EP2054594B1 - Internal combustion engine having integrated supercharging - Google Patents

Abstract

The method involves increasing and decreasing of volume of a working area (8) limited by a piston (4) moving back and forth in a cylinder (2). The load contained in the working area propels the piston for the delivery of work, with the combustion under extension of the area during a working stroke. The volume of the fresh air sucked in a compression chamber (14) is cyclically changed depending on the piston movement. A fresh air quantity is supplied to the working area and the fresh air volume sucked in between two strokes is larger than the variation in volume of the area during stroke. An independent claim is also included for an internal combustion engine with an integrated loading.

Description

The invention relates to an internal combustion engine with integrated charging.

The supercharging of piston internal combustion engines is an increasingly used means not only to increase performance, but also to reduce fuel consumption. From the DE 102 47 197 A1 an internal combustion engine is known, in the cylinder wall Überströmschlitze are formed, which release a connection between the compression chamber and the working space in the region of the bottom dead center of the cylinder, so that in the compression chamber during the downward stroke of the piston compressed fresh air can flow into the combustion chamber.

From the DE 198 25 490 A1 is an internal combustion engine is known, is sucked in the fresh charge in a sub-piston space, then moved into a transfer pipe and is trapped there, is sucked in the sub-piston space, a further amount of gas and the normal intake of the combustion chamber takes place and then spent the vorangesaugten gases in addition to the combustion chamber become. A peculiarity of this known internal combustion engine is that the sub-piston space is relatively large and funded by him charge is contaminated with lubricating oil of the crank mechanism. Further, the relatively large volume of the compression chamber causes the fresh charge located there is only slightly compressed in the downward stroke of the piston and is pressed according to only a little fresh charge in the transfer pipe.

From the DE 40 27 533 C2 is an internal combustion engine is known, the piston simultaneously rotates in its up and down movement and connected via a non-rotatably connected to the piston piston shaft which moves linearly during the up and down movement of the piston relative to the piston with an output shaft. Below the piston, a precompression space defined by the piston, the cylinder inner wall and a partition wall, through which the piston shaft is rotatably and tightly guided, is arranged in which fresh air is precompressed and subsequently supplied to the combustion space arranged above the piston.

In the DE 198 39 227 A1 an internal combustion engine is described, the piston is connected via a shaft with a crank mechanism, a linear reciprocating motion of the shaft converted into a rotational movement of at least one crankshaft. At least one further piston, which operates within a space guided between two partitions of the cylinder and compresses air which is supplied to the combustion chamber, is fastened to the shaft.

The US 5,791,303 shows another embodiment of an internal combustion engine, wherein from another shaft piston for the compression of fresh air is attached.

A so-called double crank drive, as in the DE 198 39 227 A1 is used to convert a linear reciprocating motion of the piston connected to the shaft in a rotary motion of at least one crankshaft, is also from the DE 102 47 196 B4 and the DE 102 47 197 A1 known.

The invention has for its object to provide an internal combustion engine with integrated charging, which works with high charging efficiency and provides low-emission exhaust gas.

This object is achieved with the features of claim 1.

With the features of claim 15, the internal combustion engine according to the invention can be made very compact, since the cylinder chamber can be widely used because of the low intrinsic volume of the piston.

The claim 2 identifies the internal combustion engine according to the invention in four-stroke operation.

The claim 5 characterizes the internal combustion engine according to the invention in two-stroke operation.

The other claims are directed to further advantageous embodiments and refinements of the internal combustion engine according to the invention, the advantages of which will become apparent from the following description.

The invention is explained below with reference to schematic drawings, for example, and with further details.

Figur 1:

eine schematische Schnittansicht einer Brennkraftmaschine, welche nicht Teil der erfindung ist, geschnitten in der Mittelebene des Zylinders in Bewegungsrichtung des Kolbens,

Figur 2:

eine Teilansicht eines Schnittes durch die Brennkraftmaschine gemäß Figur 1 in einer den Verdichtungsraum enthaltenden Ebene senkrecht zur Bewegungsrich- tung des Kolbens,

Figur 3:

eine Schnittansicht eines Wirbelerzeugers, der gleichzeitig als Zyklon zur Parti- kelabscheidung arbeitet,

Figur 4:

eine Schnittansicht einer erfindungsgemä- ßen Brennkraftmaschine, und

Figur 5:

eine Skizze zur Erläuterung einer Eigenschaft eines Doppelkurbeltriebs.

In the figures represent:

FIG. 1:

a schematic sectional view of an internal combustion engine, which is not part of the invention, cut in the median plane of the cylinder in the direction of movement of the piston,

FIG. 2:

a partial view of a section through the internal combustion engine according to FIG. 1 in a plane containing the compression space perpendicular to the direction of movement of the piston,

FIG. 3:

a sectional view of a vortex generator which simultaneously operates as a cyclone for particulate separation,

FIG. 4:

a sectional view of an inventive internal combustion engine, and

FIG. 5:

a sketch for explaining a property of a double crank drive.

FIG. 1 shows a section through a median plane of the cylinder in the direction of movement of the piston of an internal combustion engine which is not part of the invention, wherein also located outside of the cutting plane parts are shown. In a cylinder 2 of the internal combustion engine operates a disc-shaped piston 4, which forms a working space 8 between its top and a cylinder head 6.

The cylinder 2 is closed on its underside by a bottom wall 10, through which a shaft 12, which is preferably rigidly connected to the piston 4, is linearly reciprocatingly guided in a reciprocating fashion. Between the bottom of the piston 4 and the bottom wall 10, a compression space 14 is created in this way.

Below the cylinder in a rigidly connected to this crankcase 16, a so-called double crank drive is arranged, which includes two running in the opposite direction at the same speed crankshafts 18 and 20, which are formed with crank disks 22 and 24 via peripheral gears 26 and 28 rotatably with each other in Are engaged. The directions of rotation of the crankshafts are preferred as in FIG. 1 specified.

On each crank disc eccentrically one end of a connecting rod 30 and 32 is mounted, the other end is mounted on the shaft 12. In the position shown in solid lines, the piston 4 is in its top dead center. In the dotted position, the piston 4 is located with the connecting rods in its bottom dead center. As can be seen, the shaft 12 extends with its end facing away from the piston to below the plane in which the crankshafts are mounted. This is achieved on the one hand a compact design and on the other hand achieved that the connecting rods 30 and 32 are essentially claimed only to train. Immediately above the bottom wall 10 opens into the compression chamber, a fresh air supply passage 34 and leads from the compression chamber 14, a discharge channel 36 out.

In the region of the mouth of the feed channel 34 in the compression chamber 14 is a supply valve 38 ( FIG. 2 ) arranged. In the region of the discharge of the discharge channel 36 from the compression chamber 14, a discharge valve 40 is arranged.

The supply valve 38 and the discharge valve 40 are formed by a slotted valve disc 42 which is non-rotatably connected in a manner not shown with one of the crankshafts and rotates at the same speed as the crankshafts. More specifically, the valve disk 42 has a feed slot 44 sweeping an angular segment in the circumferential direction (FIG. FIG. 1 ) and an angular segment sweeping in the circumferential direction discharge slot 46. The radial distance of the slots 44 and 46 from the axis of rotation of the valve disc 42 is such that the slots are aligned with the mouth of the supply channel 34 and the discharge of the discharge channel 36, respectively.

The discharge channel 36 is connected to a buffer volume or a buffer container 48, which in turn is connected to an inlet channel 52 leading to a cylinder head 6 arranged inlet channel 52. In the inlet channel 52, a control valve 54 is arranged.

In the cylinder head 6, at least one outlet valve 56 is furthermore arranged in a manner known per se, which in the open state connects the working space 8 with an outlet channel 58. When trained as a gasoline engine, a spark plug 59 is disposed in the cylinder head 6, which may be missing in diesel engine training or replaced by a glow plug.

The buffer container 48 is provided with a cooler 60, which is preferably connected to a cooling system of the internal combustion engine, with which preferably also the cylinder walls are cooled. Corresponding cooling channels are designated 61. The cooler 60 may be designed as an intercooler in a conventional manner as an air cooler. The pressure in the Buffer tank 48 is preferably controllable with a blow-off valve 62 which is connected to a control unit.

Before the inlet into the buffer container 48, a check valve 64 is advantageously arranged.

The basic mode of operation of the internal combustion engine described is explained below using the example of a gasoline engine operated in a four-stroke cycle:

Suppose the piston 4 is at top dead center. Inlet valve 50 and exhaust valve 56, which are controlled in a conventional manner, are closed; into the working space 8, which has its minimum volume and contains fresh compressed charge, fuel is injected via an injection system, not shown, which is ignited by means of the spark plug 59. The piston 4 then moves downwards, wherein when the supply valve 38 is closed by the open discharge valve 40 (the discharge slot 46 covers the discharge channel 36) located in the compression chamber 14 fresh air is forced into the buffer tank 48. When the piston reaches its BDC (which is due to the double crank drive only after a crankshaft lift of about 200 ° TDC), or slightly before, the exhaust valve 56 opens and the overflow of the exhaust port 46 to the exhaust passage 36 is terminated. The piston 4 moves by increasing the volume of the compression chamber 14 and reducing the volume of the working space 8 upwards, the supply slot 44 comes into coincidence with the supply channel 34 and the supply valve 38 opens, so that in the compression chamber 14 fresh air is sucked. When the piston 4 has reached its TDC, or shortly before, closes the exhaust valve 56 and closes the supply valve 38. Then, a downward stroke of the piston begins again, again forced fresh air from the compression chamber 14 through the now opened again discharge valve 40 into the buffer tank 48 is so that there for a suction or filling cycle of the working chamber 8 is substantially twice the volume of the compression chamber 14 is available, which flows at open during the intake stroke inlet valve 50 into the working space 8 and after a subsequent compression stroke of the piston 4 to work is available.

As is apparent from the above, the internal combustion engine according to the invention is designed with integrated charging, which is extremely efficient, to which the cooling of the buffer tank 48 contributes.

In the described engine, the volume of the working chamber 8 changes by the same amount as the volume of the compression chamber 14. In the steady state and assuming isothermal conditions therefore located in the working chamber 8 at the bottom dead center of the piston air volume has about twice the pressure as the ambient pressure since this volume was conveyed twice (one intake stroke of the working space corresponds to two compression strokes of the compression chamber). The volume of the buffer container 48 has an influence on the dynamics of the system. The larger the volume of the buffer tank 48, the lower the pressure fluctuations. However, when the pressure in the buffer tank 48 is lowered, the engine will react due to the opening of the bleed valve support and will not return to full charge pressure until delayed. The buffer container 48 may include a spring-loaded membrane for pressure stabilization, wherein the spring pressure may be adjustable. The buffer container 48 may also be formed by a rubber-type container whose volume adapts to the pressure. It is possible to let the buffer tank or the buffer volume unfold completely by the charge air is only performed by required connection lines. The geometric compression ratio of the compression space may be higher than that of the working space, since in UT of the piston only the smallest possible dead volume should be present. The check valve 64 ensures that no fresh air already contained in the buffer tank 48 flows back into the compression chamber 14.

By charging, it is possible to select the timing so that there is no overlap between the open inlet and the open outlet.

For example, control times are: Inlet opens: 5 ° before TDC includes: 20 ° to UT Outlet opens: 40 ° before UT includes: 5 ° to UT

The load control advantageously takes place as follows:

If no charge is required, the blow-off valve 62 is advantageously opened so that no overpressure arises in the buffer container 48. If operation is to be performed with less filling, the cross-section of the inlet channel 52 is advantageously reduced with the control valve 54, which may be designed as a throttle valve. The control of the operation without charging is thus advantageously via the control valve 54. When charging is required, the control valve 54 is fully opened and the control is carried out via the blow-off valve 62, which is completely closed at full load.

The phase of the valve disc 42 relative to the crankshaft or the circumferential angular range of the slots 44, 46 may be adjustable. The feed valve 38 and discharge valve 40 formed by the valve disk 42 and its slots can be replaced by simple check valves, wherein the check valve 38 allows an inflow into the compression chamber 14 and the check valve 40 allows an outflow from the compression chamber 14.

The supply valve 38 and the discharge valve 40 can also be replaced by freely controllable valves, such as rotary valves. These valves can be individually controlled, whereby a load control is possible. A load control can also take place in that a non-illustrated throttle valve is arranged in the supply channel 34.

It is understood that the described possibilities to control the sucked fresh air or fresh charge from the working space 8, are primarily required for Otto engine operation and can be omitted in diesel engine operation or be applied in such a way that no increased compression work is performed. The throttle valve 54 or a valve arranged in the supply channel 34 may be formed as a tube valve whose flow area is changeable by squeezing.

The integrated charge described above can be used on any type of four-stroke stroke reciprocating internal combustion engine, for example spark-ignition gasoline engines, direct injection or direct injection diesel engines, etc. The charge described provides for spontaneously available high torque even at low speeds. If necessary, it can be supplemented by an exhaust gas turbocharger if very high boost pressures are required.

The described double crank drive is an easy way to bring about a linear guide of the shaft 12, whereby an oil-tight separation between the crank chamber and compression chamber is possible. In addition, a better efficiency is achieved because of the changed relationship between the position of the piston and the rotational position of the crankshaft.

The double crank drive may be replaced by another crank drive, such as a slider-type crank-wheel drive, which allows linear movement of the piston shaft through the opening in the bulkhead.

Fig. 3 shows a vortex generator for the separation of particles contained in the fresh air, with the help of which the conditional by a conventional air filter flow resistance can be reduced.

According to Fig. 3 For example, a cyclone 72 has an overall cylindrical housing 74 which is widened in diameter in its lower region and has a flow body 76 projecting into the axis of the cylinder in its bottom wall. An inlet 77 leads eccentrically or tangentially into the extended lower region of the cyclone 72.

The housing 74 is double-walled, at least in some areas, wherein the inner wall 78, which consists for example of sheet metal, formed by punching tabs projecting towards the outer wall or inwardly, so that tangentially to the inner wall along flowing air due to the lobes in the Space between the inner wall 78 and the outer wall is directed. From the spaces between the inner wall 78 and the outer wall exit outlets 80, which form storage volumes, which are emptied periodically or permanently.

The function of the cyclone 72 is as follows:

Air flows through the tangential inlet 77 in the extended lower portion of the housing 74 and there, supported by the flow body 76 in a circumferential helical flow whose rotational speed in accordance with Fig. 3 increased upward as a result of the narrowing cross section of the housing 74. Airborne particles As a result of their higher density, they concentrate outward in the flow and enter the area between the inner wall 78 and the outer wall of the housing 74. As a result of gravity, these particles then fall down and collect in the outlets 80 from where they originate be disposed of.

Such a cyclone 72 may for example be mounted directly in the fresh air inlet of the internal combustion engine instead of the vortex generator 70, where it replaces an air filter or arranged upstream upstream of the air filter, so that the air filter can be formed with lower flow resistance. It is understood that the vortex generator described by way of example can be varied in many ways. Furthermore, vortex generators without the possibility of particle separation may be inserted at locations where vortex generation is advantageous for other reasons, such as upstream of the cooled buffer vessel for better heat exchange or upstream of the intake valve for better combustion in the combustion chamber.

Fig. 4 shows an embodiment of an internal combustion engine according to the invention, wherein for parts of Fig. 1 corresponding parts the same reference numerals are used.

In contrast to the embodiment according to Fig. 1 instructs the machine according to Fig. 4 a further cylinder 82 in which a compressor piston 84 operates, which is attached to the guided through the bottom of the crankcase 16 under sealing shaft 12. On both sides of the compressor piston 84 compression chambers 86, 88 are formed in the cylinder 82, which are connected via inlet valves with the environment and via outlet valves 94, 96 with the buffer tank 48. The intake valves and exhaust valves may be simple check valves.

The cylinder 2 has arranged in the region of the bottom dead center of the piston 4 Überströmschlitze 98 which release a connection between the compression chamber 14 and the working space 8 in the lower region of the dead center of the piston 4.

In another peripheral region, the inner wall of the cylinder 2 is provided shortly above the dead center of the piston with outlet slots 100, which open into the outlet channel 58. In the outlet passage 58, a valve 102 operates.

The function of the engine operating in two-stroke mode is as follows:

It is assumed that the piston 4 is located as in Fig. 4 presented in his subtle. The valve 40 and the valve 102 are open. As soon as the upward movement of the piston 4 begins, the valve 40 is closed and shortly thereafter the valve 102. The valve 38, which may be a simple check valve, opens, so that the compression chamber 14 sucks in air and compressed into the working space 8 fresh air is compressed , The overflow slots 98 close as soon as they are no longer run over by the piston 4 and as a result of the closing of the valve 102, the working chamber 8 is separated from the outlet channel 58. Upon further continuation of the upstroke of the piston, air is expelled from the compression space 86 into the buffer tank 48, and fresh air is sucked into the compression space 88. After the piston has reached its UT, the power stroke continues by igniting the charge located above the piston 4 (an injection system and a spark plug in Otto engine operation are not shown). During the downward movement of the piston, during which the valve 40 can already be opened, air sucked into the compression chamber 14 is compressed and air sucked into the compression chamber 88 is conveyed into the buffer container 48. Shortly before reaching UT, the valve 102 is opened so that when the piston releases the exhaust ports 100, burnt charge may be expelled through the exhaust passage 58. As soon as the overflow slots 98 are run over, the connection from the compression chamber 14 to the working chamber 8 is released, so that the air conveyed by the compressor piston 84 and the compressed air located in the compression chamber 14 flow into the working space 8 and are available for a new working stroke. Overall, during one working cycle (up and down movement of the piston 4) thus the stroke volume of the compression chamber 14 and the stroke volumes of the compression chambers 86 and 88 promoted, so that in the example shown with equality of all stroke volumes in first approximation in neglecting thermal effects and flow losses a boost pressure is achieved in the amount of three times the ambient pressure.

For the control of the boost pressure and the load, there are in turn a variety of options that are not explained in more detail.

The engine according to Fig. 4 can be varied in many ways. For example, a two-stroke operation is also possible if in the mouth of the inlet channel into the working space 8, a valve similar to the Fig. 1 is arranged. Also, the outlet slots 100 with the additional valve 102 may by an exhaust valve according to Fig. 1 be replaced, so that the engine can be completely head-controlled.

Further it is possible to use the engine according to Fig. 1 with a charge, as is possible through the cylinder 82 to complete.

The engine according to the invention may have a plurality of, for example, successively arranged cylinder. The compressed in the individual cylinders air can be assigned to the individual cylinders or by a collecting volume, eg. B. a buffer container are performed, which is common to at least one group of cylinders.

Overall, the different illustrated features can be combined in a variety of ways with each other as long as an integrated charge is achieved, i. a charge, which is achieved directly by the movement of the piston 4 and another with the piston 4 motion-transmitting connected compressor piston 84. The individual compaction volumes do not have to be the same. Also, several compression stages can be provided by arranging a plurality of cylinders 82.

FIG. 5 shows a peculiarity of the double crank drive, which can be used advantageously in different ways:

In FIG. 5 the crank disks of the double crank drive are shown schematically and designated 22 and 24. The turning circles on which the pivot points of the connecting rods 30 and 32 move about the centers M of the crank disks 22 and 24 are shown in dashed lines. The connecting rods 30 and 32 are shown in top dead center TDC of the piston or of its shaft 12 with solid lines and dash-dotted lines in bottom dead center UT of the piston. As can be seen, the angle of rotation by which the crank disks 22 in the turn by turning the arrows so that the piston moves from the TDC to the TDC, well over 180 °. More precisely, this angle of rotation is dependent on the angle α which the connecting rods form at top dead center with a connecting line between the centers M of the crank disks 22 and 24 or a plane containing the axes of the crank disks 22 and 24. If the angle α is about 20 °, the angle of rotation from TDC to TDC in the illustrated direction of rotation is about 220 °. As the angle α increases, the angle of rotation decreases and is approximately 210 ° at an α of 30 ° and slightly above 200 ° at an α of 40 °.

Appropriate values for α are between about 20 ° and 45 °, depending on the type and design of the internal combustion engine.

At the in FIG. 5 shown direction of rotation of the crank disks 22 and 24, the lying between the top dead center and the bottom dead center working phase of a reciprocating internal combustion engine can thus be extended to a crank angle of well above 180 ° to 220 ° and above. This leads to the fact that, for example, in a two-stroke engine with two pistons, the 180 ° offset from each other, ie working in opposite phases, one of the piston in a working cycle or in a working phase can be constantly in which he generated as a result of combustion heat work on the Crank drive outputs. Thus, in a Zweizylinderzaktaktbrennkraftmaschine already with two cylinders an extremely uniform running can be achieved. Such a two-stroke internal combustion engine, for example, be designed such that your exhaust valve not, as in the internal combustion engine according to FIG. 4 is formed by a slot, but by a properly controlled separate outlet valve, such as poppet valve, in the cylinder head.

In a four-stroke internal combustion engine can be achieved for similar reasons in four cylinders whose pistons offset by 90 ° to each other, or even in a three-cylinder internal combustion engine, the piston offset by 120 ° to each other, an extremely comfortable round run can be achieved.

If the in FIG. 5 sketched double crank mechanism is used with opposite direction of rotation of the crank disks, the expansion phase from TDC to UT is correspondingly shortened and extended the suction or compression phase from UT to TDC accordingly. This direction of rotation also depends on the thermodynamic conditions of the combustion and the flow conditions can be used advantageously, for example in non-supercharged engines, including diesel engines, for the filling of a long period is favorable.

Another advantage of the basic design of the crank mechanism according to the FIGS. 1 and 5 is achieved, is that the connecting rods are essentially claimed only to train, because the point of articulation of the connecting rod on the piston shaft is constantly below the line connecting the centers of the crank disks.

LIST OF REFERENCE NUMBERS

2

cylinder

4

piston

6

cylinder head

8th

working space

10

bottom wall

12

shaft

14

compression chamber

16

crankcase

18

crankshaft

20

crankshaft

22

crank

24

crank

26

splines

28

splines

30

pleuel

32

pleuel

34

supply channel

36

discharge channel

38

supply valve

40

discharge valve

42

valve disc

44

feed slot

46

removal slot

48

buffer tank

50

intake valve

52

inlet channel

54

control valve

56

outlet valve

58

exhaust port

59

spark plug

60

cooler

61

cooling channel

62

blow-off valve

64

check valve

70

vortex generators

72

cyclone

74

casing

76

flow body

77

inlet

78

inner wall

80

outlet

82

cylinder

84

pistons compressor

86

compression chamber

88

compression chamber

90

intake valve

92

intake valve

94

outlet valve

96

outlet valve

98

transfer ports

100

exhaust port

102

Valve

Claims (15)

1. An internal combustion engine having integrated supercharging, comprising:

   at least one cylinder wherein a piston (4) can be reciprocated, thereby forming a working chamber between one side of the piston and the cylinder head (6) and forming a first compression chamber between the other side of the piston and a bottom wall (10) of the cylinder,

   a shaft (12) that is connected to the piston (4), said shaft passing through the bottom wall (10) in a sealed manner and being connected to a crank drive (22, 24, 32, 34) that transforms a linear reciprocating movement of the shaft into a rotational movement of a crankshaft (18, 20),

   a compressor piston (84) connected to the shaft, which compressor piston defines a second compression chamber (86) in a further cylinder (82), wherein

   the compression chambers (14, 86) can be communicated with the atmosphere and the working chamber (8) via conduits comprising valves such that fresh charge compressed in the compression chambers can be supplied to the working chamber,

   characterized in that

   the crank drive (22, 24, 32, 34) is arranged between the piston (4) and the compressor piston (84),

   the further cylinder (82) is isolated from the crank drive by a further bottom wall through which the shaft (12) is guided in a sealed manner so as to reciprocate, and

   a third compression chamber (88) is formed in the further cylinder (82) on the side of the compressor piston (84) facing away from the second compression chamber (86).
2. The internal combustion engine according to claim 1, characterized in that
   the internal combustion engine is operable in four-stroke operation,
   an intake valve (50) and an outlet valve (56) are arranged in the cylinder head (6),
   each compression chamber (14, 86, 88) is connected to the atmosphere via a supply valve (38, 90, 92) and to the intake valve via a discharge valve (40, 94, 96).
3. The internal combustion engine according to claim 2, characterized in that the supply valve (38) and the discharge valve (40) of the first compression chamber (14) are formed by grooves (44, 46) in a rotatable valve plate (42).
4. The internal combustion engine according to claim 2 or 3, characterized in that a buffer tank (60) is arranged upstream of the intake valve (50).
5. The internal combustion engine according to claim 1, characterized in that
   the internal combustion engine is operable in two-stroke operation,
   an intake valve leading to the working chamber (8) is formed by at least one overflow port (98) formed in the cylinder wall, which overflow port is opened in the region of the bottom dead centre of the piston (4) and leads from the first compression chamber (14) to the working chamber (8),
   an outlet valve leading out of the working chamber is formed by an outlet opening (100) passing through the cylinder wall, and uncovered before the piston (4) reaches its bottom dead centre, and
   the second and third compression chambers (86, 88) are communicated with the atmosphere by means of a respective supply valve, and communicated with an intake to the first compression chamber (14) by means of a respective discharge valve.
6. The internal combustion engine according to claim 5, characterized in that a buffer tank (48) is arranged upstream of the intake into the first compression chamber (14).
7. The internal combustion engine according to claim 4 or 6, characterized in that the buffer tank (48) is cooled.
8. The internal combustion engine according to claim 7, characterized in that the buffer tank (48) comprises a blow-off-valve (62).
9. The internal combustion engine according to one of claims 1 to 8, characterized in that the crank drive formed as a double crank drive having two crankshafts (18, 20) rotating at the same speed and in opposed directions, which crankshafts are each connected to the shaft (12) via a respective piston rod (30, 32).
10. The internal combustion engine according to claim 9, characterized in that the shaft (12) is connected to the piston rods (30, 32) on the side of the double crank drive (18, 20), which faces the compressor piston.
11. The internal combustion engine according to claim 9 or 10, characterized in that the double crank drive is designed such that the angle of rotation of the crank discs (22, 24) from the top dead centre OT of the piston (4) to the bottom dead centre UT is larger than 180°.
12. The internal combustion engine according to claim 11, characterized in that plural piston/cylinder units are provided, which work phase shifted relative to each other in such a way that at least one of the piston/cylinder units permanently delivers work to the crank drive.
13. The internal combustion engine according to claim 9 or 10, characterized in that the double crank drive is designed such that the piston rods (30, 32) form an angle of 20° to 45° with a plane extending through the axes of the crank discs (22, 24), when the piston (4) is in its top dead centre OT.
14. The internal combustion engine according to one of claims 1 to 13, characterized in that the path of the fresh air supplied to the working chamber (8) leads through at least one vortex generator (70), which generates a turbulence, whose axis is approximately parallel to the overall flow direction, in the fresh air flowing therethrough, the vortex generator (70) being formed as a cyclone (72) for separating particles contained in the fresh air flowing therethrough.
15. The internal combustion engine according to one of claims 1 to 14, characterized in that the piston (4) is substantially disk-shaped.

Images