WO2021180849A1

WO2021180849A1 - High pressure valve for delivering gaseous fuel to an internal combustion engine, and internal combustion engine

Info

Publication number: WO2021180849A1
Application number: PCT/EP2021/056188
Authority: WO
Inventors: Erwin Junker
Original assignee: Erwin Junker Grinding Technology A.S.
Priority date: 2020-03-12
Filing date: 2021-03-11
Publication date: 2021-09-16
Also published as: DE102020203194A1

Abstract

The invention relates to an internal combustion engine for operation with gaseous fuel, more particularly hydrogen, which has a high pressure valve (4) which delivers hydrogen by means of a control valve piston (5) to a cylinder (3) using cylindrical faces and control edges (5.1) or using conical elements (5.2). The control valve piston (5) is electromagnetically actuated, achieves short control times/high switching frequencies, is sealed in the housing (6) in at least two stages and without elastomers and prevents or at least hinders to a great degree any backflow of gaseous fuel, particularly hydrogen, meaning that backfiring is avoided, and has a reduced-weight lightweight design.

Description

HIGH PRESSURE VALVE FOR INTRODUCING GASEOUS FUEL INTO A COMBUSTION ENGINE, AND COMBUSTION ENGINE

The invention relates to an internal combustion engine for gas operation, in particular what hydrogen operation, and a high pressure valve for introducing gaseous fuel into such an internal combustion engine.

In the field of the operation of internal combustion engines with gaseous fuel, in particular hydrogen, a great deal of the state of the art has been published due to the many years in which the industry and associations have dealt with this topic, especially from an ecological point of view. In addition to the most frequently used liquid fuels, gaseous fuels such as natural gas or hydrogen are also increasingly being used to operate vehicles. The injection nozzles, also called injectors, for liquid fuels are largely perfected in their development, but with gaseous fuels a number of problems do not occur with liquid fuels. The known injectors for liquid fuels are therefore only suitable to a limited extent.

Gaseous fuels have different energy densities and volumes from liquid fuels.

A problem with the use of hydrogen or gaseous fuels is that, on the one hand, a relatively large amount of fuel with a significantly larger volume than liquid fuels has to be introduced into the combustion chamber of an internal combustion engine in a relatively short time, and, on the other hand, also the introduction must be implemented very precisely in terms of time and with regard to the metering of the amount of fuel introduced into the combustion chamber. This is necessary so that internal combustion engines used with natural gas or hydrogen or with other gaseous fuels do not have excessive consumption and minimal pollutant emissions. For this purpose, it is necessary that the gas quantities dosed as precisely as possible per injection process and at a defined point in time of the injection process that is coordinated with optimized combustion in the cylinder. In principle, two basic injection methods for gaseous fuels, in particular hydrogen, are known. One possibility of introducing gaseous fuel is that this fuel is introduced into the combustion chamber of the internal combustion engine in the end area of the inlet line, preferably immediately before the inlet area of the inlet line. Another possibility is that the gaseous fuel is blown directly into the combustion chamber with the appropriately developed, optimized and suitable for gaseous fuels injectors, which is also referred to as “injected”. The blowing in or injection of gaseous fuels is implemented in such a way that all of the fuel required for a combustion cycle is introduced in one blow-in process or in several blow-in processes per combustion cycle. Preferably, in addition to the need to be able to inject a certain maximum amount of fuel in a given period of time, it must also be possible to enter defined small amounts or very small amounts in precise doses in the cylinder. Another general requirement for the gas injectors or injection valves is that they must be precisely and reliably sealed off from the combustion chamber into which the gas, preferably hydrogen, is introduced, so that reignition in the area in front of the combustion chamber is avoided.

In Christian Spuller, Diesel Combustion Process with Hydrogen for Passenger Car Applications, PhD at the Technical University Graz, 2011, the specifics and peculiarities are necessary for the hydrogen operation of internal combustion engines from the studies carried out. Both the gas exchange and the combustion differ from the conventional operation of internal combustion engines with liquid fuels and require special technology for the introduction of hydrogen or other gaseous fuels into the combustion chamber of these internal combustion engines.

EP 3 225 827 A1, according to which the valve element of the gas valve for supplying the gaseous fuel is actuated by means of a magnetic actuator and in which two Sealing areas are provided, DE 102004 049 589 A1, which describes a hydrogen engine with an optimized fuel injection device, by means of which hydrogen flows into the inlet channel via a hydrogen channel and is introduced from there into the combustion chamber of the hydrogen engine, and DE 3904480 A1, in which gaseous fuel , for example hydrogen, is introduced into an intake manifold of an internal combustion engine intermittently, the valve member being electrically actuatable. Examples in the prior art for injecting gaseous fuel, in particular hydrogen, into the combustion chamber of an internal combustion engine are mentioned in DE 4308775 C1, in which the valve is designed as a piston valve, has the shape of a poppet valve in the opening area and a hydraulic control system by means of liquid actuated is taken, US 7 117 849 B1, in which a fuel! injector a gaseous fuel at high pressure via a fuel line by means of the main part of the fuel injector bil Denden nozzle is introduced directly into the combustion chamber of the internal combustion engine by means of a needle controlled with respect to its movement, DE 102009 012688 B3, according to which a valve for injecting gas into the combustion chamber of an internal combustion engine is introduced at high pressure, with a closing element and an actuator being driven by means of a magnetic coil and movably arranged in the housing, and EP 3267028 A1, in which an injection valve for injecting high-pressure natural gas using a controlled needle into the combustion chamber of a Internal combustion engine can be introduced, with two valve seats to ensure the appropriate tightness.

Furthermore, EP 3 153701 A1, DE 102017218267 A1 and DE 10353011 A1 also describe a valve for controlling a gas to be introduced into the combustion chamber of an internal combustion engine, the need for a reliable seal being pointed out in these prior art documents. In EP 3 153693 A1, a high-pressure valve for gaseous fuel is described, which ensures a corresponding tightness with respectively arranged bellows devices. In DE 102014224348 A1, DE 102014224340 A1, DE 102014224341 A1 and DE 102015201 293 A1, high-pressure valves are described which all refer to two or more sealing seats to ensure the tightness of such a fuel suitable for hydrogen, with elastomer seals being recommended in some cases Have a good tightness, which, however, can easily be damaged during operation of the internal combustion engine at full load and at high temperatures, which is why DE 102015201 392 A1 obviously has a thermal insulation element on one of two sealing seats, one of the two sealing seats being made of an elastomer sealing element exists, is provided in order to keep the temperature load of the elastomer sealing element within limits. DE 102014224343 A1 describes a reliable sealing and protection of a sealing seat by means of an additional thermal protection device, in DE 102014224339 A1 it is described that a shielding element and a cooling ring are used to reduce the temperature load on the sealing areas. DE 102014224344 A1 describes a gas injector for direct injection of a gaseous fuel into a combustion chamber of an internal combustion engine for better and more uniform distribution of the gaseous fuel in the combustion chamber with an additional control element to inject the gas jet according to the geometry of the combustion chamber for better mixture formation and combustion to shape. And finally, DE 102014205454 A1 describes a gas injector for injecting gaseous fuels, in which a double valve needle is provided, an outer needle being designed as a hollow needle and an inner needle being arranged in a hollow area of the outer needle.

The well-known injectors or gas or hydrogen injection valves for internal combustion engines have been adapted to different operating conditions, but usually only based on one or a maximum of two defined operating conditions that are to be covered with the respective design.

For use under two different operating conditions, it is normally always necessary that compromises inevitably had to be made in the technical design for both operating conditions; i.e. an optimal design was technically not aimed at.

It is therefore the object of the present invention to provide an internal combustion engine with a high pressure valve and a high pressure valve for an internal combustion engine for gas operation, preferably hydrogen operation, which provide improved operating conditions, optimal gas operation, very short switching cycles and control with regard to optimized properties, including combustion realized.

This object is achieved by an internal combustion engine for hydrogen operation with the features according to claim 1 and by a high-pressure valve provided for this internal combustion engine for hydrogen operation according to claim 12. Expedient developments are defined in the dependent claims.

The gas, preferably hydrogen-powered internal combustion engine according to the invention has, in a manner known per se, a cylinder in which a combustion chamber is formed and a piston is guided therein. According to the invention, the internal combustion engine has a high-pressure valve which has control edges or a cone-shaped control valve piston guided in a housing. By means of the control valve, hydrogen is fed directly into the combustion chamber or indirectly via an inlet line of the combustion The engine is blown or injected into the combustion chamber shortly before an inlet valve. The term “injection” is used here for the introduction of a gaseous fuel into the cylinder. The control valve piston of the high-pressure valve, which is also designed according to the invention, is electromagnetically actuated and, among other things, realizes short control times and high switching frequencies, so that the inlet cross sections of the injection device for the hydrogen into the combustion chamber are quickly released in accordance with an optimized mixture formation and combustion in the combustion chamber. The control valve piston is sealed in the housing in at least two stages and is elastomer-free in such a way that a backflow of a principally possible small amount of combustion gas, in particular hydrogen on contact with oxygen, does not allow backfire to occur. This means that the high-pressure valve has a high and reliable sealing effect both towards the combustion chamber and towards the damping cushion. So that short control times and high switching frequencies of the high-pressure valve can be achieved, this is designed to be weight-reduced and lightweight. The seal is designed in such a way that, if at all, only such small amounts of hydrogen flow back that when these small amounts of hydrogen come into contact with oxygen, no backfires occur, which can also be referred to as explosions.

For the hydrogen operation of an engine, the gaseous fuel is stored in the form of hydrogen in filled hydrogen bottles at approx. 350 bar. This supply pressure of course does not correspond to the injection pressure for liquid fuels, as it is nowadays implemented with common rail systems, for example, and how it is used, in particular for internal mixture formation. For this reason, the feed pressure must be queried by means of sensors upstream of the valve or the injection nozzle or the injection valve in the cylinder and, on the basis of this pressure information, or depending on the opening time or the opening path of the feed of gaseous fuel, in particular hydrogen , be managed. However, it is also possible that a pressure reduction is implemented before the supply of the gaseous fuel under the previously specified high pressure, so that the opening time or the opening path of the supply is essentially constant in the same operating state. Depending on the operating conditions, the pressure range for the gaseous fuel can be between 20 and 350 bar.

In addition to the high-pressure valve, the internal combustion engine preferably has an injector for fine metering of combustion gas or hydrogen into the combustion chamber. With such a preferred design of the internal combustion engine, two introduction organs for combustion gas or hydrogen are present in the combustion chamber. The high pressure valve is primarily used for the introduction of larger quantities of gas shaped fuel or hydrogen is provided in the cylinder, whereas the injector enables the fine metering of smaller amounts of gaseous fuel or hydrogen into the combustion chamber at defined and very short times or time intervals.

Furthermore, the injector is preferably designed in such a way that an intermittent or multi-stage supply of the hydrogen can be carried out directly into the combustion chamber. Intermittent supply should be understood to mean that the introduction of hydrogen in a discontinuous manner, i.e. with precisely defined and controllable intervals, is possible so that a direct improvement or optimization of the combustion in the combustion chamber can be achieved through the fine metering.

The high-pressure inlet valve is preferably designed to inject larger amounts of hydrogen, for example, than the injector which introduces smaller amounts of hydrogen into the combustion chamber to optimize combustion. Preferably, larger amounts mean a multiple of the smaller amounts of gaseous fuel injected with the injector.

In terms of the lightweight construction of the high-pressure valve, in particular its control valve piston is designed to be hollow, the wall thickness and shape being designed with a high degree of rigidity so that the lightweight construction is implemented by reducing the weight of the control valve piston in particular, without the required strength of the components suffering.

Instead of the high-pressure valve and injector being made from steel, it can therefore preferably be provided that the high-pressure valve and / or the injector are made from ceramic or from a ceramic-coated light metal. In addition, the moving parts in the high-pressure valve and in the injector can be made hollow and ceramic-coated in terms of lightweight construction.

According to a further exemplary embodiment, the high-pressure valve can preferably have other metal alloys. This ensures that the parts moving in the high-pressure valve and in the injector have a corresponding strength and rigidity, but are nevertheless weight-reduced and therefore mass-reduced due to the significantly lower density of light metal alloys compared to a steel alloy.

According to a preferred embodiment, the control valve piston of the high pressure valve is provided in its housing with a guide piston on which the control edges are are formed which interact with a hydrogen supply line. The control edges open the times of the supply of gaseous fuel, in particular hydrogen, and the size of the supply cross-sections and thus the amount of gaseous fuel that is introduced into the cylinder, but on the other hand also close the supply cross-sections at defined times after the desired Amount of gaseous fuel injected.

According to a further preferred exemplary embodiment, blow-in bores arranged in a ring are formed on a surface of the high-pressure valve that faces the combustion chamber and are arranged concentrically in the axial direction in the high-pressure valve. This means that the essentially flat rim surface of the high-pressure valve in this ring-shaped rim surface has injection bores arranged on an imaginary circular line. These injection bores are arranged concentrically in the axial direction in the outer rim of the high-pressure valve. The concentrically arranged injection holes therefore make it possible to introduce a relatively large gaseous amount of fuel into the cylinder in short time units.

The high-pressure valve of the internal combustion engine furthermore preferably has a gaseous damping pad, into which the control valve piston in the housing in the area of its end positions for stop avoidance or for stop damping is immersed. This prevents the control valve piston in its end position from hitting corresponding mating surfaces in the housing with its corresponding piston surface. When dimensioning the control of the control valve piston or the high-pressure valve as a whole, the existing cushioning pad is accordingly included in the control concept so that the slight delay in the movement of the control valve piston in the end positions does not have a disadvantageous effect on the introduction of gaseous fuel, in particular hydrogen in the combustion chamber.

According to a further exemplary embodiment, the internal combustion engine according to the invention for gaseous fuels, in particular hydrogen, has a high-pressure valve preferably standing in the cylinder head with respect to the axial alignment of the combustion chamber, with injection lines for the hydrogen arranged radially in the housing from the control valve piston by means of its control edges Injection cross-sections or injection cross-sections can be released or closed at one piston position. The upright arrangement of the high-pressure valve has the advantage that the space available in the cylinder head, which is limited anyway, for the arrangement of an additional additional, in addition to the inlet and outlet valves, which are already arranged in the cylinder head, can be accommodated in terms of space.

According to a further aspect of the invention, a high pressure valve for an internal combustion engine has the following: a) a housing; b) a control valve piston guided in the housing with cylindrical piston sides surface-delimiting control edges which cooperate with guide surfaces formed in the housing, or with a conical shape cooperating with a conical seat in the housing; c) by means of the guide surfaces and the control edges or the conical shape and the conical seat surface with a corresponding axial movement of the control valve piston, releasable or reclosable outflow cross-sections; d) an electromagnetic actuation for the control valve piston realizing high switching frequencies; e) at least two stages in the housing for sealing the control valve piston in the hous se provided elastomer-free sealing areas; f) such a sealing design of the sealing areas provided that at most only such small amounts of hydrogen backflow are allowed through that no backfires occur; and g) the weight-reducing lightweight design, a movable element of the high-pressure valve representing control piston.

The elements defining the high pressure valve according to the invention form a high pressure valve which is designed for gaseous fuels, in particular for hydrogen, and with the synergy existing between the individual features for the first time a high pressure valve is provided which meets the requirements for operating an internal combustion engine with hydrogen fully and not only selectively for individual requirements, as has only been the case in the prior art so far.

Further advantages, details and possible applications of the present invention will now be described with reference to exemplary embodiments using the following drawing. In the drawing show:

Figure 1: a first embodiment of a high pressure inlet valve according to the invention in the closed position with poppet valve; FIG. 2: a high pressure inlet valve according to FIG. 1 in the passage position; FIG. 2a: a control valve piston of the high pressure inlet valve in lightweight construction; FIG. 3: a sectional view through the housing and shaft of the control valve piston according to a further exemplary embodiment;

FIG. 4: a further embodiment of the high-pressure inlet valve according to the invention with a control valve piston with two cylindrical guide pistons which are guided in guide surfaces inside the valve housing, a plurality of axial injection bores being provided like a ring for introducing the gaseous fuel into the combustion chamber;

FIG. 5: the high pressure inlet valve according to FIG. 4, but in the passage position for supplying gaseous fuel through the high pressure inlet valve into a combustion chamber of an internal combustion engine;

FIG. 6: an exemplary embodiment according to FIGS. 4 and 5, but with injection bores which, in relation to the longitudinal axis of the control valve piston, have a diverging direction;

FIG. 7: an exemplary embodiment according to FIG. 6, but with injection bores which, based on the longitudinal axis of the control valve piston, have a converging direction;

FIG. 8: a further exemplary embodiment of a high-pressure inlet valve in the closed position according to the invention with inlet and outlet for gaseous fuel in planes arranged offset to one another;

FIG. 9: the exemplary embodiment of the high-pressure inlet valve according to the invention according to FIG. 8, but in the passage position; FIG. 10: a detailed sectional view of the arrangement of the high pressure inlet valve according to the invention in the cylinder head of an internal combustion engine in the passage position for introducing gaseous fuel into the inlet line;

FIG. 11: a detailed sectional view of a cylinder and a cylinder head with a built-in high-pressure inlet valve according to the invention in the passage position;

FIG. 12a: a high-pressure inlet valve according to the invention with a poppet valve as the first pressure application area and with a cylindrical guide piston with an annular surface as the second pressure application area and with an additional piston for opening and closing the valve;

FIG. 12b: the high-pressure inlet valve according to FIG. 12a, but in the open position for gaseous fuel to enter the cylinder through the interior of the additional piston and the poppet valve seat area; FIG. 12c: a sectional view through the shaft of the control valve piston of the high pressure inlet valve according to the invention with a view of the additional piston in section AA (cf. FIG. 12b);

FIG. 13: a high-pressure inlet valve according to a second exemplary embodiment, in which the second pressure application area in the form of a cylindrical guide piston is dimensioned larger with respect to the effective annular area than the effective annular area of the first pressure application area in the form of a poppet valve;

FIG. 14: a high-pressure inlet valve for the method according to the invention in a sectional illustration in the closed state;

FIG. 15: the high pressure inlet valve according to FIG. 14 in the open state; FIG. 16: a detailed sectional view of a cylinder and a cylinder head with a built-in high-pressure inlet valve according to the invention in the open position and with the injector in the closed position, each with a direct inlet into the combustion chamber of the cylinder;

FIG. 17: a detailed sectional view of a cylinder and a cylinder head with built-in injector according to the invention in its closed position in a sectional plane to show the inlet valve, but not the high-pressure inlet valve; and

FIG. 18: a detailed sectional view of a cylinder and a cylinder head with a built-in injector according to the invention and a corresponding sectional plane, not shown high pressure inlet valve, but provided injection nozzle for dual fuel operation of the internal combustion engine.

In the following description of the figures, hydrogen is generally described as a fuel. It goes without saying that other gaseous fuels are also possible.

In Figure 1, a high pressure inlet valve 4 according to the invention is shown in cross section. The valve has a housing 6 within which a control valve piston 5 is guided. For this purpose, the control valve piston 5 has an area designed as a cylindrical guide piston 5.3, which is slidably guided in the housing 6 on a guide surface 16 designed to be congruent in shape to the cylindrical guide piston 5.3. The cylindrical guide piston 5.3 of the control valve piston 5 is larger in diameter than a shaft 5.4, which extends downward from the cylindrical guide piston 5.3 in the direction of an inlet opening in the form of a hydrogen inlet 20 in the direction of a combustion chamber 1, not shown in FIG for example Figure 11) extends. On the opposite side of the cylindrical guide piston 5.3 is an extension of the Shank 5.4 of the control valve piston 5 is provided with an insert in which a spring 22 is arranged, which is used to close the high-pressure inlet valve 4, with wel chem pre-compressed hydrogen is introduced into the combustion chamber 1 of an internal combustion engine. A compressive force F _N (see perpendicular arrow pointing downwards in FIG. 2 above) pushes the control valve piston 5 downwards by an opening stroke 21 of the high pressure inlet valve 4, so that the outflow cross section 18 is fully open, ie the high pressure inlet valve 4 is in the passage position 4.2.

Figure 1 shows the closed position 4.1 of the high pressure inlet valve 4. In the outflow cross section 18 (see Figure 2) closes a closing plate 5.5 in the manner of a poppet valve with a conical seat 17 formed in the housing 6 (see Figure 2) and thereby prevents the passage of hydrogen , the hydrogen inlet 20 of which is provided on the left side through an inlet opening. The hydrogen itself is indicated by the arrow pointing horizontally to the right. In the closed position 4.1 of the high-pressure inlet valve 4, the control valve piston 5 is immersed with its upper annular surface 25, which is aligned in the direction of the spring insert, into a chamber 23 which is connected to the outside via a vent hole 24. When the control valve piston 5 with its upper annular surface 25 of the cylindrical guide piston 5.3 is immersed, uncompressed air is expelled from the chamber 23 provided there (see FIG. 2) via the vent hole 24.

An essential criterion for the functioning of the high pressure inlet valve 4 according to the invention is that the annular surface 25 facing the passage channel forms a second pressure application area 26 and the closing plate 5.5 of the poppet valve, which faces the passage area 28 for the hydrogen, forms a first pressure application area 27. The first pressurization area 27 forms a projected area which is perpendicular to the longitudinal axis of the control valve piston 5, and has a size which is approximately equal to the projected area of the Ringflä surface 25 on the cylindrical guide piston 5.3 of the control valve 5, ie almost the same or equal to projected area of the second pressurizing area 26 is. Due to this equality of area of the projected areas, no relevant resulting axial forces are present, regardless of the level of the pressure of the hydrogen wel cher is provided for the inlet into the combustion chamber 1 of an internal combustion engine. _{The control valve piston 5 itself is pressed against the spring force F N} from its closed position 4.1 into its passage position 4.2 by means of a cam, a camshaft or some other drive device or, for example, an electromagnetic actuating device, and when the cam is released, the action of the spring force F _N depresses it. speaking of its strength quickly brought back into the closed position 4.1, in which the closing plate 5.5 of the poppet valve strikes the conical seat surface 17 and seals there (see also FIG. 13). In FIG. 1, the shaft 5.4 of the control valve piston 5 of the high pressure inlet valve 4 has a control valve piston with a cavity, ie has a hollow shaft (see FIG. 2a). For the sake of simplicity, the axially extending bore provided in the shaft of the control valve piston 5 is not shown in FIG. 2 and in FIG. The cavity in the interior of the shaft 5.4 of the control valve piston 5 extends essentially over the greatest possible length of the shaft 5.4. On the one hand, this means that a significant weight reduction is achieved for use in hydrogen operation. In connection with the schematically drawn electromagnetic drive 9, very short reaction times and thus high switching frequencies can be realized due to the reduced weight of the control valve piston 5, which are necessary for hydrogen operation in particular. In addition, a ceramic coating is provided in the lower end of the control valve piston 5 facing the combustion chamber, especially in the first pressure application area 27. For reasons of further weight savings, it is also possible for the entire control valve piston 5 to consist of ceramic.

FIG. 2 shows the high-pressure inlet valve 4 in which the control valve piston 5 is, however, in the passage position 4.2, which is indicated by the arrow in the outflow cross-section 18. When the outflow cross-section 18 is open, the passage area 28 is cleared for the hydrogen, so that the hydrogen flows through between the sealing seat 17 and closing plate 5.5 at high pressure and also at a high flow rate and reaches the combustion chamber 1 (not shown) of the internal combustion engine. Clearly visible is the chamber 23 formed when the control valve piston 5 is pressed down by the opening stroke 21 on the top of the cylindrical guide piston 5.3 in the direction of the spring insert with the spring 22. This chamber 23 is provided with a vent hole 24 so that when closing takes place the cylindrical guide piston 5.3 dips with its upper annular surface into this chamber 23 and presses the uncompressed air there located via the vent hole 24 to the outside. The diameter of this vent hole 24 is now selected so that no throttling effects worth mentioning occur, so that when the cylindrical guide piston 5.3 is immersed into the chamber 23 (when the valve is closed) there is no high resistance forming pressure cushion, but only a certain damping cushion.

In Figure 2a, the control valve piston 5 is designed to be hollow to reduce weight and has a cavity 44 in the interior of the shaft and the plate. In order to achieve a further reduction in weight, the guide piston 5.3 is in each case with its end faces 25, 26 Weight-reducing recesses 43 provided. Through these recesses 43 it is possible that the longitudinal extension of the guide piston 5.3 can be made relatively long even with greatly reduced mass, which results in an improved sealing effect between the piston side surface 15 and the guide surface 16 (see, for example, FIG. 1) .

FIG. 3 shows a sectional view through a sectional plane through the valve parallel to the valve plate plane, which shows guide webs 29 extending radially from the shaft 5.4 between the shaft 5.4 and the housing 6. These guide webs 29 ensure additional stability for an exact axial and additionally a radial guidance of the control valve piston 5 in the housing 6, which is important for a reliable sealing of the cylindrical piston side surfaces 15 of the cylindrical guide piston 5.3 on the likewise cylindrical, appropriately designed, precisely fitting guide surfaces 16 in the hous se 6. Via this exact design of these two surfaces 15, 16 sliding relative to one another, the tightness of the valve inside is ensured or further improved.

FIG. 4 shows a further exemplary embodiment of the high-pressure inlet valve 4 according to the invention, in which the control valve piston 5 has two cylindrically designed guide pistons 5.3, which are guided in corresponding guide surfaces 16 of congruent shape. For this purpose, three cylindrical guide surfaces 16 of congruent shape are provided in the interior of the housing 6. FIG. 5 shows the closed position 4.1 of the control valve piston 5 within the housing 6. The basic structure explained with reference to FIGS. 1 and 2 with the spring insert is identical and will therefore not be repeated here.

In the closed position 4.1 shown in FIG. 4, the axial length of the larger cylindrical guide piston 5.3, which is shown in the lower part of the high-pressure inlet valve 4 shown, is provided for opening and closing the actual axial hydrogen injection bore 13. For this purpose, in the housing 6 in the closed position 4.1 shown in FIG Is blocked.

Underneath the top of the piston, a chamber 23 is formed, into which the lower cylindrical guide piston 5.3 dips to release the axial injection bores 13. Since no counterpressure is formed in the air present in the chamber 23, a vent hole 24 is provided in the interior along the longitudinal axis of the control valve piston 5 and ra- dial provided in the housing 6. With appropriate dimensioning of the vent hole 24, throttling can largely be avoided, but it can still be ensured that a certain damping function is built up. The damping function prevents hard hitting of the upper side, in the case of the illustration according to FIG. 4, of the upper cylindrical guide piston 5.3 in the interior of the housing 6 on the bottom of the chamber 23. The annular surfaces 25 facing the passage area 28, ie first and second pressure application areas 27, 26 of the cylindrical guide piston 5.3 of the control valve piston 5, are dimensioned so that they are of the same size. This ensures that regardless of the pressure at which the hydrogen enters the passage area 28 inside the housing 6 of the high-pressure inlet valve 4, no additional resulting axial forces are caused. Thus, regardless of the pressure of the hydrogen to be admitted into the combustion chamber 1, the high-pressure inlet valve 4 can only be opened with a corresponding drive, for example a cam or camshaft or an electromagnetic actuator 9, against the action of the spring 22 and closed using the spring 22.

_{FIG. 5 shows how this opening force F N,} applied by a cam or an electromagnetic actuator, dips the control valve piston 5 into the chamber 23, so that the radially directed feed areas leading to the axial injection bores 13 are opened in the manner of an annular chamber and the Hydrogen can be introduced from the outflow cross-section 18 into the cylinder or combustion chamber 1 of the internal combustion engine. By opening the high pressure inlet valve 4, the chamber 23 is formed on the upper cylindrical guide piston 5.3 for guiding the control valve piston 5 in the housing 6 on the corresponding guide surface 16. This chamber 23 is also connected to a vent hole 24 so that the air in the chamber 23 can escape via the vent hole 24 when the closing movement is carried out by the control valve 5, ie when moving upward in the drawing. The axial injection bores 13 are preferably arranged equidistantly; however, an irregular arrangement can also be provided, in particular if the air flow into the combustion chamber 1 is intended to be used to improve the mixture formation.

FIG. 6 shows a detailed sectional view of the area of the axial injection bores 13, ie the lower area of the high pressure inlet valve 4, in which, in contrast to the embodiment according to FIG. 4 and FIG. 5, the injection bores 13 are arranged diverging with respect to the longitudinal axis of the control valve piston 5. The other geometrical conditions correspond to those of FIGS. 4 and 5. In Figure 7, an embodiment in the form of a detailed area according to Figure 6 is Darge, but the injection bores 13, relative to the longitudinal axis of the control valve piston 5, are arranged converging. However, it is also possible that in a single embodiment, based on the longitudinal axis of the control valve piston 5, both divering and converging injection bores 13 are provided.

FIG. 8 shows a further exemplary embodiment of a high-pressure inlet valve 4 according to the invention, the basic structure of which with regard to housing 6 and spring insert corresponds to the previous exemplary embodiments, so that these parts are not described again here. The high-pressure inlet valve 4 shown is in its closed position 4.1 of the control valve piston 5. The difference to the previous exemplary embodiments is that the hydrogen inlet line and the outflow cross-section 18 are arranged in different planes with respect to the longitudinal axis of the housing 6 of the high-pressure inlet valve 4. In this case, the hydrogen is present under high pressure on the hydrogen inlet line 20, coming from a high-pressure line (not shown). In the closed position 4.1, the lower cylindrical guide piston 5.3 covers this passage area 28 so that no hydrogen can get into the passage area 28 and finally into the combustion chamber 1 (see FIG. 10) of the cylinder. Facing the passage area 28 are two ring surfaces 25 which are of the same size, so that no resulting axial forces are present regardless of the pressure of the supplied hydrogen. A displacement of the control valve piston 5 can therefore only be applied against the force of the spring 22. Below the front of the large cylindrical guide piston 5.3 there is again the chamber 23, so that when the control valve piston 5 is moved, it plunges into the chamber 23 and thus ultimately the passage position 4.2 of the control valve piston 5 shown in FIG. 9 is reached when the opening stroke 21 is executed . In the passage position 4.2, the hydrogen can flow via the hydrogen inlet line 20 from the lower level to the upper level of the recess of the passage area 28 into the housing 6 and finally to the outflow cross-section 18, from where the hydrogen flows directly into the combustion chamber 1 of the internal combustion engine ( not shown) or can flow indirectly via an inlet line into the combustion chamber 1.

So that reliable guidance of the control valve piston 5 in the housing 6 is ensured, the lower, larger cylindrical guide piston 5.3 is guided into the chamber 23 on guide surfaces 16 of congruent shape. In the closed position 4.1 according to FIG. 8, this cylindrical guide piston 5.3 is then guided in the lower area and in the intermediate area on corresponding guide surfaces 16, the intermediate area being between the lower level on the hydrogen inlet line 20 and the passage step area 28 is arranged in the upper level on the outflow cross-section 18. And finally, the smaller cylindrical guide piston 5.3, the upper one, which is arranged in the direction of the spring insert, is slidably guided on a third guide section 16.

While FIG. 8 shows the high pressure inlet valve 4 in its closed position 4.1, its passage position 4.2 is shown in FIG.

FIG. 10 shows an exemplary embodiment of how a high-pressure inlet valve 4 according to the invention can be arranged in the cylinder head 30 of an internal combustion engine in its inlet line 7. The high-pressure inlet valve 4 is driven by means of a cam, not shown, which preferably belongs to a camshaft, but can of course also be driven by an electromagnetic actuator so that in the case of a camshaft drive, the spring 22 present in the spring insert can be compressed when the cam engages . The compression of the spring 22 and thus the opening of the high-pressure inlet valve are likewise achieved by an electromagnetic actuator 9. By compressing the spring 22, the hydrogen, which is guided via the high-pressure line 32 to the hydrogen inlet line 20 and from there via the illustrated passage position 4.2 through the high-pressure inlet valve 4 in its passage area 28 to the outflow cross-section 18, arrives via the inlet line 7 and the Inlet valve 8 with high pressure into the combustion chamber 1. This is indicated by the arrows, which characterize the hydrogen flow of the hydrogen under high pressure and also the combustion air. On the left at the top of FIG. 10, an outlet valve 33 is shown, which is in the closed state so that the gaseous fuel cannot escape into the exhaust line. In the cylinder 3, a piston 2 is shown, which is connected to a crankshaft, not shown, by means of a piston pin 34 and a connecting rod 35. The high-pressure inlet valve 4 can now preferably be controlled in such a way that basically at almost any position during the movement of the piston 2 from bottom dead center to top dead center, individual amounts of hydrogen are specifically targeted in connection with the control of the inlet line valve 46 in the Zy can be filled linder.

And finally, FIG. 11 shows a cylinder 3 with a cylinder head 30 according to FIG. 10, but with both a high-pressure inlet valve 4 and an injector 10. The high-pressure inlet valve 4 is arranged in the cylinder head 30 in its passage position 4.2 so that hydrogen flows directly into the cylinder 3 can be blown in together with the combustion air from the inlet line 7 via the outflow cross-section 18 in relatively large quantities. In addition, the injector 10, to which a high pressure line for hydrogen is connected and which in the passage position 4.2 of the injector 10 leads hydrogen indirectly into the combustion chamber 1 via the inlet line 7 in targeted amounts at the desired times to directly influence the subsequent mixture formation and combustion in the combustion chamber 1. The piston 2 in the cylinder 3 is connected to a crankshaft (not shown) by means of its connecting rod 35 and via the piston pin 34.

In Figure 12a, a further embodiment of the high pressure inlet valve 4 is shown according to the invention. In Figure 12b, this high pressure inlet valve 4 is shown in the open position. The closed position of the high-pressure inlet valve 4 shown in FIG. 12a is reached in the position of the control valve piston 5, in which the hydrogen inlet line 20 closes off inside the housing 6, and when it opens, hydrogen is supplied under high pressure, namely in a valve seat sealingly seated and there with the supply of hydrogen in the combustion chamber 1 also sealingly arranged Ven tilteller or closing plate 5.5 of a poppet valve. The closing plate 5.5 of the poppet valve goes in the usual way for such valves, which are used in the cylinder head 30 of internal combustion engines, continuously in the shaft 5.4. The control valve piston 5 has in the area of the shaft 5.4 located in the housing 6 a cylindrical guide piston 5.3 or a guide surface 16, which forms an annular surface 25 which faces in the direction of the passage area 28. On a side opposite the annular surface 25, the shaft 5.4 has a closing plate 5.5 of the poppet valve, which preferably forms a sealing seat 17 or valve seat 17 with the housing 6 at an angle of 45 degrees.

The sealing force of this valve seat 17 is ensured by the spring 22, which is held under prestress in the housing 6 by means of a yoke-like support ring 37. The annular surface 25 and the effective surface of the closing plate 5.5 of the poppet valve projected in a plane perpendicular to the longitudinal axis of the control valve piston 5 are both equal, so that the pressure of the hydrogen which enters the passage area 28 for entry into the cylinder 1 when the high pressure inlet valve 4 is open ( see FIG. 12b), the pressure application surfaces 27 and 26 are loaded against one another without significant resulting surfaces. As a result, the control valve piston 5 is displaced in the housing 6 without additional forces to the compression spring 22. In the area of the shaft 5.4, the control valve piston 5 has an additional piston 38, which also has a cylindrical guide surface 15 on its outer circumference, which is guided on correspondingly shaped guide sections 16 in the housing 6. The axial dimension of this additional piston 38 is now such that in the position as shown in FIG. 12a, ie in which the supply of hydrogen is blocked, the additional piston 38 interrupts the cross-section of the high pressure hydrogen supply line. For this purpose, the additional piston 38 as well as the guide piston 5.3 or guide surfaces 15, 16 are ground in to ensure a corresponding sealing force and tightness. A second sealing surface results in the valve seat 17 of the poppet valve, the sealing force being determined by the spring force of the spring 22. A pressure chamber is formed between the upper side of the guide piston 5.3 shown in FIG .

With a corresponding force acting against the spring force of the spring 22 to adjust the slide valve piston 5 in the housing 6, air is sucked in again via this vent hole 24, so that the pressure space 23 present between the top of the cylindrical guide piston 5.3 and the housing 6 does not enter significant negative pressure arises.

In Figure 12b, the high pressure inlet valve 4 according to Figure 12a is shown, but in the opened position. For this purpose, the control valve piston 5 is shifted downward against the action of the spring force of the spring 22 in the illustration shown, so that the additional piston 38 releases the cross section of the hydrogen inlet line 20 via the passage area 28 on the seat area 17 of the closing plate 5.5 of the poppet valve and releases hydrogen can be pressed into the combustion chamber 1 (not shown) with high pressure. The other elements and functions are identical to those in FIG. 12a and are therefore not described again here. It can be seen from FIG. 12b that the additional piston 38 is slidably displaced on the ground cylindrical guide surfaces 16 formed in the interior of the housing 6, ie in the interior of the passage area 28, so that the hydrogen, which is under high pressure, ultimately enters the cylinder 1 can flow in.

And finally, FIG. 12c shows a sectional view through the control valve piston 5 in its lower part of the shaft 5.4, looking towards the additional piston 38 along the section AA (cf. FIG. 12b). The piston 38 has a cylindrical Kolbenseitenflä surface 15 on its outer circumference, which is ground in and cooperates in a congruent shape with the guide surfaces 16 correspondingly formed in the housing 6 in a sealing manner. The interior of the piston 38 is made stable enough by webs 39, between which there are openings 40, and thus enables the hydrogen to flow through when the hydrogen inlet is released, in order then to pass the area of the valve seat 17 of the closing plate 5.5 of the poppet valve the combustion chamber 1 to flow. This is through the Arrows indicating the flow path are shown. In addition, the control valve piston 5 is guided reliably and precisely by the cylindrical piston side surfaces 15 in the upper part of the housing 6, since these areas are also ground in.

And finally, FIG. 13 shows a further exemplary embodiment in which the effective pressure application areas 27, 26 facing the passage area 28 in the interior of the housing 6 are of different sizes. In FIG. 13, a state of the high pressure inlet valve 4 is shown in which the supply of hydrogen into the combustion chamber 1 through the control valve piston 5 does not take place. Due to the fact that the second pressure application area 26, designed as an annular surface 25, is larger than the first pressure application area 27 at the transition from the closing plate 5.5 of the poppet valve to its shaft 5.4, the housing 6 is designed in two parts, so that a corresponding assembly of the control valve piston 5 and the Guide piston 5.3 in the interior of the housing 6 can be done. The guide piston 5.3 must be mounted on the control valve piston 5 by an additional assembly in an assembly embodiment not shown. Otherwise, the basic structure is analogous to that described in FIG. Because the area of the second pressure application area 26 is larger than that of the first pressure application area 27, a greater closing force of the closing plate 5.5 of the poppet valve in the area of its seat 17 is ensured in connection with the high pressure of the hydrogen. In this respect, the imbalance based on the differently sized effective areas benefits. The great force thus achieved ensures a significantly improved sealing performance of the valve seat 17 during operation of the engine. The principle of the function of such a high pressure valve 4 is that which is similar to a pneumatic cylinder.

In addition to the illustration in FIG. 12, FIG. 13 also shows a securing ring 41, which prevents the support ring 42 from loosening during operation, since the support ring 42 is placed on the upper shaft part of the control valve piston 5 so that the spring tension is set. The control valve piston 5 shown in FIG. 13 is sealed off from the chamber 23 with its guide piston 5.3. In the direction of the valve disk 5.5. a conical area is present in the interior of the housing 6. The further sealing area is the conical seat formed directly on the poppet valve. The latter ensures that the hydrogen supply line is reliably sealed off from the combustion chamber 1, whereas the guide piston 5.3 forms an additional sealing surface between the hydrogen supply area and the chamber 23. In principle, it is also possible for the guide piston 5.3 in the second pressure application area 26 to be smaller than the first pressure application area 27. Figure 14 and Figure 15 show a sectional view of two positions for realizing the function of the high pressure inlet valve 4 according to the invention in a further embodiment of the invention in the closed state (Figure 14), whereas in Figure 15 this high pressure inlet valve 4 is shown in the open position.

The high pressure inlet valve 4 has a piston part formed from a piston tappet 100 and a piston 200 and guided in a housing 300. The piston 200 has a circumferential piston groove 50 which forms a control edge 45 and which has an area with an indentation opposite the outer maximum diameter of the piston 200. In the position according to FIG. 14, the piston 200 forms a valve chamber 90 within the housing 300 on its end face or piston top, which is opposite the piston tappet 100, which is closed on the end face of the high pressure inlet valve 4 by means of a cover plate 60. Between the cover plate 60 and the end face of the piston 200, the valve chamber 90 forms, so to speak, an air cushion into which the piston 200 moves with its stroke 101, so that the short times required for the inlet processes for hydrogen into the cylinder prevent the Piston 200 could hit the cover plate 60 te.

In FIG. 15 it is shown that the valve chamber 90 is vented via a vent hole 70 which is guided through the piston part in the region of its longitudinal axis. In particular at higher speeds of the internal combustion engine, the gas exchange in the cylinder must be carried out in very short periods of time, based on absolute temporal standards. Therefore, the high-pressure inlet valve 4 and, as an essential core element thereof, its piston 200 must also execute very rapid movements for opening and closing, i.e. for controlling the supply of hydrogen. Lightweight construction is an essential feature for the implementation of higher switching frequencies.

In the dead centers during the movement of the piston 200 of the high-pressure inlet valve 4, relatively large acceleration and deceleration forces occur due to the inertia of this component. The space that changes on the piston top when the piston 200 moves, ie the valve chamber 90, dampens the piston movement due to the compression of the air contained therein, which is why a vent hole 70 is provided inside the piston 200 in the region of its longitudinal axis is. The diameter of the vent hole 70 is now designed such that when the actual piston of the piston 200 moves rapidly, the air is pressed out of the valve chamber 90 at least for the most part via the vent hole 70. The diameter the vent hole 70 is only so large that only so much air remains in the valve chamber 90 that with the rapid movement of the piston 200 and its inertia, a stops from its piston top on the inner end of the game formed by the cover plate 60 in this Ausführungsbei High pressure valve 4 does not strike. On the other hand, the vent hole 70 must be able to interrupt the passage of hydrogen through the high pressure inlet valve 4 during the backward movement of the piston away from the cover plate 60 towards its position, to allow a backflow to refill the valve chamber 90. The vent hole 70 therefore has a diameter such that essentially the air in the valve chamber 90 can be discharged or fed back into this chamber, even though there is a certain low throttle function, so that there is no vacuum or negative pressure in this valve chamber 90 occurs during the reciprocating movement of the piston 200 in the housing 300 of the high pressure inlet valve 4. The part of the air remaining in the valve chamber 90 serves a certain damping effect when the piston top side moves in the direction of the cover plate 60, in which, among other things, due to the still existing throttling effect of the vent hole 70, a certain damping cushion is formed, which causes the piston top side to strike on the inside of the cover plate 60 or at least counteracts any attacks. The vent hole in the shaft of the piston 200 already represents a measure to reduce mass in the sense of supporting rapid or high switching frequencies.

On the side of the piston 200 opposite the end face of the piston, on which the piston tappet 100 is arranged, a lower or rear valve chamber is arranged inside the housing 300 between the piston underside and the passage opening of the piston tappet 100 through the material of the housing 300, which also has a damping function analogous to that described on the top of the piston. For this purpose, a vent hole 70 is also provided from this damping space on the piston underside, which is formed and functions analogously to the vent hole 70, which passes through the piston part in the longitudinal direction and has a connection to the valve chamber 90.

In the upper region of the housing 300 of the high-pressure inlet valve 4, the piston tappet 100 is surrounded by a spring which is arranged in a housing recess 130 and is held by a guide plate flanged upwardly to the housing recess 131. The piston thus works against the spring 80 which, depending on the direction of movement, is compressed or stretched within the piston stroke 100. In the position of the piston 200 shown in FIG. 14, its control edge 45 is located above a channel arranged transversely to the direction of movement of the piston 200 for the supply 121 of hydrogen under high pressure to the cylinder, so that the hydrogen supply 111 is prevented by the valve. Only in the position of the piston 200 shown in FIG. 15 is the control edge 45 immersed in the channel for hydrogen supply 121 to the cylinder, which extends transversely to the longitudinal axis of the piston and penetrates the housing 300 of the high pressure inlet valve 4. When the control edge 45 has released this channel of the hydrogen supply 121 to the cylinder, the hydrogen supply 111 can over the piston groove 50, which runs around the piston 200 and, so to speak, represents the indentation in relation to the maximum diameter of the piston, in the direction of and through the channel for the Hydrogen feed 121 flow to the cylinder. Due to the high pressure with which the hydrogen supply 111 to the valve is applied to the corresponding channel of the Hochdru ckeinlassventils 4, there is an immediate passage of the high pressure hydrogen into the cylinder after release and thus connection to the channel of the What hydrogen supply 121 to the cylinder.

Since during the movement of the piston 200 in the housing 300, the piston 200 only acts against the respective air cushions, ie with its upper side of the piston into the air cushion of the valve chamber 90 or with the lower side of the piston into the air cushion Piston groove 50 has formed an area of the same size at both ends in the longitudinal direction, there are no significant additional resulting axial forces which act on piston 200. The piston 200 can therefore be easily adapted to the high required speeds of a corresponding speed of the internal combustion engine despite high pressures of the hydrogen applied.

The high-pressure inlet valve 4 provided according to the invention thus offers the possibility of providing hydrogen provided under high pressure to a consumer, in this case the cylinder of an internal combustion engine. The pressures of the hydrogen provided are at a level of, for example, 20 to 350 bar.

Because the axial forces acting on the piston 200 are essentially balanced due to the same applied surfaces, there is no one-sided force component on the piston 200 or piston tappet 100 to the detriment of the other direction of movement. This makes it possible to bring the piston into the respective switching states with little application of force. The respective switching states are on the one hand the closed valve and on the other hand the open valve. The size of the opening in the open switching state can be varied by the size of the axial displacement of the piston 200. When the piston is moved, the control edge 45 of the piston 200 is moved on the pressure side to such an extent that, with the corresponding width of the piston groove 50 viewed in the longitudinal direction of the piston 200, the supply and discharge channels arranged offset to one another in the axial direction (hydrogen supply 111 or hydrogen supply 121) are brought into connection with the cylinder via the piston groove 50, which corresponds to the open state of the high-pressure inlet valve 4. By changing the position of the piston 200, the cross section of the hydrogen supply 121 to the cylinder can be varied in such a way that the flow rate, ie the mass flow of the hydrogen to be introduced into the cylinder, can be varied.

The cross-sections are now selected so that, when open, large amounts of hydrogen can be supplied to a consumer, in this case the cylinder of an internal combustion engine, in a short unit of time, i.e. high mass flows. If a transition is to be made from an open state (see FIG. 15) to a closed state (see FIG. 14), the piston 200 is accordingly shifted in the axial direction so far that a connection of the hydrogen supply 111 to the high-pressure inlet valve 4 is via a hydrogen source the piston groove 50 to the hydrogen supply 121 to the cylinder is interrupted. Before the actual interruption takes place according to the corresponding position of the piston 200 in the housing 300, for a further improvement of the operating behavior of the engine it can be provided that the closing process is delayed again to a predetermined extent, so that a certain reloading effect in the cylinder can be realized. This reloading usually takes place in the cylinder at a point in time when the piston 200 in the cylinder of the internal combustion engine is already in its upward movement, i.e. in the compression phase. The advantage of using compressed hydrogen in connection with the high-pressure inlet valve 4, as described above, is, among other things, that after the corresponding cross-sections have been released, the compressed hydrogen spreads rapidly, since the compressed hydrogen expands rapidly when the cross-section is free. This also supports the ability of the high-pressure inlet valve 4 according to the invention that high amounts of hydrogen can be passed through in a short unit of time.

The supply of hydrogen to a respective cylinder can now take place in such a way that all of the hydrogen for a cycle with a single introduction into the cylinder is carried out in one intake process. In terms of optimizing, for example, the The compression work to be performed by the piston 200, the high-pressure inlet valve 4 can also be controlled in such a way that the supply of hydrogen into the cylinder takes place intermittently in several bursts, so to speak. Each individual burst of supplied hydrogen can be varied with regard to the length of the opening of the high-pressure inlet valve 4, so that the engine operation can be directly influenced via the amount of hydrogen introduced into the cylinder in a defined time unit. Two such joints are preferably provided. A large number of bursts of supplied hydrogen can also be of advantage in terms of optimizing the overall process of operating the engine. If the hydrogen is introduced in partial amounts in several shocks during the movement of the piston 200 in the cylinder on its way from bottom dead center to top dead center during the compression stroke, the total amount of hydrogen corresponds to the total amount required for the respective cycle, with which a reliable, high efficiency of the internal combustion engine guaranteeing operation can be achieved.

The piston 200 is sealed within the housing 300 by a corresponding fit between the piston 200 and the bore in the housing 300.

The high-pressure inlet valve 4 is preferably made of high-strength and heat-resistant metal alloys or of light metal or light metal alloys such as magnesium or ceramic materials, it being possible for different materials to be used for the piston 200 and the housing 300. It is also conceivable to select a specific base material with a coating of the respective parts in order to achieve optimal sliding and sealing properties of the piston 200 moving in the housing 300 at the high pressures of the supplied hydrogen. In addition to a selected coating, a different heat treatment of the parts moving against one another in the high-pressure inlet valve 4 is also conceivable. To reduce friction, lubrication can also be provided between the piston 200 and the housing 300, it being possible for a feed line, not shown in the figures, to be provided for feeding in small amounts of lubricant.

For the hydrogen operation of the internal combustion engine, the high pressure inlet valve 4 is expediently connected to the place of conventional inlet lines and inlet valves in the cylinder head 30 of an internal combustion engine, whereas the exhaust valves and the exhaust lines can remain designed in conventional technology.

The high pressure inlet valve 4 can of course also be used for other types of supply of gases in rooms of other facilities. To realize correspondingly rapid opening and closing processes of the high-pressure inlet valve 4 so that optimal engine operation can be carried out effectively, it is also possible that the control valve piston of the high-pressure inlet valve 4 is actuated with mechanical components such as a camshaft or electromagnetically.

Despite the comparatively small opening cross-sections on the side of the hydrogen supply 111 to the valve, the supply of hydrogen at high pressures of approx.

20 to 350 bar large amounts of hydrogen can be introduced into the combustion chamber. This is also possible because the compression of the hydrogen on the side of the hydrogen supply 111 to the valve is already relaxed in the valve. The relaxation of the hydrogen already in the valve supports, so to speak, the "flow rate" of the hydrogen in the direction of the hydrogen supply 121 to the cylinder and into the cylinder, which automatically causes a larger amount of hydrogen in the same time unit, ie a larger mass flow B, the cylinder 1, is promoted.

Since the control valve piston 5 experiences a controlled linear movement, the opening cross-sections can be controlled in a simple manner via the time units for the open state of the high-pressure inlet valve 4.

FIG. 16 shows a partial sectional view of a cylinder with a cylinder head in which an outlet valve 33, a high-pressure valve 4 according to the invention and an injector 10 are arranged. The exhaust valve 33 arranged in the cylinder head 30 is in the closed position so that hydrogen can be introduced directly into the combustion chamber 1 via the high pressure valve 4, the guide piston 5 being shown in the open position, in which hydrogen can be introduced into the cylinder on the one hand and combustion air on the other can be supplied from the inlet line 7 via the outflow cross-sections 18. In its passage position 4.2, the high pressure valve 4 can supply hydrogen alone or combustion air from the inlet pipe 7 alone or both together in the sense of a hydrogen-combustion air mixture to the combustion chamber 1. Furthermore, an injector 10 is provided in the cylinder head, via which additional hydrogen can be introduced directly into the combustion chamber 1 via a hydrogen pressure line 32. In the illustration shown in FIG. 16, the injector 10 is closed. The injector 10 is actuated electromagnetically, whereby high switching frequencies, ie the shortest switching times, can be achieved. The injector 10 is suitable for introducing hydrogen into the combustion chamber 1 intermittently at selected times in order to optimize mixture formation and combustion in the combustion chamber 1. In the cylinder, a piston 2 is guided on the cylinder wall 47, the piston 2 having a piston pin 34, at which on connecting rod 35 is connected to a crankshaft, not shown, in a manner known per se.

FIG. 17 shows a detailed view of a cylinder with a cylinder head, similar to that according to FIG. 16, but with the difference that instead of the high-pressure inlet valve 4 according to the invention, a conventional inlet valve is provided, which is shown in the open position in FIG. 17 and combustion air from the inlet line 7 can flow into the combustion chamber 1 via the outflow cross-sections 18. In the cylinder head 30, an exhaust valve 33 is also arranged, which is shown in the closed position. In the cylinder head 30 there is an injector 10, by means of which hydrogen can be introduced directly into the combustion chamber 1 via the high pressure hydrogen line 32 when the injector 10 is open, i.e. in its passage position. In Figure 17, the injector 10 is shown in its closed position. On the upper side of the guide piston 5.3 (see Figure 1) inside the housing 6 there is an air-filled chamber 23, which serves as a cushioning pad and from which, when the guide piston 5.3 dips into this chamber, air is discharged via the vent line 24 can be, wherein the vent line 24 is dimensioned so that no or no significant throttling occurs when air flows out of the chamber. With the aid of the inlet valve 8, only the supply of combustion air via the inlet line 7 is controlled. The engine-like structure of the piston 2 with the piston pin 34 and the connecting rod 35 corresponds to that described in FIG.

And finally, FIG. 18 shows a detailed sectional view with a section through the cylinder and cylinder head that is different from that in FIG. 17, so that the structure described in FIG. 18 still shows the injection nozzle. This injection nozzle can also be used to inject gaseous fuel into the cylinder. The injection nozzle is also suitable for introducing liquid fuel, so that the exemplary embodiment of an internal combustion engine shown in FIG. 18 also enables so-called duel fuel operation. This means that both conventional liquid fuel can be introduced into combustion chamber 1 of the internal combustion engine by means of the injection nozzle, and hydrogen can also be introduced into combustion chamber 1 by means of injector 10. The other structure corresponds to that according to FIGS. 16 and 17 and therefore does not have to be explained again here. LIST OF REFERENCE NUMERALS Combustion chamber 24 Ventilation bore Piston 25 End face / annular surface cylinder 26 Second pressurizing valve High pressure inlet valve / high pressure valve 27 First pressurizing valve Closing position rich passage position 28 Passage area of hydrogen control valve piston 29 Guide web, control edge 30 Cylinder head, conical shape 32 High pressure line, guide piston 33 Outlet valve, shaft 34 Piston pin 36 Injection plate, poppet nozzle Inlet line 37 Support ring, inlet valve 38 Additional piston, electromagnetic actuation 39 Additional piston, injector web 40 Openings between the webs Hydrogen supply line 41 Circlip facing the combustion chamber surface 42 Support ring surface of the high pressure valve 43 Weight-reducing recess, axial injection bores, high pressure valve 44 Cavity, control valve piston, end position of control valve piston 45 Control edge, piston side surfaces 47 50 conical piston groove ige seat surface, sealing seat 60 cover plate outflow cross-section high pressure 70 venting hole valve 80 spring sealing areas 90 valve chamber hydrogen inlet line 100 piston tappet opening stroke 101 piston stroke spring 111 hydrogen supply to valve chamber 121 hydrogen supply to cylinder 131 housing recess 200 piston 300 housing H2 hydrogen

Claims

EXPECTATIONS

1. Internal combustion engine for operation with gaseous fuel, in particular hydrogen, with a cylinder (3) having a combustion chamber (1) and a piston (2) guided therein, with a high-pressure valve (4) with control edges (5.1) or a conical shape (5.2) having control valve piston (5) guided in a housing (6), and with which hydrogen can be blown directly into the combustion chamber (1) or indirectly via an inlet line (7) shortly before an inlet valve (8) into the combustion chamber (1) is, wherein the control valve piston (5) has an electromagnetic actuator (9) with high switching frequencies and is sealed in the housing (6) at least in two stages and elastomer-free in such a way that a backflow of the hydrogen in al lenfall a backfire on contact with oxygen is not possible Smallest amount occurs, and the high-pressure valve (4) is lightweight and lightweight.

2. Internal combustion engine according to claim 1, which additionally has an injector (10) for fine metering of hydrogen into the combustion chamber (1).

3. Internal combustion engine according to claim 2, wherein the injector (10) carries out a termittende or multi-stage supply of the hydrogen directly into the combustion chamber (1).

4. Internal combustion engine according to claim 2 or 3, in which the high-pressure valve (4) is designed for injecting larger amounts of hydrogen than the small amounts of hydrogen for combustion optimization in the combustion chamber (1) introducing injector (10).

5. Internal combustion engine according to one of claims 1 to 4, in which the control valve piston (5) is hollow.

6. Internal combustion engine according to one of claims 1 to 5, in which the high-pressure valve (4) and / or injector (10) are formed from ceramic or from ceramic-coated light metal system.

7. Internal combustion engine according to one of claims 1 to 6, in which the high-pressure valve (4) has a magnesium alloy as material.

8. Internal combustion engine according to one of claims 1 to 7, wherein the control valve piston (5) of the high pressure valve (4) in its housing (6) Führungskol ben (5.3), on which the control edges (5.1) are formed, which with a hydrogen - Feed line (11) interact.

9. Internal combustion engine according to one of claims 1 to 8, in which on one of the combustion chamber (1) facing surface (12) of the high pressure valve (4) annularly arranged injection bores (13) are formed, which valves with high pressure (4) in the axial direction are arranged concentrically.

10. Internal combustion engine according to one of claims 1 to 9, in which the control valve piston (5) in the housing (6) in the region of its end positions (14) is immersed in a gaseous cushioning to avoid impact.

11. Internal combustion engine according to one of claims 1 to 10, in which the high pressure valve (4) to the combustion chamber (1) is arranged upright and from the control valve piston (5) by means of its control edges (5.1) a radially in the housing (6) of the high pressure valve ( 4) arranged injection line (20) for the hydrogen and / or combustion air and / or hydrogen-combustion air mixture depending on a piston position in the combustion chamber (1) releases or closes introduction cross-sections.

12. High-pressure valve (4) for a hydrogen-powered internal combustion engine, wel Ches comprises: a) a housing (6); b) a control valve piston (5) guided in the housing (6) with cylindrical piston side surfaces (15) delimiting control edges (5.1) which interact with guide surfaces (16) formed in the housing (6), or with one for the hydrogen from the High pressure valve (4) kegelförmi gene seat surface (17) in the housing (6) cooperating cone shape; c) outflow cross-sections (18) which release or close by means of the guide surfaces (16) and the control edges (5.1) or the conical shape and the conical seat surface (17) with a corresponding axial movement of the control valve piston (5) from the high pressure valve (4); d) an electromagnetic actuation of the high switching frequencies realize the control valve piston (5); e) at least two stages in the housing (6) by means of elastomer-free sealing areas (19) for sealing the control valve piston (5); f) the sealing areas (19) are designed to be sealed in such a way that at most only such small amounts of hydrogen backflow are allowed through that no re-ignitions occur; and g) the control valve piston (5) forming a movable element of the high pressure valve (4) is designed in a weight-reduced lightweight construction.