takt-Ottomotoren", which describes the oral presentation by G.K.Fraidl, R.Knoll, and H.P. Hazeu at a conference held m Dresden on 3-4 June 1993. In the engine head, a feed chamber is made which is connected with the cylinder space by means of a feed canal with an electromagnetically opera¬ ted cut-off valve. A spray nozzle is installed m the feed chamber. The operation of the nozzle and the cut-off valve are controlled by a processor performing a program based on a general principle: the valve is opened at the end of the compression stroke and is closed after the moment of igni¬ tion; fuel is injected during the power stroke. With the- cut-off valve open, the direction of gas flow depends on the pressure difference between the two connected spaces. In the first period after the valve is opened, a rich fu¬ el-exhaust gas mixture, prepared m the previous phase, le- aves the feed chamber. The increase in pressure in the cy¬ linder space, caused by the piston movement, results in the reversed flow direction even before the moment of ignition. The computer-controlled valve is closed after the mixture is ignited, and the pressure in the feed chamber is suffi¬ cient to prepare the mixture in the next cycle, the exact moment depending on the engine load. During the phases of power, charge exchange, and the first moments of compres¬ sion, a computer-controlled amount of fuel is injected to the gases accumulated in the feed chamber under high pres¬ sure. The fuel vaporizes quickly in hot exhaust gases, thus producing a rich, chemically active fuel-exhaust gas mixtu¬ re used in the next engine operation cycle. In a multi-cy¬ linder engine, each cylinder has its own feed chamber equ¬ ipped with a cut-off valve and a spray nozzle.

Exhaust gases are also used in the operation of the engine described in the specification of the Polish patent No. 140 368. In this design the feed chamber is connected with the working space by means of a feed canal leading to the cylinder wall, its outlet being located between the upper edge of the exhaust port and the top dead centre. The con¬ nection of the fuel chamber with the working space is con¬ trolled by the piston edge. The feed chamber is connected by means of a non-return valve with a vacuum device which sprays fuel into the air jet that is sucked into the fuel chamber, or the exhaust gas taken from the exhaust canal. Gases are sucked into the fuel chamber when it is periodi¬ cally connected with the crankcase space. The two spaces are connected via an additional suction canal which ends on the cylinder wall below the upper edge of the piston in its top dead centre. Exhaust gases from the engine cylinder space are introduced, during the power stroke, to the fuel chamber containing a rich fuel charge. The chamber space is then tightly closed for, at least, the charge exchange pha- se; the chamber is opened again m the compression phase. The control of the connection between the fuel chamber and the working space is done at the two control edges appro¬ priately spaced on the piston. The control edges are made in a special projection of the piston head; they are formed by the upper edge and an additional transfer canal made in¬ side the piston. Necessitated by the control function, the asymmetrical distribution of the piston mass not only inc¬ reases its inertia but also creates problems with dilata¬ tion, wear, and affects the tightness of the connections controlled by these edges.

Disclosure of the invention

The engine developed by this invention prepares the com¬ bustible charge using a method similar to that described above, however with a different design, using different technical means. The essence of this design consists m that the engine feed chamber is formed by the inner space of a rotary distributor, which is closed by a rotary con¬ trol element driven by a transmission from the engine cran¬ kshaft. The control element has two openings, an inlet and outlet one, spaced at such a central angle, and coupled with the transmission in such a position that, when the element is rotating, the inlet opening meets the feed canal outlet in the rotary distributor during the power stroke, and the outlet opening is met in the compression stroke. The two spaces become connected when the piston is below the feed canal opening in the cylinder wall.

In such a design the feed chamber is cut off by two pairs of sliding surfaces connected m series, between the piston and the cylinder wall, and m the rotary distributor. Owing to such a design, there is no pressure loss during forma¬ tion and storage of the fuel-exhaust gas mixture in the fe- ed chamber, which is of fundamental importance to appro¬ priate stratification of the charge and the engine effi¬ ciency. With such a design, the fuel spraying device can operate either in a continuous mode - with the amount of fuel controlled by its pressure, or in a cyclic mode - with the amount of fuel controlled by the valve opening time.

This design is especially advantageous in a multi-cylin¬ der engine. The cylinder spaces are connected with one com¬ mon feed chamber by means of feed canals, the openings of which are spaced at symmetrical pitch of the rotary distri¬ butor central angle, corresponding to the number of cylin¬ ders and the sequence of ignition. In such an engine, there are particularly advantageous conditions for gas flow, which minimize the effect of inertia. The possibility of uncovering simultaneously the inlet opening which comes from the cylinder that performs the power stroke, and the outlet opening leading to the cylinder which performs the compression stroke, creates conditions that enhance the flow - the feed chamber acts as a pressure accumulator which simultaneously discharges the fuel-exhaust gas mixtu¬ re produced in it and is fed with exhaust gases. Such an operation system diminishes the importance of cutting off the controlled spaces tightly. Pressure pulsation is consi¬ derably reduced which favourably reduces wave phenomena which disturb the flow of gas.

The rotary distributor can actually be of any design. The design that is particularly advantageous has the feed cham¬ ber formed by the inner space of the control element - de¬ signed as a rotary chamber supported by bearings in the distributor body. One end of the chamber is connected with a non-slip transmission by means of a coupling and a pres¬ sure spring. The other end of the chamber, which has an in¬ let and outlet openings, is pressed against the cover of the body in which the opening of the feed canal is placed to mate with the two openings mentioned above. In the co¬ ver, positioned in the distributor rotation axis, there is a fuel spraying device directed towards the axially posi¬ tioned opening made in the bottom of the control element.

In the engine presented here, the combustion chamber is connected with the feed chamber by means of one feed canal with two directions of flow, to transfer exhaust gas or the fuel-exhaust gas mixture. During each power stroke the flow of gases is reversed in the feed canal zone of the feed chamber. A further development of the invention aims at en¬ suring an orderly flow in the feed chamber, increasing ho¬ mogeneity of the mixture at high frequencies caused by high rotation speeds of the engine and/or the high number of cy¬ linders controlled by one distributor. In such an engine the control element of the rotary distributor is made as a shaft with a machined concentric chamber at the front end, closed by the distributor body cover in which a fuel spraying device is installed. The cylinder space is connec¬ ted with the feed chamber by means of the exhaust gas ca¬ nal, in addition to the feed canal. The exhaust gas canal ends at the cylinder wall with an opening positioned above the upper edge of the exhaust port. The feed and exhaust gas canals are connected separately with two control sec¬ tions of the rotary distributor; the sections are spaced along the axis of the annular wall of the shaft. The ex¬ haust gas canal section has an inlet opening, and the feed canal section has an outlet opening. The inlet and outlet openings are spaced at such a central angle and the non-slip transmission is coupled at such a ratio that, whi¬ le rotating, the inlet opening meets the opening of the ex¬ haust canal during the power stroke, and the outlet opening meets the feed canal opening during the compression stroke. The connections are open when the piston is below the ope- nings of the feed and the exhaust gas canals positioned on the cylinder wall.

A further development of the invention consists in placing the outlet. opening and feed canal section closer to the ro¬ tary distributor cover. Similarly as in the engine descri¬ bed above, where the feed chamber is connected with the cy¬ linder space by means of the feed canal only, this design has, in the case of a multi-cylinder engine, one common fe¬ ed chamber and the exhaust gas canals and the feed canals are spaced on the circumference of the rotary distributor sections at a symmetrical pitch of the rotary distributor central angle, corresponding to the number of cylinders and the sequence of ignition.

In the design presented here, irrespective of the number of cylinders, there is one direction of flow through the feed chamber, in countercurrent to the flow of the sprayed fuel; thus producing higher homogeneity of the mixture and a better flow dynamics.

Brief description of the drawings

The several examples of engine designs presented below will permit the essence of the invention to be understood thoroughly. The engines are shown schematically; the follo¬ wing figures show: Fig. 1 - Cross section of the engine, Fig. 2 - longitudinal section of a three-cylinder engine equipped with a rotary distributor having control openings positioned on the circumference of the control element which has the form of a hollow shaft, Figs. 3, 4, and 5 - cross sections through the engine shaft of Fig. 2; the cross sections are taken through the feed canal planes of individual cylinders. Fig. 6 - an axial cross section thro¬ ugh another distributor with control openings located on the front surface. Fig. 7 - view of the front surface of the distributor of Fig. 6 designed to co-operate with a three cylinder engine, and driven by 1:1 transmission, Fig. 8 - a longitudinal section of a three-cylinder engine controlled by a two-sectional distributor, Figs. 9 and 10 - sections through the exhaust gas section and the feed canal section, respectively.

Modes of carrying.-out the invention

In a single-cylinder engine shown in Fig. 1, the working space 8 is enclosed by the walls of the cylinder 1, the he¬ ad 6, and the bottom of the piston 5. The piston 5 is con¬ nected with the crankshaft 10 by means of a connecting rod 9. The crankshaft 10 is supported on bearings in the crank- case 11. On the reverse movement, the piston 5 uncovers the inlet 3 and exhaust 4 ports located in the wall of the cy¬ linder 1. Air is sucked into the crank case 11 through a suction canal and a self-closing, one-way plate valve 12. The basic design of the two-stroke engine with precompres- sion of charge in the crankcase, as described above, is supplemented with a device for preparing the combustible load. The rotary distributor unit A is equipped with a sle¬ eve-type control element 16 driven by 1:1 non-slip trans¬ mission 17 from the crankshaft 10. The inner space of the control element 16 constitutes the feed chamber 13 which is periodically connected with the cylinder space 8 through the inlet 18 and outlet 19 openings, and the feed canal 14. The nozzle of the fuel spraying unit 15, in this case - an injector with electromagnetic control, is built into the feed chamber 13. The feed canal 14 ends at the wall of the cylinder 1, with the opening situated slightly above the upper edge of the outlet port 4 and directed towards the hole in the head 6 where the spark plug 7 is installed. The operation of the feed chamber 13 is controlled on a geome¬ tric basis: the value of the central angle α between the inlet 18 and outlet 19 openings on the circumference of the control element 16 is slightly greater than the angle of rotation of the crankshaft 10 for the travel of the piston 5 between covering and uncovering of the feed canal 14. In the single-cylinder engine described here, the angle a. equ¬ als 220°.

The description of the process occurring in the engine begins with the situation shown in Fig. 1 when the piston 5 is at the bottom dead centre during the charge exchange phase. Rotation of the crankshaft 10 and the upward move¬ ment of the piston 5 result in closing the inlet ports 3 and then the exhaust port 4 thus beginning the compression phase. Subsequently, as the feed chamber 13 is opened, a very strong, pulse of a rich fuel-exhaust gas mixture, produced in the previous cycle, flows into the cylinder space 8 through the feed canal 14 and the inlet opening 19. As the mixture stream moves towards the spark plug 7, it mixes with the air, which results in qualitative differen¬ tiation of the combustible mixture, the ultimate pattern of which is shaped by the piston 5. The opening of the feed canal 14 is closed by the piston head edge before the ins¬ tance of ignition. During the power stroke, after the ope¬ ning of the feed canal 14 is uncovered, the feed chamber 13 connected with the cylinder space 8 for the second time in the same cycle - this time through the inlet opening 18. Some portion of the exhaust gases flows into the feed cham¬ ber 13 which acts as a pressure accumulator and a generator of the fuel-exhaust gas mixture. The period including the final part of the power stroke, the charge exchange phase and the beginning of the compression stroke is long enough to ensure a complete vaporization of the fuel injected and chemical activation of thus produced gaseous mixture. The position of the opening of the feed canal 14 on the wall of the cylinder 1 controls the timing of connecting the feed chamber 13 with the cylinder space 8. In the process of preparing the combustible mixture, the connecting operation must meet two opposing conditions, the introduction of the mixture must sufficiently precede the moment of ignition and the pressure in the feed chamber 13 must reach a suffi¬ cient value.

The engine shown in Fig. 2 has a rotary distributor A with one common feed chamber 13 for three cylinders. The control element 16 has the form of a shaft with a machined concen¬ tric chamber at one end, closed by the cover 20 of the dis¬ tributor body 21. In the cover 20, the fuel spraying device 15 is mounted. On the side surface of the control element 16, three sections can be distinguished, which correspond to individual cylinders. Each section has the input opening 18 and the output opening 19 in the shaft wall; the ope¬ nings mate with the feed canals 14.1, 14.2, and 14.3 con¬ necting the distributor with individual cylinders. The cen¬ tral angle α at which the inlet 18 and outlet 19 openings are spaced equals 240°. With three cylinders, the central angle β representing the relative difference in the posi¬ tion of openings between the sections, must be 120°, in the direction opposite to the rotation of the crankshaft 10 and in accordance with the ignition sequence. With the geometry of control adopted here, which is thoroughly explained by cross sections taken along the sections of the control ele¬ ment, as shown in Figs. 3, 4, 5, and with the ignition se¬ quence being 1-2-3, the feed chamber 13 is always simulta¬ neously connected with cylinders on the power and compres¬ sion strokes. Fig. 2 shows the first and the second cylin¬ ders in this situation, connected by means of the canals 14.1 and 14.2.

Fig. 6 shows an advantageous design of the rotary distri¬ butor A. The control element 16 takes in this design the form of a chamber supported by bearings in the distributor body 21; one end of the control element 16 is connected with the shaft of a non-slip transmission 17 by means of a dog clutch 23 movable along its axis. Unlike in the dis¬ tributor used in the engine of Fig. 2, where the side sur¬ face acts as the control surface, in this design the inlet opening 18 and the outlet opening 19 are situated in a flat bottom of the control element 16, which is pressed against the cover 20 by means of a helical spring 24 incorporated in the clutch unit 23. The feed canals 14.1, 14.2, and 14.3 of the three cylinders are connected to the cover 20 in which a spray nozzle 15 is installed in the centre, along the axis of rotation. In such a design the control surface also seals the feed chamber 13.

Fig. 7 shows the position of the control openings in the distributor of Fig. 6 in a three-cylinder engine with a non-slip 1:1 transmission 17. It is an obvious solution to use a reduction transmission to drive the distributor with the transmission ratio expressed by a natural number, with a resulting division of the central angle β.

A three-cylinder engine as shown in Fig. 8 embodies so¬ mewhat modified, relative to those described above, prin¬ ciple of preparing the mixture. In addition to the feed ca¬ nal 14.2, 14.2, or 14.3, each cylinder is equipped with a exhaust gas canal 22.1, 22.2, and 22.3, respectively, en¬ ding with an opening in the cylinder wall, positioned above the upper edge of the exhaust port 4. These canals run to the rotary distributor A separately to two control sections allocated to the functions of exhaust gas transfer and mix¬ ture feed, rather than to individual cylinders. The exhaust gas flows through the feed chamber in one direction. The section with the outlet opening 19 corresponding to the fe¬ ed canals 14.2, 14.2, and 14.3, is situated closer to the distributor cover 20, which ensures the counter-current flow which intensifies evaporation and mixing of the spray¬ ed fuel with the gas stream.

In traction engines, exist varying operating conditions, especially as regards the rotation speed and load. Due to the flow inertia it is expedient to control in the rotary distributor A the angle at which the feed chamber 13 is connected with the cylinder space 8. With the double con¬ trol system arranged in series, both in the distributor and on the cylinder wall, some improvement can be brought about by making the inlet 18 and outlet 19 openings oval rather than round. The rotation speed can be taken into account by using a coupling with controllable delay/advance angle 23 connected to the non-slip transmission 17. In the simplest design, such a coupling can be controlled by a centrifugal governor. The full range of optimal control can be ensured with the assistance of a processor-based control unit 26 which, based on signals coming from numerous sensors which scrutinize the engine operation, external conditions, the throttle position, determines the required setting of the fuel feed, controllable clutch and other controllable engi¬ ne units.

Claims

1. A two-stroke engine with spark ignition, with the air charge or a lean fuel-air mixture precompression in the crankcase, with ports controlled by the piston; with the cylinder space fed with a jet of a rich fuel-exhaust gas mixture from the feed chamber to which it is connected via a feed canal ending at the cylinder wall with an opening situated between the upper edge of the exhaust port and the position of the piston top edge at the moment of ignition, the opening of the feed canal being oriented towards the spark plug zone; with the spraying device installed in a feed chamber; characterised in that the feed chamber (13) is formed by the inner space of the rotary distributor (A) closed by a rotary control element (16) driven by a non-slip transmission (17) from the engine crankshaft (10); the control element (16) having two openings, an in¬ let one (18) and an outlet one (19), spaced at such a cen¬ tral angle (α) and coupled by the non-slip transmission (17) in such a position, that, while rotating, the inlet opening (18) meets the opening of the feed canal (14) in the rotary distributor (A) during the engine power stroke, and the outlet opening (19) - in the compression stroke, the connection being open when the piston (5) is below the opening of the feed canal (14) on the wall of the cylinder (1) .

2. The engine as claimed in the claim 1, characterised in that the spaces (8) inside the cylinders (1) in a multi-cy¬ linder engine are connected with one common feed chamber (13) by means of the feed canals (14.1, 14.2, 14.3), the openings of which are spaced in the rotary distributor (A) at the central angle (β) corresponding to the division of the cycle by the number of cylinders, in the sequence of ignition.

3. The engine as claimed in the claim 1, characterised in that the feed chamber (13) is formed by the inner space of the control element (16) which is designed as a rotary con¬ tainer supported by bearings in the body (21) of the rotary distributor; one end of the control element being connected with the shaft of the non-slip transmission (17) by means of a coupling (23) and a helical pressure spring (24); the other end, which has the inlet opening (18) and the outlet opening (19), being pressed against the cover (20) of the regulator body (21), the cover having an opening of the fe¬ ed canal (14) mating with the inlet (18) and outlet (19) openings, and equipped with a fuel spray nozzle (15) direc¬ ted towards the axial opening in the bottom of the control element (16) .

4. The engine as claimed m the claim 1, characterised m that the non-slip transmission (17) has a reducing ratio expressed by a natural number, and the control element (16) has pairs of inlet (18) and outlet (19) openings spaced ac¬ cording to the transmission ratio.

5. The engine as claimed in the claim 1, characterised in that the coupling (25) with controllable delay/advance ang¬ le is built into the non-slip transmission (17) .

6. A two-stroke engine with spark ignition, with the air charge or a lean fuel-air mixture precompression in the crankcase, with ports controlled by the piston; with the cylinder space fed with a jet of rich fuel-exhaust gas mixture from the feed chamber to which it is connected via a feed canal ending at the cylinder wall with an opening situated between the upper edge of the exhaust port and the position of the top edge of the piston at the moment of ig¬ nition, with the opening of the feed canal oriented to the spark plug zone; with the spraying device installed in the feed chamber; characterised in that the feed chamber (13) is formed by the inner space of the rotary distributor (A) closed by a rotary control element (16) driven by a non-slip transmission (17) from the engine crankshaft (10); with the control element (16) in the form of a hollow shaft forming a concentric chamber at one end, closed by the cover (20) of the distributor body, fitted with a fuel spraying device (15); with the engine cylinder space (8) connected to the feed chamber (13) by means of the exhaust gas canal (22), in addition to the feed canal (14), with the exhaust gas canal ending at the wall of the cylinder (1) with an opening positioned above the upper edge of the exhaust port (4); the canals (14 and 22) being connected separately to two corresponding control sections of the rotary distributor (A) , the sections being placed along the axis of the annular wall of the shaft, the section connec¬ ted to the exhaust gas canal (22) having an inlet opening (18) and the section connected to the feed canal (14) ha¬ ving an outlet opening (19), the openings (18, 19) being spaced at such a central angle (α) and coupled with the non-slip transmission in such a position, that, while rota¬ ting, the inlet opening (18) meets the opening of the ex¬ haust gas canal (22) during the power stroke, and the out¬ let opening (19) meets the opening of the feed canal (14) during the compression stroke; with the two spaces being connected when the piston (5) is below the openings of the exhaust gas canal (22) and the feed canal (14) which are located on the wall of the cylinder (1) .

7. The engine as claimed in the claim 6, characterised in that the section corresponding to the outlet opening (19) and the feed canal (14), is situated closer to the cover (20) of the rotary distributor (A) .

8. The engine as claimed in the claim 6, characterised in that the spaces (8) of the cylinders (1) in a multi-cylin¬ der engine are connected with one common feed chamber (13) with the exhaust gas canals (22.1, 22.2, and 22.3) and the feed canals (14.1, 14.2, and 14.3) spaced on the circumfe¬ rence of the corresponding section at the angle (β) , depen¬ ding on the number of cylinders (1) and the sequence of ig¬ nition.

AMENDED CLAIMS

[received by the International Bureau on 29 January 1996 (29.01.96); original claims 1 and 2; 6 and 8 replaced by amended claims 1 and 5; claims 3-5 and 7 unchanged but renumbered as claims 2-4 and 6

(4 pages)]

1. A two-stroke multi-cylinder internal combustion engine with spark ignition, with the air charge or a lean fu¬ el-air mixture precompression the crankcase, with ports controlled by the piston; with the space of each cylinder connected via

- a feed canal ending at the cylinder wall with an ope¬ ning situated between the upper edge of the exhaust port and the position of the piston's top edge at the moment of ignition with the spraying device installed m a feed chamber which is formed by the inner space of the rotary dis¬ tributor closed by a rotary control element driven by a non-slip transmission from the engine crankshaft; wherein the control element has two openings, an inlet one and an outlet one, spaced at such a central angle and coupled by the non-slip transmission m such a po¬ sition, that, while rotating, the inlet opening meets the opening of the feed canal m the rotary distributor during the power stroke, and the outlet opening meets the canal the compression stroke, the connection be¬ ing open when the piston is below the opening of the feed canal on the wall of the cylinder,

- and further, the engine m which the fuel spray devi¬ ce is built inside the feed chamber, characterised m that the spaces (8) inside the cylinders (1) are con¬ nected with one common feed chamber (13) by means of the feed canals (14.1, 14.2, 14.3), the openings of which are spaced in the rotary distributor (A) at the central angle (β) corresponding to the division of the cycle by the number of cylinders (1), m the sequence of ignition. 2. The engine as claimed the claim 1, characterised in that the feed chamber (13) is formed by the inner space of the control element (16) which is designed as a ro¬ tary container supported by bearings m the body (21) of the rotary distributor; one end of the control ele¬ ment being connected with the shaft of the non-slip transmission (17) by means of a coupling (23) and a he¬ lical pressure spring (24); the other end, which has the inlet opening (18) and the outlet opening (19), be¬ ing pressed against the cover (20) of the regulator bo¬ dy (21 i , the cover having an opening of the feed canal (14) mating with the inlet (18) and outlet (19ι ope¬ nings, and equipped with a fuel spray nozzle (15) di¬ rected towards the axial opening the bottom of the control element (16) .

3. The engine as claimed the claim 1, characterised in that the non-slip transmission (17) has a reducing ra¬ tio expressed by a natural number, and the control ele¬ ment (16) has pairs of inlet (18) and outlet (19) ope¬ nings spaced according to the transmission ratio.

4. The engine as claimed m the claim 1, characterised m that the coupling (25) with controllable delay/advance angle is built into the non-slip transmission (17) .

5. A two-stroke multi-cylinder internal combustion engine with spark ignition, with the air charge or a lean fu¬ el-air mixture precompression in the crankcase, with ports controlled by the piston; with the space of each cylinder connected via

- a feed canal and an exhaust gas canal, both ending at the cylinder wall with openings situated between the upper edge of the exhaust port and the position of the top edge of the piston at the moment of ignition - with the feed chamber formed by the inner space of a rotary distributor, which is closed by a rotary con¬ trol element driven by a non-slip transmission from the engine crankshaft, wherein the control element has two openings, an inlet one and an outlet one, spaced at such a central angle, and coupled with the transmission in such a position that, when the element is rotating, the inlet opening meets the exhaust gas canal outlet in the rotary distributor during the power stroke, and the outlet opening is met in the compression stroke, and the two spaces become connected when the piston is be¬ low the feed canal opening in the cylinder wall,

- further, wherein the spraying device is built in the feed chamber, characterized in that the spaces (8) of the cylinders (1) are connected to one common feed chamber (13) whose control element (16) takes the form of a shaft, i.e. with a concentric chamber at one end, closed by the cover (20) of the distributor body, fit¬ ted with a fuel spraying device (15), with the feed ca¬ nals (14.1, 14.2, and 14.3) the exhaust gas canals (22.1, 22.2, and 22.3) connected separately to two con¬ trol sections of the rotary distributor (A) , the sec¬ tions being placed along the axis of the annular wall of the shaft, having an inlet opening (18) in the sec¬ tion connected to the exhaust gas canal (22) and the outlet opening (19) in the section connected to the fe¬ ed canal (14), with the exhaust gas canals (22.1, 22.2, and 22.3) and the feed canals (14.1, 14.2, and 14.3) spaced on the circumference of the corresponding sec^¬ tion at the angle (β) , depending on the number of cy^¬ linders (1) and the sequence of ignition. 6. The engine as claimed in the claim 5, characterised in that the section corresponding to the outlet opening (19) and the feed canal (14), is situated closer to the cover (20) of the rotary distributor (A) .

STATEMENT UNDER ARTICLE 19

1. Two essential cited solutions are indicated in accordance with the following patent specifications:

- DE 41 16 303 - which makes it necessary to amend the claims and to limit the extent of the claimed protection, and

- WO 91/02144, pertaining to the engine which in spite of many common design features operates on a different principle. The rotary chamber acts only as a reservoir of compressed air taken from the crankcase during the power stroke, or from the cylinder space during the compression stroke. The high energy of the exhaust gas (pressure, temperature) is not utilized; the fuel is introduced to the air stream flowing through the feed canal.

Utilization of hot exhaust gas in the engine according to this patent application PCT/PL95/00015, makes possible the evaporation of heavy fuels as well, thus involving the use of various fuels in a spark ignition engine.

2. All features of the solution according to the new formulation of the claims were included in the previous version. The changes consist in limiting the substantive extent of the invention protection, which was done in the following way: a. the preamble of the amended claims 1 and 5 was extended to include the features known from DE 41 16 303, earlier referred to as characteristic features in claims No. 1 and No 6, b. the title of the invention was changed so as to limit the extent of the invention to multi-cylinder engines only, in the new formulation, the features mentioned earlier inclaims Nos . 2 and 8 became the essential, distinctive features (which constitute the common general concept of the designs of independent claims 1 and 5) imposing the mode of operation of the engine wherein: there in one feed chamber common to all cylinders, situated inside the rotary distributor, to which fuel is supplied (the chamber performs two roles: it acts as a generator of the fuel-exhaust gas mixture, and as a distributor), and wherein the position of the control openings and canals ensures simultaneous inflow of exhaust gas to the distributor and outflow of the fuel-exhaust gas mixture to the cylinder which is in the compression stroke. The advantages of such a solution are indicated in the patent description on page 5 in lines 8 through 26 from the top. The engines according to the independent claims 1 and 5 differ in the number of canals connecting the feed chamber with the cylinder space: according to claims 1 through 4, it is a single feed canal operating on a two-way basis, whereas according to claims 5 and 6 there are two one-way canals, a feed canal and an exhaust gas canal. Further, the engines differ in the particular design of the distributors, as described in claims 2 , and in claims 5 and 6. Particular advantages of the solution described in claims 5 and 6 are indicated in the patent description on page 7 in lines 16 through 20 from the top.