WO1996019650A2

WO1996019650A2 - Method of generating physical power output using a reciprocating internal combustion engine

Info

Publication number: WO1996019650A2
Application number: PCT/EP1995/005086
Authority: WO
Inventors: Martin Wimmer, Jr.
Original assignee: Wimmer Martin Jr
Priority date: 1994-12-22
Filing date: 1995-12-22
Publication date: 1996-06-27
Also published as: DE4446057A1; AU5095896A; WO1996019650A3

Abstract

The invention concerns a method of generating a physical power output using a reciprocating internal combustion engine. In at least one piston-cylinder unit, a piston reciprocates in a cylinder and the reciprocal motion is transmitted via a connecting rod to a crankshaft; fresh gas flows in through an inlet channel and through a valve aperture which can be closed off by at least one inlet valve into the cylinder chamber formed in the cylinder; fuel is introduced into the fresh gas and the mixture of fresh gas and fuel is compressed as it moves in a first direction and ignited; the ignited mixture then burns and drives the piston in a second, diametrically opposing direction; the exhaust gas produced by combustion flows through at least one outlet valve and one outlet channel out of the cylinder chamber, the opening and closing of the inlet and outlet valves being effected by at least one control shaft which is driven by the crankshaft with a transmission ratio of 1:1. Each reciprocating displacement of the piston causes the gas in the cylinder chamber to be changed and the mixture to ignite.

Description

Method for generating physical performance with a

Reciprocating internal combustion engine

The invention relates to a method for generating physical power with a reciprocating piston internal combustion engine according to the preamble of claim 1.

Such a method is generally known and is used in four-stroke engines, which is known to have the four strokes of suction - compression - working - ejection. In these four cycles, two reversing cycles of the piston take place, with the crankshaft making two revolutions (720 °). During these two revolutions, the mixture in the combustion chamber is ignited, the ignition initiating the work cycle. In this known method, the exhaust valve usually opens at the end of the work cycle and closes shortly after the start of the intake cycle, so that the exhaust valve is open during the entire exhaust cycle. The inlet valve opens towards the end of the

REPLACEMENT BLUE (RULE 26) Ejection stroke and closes shortly after the start of the compression stroke, so that the inlet valve is open during the entire intake stroke. The mixture is ignited shortly before the end of the compression stroke.

This four-stroke process has the advantage that a good cylinder charge is achieved over the entire speed range and that it has a relatively good sensitivity to pressure losses in the exhaust system. Furthermore, the combustion process can be influenced well by the choice of the control times, that is to say the opening and closing times of the valves. However, by using only every second crankshaft revolution to generate work, the power density of a four-stroke engine is low.

The so-called two-stroke method is also generally known, in which one working stroke takes place during each revolution of the crankshaft, so that the power density is also higher than in the four-stroke method. In the time-of-stroke method, the mixture is sucked in through the crankshaft chamber located below the piston and precompressed when the piston moves downward. The precompressed mixture reaches the cylinder chamber from the crankshaft chamber via an overflow channel and is compressed there when the piston moves upwards. The compressed mixture is then ignited with the piston moving down and performing the stroke. When the piston moves downward, the outlet channel is released, as a result of which the exhaust gas is expelled because, at the same time, the mixture, which has been precompressed again, flows into the combustion chamber through the overflow channel and drives off the exhaust gas.

REPLACEMENT BLAπ (RULE 26) Although the two-stroke process has the great advantage that a work cycle is assigned to each crankshaft revolution, the two-stroke process is no longer used frequently because of its poor exhaust gas behavior. A major disadvantage, which leads to poor exhaust gas behavior, is the fact that due to the flow through the crankshaft housing, oil must be added to the fuel in order to provide lubrication in the area of the crankshaft and also the cylinder, and that unburned fresh gas is produced when the gas is changed parts are emitted through the exhaust system, which gives the two-stroke engine its typical exhaust gas odor and its poor exhaust gas behavior.

It is therefore the object of the present invention to provide a generic method for generating physical power with a reciprocating piston internal combustion engine, which has both a high power density and good exhaust gas behavior.

Another object is to provide a reciprocating piston internal combustion engine which operates using such a method.

The first object is achieved according to the characterizing part of claim 1 in that each reversing cycle causes a gas change in the cylinder space and that the mixture is ignited with each reversing cycle of the piston.

By the provision of a gas change in the cylinder space with each reversing cycle of the piston, that is to say with each revolution of the crankshaft and the ignition of the mixture with each reversing cycle of the piston, the known four-stroke method is modified to such an extent that it is suitable for each Crankshaft revolution has a work cycle - as in a two-stroke process - and thus enables a power density that corresponds to that of the two-stroke process.

The invention is based on the knowledge of the inventor that, in the case of high-speed two-stroke engines in which a rotary slide valve is provided in the opening of the intake duct in the crankcase for controlling the mixture entering the crankcase, even when the rotary valve is removed, that is to say with the mouth of the opening open Inlet channel in the crankcase, a smooth running of the engine with perfect performance is possible. This finding by the inventor led to the inventive linking of features of the four-stroke process with features of the two-stroke process, since, based on this knowledge of the applicant, a gas exchange of an engine provided with an intake and an exhaust valve and designed for operation according to the four-stroke process also works when both the inlet valve and the outlet valve are open for a long period of time.

On the one hand, the method according to the invention has the advantage that a work cycle is assigned to each crankshaft revolution, so that the power density in the method according to the invention corresponds to that of the two-stroke method, but without the mixture containing the oil fraction required for the two-stroke method, because the crankshaft space is - as with the four-stroke process - separated from the cylinder chamber and is not flowed through by the mixture. This leads to significantly better exhaust gas behavior than with the conventional two-stroke process.

SPARE BLADE (RULE 26) In the method according to the invention, the fuel is preferably supplied to the fresh gas before it flows into the cylinder space, which can be done, for example, by a carburetor or by an intake manifold injection.

In another embodiment, the fuel is supplied to the fresh gas after it flows into the cylinder space, which can be done, for example, by an injection valve.

In a third embodiment of the method according to the invention, the fuel is supplied to the fresh gas after it has flowed into a prechamber connected to the cylinder space.

The fuel is preferably supplied to the fresh gas by at least one injection valve.

According to a further embodiment of the method according to the invention, the fresh gas can flow into the cylinder chamber under pressure, the pressure increase of the fresh gas being able to take place, for example, in a mechanical charger or in an exhaust gas turbocharger or by means of resonance charging.

The mixture is preferably ignited by at least one spark ignition device, such as, for example, in a gasoline engine.

However, the mixture can also be ignited by compression of the mixture as self-ignition, as is the case, for example, with a diesel engine. According to a preferred embodiment of the method, the outlet valve opens before the inlet valve and closes before the inlet valve, so that both the outlet valve and the inlet valve are open for a predetermined period of time.

According to a further embodiment of the method of the invention, the outlet valve opens before the inlet valve and closes after the inlet valve, the outlet valve being open during the entire opening time of the inlet valve.

According to a further embodiment of the method according to the invention, the outlet valve opens before the inlet valve and the outlet valve and the inlet valve close essentially simultaneously. As a result, the exhaust valve is open during the entire opening time of the intake valve.

According to yet another embodiment of the method according to the invention, the outlet valve opens essentially at the same time as the inlet valve and closes before the inlet valve, the inlet valve being open during the entire opening time of the outlet valve.

A further embodiment is characterized in that the outlet valve opens essentially at the same time as the inlet valve and closes after the inlet valve, the outlet valve being open during the entire opening time of the inlet valve.

Yet another embodiment of the method according to the invention is characterized in that the outlet valve opens essentially at the same time as the inlet valve and in

REPLACEMENT BLAπ (RULE 26) closes substantially simultaneously with the inlet valve, the outlet valve and the inlet valve being opened substantially simultaneously.

The second object underlying the invention is achieved by a reciprocating piston internal combustion engine with at least one cylinder closed by a cylinder head at one end, in which an axially movable piston is inserted, a connecting rod pivotally connected to the piston at one end, the other end of which is rotatable is mounted on a crankshaft, at least one intake valve and at least one exhaust valve which are provided in the cylinder head, at least one control shaft which acts on the intake and exhaust valves in an opening and a closing movement, preferably a camshaft which is connected to the crankshaft via a Drive device is in drive connection, which reciprocating piston internal combustion engine is characterized in that the drive device between the crankshaft and the control shaft has a transmission ratio of 1: 1.

By means of this transmission ratio of 1: 1, the camshaft acting on both the intake valve and the exhaust valve or an intake camshaft acting on the intake valve and an exhaust camshaft acting on the exhaust valve are driven at the speed of the crankshaft, so that every reversing cycle of the piston, i.e. everyone Rotation of the crankshaft, an opening and closing process of both the intake valve and the exhaust valve are assigned. This ensures that a gas change can take place in the cylinder space with each crankshaft revolution.

REPLACEMENT BLAπ (RULE 26) In the reciprocating piston internal combustion engine according to the invention, an ignition device is preferably provided which causes the mixture located in the cylinder space to be ignited with each revolution of the crankshaft.

Furthermore, an injection device is preferably provided which, with each revolution of the crankshaft, measures a predeterminable amount of fuel to the fresh gas intended for combustion.

In the case of a mechanical injection device with an injection camshaft, it is advantageous if the injection device has at least one injection valve acted upon by the injection camshaft, the injection camshaft being rotated by the crankshaft with a transmission ratio of 1: 1.

In a preferred embodiment, an exhaust system with low back pressure, preferably a resonance exhaust system, is connected to the exhaust duct.

The invention is explained in more detail below using an example with reference to the drawing; in this shows:

Fig. 1: the schematic representation of an internal combustion engine according to the invention and

2A to 2F: Diagrams of the opening and closing times of the valves depending on the crankshaft angle.

REPLACEMENT BLAπ (RULE 26) Figure 1 shows a reciprocating internal combustion engine according to the invention, which is shown as a single-cylinder engine with two overhead cam shafts. However, multi-cylinder engines are also conceivable in the common cylinder arrangements (for example in-line engines, V-engines, boxer engines, radial engines, counter-piston engines, etc.). The intake and exhaust valves can also be controlled in a known manner with only one camshaft via rocker arm mechanisms or other transmission means.

A piston 2 is arranged axially displaceably in the cylinder 1. The cylinder 1 is connected at its upper end in the usual way to a cylinder head 3, a cylinder head gasket 13 being arranged between the cylinder 1 and the cylinder 3. In the cylinder head 3 there is formed a cylinder head space 15 which is arranged coaxially to the cylinder and essentially merges continuously into the cylinder space 16 enclosed by the cylinder 1.

The piston 2 is connected in a known manner via a connecting rod 5 to a crankshaft 4 which is rotatably mounted in a crankshaft space below the cylinder 1. The connecting rod 5 is pivotally mounted on its upper end on the piston 2 and rotatably supported on the crankshaft 4 with its other lower end. In this way, a vertical reversing movement of the piston 2 is converted in a generally known manner into a rotary movement of the crankshaft 20.

In the cylinder head 3, an inlet channel 12 is provided which opens into the cylinder head space. The mouth of the inlet channel 12 into the cylinder space 15 is from an inlet valve 6 locked. The inlet valve 6 is acted upon in a known manner by a rotating inlet camshaft 8 for opening and closing the mouth of the inlet channel 12 into the cylinder head space 15. Conventional valve spring mechanisms, which are not shown in the schematic illustration in FIG. 1, pretension the inlet valve 6 in its closed position.

Furthermore, an exhaust port 14 is provided in the cylinder head 3, which opens into the cylinder head space 15 opposite the mouth of the intake port. The mouth of the outlet channel 14 is closed by an outlet valve 7, which is acted upon by an outlet camshaft 9 for opening and closing, the outlet valve 7 also being known by a known valve reset mechanism (for example spring, mechanics, pneumatics or hydraulics) the closed position is biased.

The cross-current principle shown in FIG. 1 with the mutually opposite mouths of the inlet channel 12 and the outlet channel 14 is particularly advantageous for carrying out the method according to the invention, because this enables a very rapid gas change to take place; in principle, however, other arrangements of the mouths are also conceivable, such as, for example, countercurrent guidance of the inlet channel and the outlet channel. Several inlet and / or outlet valves can also be provided.

A spark plug 10 is provided in the cylinder head, essentially in the area of the cylinder axis, and an injection valve 11 is laterally offset from it. The spark plug 10 and the injection valve 11 function in a manner known to the person skilled in the art and can also be arranged in another way. For example, the injection valve can also be provided in the intake manifold, that is to say in the inlet duct 12; However, an injection valve can also be dispensed with if a carburetor is connected upstream of the inlet duct. In addition, several spark plugs and / or injection valves can be provided in a respective arrangement.

If the internal combustion engine according to the invention is designed as a self-igniter, the spark plug 10 can be omitted and replaced by a glow plug if necessary. In the case of a compression-ignition engine (diesel engine), a prechamber can also be provided in the cylinder head, which is connected to the cylinder head space 15 and into which the injection valve opens. In principle, the injection valve 11 can also open directly into the cylinder head space 15 in the case of a compression-ignition engine.

According to FIG. 1, the crankshaft is provided with a drive wheel 20 shown in dash-dot lines, and the camshafts 8, 9 are each provided with a corresponding drive wheel 22, 24. The drive wheels 20, 22 and 24 are connected to one another via a rotating drive means 18. The drive wheels 20, 22 and 24 can be chain sprockets, for example, the rotating drive means 18 being formed by a drive chain. The diameter of the drive wheels 20, 22 and 24 is essentially identical, so that the respective speed of the camshafts 8, 9 corresponds to that of the crankshaft 4.

Instead of the chain drive shown schematically in FIG. 1, a toothed belt drive can also be provided, the drive wheels 20, 22 and 24 being formed by gear wheels and the 'rotating drive means 18 by a Timing belt is formed. However, other power transmission mechanisms between the crankshaft 4 and the camshafts 8, 9 are also conceivable, such as, for example, a gear transmission or a vertical shaft transmission; it is only important that the gear ratio between the crankshaft 4 and the individual camshafts 8, 9 is 1: 1, so that the camshafts rotate at the same speed as the crankshaft.

FIG. 2A shows a circle which schematically shows one revolution of the crankshaft, the direction of rotation corresponding to the clockwise direction (arrow x).

The diagram of the piston-cylinder unit with the inlet valve E and the outlet valve A within the circle symbolizes the crankshaft angle which is represented by the circle. The top dead center OT, in which the piston assumes its uppermost position, and the bottom dead center UT, in which the piston assumes its lowest position, are drawn on the circle.

The point in time at which the outlet valve A opens is designated AO on the circle and is preferably in the range between 105 degrees and 45 degrees, preferably between 90 degrees and 65 degrees, more preferably between 80 degrees and 65 degrees before bottom dead center UT.

The time of opening of the inlet valve E is designated EO and is after the opening time AO of the exhaust valve, preferably between 65 degrees before bottom dead center UT and bottom dead center UT. The time of closing the exhaust valve A is labeled AS and is preferably in a range between bottom dead center UT and about 105 degrees after bottom dead center UT, preferably 5 degrees to 90 degrees after bottom dead center UT.

The closing time of the inlet valve E is designated ES and is preferably after the closing of the outlet valve; preferably in the range between 30 degrees and 70 degrees after bottom dead center UT.

The angular ranges given in connection with FIG. 2A also apply to the following examples of FIGS. 2B to 2F, only the ratios of the opening and closing times of the intake valve and the exhaust valve being changed to one another. It is advantageous if the position of the opening time and the closing time of the intake valve and the position of the opening time and the closing time of the exhaust valve are each asymmetrical with respect to the bottom dead center. For example: EO = 40 ° before UT, ES = 65 ° after UT, AO = 90 ° before UT, AS = 30 ° after UT. This control diagram cannot be implemented with conventional two-stroke engines.

FIG. 2B shows a special embodiment of the method according to the invention, the opening times of the exhaust valve and the inlet valve corresponding to the opening times described in connection with FIG. 2A; However, the closing time AS of the exhaust valve A is later than the closing time ES of the intake valve E. This arrangement in connection with a resonance exhaust of a conventional type of a two-stroke engine enables a particularly high power delivery:

REPLACEMENT BLADE (RULE 26) FIG. 2C shows an embodiment in which the opening time AO of the exhaust valve A is equal to the opening time EO of the intake valve E, while the intake valve closes after the exhaust valve, as has been described in connection with FIG. 2A.

In FIG. 2D, the opening time AO of the exhaust valve A is also equal to the opening time EO of the intake valve E, while the closing time AS of the exhaust valve is later than the closing time ES of the intake valve, as has been described in connection with FIG. 2B.

In FIG. 2E, the exhaust valve A opens before the intake valve E, as described in connection with FIG. 2A, while the closing time AS of the exhaust valve A is equal to the closing time ES of the intake valve.

Finally, in FIG. 2F, the opening time AO of the exhaust valve is equal to the opening time EO of the intake valve, while the closing time AS of the exhaust valve A is equal to the closing time ES of the intake valve E. In this example, the exhaust valve and the intake valve are open for an equal period of time.

It should be noted that the outlet valve A opens before the inlet valve E, but at the same time at the same time as the inlet valve E, while the closing of the outlet valve A before the closing of the inlet valve, after the closing of the inlet valve or at the same time as the closing of the inlet valve can be done. LIST OF REFERENCE NUMBERS

1 cylinder

2 pistons

3 cylinder head

4 crankshaft

5 connecting rods

6 inlet valve

7 exhaust valve

8 intake camshaft

9 Exhaust camshaft 0 Spark plug 1 Injector 2 Inlet duct 3 Cylinder head gasket 4 Exhaust duct 5 Cylinder head space 6 Cylinder chamber 8 Drive means 0 Drive wheel 2 Drive wheel 4 Drive wheel

Claims

Method for generating physical power with a reciprocating piston internal combustion engine, ^v in which in at least one piston-cylinder unit a piston (2) reverses in a cylinder (1) and the reversing movement via a connecting rod (5) to a Transmits crankshaft (4); in which fresh gas flows through an inlet channel (12) and a valve opening which can be closed by at least one inlet valve (6) into the cylinder space (16) formed in the cylinder (1); in which a fuel is supplied to the fresh gas; in which the mixture of fresh gas and fuel is compressed and ignited by the piston (2) moving in a first direction; in which the ignited mixture burns and thereby moves the piston (2) in a second direction opposite to the first direction, in which the exhaust gas produced by the combustion exits through at least one outlet valve (7) and one outlet channel (14) flows out of the cylinder chamber (16), the opening and closing of the inlet valve (6) and the outlet valve (7) being effected by at least one control shaft (8; 9) which is subjected to rotation by the crankshaft (4), a reversing cycle of the piston (2) corresponds to a complete crankshaft revolution, characterized in that each reversing cycle causes a gas change in the cylinder chamber (16) and in that the mixture is ignited with each reversing cycle of the piston (2).

2. The method according to claim 1, characterized in that the fuel is supplied to the fresh gas before it flows into the cylinder space.

3. The method according to claim 1, characterized in that the fuel is supplied to the fresh gas after its inflow into the cylinder space.

4. The method according to claim 1, characterized in that the fuel is supplied to the fresh gas after its inflow into a prechamber connected to the cylinder space.

5. The method according to any one of the preceding claims, characterized in that the fuel is supplied to the fresh gas by at least one injection valve (11).

6. The method according to any one of the preceding claims, characterized in that the fresh gas flows under pressure into the cylinder chamber. - 18 -

Method according to one of the preceding claims, characterized in that the mixture is ignited by at least one external ignition device.

Method according to one of claims 1 to 6, characterized in that the ignition of the mixture by the compression of the

Mixture occurs as self-ignition.

9. The method according to any one of the preceding claims, characterized in that the outlet valve (7) before the inlet valve (6) opens and before the inlet valve (6) closes and that during a predetermined period of time both the outlet valve (7) and the inlet valve ( 6) are open.

10. The method according to any one of claims 1 to 8, characterized in that the outlet valve (7) before the inlet valve (6) opens and after the inlet valve (6) closes, the outlet valve (7) during the entire opening time of the inlet ¬ valve (6) is open.

11. The method according to any one of claims 1 to 8, characterized in that the outlet valve (7) opens before the inlet valve (6) and that the outlet valve (7) and the inlet valve (6) close substantially simultaneously, the outlet valve (7 ) is open during the entire opening time of the inlet valve (6). 12. The method according to any one of claims 1 to 8, characterized in that the outlet valve (7) opens substantially simultaneously with the inlet valve (6) and closes before the inlet valve (6), the inlet valve (6) during the entire opening time of Exhaust valve is open.

13. The method according to any one of claims 1 to 8, characterized in that the outlet valve (7) opens substantially simultaneously with the inlet valve (6) and closes after the inlet valve (6), the outlet valve (7) during the entire opening time of Inlet valve (6) is open.

14. The method according to any one of claims 1 to 8, characterized in that the outlet valve (7) opens substantially at the same time as the inlet valve (6) and closes substantially at the same time as the inlet valve (6), the outlet valve ( 7) and the inlet valve (6) are opened essentially simultaneously.

15. Reciprocating piston internal combustion engine with at least one cylinder (1) closed by one cylinder head (3) at one end, in which an axially movable piston (2) is inserted; a connecting rod (5) pivotally connected to the piston (2) at its first end, the other end of which is rotatably mounted on a crankshaft (4); at least one inlet valve (6) and at least one outlet valve (7) which are provided in the cylinder head (3);

FRESATZBLATT (RULE 26) at least one control shaft (8; 9) acting on the inlet and outlet valves (6; 7) in an opening and a closing movement, preferably a camshaft, which is connected to the crankshaft (4) via a drive device (18, 20, 22 , 24) is in drive connection, characterized in that the drive device (18, 20, 22, 24) between the crankshaft (4) and the control shaft (8; 9) has a transmission ratio of 1: 1.

16. Reciprocating internal combustion engine according to claim 15, characterized in that an ignition device (10) is provided which causes ignition of the mixture in the cylinder chamber (16) with each revolution of the crankshaft (4).

17. Reciprocating internal combustion engine according to claim 15 or 16, characterized in that an injection device (11) is provided, which for each revolution of the crankshaft (4) measures a predeterminable amount of fuel to the fresh gas intended for combustion.

18. Reciprocating piston internal combustion engine according to claim 17, characterized in that the injection device (11) has at least one injection valve acted upon by an injection camshaft, the injection camshaft being subjected to rotation by the crankshaft (4) with a transmission ratio of 1: 1. 19. Reciprocating internal combustion engine according to one of claims 15 to 18, characterized in that an exhaust system with low back pressure, preferably a resonance exhaust system, is connected to the exhaust port (14).