JP2013545028A - Internal combustion engine, exhaust valve and cylinder head therefor, and manufacture, operation and use of internal combustion engine - Google Patents

Abstract

  The invention relates to an internal combustion engine, in particular a two-cycle large diesel engine, having at least one combustion chamber 2 defined by a cylinder 1 and a piston 3 cooperating with a crankshaft, each of which is a valve of an exhaust valve 9. At least one fuel gas outlet 20 and at least one supercharged air inlet 4 formed between the head 8 and the disposed valve seat, the exhaust valve being open and closed Can operate between positions. The fuel gas outlet is connected to at least one exhaust pipe 11 and at least one fuel gas outlet pipe 18; 118a, so that part of the fuel gas generated during combustion is supplied to the supercharged air inlet 4 Will be returned. The present invention relates to an exhaust valve and a cylinder head for an internal combustion engine. In the present invention, the fuel outflow is performed in a specific manner by the throttle device 10 fixed to the exhaust valve or formed integrally with the exhaust valve. The invention further relates to a method for producing, operating and using an internal combustion engine.

Description

  The present invention relates to an internal combustion engine, in particular a two-cycle large diesel engine having the characteristics described in the preamble of claim 1, and an exhaust valve and a cylinder head according to claims 13 and 19 for the internal combustion engine. The internal combustion engine manufacturing method according to the preamble of claim 20, the use of the internal combustion engine according to claim 26 of the preamble, and the internal combustion engine operating method according to claim 27 of the preamble.

In internal combustion engines of the same genus, fuel gas recirculation is known for supplying recirculated combustion gas to supercharged air supplied to one or more combustion chambers of the internal combustion engine. Thereby, the emission amount of nitrogen oxides (NO _x ) is to be reduced. That is, the supercharged air is pre-compressed and optionally pretreated such as drying, filtration, temperature control, etc., in addition to pure cleaning air from the surroundings, other cleaning gas components such as cleaning A mixture of air and recirculated fuel gas may be included. In addition to the cleaning gas and / or pure cleaning air, the supercharging air may contain further components, for example evaporated natural gas.

  To return the fuel gas to the combustion chamber, for example, mixing the fuel gas recirculated into the cleaning air, and cleaning the combustion chamber with this mixture through one or more common inlets, for example, intake ports It is known to do. In addition, the fuel gas recirculated in the combustion chamber on the one hand and the remaining supercharged air on the other side are introduced into the combustion chamber through individual intakes, producing a mixture that produces supercharged air in the combustion chamber. It is known to be done. At this time, the present invention can be combined with any conventional type of return of fuel gas to the combustion chamber.

  Regarding this, an internal combustion engine of the same genus is known from Patent Document 1. In the internal combustion engine, in addition to the exhaust valve that connects or separates the combustion chamber from the exhaust pipe, an individual second exhaust valve is provided, and the exhaust valve connects the combustion chamber to the recirculation pipe. Or separate from the recirculation pipe. This structure is relatively expensive.

  Furthermore, Patent Document 2 discloses an internal combustion engine. In the internal combustion engine, a recirculation conduit branches off in an exhaust pipe placed downstream of an exhaust valve in accordance with the flow. The valve can be opened and closed by a second valve structure provided on the valve stem of the valve and a valve receiving portion (Ventilaufnahme) disposed in the exhaust pipe. For this purpose, for example, a bush having a circumferential slit provided on the valve rod of the exhaust pipe is provided. A valve receptacle, which is fixedly arranged in the exhaust pipe, has a bush with a slit, which also covers the branch to the recirculation conduit. In order to avoid unequal actuation of the valve seat (Einlaufen), the branch to the recirculation conduit can be opened and closed by always rotating the exhaust valve and the associated valve stem by a rotating mechanism. Here, even if a second individual valve is not required to open and close the recirculation conduit, it is suitable for the opening frequency and phase determined by the rotating mechanism and the recirculation phase during the engine work cycle and engine cycle. It seems difficult to tune with the phase.

  Furthermore, a 4-cycle engine is known from Patent Document 3, and in this 4-cycle engine, a recirculation conduit branches off in an exhaust pipe placed after an exhaust valve. This valve is also configured as a throttle valve for the exhaust pipe at the same time, thus restricting the flow through the exhaust pipe when the recirculation conduit is opened. At this time, the recirculation valve-exhaust conduit throttle valve remains in a position to throttle the exhaust pipe and open the recirculation conduit during the scavenging stroke.

  Finally, an internal combustion engine is known from patent document 4, in which the recirculation conduit is branched for the first time in an exhaust pipe that is placed downstream of the exhaust valve in the direction of flow. The conduit is again opened and closed through a separate valve. In one embodiment, a throttling device is provided in the exhaust pipe in a region after the valve preceding the recirculation conduit, the throttling device having a deflectable valve. This valve is opened by a pressure generated when the main exhaust valve is opened, and is closed by a pretension spring when the pressure is sufficiently reduced. This solution is relatively complex in view of the tuning of the exhaust valve, the throttle device and the valve in front of the recirculation conduit, the overall structure, and the adjustment of the pretension of the spring that closes the throttle device.

German Patent Application No. 102005057207 European Patent Application No. 2151569 JP-A-6-241127 German Patent Application No. 102008058612

  In view of the above, an object of the present invention is to provide an internal combustion engine, an exhaust valve and a cylinder head therefor, and a method of operating the engine, thereby increasing the amount of fuel gas mixed with as little outside air as possible. At the pressure level, to drain for recirculation or other purposes. In addition, a breakthrough use and manufacturing method for the internal combustion engine is also described.

  The object is according to the features of claim 1 for internal combustion engines, according to the features of claim 13 for exhaust valves, according to the features of claim 19 for cylinder heads and according to the features of claim 20 for manufacturing methods. This is solved by the feature of claim 26 and by the feature of claim 27 regarding the method of operating the internal combustion engine.

  According to the invention, for this purpose, a throttle device fixed to the exhaust valve or formed integrally with the exhaust valve is provided. The throttle device prevents the fuel gas from flowing into the exhaust pipe in the exhaust gas outflow opening region of the exhaust valve from the closed position of the exhaust valve to the desired opening degree, or at least the desired From the opening degree larger than the opening degree of the exhaust valve to the open position, the exhaust gas exhaust opening area of the exhaust valve is more strongly throttled, and in the exhaust gas discharge opening area, the throttle device is The inflow of the fuel gas into the exhaust pipe is preferably not throttled at all, or at least less than in the fuel gas outflow opening region of the exhaust valve. The throttle device and the branch portion of the fuel gas outlet pipe located near the exhaust port side or the combustion chamber exhaust port controlled by the exhaust valve are the fuel gas of the fuel gas in the fuel gas outlet opening region. The inflows to the outflow tubes are preferably arranged relative to one another so that they are not throttled at all or at least not unnecessarily.

  In the fuel gas outflow opening region, the exhaust valve forms a relatively narrow annular gap and, due to its throttling structure, shuts off the exhaust conduit that ultimately leads to the surrounding environment, or at least the diameter or flow of the exhaust conduit. Narrow in product. On the other hand, the fuel gas outlet pipe is opened. As a result, the fuel gas pressure in the combustion chamber, which is still very high at the start of the exhaust valve opening process, is first converted into a flow that passes through the annular clearance of the exhaust valve, with a large velocity and the associated high dynamic pressure. Is done. This flow is then converted back to dynamic pressure by a throttling device that closes the exhaust pipe or at least reduces or throttles the flow, so that the fuel gas is at a high pressure and not simultaneously shut off by the throttling device, or It flows into the fuel gas outflow tube which is blocked at least to an unimportant degree.

  At the same time, during the period of the initial fuel gas outflow opening region of the exhaust valve (when the exhaust valve is open), the fuel gas that is pure or at least does not substantially contain cleaning air is present in the combustion chamber, It is not a mixture of fuel gas and supercharged air that may exist during the period of the exhaust gas exhaust opening area. At this time, the initial opening period of the exhaust valve is particularly important, and the phase at the end of the closing process is not so important. This is because only during the downward stroke of the piston, the pressure of the fuel gas is such that the fuel gas is supercharged when the discharged fuel gas is recirculated to the combustion chamber inlet side without using a pump provided in the middle. This is because the height is high enough to be returned to the inlet.

  Depending on the synchronization of the exhaust valves, completely or at least relatively pure fuel gas reaches the fuel gas outlet pipe. The fuel gas outflow pipe may be a recirculation conduit when the fuel gas flows out for recirculation of the fuel gas to the combustion chamber. In contrast, the fuel gas supercharged air mixture present during the exhaust gas exhaust opening region of the exhaust valve (when the exhaust valve has a relatively large opening) is completely or at least largely unsqueezed. Or at least slightly vented exhaust pipes, and in the case of fuel gas outlet pipes or fuel gas recirculations, they do not reach the recirculation conduit or are only a small part.

  Here, it is technically easy to construct the throttle device integrally with the exhaust valve, or at least to attach or fix the throttle device in synchronism with the exhaust valve. Especially in terms of timely selection of fuel gas outflow for gas recirculation to the combustion chamber inlet or other purposes, and in terms of simple construction and easy modification of existing engines and engine concepts. It is advantageous. The desired degree of opening of the exhaust valve to be reached by the fuel gas outflow opening region may also be affected by the shape of the exhaust valve or the throttle device formed on or fixed to the exhaust valve. It is not tied to the pressure sometimes generated.

  Exhaust valves constructed in accordance with the present invention, in many cases with existing engines, simply replace one or more exhaust valves in order to allow fuel gas to flow out in accordance with the present invention. It is enough. This is especially true for throttle devices that simply throttle the exhaust valve and do not close completely. In contrast, if the throttling device completely closes the exhaust pipe, it may be necessary to rework the exhaust pipe with an appropriate contact surface that is aligned with the valve stem. In this case, or if no fuel gas outlet pipe is present in the cylinder head provided in the engine, the replacement of all existing cylinder heads can be advantageous by a cylinder head constructed according to the invention. . In particular, when the existing internal combustion engine is changed to fuel gas outflow or fuel gas recirculation, the manufacturing method according to the present invention is advantageous.

  In the present invention, a method of letting out fuel gas in an operating internal combustion engine, particularly a two-cycle large diesel engine, particularly for fuel gas recirculation is further defined. The internal combustion engine has at least one combustion chamber defined by a piston cooperating with a cylinder and a crankshaft, each of which is a valve seat arranged with a valve head (Ventilteller) of an exhaust valve. (Tellersitz) and at least one fuel gas exhaust port and at least one supercharged air inlet. At this time, for example, in order to return part of the fuel gas generated during combustion to the supercharged air inlet, the fuel gas outlet is connected to at least one exhaust pipe and at least one fuel gas outlet pipe. Yes. The exhaust valve is operated between an open position and a closed position. In the fuel gas outflow opening region of the exhaust valve, the inflow of fuel gas to the exhaust pipe is fixed to the exhaust valve or integrated with the exhaust valve. This is prevented by a specially shaped throttle device, or at least tighter than in the exhaust gas discharge opening region from the relatively large opening degree of the exhaust valve to the open position. In contrast, in the fuel gas outflow opening region, the inflow of the fuel gas into the fuel gas outflow pipe is preferably not throttled at all, or at least not unnecessarily throttled by the throttle device.

  According to the present invention, a throttle device fixed to the exhaust valve or molded integrally with the exhaust valve has advantages especially in a two-stroke engine with fuel gas recirculation. Energy loss can be avoided by opening the exhaust valve later than in a typical two-cycle engine with fuel gas recirculation. In a typical two-cycle engine, an exhaust valve (or a separate recirculation exhaust valve) is provided well before it passes through the inlet air slit to prevent mixing of the returned fuel gas with the newly introduced supercharging air. ) Often have to be opened. According to the present invention, a crankshaft angle of up to 40 ° above the piston position at which the opening of one or more inlets (inlet air slits) starts to allow fuel gas to flow into the fuel gas outlet pipe. It is not necessary to open the exhaust valve before the piston position is reached in the down stroke. In many cases, it is advantageous to open the exhaust valve late, but in any case before the combustion chamber cleaning starts through one or more inlets (inlet air slits). is there. Here, the high pressure of the recycle gas is also particularly important. This is because the pressure of the supercharged air should be relatively high. If the recirculation pressure is high enough, no pump is needed.

  Particularly advantageous here is that the relatively high pressure prevailing on the fuel gas outlet side is maintained in the fuel gas outlet pipe by keeping the return valve closed against the flowing fuel gas-supercharged air mixture. This is a case where the provided return valve prevents the inflow of the fuel gas-supercharged air mixture flowing in the exhaust pipe not throttled in the exhaust valve existing in the exhaust gas discharge opening region. At this time, the return valve in the fuel gas outflow pipe can also be an actively controlled return valve in order to better control the amount of fuel gas discharged, particularly when the exhaust valve is operated by a camshaft. . In the case of an exhaust valve that is electronically controlled and operates by a unique drive rather than a camshaft, the control time of the exhaust valve can be set appropriately to control the fuel gas that has flowed out.

  As another option or in addition to the above measures, whether the throttle device is configured so that the throttle device in the exhaust gas exhaust opening area of the exhaust valve prevents or at least throttles the flow of fuel gas into the fuel gas outlet pipe Or the throttle device and the outlet side branch of the recirculation conduit can be arranged with respect to each other, so that the fuel of the fuel gas-supercharged air mixture present during the exhaust gas discharge opening region The effect of preventing the inflow to the gas outflow pipe is obtained.

  In a further advantageous configuration of the invention, the throttle device has a throttle projection that projects radially from the valve stem of the exhaust valve, preferably over one turn, which throttle projection extends in the fuel gas outlet opening area. Is provided in the region of the valve stem existing in the region of the exhaust pipe that is placed downstream in the direction of flow at the exhaust port side branch of the fuel gas outflow pipe. While the exhaust valve is in the fuel gas outflow opening region, the flow through the exhaust pipe is throttled and pumped or bypassed into the fuel gas outflow pipe based on the dynamic pressure generated in the throttle projection.

  In particular, when the throttle protrusion is at least loosely in contact with the inner periphery of the exhaust pipe in a part of the exhaust pipe formed as an exhaust cylinder, such as a movable piston, the fuel gas is discharged from the fuel gas outflow opening region. In the case of opening in the fuel gas, the fuel gas outflow pipe is reached without significantly reducing the amount or pressure. Therefore, no additional pump may be used in the recirculation conduit returning to the inlet side. The recirculation conduit is used as a fuel gas outlet when fuel gas is allowed to flow out for recirculation. In the region where the exhaust cylinder is disposed in the direction of flow at the exhaust port side branch of the fuel gas outflow pipe, and in the region where the throttle protrusion is present when the exhaust valve is present in the fuel gas outflow opening region, the cylinder In general, the valve rotation mechanism generally provided in a two-cycle large diesel engine of the same genus often uses a propeller structure (Umschaftpropellergestaltung) to ensure intermittent rotation of the valve. The rotating mechanism can be maintained in a general manner.

  In said advantageous further configuration of the invention, the fuel gas outlet pipe may branch off in the exhaust pipe away from the fuel gas outlet. At this time, when the exhaust valve is open in the exhaust gas discharge opening region, the throttle protrusion may be provided in the region of the valve rod that is generally located at the height of the branch portion of the fuel gas outflow pipe in the exhaust pipe. The exhaust pipe can be enlarged in an annular shape in the region of the branch portion of the fuel outflow pipe, so that the fuel gas flowing into the exhaust pipe can be opened when the exhaust valve opens in the exhaust gas discharge opening area. In addition, the fuel gas outflow pipe can flow around the throttle protrusion at a position at the height of the branch portion. Preferably, the diameter-enlarged portion is sized so that the inflow of the fuel gas into the exhaust pipe is preferably not restricted at all, but at least an exhaust valve in which the inflow of the fuel gas is opened in the fuel gas outflow opening region, or The size of the fuel gas outflow pipe is narrower than that of the throttling protrusion existing in the region disposed in the flow direction at the branch portion of the fuel gas outflow pipe.

  On the other hand, similarly, it is conceivable to arrange the throttle protrusion in a region located near the valve head of the valve stem. The throttle protrusion is present in the combustion chamber in the exhaust valve opened in the exhaust gas discharge opening region, so that the inflow to the exhaust pipe is possible through an annular flow path formed between the throttle protrusion and the valve seat. . In this case, the branch of the recirculation conduit is preferably arranged in the valve seat itself or in a region directly connected to the exhaust pipe valve seat. At the same time, in the throttle protrusion present in the combustion chamber, in order to ensure the opening degree of the exhaust valve large enough to discharge the fuel gas-air mixture, and in the exhaust valve opened in the fuel gas outflow opening region, An excessively large stroke of the exhaust valve is not required to move the throttle protrusion to the region of the exhaust pipe that is placed downstream in the direction of flow at the branch of the fuel gas outflow pipe.

  Obviously, the throttling protrusion flows around at least in the case of an exhaust valve opened in the exhaust gas discharge opening region, and in the case of an exhaust valve opened in the fuel gas outflow opening region, the flow is directed to the fuel gas outflow pipe. To guide. Therefore, advantageously, the throttle protrusion does not have an inconvenient angle for the flow conditions, and at least on its front face, i.e. the face where the throttle protrusion faces the branch of the recirculation conduit in the fuel gas outlet opening region. In the case of an exhaust valve opening in the fuel gas outflow opening region, the fuel gas flowing into the region of the exhaust pipe before the throttle projection is To the fuel gas outlet pipe branching laterally.

  According to a further advantageous configuration of the invention, the exhaust pipe has an exhaust cylinder arranged downstream in the direction of flow at the fuel gas outlet, at its outer periphery at least one exhaust conduit and at least one fuel gas. The outflow pipe is branched. At this time, the branch portion of the exhaust conduit is provided downstream of the branch portion of the fuel gas outflow pipe. The throttling device may further comprise a slider that is slidably received in the exhaust cylinder exclusively in the axial direction, which in the case of an exhaust valve that opens in the fuel gas outflow opening region. In the case of the exhaust valve opened in the exhaust gas discharge opening region, it is shaped so as to at least partially cover the branch portion of the fuel gas outlet pipe and is connected to the exhaust valve.

  Here, it is advantageous not only to completely prevent or at least prevent the inflow to the exhaust conduit in the exhaust valve present in the fuel gas outflow opening area, but also in the exhaust valve open in the exhaust gas discharge opening area. The inflow of the air mixture into the fuel gas outlet tube or the flow of the fuel gas collected there back to the exhaust cylinder is also completely prevented or at least prevented.

  As already mentioned, the slider does not necessarily have to operate completely in close contact with the inner periphery of the exhaust cylinder. Even if some gas leaks from between the slider and the exhaust cylinder wall surface, the basic action of the slider, that is, the action as a throttle in the exhaust pipe in the case of the exhaust valve existing in the fuel gas outflow opening region, and advantageous This is not an important problem as long as the function of the throttle at the branch portion of the fuel gas outlet pipe in the case of the exhaust valve opened in the exhaust gas discharge opening region is satisfied.

  In the sense of the already mentioned functionality of a typical valve rotation mechanism, it is advantageous if the slider is configured as a cylindrical slide sleeve and the exhaust cylinder is likewise cylindrical. However, in the case of an exhaust valve that does not have such a valve rotation mechanism, a completely different geometry is conceivable.

  The slider or slide sleeve can be connected to the valve stem of the exhaust valve, for example, through a radial strut. However, it is also conceivable that the slide sleeve is configured as a tube starting from the side facing the combustion chamber of the valve head. The tube is provided with an outflow opening for flow in a region close to the valve head.

  In this case, preferably, there are provided a plurality of exhaust conduits or one exhaust conduit branched from the exhaust cylinder, having a plurality of branches distributed over the circumference of the exhaust cylinder, and thereby opened in the exhaust gas exhaust opening region. In the exhaust valve, the inflow of the fuel gas-supercharged air mixture is promoted. As an alternative or in addition, the exhaust conduit extends annularly around the exhaust cylinder and can be opened annularly relative to the exhaust cylinder, or annularly relative to the exhaust cylinder It may have an open branch.

  In the case of an exhaust valve opened in the exhaust gas discharge opening region, in the case of a further configuration having a throttle projection present in the exhaust pipe, the same as when the diameter is enlarged to allow flow around the throttle projection In a further advantageous configuration with an exhaust conduit / fuel gas outlet conduit that can be throttled or closed by a slider or a slide sleeve, the throttle device, i.e. the throttle projection or slider or slide sleeve, is relatively distant from the combustion chamber in the exhaust pipe. Can be arranged. Therefore, the expansion device cannot be subjected to a high thermal load, and therefore can be formed relatively inexpensively when the expansion protrusion is hollow, for example. In this case, since the branch portion of the fuel gas outflow pipe is located relatively far from the combustion chamber, the thin material portion having a high thermal load is located between the branch portion of the fuel gas outflow pipe and the combustion chamber wall. Does not exist.

  On the other hand, certain design dimensions of the exhaust cylinder must be provided that can accommodate the branch of the fuel gas outlet pipe and the sliding area of the throttle device. Therefore, a further configuration having a throttle projection present in the exhaust gas exhaust region in the combustion chamber and a fuel gas outlet pipe branching near the combustion chamber exhaust or valve seat is also advantageous. In addition, it provides a more direct and lossless flow of fuel gas into the fuel gas outlet tube.

  Proceeding further in this direction is a third advantageous further configuration of the invention. In this configuration, the exhaust pipe likewise has a preferably cylindrical exhaust cylinder that is placed downstream in the direction of flow at the fuel gas outlet, which further has the exhaust cylinder already described. It can be much shorter than in the configuration. This is because the exhaust cylinder here is simply the axial direction of the valve stem on the side facing away from the combustion chamber of the valve head as long as the exhaust valve is closed or opened in the fuel gas outflow opening area. This is because the exhaust valve is closed, or at least the inflow to the exhaust pipe is restricted, because the protruding step must be received in the shape of the cross section of the exhaust cylinder. At this time, the fuel gas outflow pipe branches in a branch region located outside the step portion in the radial direction (that is, the valve seat valve seat region). Covered by the back side. Therefore, when the exhaust valve is closed, the fuel gas outflow pipe is separated from the combustion chamber.

  Preferably, however, the bifurcation region is present in a region radially adjacent to the stepped portion, or at least near the outer periphery of the stepped portion, so that the closed exhaust valve faces the combustion chamber of the valve head. The valve seat on which the side rests extends radially outward from the branch region, so that the exhaust port of the combustion chamber can be reliably closed when the exhaust valve is closed.

  The advantage of this further configuration is in particular that the manufacturing costs of the throttle device are low. Only the back of the valve head has to be extended slightly by the step, and when installing the step on the outer periphery of the exhaust cylinder, the inner peripheral surface of the exhaust cylinder is properly and precisely machined to It must be configured to line up accurately. The inlet or branch of the recirculation conduit is placed in front of or juxtaposed to the branch or inlet of the exhaust pipe, or the branch of the fuel gas outlet pipe is directly open to the combustion chamber. It has proved advantageous from the point of view of optimizing the inflow of gas into the fuel gas outflow pipe. On the other hand, a high thermal load is generated in the region of the branch portion of the fuel outflow pipe, particularly in the thin material portion of the wall surface of the combustion chamber between the combustion chamber and the fuel gas outflow pipe. Therefore, in order to ensure sufficient cooling, a coolant conduit provided in the material of the combustion chamber wall in the region of the fuel gas outlet, particularly in the material between the valve seat and the fuel gas outlet pipe, is advantageous. is there.

  If the fuel gas outlet pipe extends annularly towards the combustion chamber or branches off from the fuel gas outlet through a branch opening annularly towards the exhaust cylinder, the coolant conduit is preferably At least partially surrounding the perimeter. The annularly open branch is advantageous for collecting the fuel gas to be transported to the fuel gas outlet pipe, and for this purpose, preferably the branch is wulstartig on the combustion chamber wall surface. Can be opened into the material.

  In the following, advantageous embodiments of the invention will be described with the aid of arbitrary figures.

1 is a schematic view of an internal combustion engine according to a first embodiment of the present invention. FIG. 2 is a partial cross-sectional view of a combustion chamber exhaust port of the internal combustion engine shown in FIG. 1 when an exhaust valve is closed. FIG. 3 is a view corresponding to FIG. 2 when the exhaust valve opens in a fuel gas outflow opening region. FIG. 6 is a schematic view of a region of a combustion chamber exhaust port according to a further embodiment of the present invention when the exhaust valve opens in a fuel gas outflow opening region. FIG. 5 is a view corresponding to FIG. 4 when the exhaust valve opens in an exhaust gas discharge opening region. FIG. 6 is a schematic view of a combustion chamber exhaust region according to a further embodiment of the present invention when the exhaust valve is closed. FIG. 7 is a view corresponding to FIG. 6 when the exhaust valve opens in the fuel gas outflow opening region. FIG. 8 is a view corresponding to FIGS. 6 and 7 when the exhaust valve opens in an exhaust gas outflow opening region. FIG. 9 is a schematic view of a combustion chamber exhaust region in which the embodiment shown in FIGS. 6 to 8 is slightly modified. It is a diagram of the pressure transition displayed through the crank angle. It is a diagram of the flow product displayed through the crank angle.

The main application range of the present invention is a two-cycle large diesel engine, which is used for driving a ship, for example. The basic structure and operation of this type of equipment is known per se. Here, often a part of the exhaust gas, in order to reduce emissions of NO _x, and returns to the working chamber 2, that is, must be recycled. This so-called recirculated gas is an exhaust gas that is as dilute as possible with the purest possible fuel gas, i.e. cleaning gas, in order to facilitate management and ensure accurate metering.

  FIG. 1 is an example of an internal combustion engine with fuel gas recirculation, which is further configured according to an embodiment of the present invention. However, the present invention is not limited to the structure of the recirculation device shown purely by way of example in FIG. A variety of exhaust valves and cylinder heads constructed in accordance with the present invention may be used, as illustrated in FIGS.

  The invention is further not limited to engines with fuel gas recirculation, but can also be used to drain fuel gas for other purposes. Therefore, in the following, when referring to the “recirculation opening area” of the exhaust valve, “fuel gas outflow opening area” in an internal combustion engine having fuel gas recirculation is intended, and the description “recirculation conduit” It replaces the more general description of “gas outflow pipe”. However, the above-described embodiments of the present invention can be used as well when the fuel gas is flushed or removed for purposes different from fuel gas recirculation.

  FIG. 1 shows a cylinder 1 of an internal combustion engine. The internal combustion engine may have a plurality of cylinders arranged in series. Each cylinder 1 has a combustion chamber 2 which, in the downward direction, cooperates with the crankshaft through a piston rod, its head and a connecting rod in a manner not shown in detail. , Defined by a vertically movable piston 3. An air inflow slit 4 is provided in the lower region of the cylinder 1, and the slit is passed by the piston 3 and is thus increased and decreased (auf-und abgesteuert). The air inflow slit 4 of each cylinder 1 communicates with a provided supply pipe 5, and the supply pipe is connected to a distribution pipe 6 that can supply supercharged air that leads to all cylinders. The inflow slit 4 functions as an air inlet, and combustion air is supplied to the combustion chamber 2 through the inflow slit.

  An exhaust valve 9 is provided in an area of the cylinder cover that delimits the combustion chamber 2 upward, and the fuel gas exhaust port 20 can be opened and closed through the exhaust valve. Here, a fuel injection device not shown in detail may be provided.

  The fuel exhaust port 20 is connected to the exhaust pipe 11. The exhaust pipe 11 of all cylinders is usually connected to a common exhaust gas collection pipe 12 for all cylinders. An exhaust gas conduit 13 branches from the exhaust gas collecting pipe, and the exhaust gas conduit supplies exhaust gas to the turbines 14 of the exhaust turbochargers 14 and 15. The turbine 14 drives a compressor 15, and the compressor supplies the cleaning air compressed through the cleaning air conduit 16 to the supercharged air distribution pipe 6. A cleaning air cooler 17 may be disposed in the cleaning air conduit 16.

The exhaust gas leaving the turbine 14 is discharged to the surrounding environment. In order to reduce as much as possible NO _x content of the exhaust gas, a part of gas generated during combustion in the combustion chamber 2, directly or indirectly, it is again returned the (recirculated to the combustion chamber 2 ) For this purpose, a recirculation conduit 18 is provided which branches in the region of the fuel gas outlet 20 and is connected to a recirculation gas collection chamber 19 which leads over all cylinders 1. The gas collection chamber is connected to the supercharged air distribution pipe 6 at a part of the recirculation conduit 18 via an optional processing unit 21 for cooling and / or cleaning and / or filtering the recirculated gas removed. Has been. Finally, the recirculation conduit 18 is connected to the inflow slit 4 which functions as a supercharged air inlet.

  In the configuration shown in FIG. 1, the recirculation gas is mixed with cleaning air or cleaning gas and supplied to the fuel chamber 2 as supercharged air, that is, indirectly. For this purpose, the recirculation conduit 18 is connected to the supercharged air distribution pipe 6. As indicated by broken lines in FIG. 1, the connection of the recirculation conduit 18 may precede the cooler 17. In such a case, it is not necessary to independently cool the recirculated gas.

  Since the pressure of the recirculated gas taken out from the combustion chamber 2 and supplied to the recirculation conduit 18 is higher than the cleaning air pressure in the cleaning air conduit 16, there is a spontaneous flow and the pressure in the recirculation conduit 18. No additional unit is required to increase In order to reliably prevent the return to the recirculation conduit 18 in the case of a short pressure peak in the supercharged air, for example in the region between the supercharged air distribution pipe 6 and the recirculation gas collection chamber 19, respectively. A return valve that opens toward the inlet side of the combustion chamber may be provided in the recirculation conduit 18.

  Further, for example, in the region between the recirculation gas collection chamber 19 and each combustion chamber 2, a return valve 23 that opens toward the inlet side of the combustion chamber may be provided in the recirculation conduit 18. Accordingly, when the pressure on the fuel gas exhaust port 20 side is higher than that on the recirculation gas collection chamber 19 side, only the fuel gas can flow through the recirculation conduit 18 and the pressure on the fuel gas exhaust port 20 side is recirculated. At the same time, it is ensured that the fuel gas collected as the recirculation gas does not flow backward when it is lower than the gas collection chamber 19 side.

  As already mentioned, since the pressure of the fuel gas taken out from the combustion chamber 2 and recirculated is higher than the pressure of the supercharged air, no additional device such as a pump or a compressor is required. For this purpose, the diaphragm device provided by the present invention is mainly used.

  Various variations of fuel gas recirculation systems are known, and the fuel gas recirculation system shown in FIG. 1 is exemplary only. For example, there can be several layers of elements that can be compared to the elements already mentioned to ensure parallel operation. In order to obtain the desired functionality during operation of the engine, some of the elements shown can also be divided into functionally separated units arranged in series. Furthermore, such a system may constitute the core of the expanded system. This expanded system has, for example, further elements upstream or downstream of the turbine 14, thereby further utilizing the energy contained in the exhaust gas, or finally exhausting the exhaust gas into the environment. It becomes possible to wash before being done. The upstream / downstream air flow of elements such as the compressor 15 can also be further processed by devices not shown in FIG. This air stream can also be mixed with substances different from pure ambient air, so that the recirculated fuel gas is mixed with the gas stream provided for cylinder cleaning before the cleaning air Instead, there is a cleaning gas containing additional gaseous and flammable or non-flammable substances. The last air-fuel mixture provided for cleaning the cylinder has a very diverse composition and is called “supercharged air”. Obviously, the present invention is applicable to all the fuel gas recirculation systems.

  2 and 3, a first embodiment of a fuel gas outlet having a throttle device 10 of the kind described above can be seen. FIG. 2 shows the combustion chamber 2 in a state separated from the exhaust pipe 11 by a closed exhaust valve 9. On the other hand, the broken line indicates the position where the exhaust valve 9 is completely opened. That is, the exhaust valve 9 moves up and down in a control time synchronized with the movement of the piston 3 as indicated by a double arrow.

  Here, the exhaust valve 9 has a valve head 8, which is mounted on the valve seat in the closed position, thus closing the fuel gas exhaust port 20, and in the downward movement of the valve 9, the fuel The gas exhaust port 20 is opened. At this time, the valve head 8 is fixed to the valve stem 7, which is supported by the cylinder head in a conventional manner and is generally driven by a camshaft not shown here. . Other valve actuating devices such as electronic valve direct control with valve actuation by electromagnets, etc. found in recent years, for example based on the so-called electronic valve control principle, which do not have a mechanical connection between the crankshaft and the valve stem Is also possible.

  The valve stem 7 has a rotationally symmetric throttle projection 10 at the exhaust valve 9 with the throttle projection 10 closed (FIG. 2) and to the desired degree of opening (FIG. 3) to exhaust the recirculation conduit 18. It is provided at a position that is arranged in a region that is placed downstream of the pipe 11 in the direction of flow at the branching portion. The region between the positions shown in FIGS. 2 and 3 of the exhaust valve 9 corresponds to the recirculation opening region of the exhaust valve 9, in which the throttle protrusion 10 is located on the outer periphery of the exhaust pipe 11. The exhaust pipe 11 is closed at least for the fuel gas flowing out of the combustion chamber 2 at least mainly by the inner periphery of the cylindrical part of the cylinder. As long as is obtained, it is not forced to be absolute.

  At this stage, the fuel gas flowing out of the combustion chamber 2 is guided in the direction of the recirculation conduit 18 as indicated by the arrows in FIG. 3, and for this reason, the hyperbola on the side of the throttle projection 10 facing the combustion chamber 2. A round or round surface and an enlarged diameter part 22 that also has a rounded side surface surrounding the exhaust pipe 11 in an annular shape in the branch region of the recirculation conduit 18 are used.

  The exhaust valve 9 defines the upper limit of the recirculation opening area, down from its desired opening degree position shown in FIG. 3 towards its fully open position (shown in broken lines in FIG. 2). When moving, the throttle protrusion 10 reaches the region of the branch of the recirculation conduit 18 and the enlarged diameter portion 22 where it surrounds the throttle protrusion 10 through the fully open fuel gas outlet 20 and the combustion chamber. The gas flowing out of the gas 2 flows, and the gas can be discharged through the exhaust pipe 11.

  This illustrated embodiment is advantageous in several respects. For example, during the initial opening phase between the position shown in FIG. 2 and the position shown in FIG. 3 of the exhaust valve 9, ie in the recirculation or fuel gas outflow opening region, it is pure or substantially pure in the combustion chamber 2. Fuel gas is present. This is because, at this stage, the air inlet slit 4 is not passed or at least not yet fully passed, and this fuel gas has a higher pressure. The fuel gas flowing into the recirculation conduit 18 has a desirable characteristic for recirculation, ie, the pressure of the gas present in the cleaning system, that is, the cleaning gas or the cleaning air to be mixed with the fuel gas flowing into the recirculation conduit 18. Due to the overpressure, the return valve 23 opens in the recirculation conduit 18 as shown in FIG. On the other hand, the fuel gas has a desired low oxygen concentration, which increases only after opening the air inlet slit 4 and the supercharged air.

  On the other hand, in the subsequent exhaust gas discharge opening stage, that is, in the state where the exhaust valve 9 is further opened as shown by the broken line in FIG. 2, the piston 3 has already passed through the supercharged air inflow slit 4. In the combustion chamber 2, there is an air-fuel mixture having a low pressure that is inconvenient for recirculation. This air-fuel mixture passes through the opened fuel gas exhaust port 20 to reach the inlet region of the exhaust pipe 11 and reaches the region of the enlarged diameter portion 22 where the throttle protrusion 10 also exists. Therefore, it is possible to flow around the throttle protrusion 10 without applying a large dynamic pressure to the gas flowing out from the combustion chamber 2. The gas finally flows out of the combustion chamber. This is because the pressure in the exhaust gas collecting pipe 12 is generally lower than the pressure of the supercharged air. This air-fuel mixture cannot flow into the recirculation conduit 18 during the exhaust gas discharge opening stage, or cannot open the return valve 23, and the exhaust projection 12 or the throttle body 10 is surrounded by the exhaust gas collecting pipe 12. Flows in the direction and is excluded from recirculation.

  4 and 5 show a further embodiment of the present invention, in which the modified exhaust valve 109 and the modified branch from the exhaust pipe 11 of the recirculation conduits 118a, 118b. However, the combustion chamber 2 itself may not be changed from the embodiment shown in FIGS. 1 to 3, and the same applies to the remaining engine components shown in FIG. is there.

  Here, the valve rod 107 is provided with a throttle protrusion 110 that also surrounds the periphery. However, this throttling protrusion is placed directly behind the valve head 108. At the same time, the branch of the recirculation conduit or, in this embodiment, the branch of the recirculation conduit 118a, 118b is directly in the connection region to the fuel gas outlet 120. The fuel gas exhaust port 120 is formed by the back surface of the valve head 108 and the valve seat in contact with the combustion chamber wall surface at the recirculation opening position of the exhaust valve 109 shown in FIG. 5 is formed between the rear surface of the throttle projection or baffle 110 and the radially outer surface and the valve seat at the exhaust gas discharge opening position of the exhaust valve 109 shown in FIG.

  As in the first embodiment of the present invention, the throttle protrusion 110 is again placed in the direction of flow in the recirculation conduit branches 118a, 118b when the exhaust valve 109 is in the recirculation opening region. Since the region of the exhaust pipe 11 is at least sufficiently closed, the fuel gas flowing out of the combustion chamber 2 flows into the recirculation conduits 118a and 118b in the recirculation opening region of the exhaust valve, as indicated by arrows in FIG. Be guided. As shown in FIGS. 4 and 5, it is possible to provide one return valve in each recirculation conduit or in the portion of the recirculation conduit where each recirculation conduit 118a, 118b joins. This return valve is not shown in FIG. 4 in the recirculation conduit 118b simply due to space issues. If the fuel gas has a higher pressure than the recirculation gas collected in the collection container 19, the return valve allows the recirculation gas or fuel gas to flow into the recirculation collection container 19.

  On the other hand, when the exhaust valve 108 has a larger opening degree, or when it exists in the exhaust gas discharge opening region, the restricting projection 110 surrounding the periphery no longer closes the exhaust pipe 11, so that FIG. As indicated by the arrows in FIG. 2, the existing gas flows to the exhaust pipe 11 and from there to the exhaust gas collection pipe 12. It should be noted that not only the two recirculation conduits 118a, 118b but also a plurality of pipes distributed over the circumference of the exhaust pipe 11 that is cylindrical at this position are intended to improve the flow of fuel gas into the recirculation side. A recirculation conduit may be provided. Therefore, a cavity may be provided in the inner wall of the circumference from which the recirculation conduit 118 branches.

  FIGS. 6 to 8 show further embodiments of the present invention, FIG. 6 shows an embodiment where the exhaust valve 308 is closed, and FIG. 7 shows that the exhaust valve opens in the recirculation region. FIG. 8 shows an embodiment in which the exhaust valve is open in the exhaust gas discharge region.

  In this embodiment, the throttle device is constituted by a step portion 310 protruding from the back surface of the valve head 308, and the step portion is shown in FIG. 7 from the closed position of the exhaust valve 309 shown in FIG. In the recirculation opening region to the position of the exhaust valve having the desired opening degree, the exhaust pipe 11 is closed, but the recirculation conduit 318 or the branch portion 318a surrounding the exhaust pipe 11 in an annular shape, or The inlet 318a for inflow of the fuel gas flowing out from the combustion chamber 2 through the fuel gas exhaust port 320 is opened around the periphery of the exhaust pipe 11 in an annular shape. On the other hand, in the exhaust gas discharge region shown in FIG. 8, the exhaust valve 307 is not adjacent to the cylindrical wall surface of the exhaust pipe 11 at the position where the step portion 310 no longer corresponds to the recirculation opening region. The exhaust pipe 11 is slid into the combustion chamber as long as the exhaust pipe 11 is opened. As already mentioned, a return valve can again be provided in the recirculation conduit 318.

  In this embodiment, the inlet or branch 318a to the recirculation conduit 318 is located directly at the exhaust port 320 of the combustion chamber 2, so between the combustion chamber wall and the recirculation conduit 318 or branch 318a. High thermal loads are applied to the materials present. At the same time, a very thin material portion stands. In order to avoid this drawback, the embodiment of the present invention shown in FIGS. 6 to 8 can be partially changed as shown in FIG.

  At this time, a coolant pipe 24 is provided in a material portion standing between the combustion chamber side surface and the inlet 418 a of the recirculation conduit 418, and this coolant pipe also surrounds the exhaust pipe 11. It is out. At the same time, the collection volume of the recirculation inlet 418a, which is open in the material, and the inlet region of the recirculation conduit 418 are moved further back into the material away from the combustion chamber. The wider material portion can withstand higher thermal loads than in the embodiment of the invention shown in FIGS. In addition, in contact with the valve stem 307, a known rotating blade ring is shown at 25, which performs a valve rotating motion with gas passing therethrough, the valve rotating motion comprising the exhaust valve 309 and Wear that is earlier than planned for the valve seat should be prevented.

  In FIG. 11, in an exemplary and purely quantitative manner with respect to the internal combustion engine according to the present invention, the inflow slit forming the cleaning gas inlet 4 in response to the movement of the piston 3 represented by the crank angle after the top dead center. The transition of the free product in the region is shown by curve b. On the other hand, the curve a shows the transition of the free flow product in the region of the fuel gas exhaust port 20. At this time, the straight line portion shows the transition when the exhaust valve 9 is driven by the camshaft. The dotted line portion shows the free flow transition that can be considered when the exhaust valve is electronically operated without mechanical connection between the crankshaft and the valve stem.

  According to the curve a, the opening of the exhaust valve 9 actuated by the camshaft is carried out, for example, at a crank angle of 115 ° after top dead center, ie 65 ° above bottom dead center during the downward stroke. In the case of an exhaust valve that is electronically controlled and actuated, the opening is somewhat earlier, for example starting at a crank angle of 110 ° after top dead center and before fully opening and before the exhaust valve has advanced into the exhaust gas discharge area. In addition, it can be interrupted to extend the fuel gas outflow opening area.

  According to curve b, the cleaning gas inlet 4 opens at a crank angle of about 135 ° after top dead center (ie 45 ° above bottom dead center during the downward stroke). Assuming that the drive formed by the piston 3 and the crankshaft is substantially symmetrical, the cleaning gas inlet 6 is closed again at a crank angle of about 135 ° before top dead center in the ascending stroke of the piston 3. The closing of the exhaust valve 9 is often not controlled symmetrically at the top dead center and is performed somewhat later in the ascending stroke, so that when the exhaust valve 9 is open, the working chamber 2 is reliably Washed. Here, since the fuel gas is no longer taken out, there is no fuel gas outflow opening area in the piston stroke, and the control of the electronically controlled and actuated exhaust valve is a common actuated by the camshaft. This can be done in response to the exhaust valve.

  The exhaust gas leaking when the exhaust valve 9 is opened causes an increase in pressure in the exhaust pipe 11. In FIG. 10, the transition of the pressure in the exhaust pipe 11 is indicated by the curve c in accordance with the movement of the piston, that is, through the crank angle. It is clear from this that when the exhaust valve 9 is opened, the pressure in the exhaust pipe 11 rapidly increases. This results in a pressure impulse e having one or more vertices starting at a crank angle of about 115 ° after top dead center. The pressure impulse e has a relatively short duration and simply extends beyond a crank angle of about 20 °. Therefore, the pressure impulse e ends before the inflow slit 4 is opened. In either case, the opening of the cleaning gas inlet 4 can lead to the final termination of the pressure impulse e.

  A further curve d in FIG. 10 shows the change in pressure in the combustion chamber 2 through the crank angle. Since the pressure in the combustion chamber 2 becomes relatively high, a different scale is effective for the curve d than for the curve c on the x coordinate assigned to the pressure. In FIG. 10, the curve c and the curve d intersect. However, this is simply based on the different scales. When the same scale is used, the curve c and the curve d do not intersect each other, or at most, intersect in the region of the pressure impulse e. According to the curve a (FIG. 11), the exhaust valve 9 is completely opened after the crank angle of about 130 ° after the top dead center. Therefore, the pressure in the combustion chamber 2 and the pressure in the exhaust pipe 11 are substantially the same after the end of the pressure impulse e from about 150 ° after top dead center to 180 ° after top dead center. According to the curve b, the cleaning gas inlet 4 is completely open after about 160 ° after the top dead center.

  Therefore, the pressure in the combustion chamber 2 and the exhaust pipe 11 is only slightly lower than the cleaning gas pressure, which is indicated by the curve f in FIG. Curve f shows the pressure in the cleaning system and is shown on the same scale as curve c. It is clear at e that the pressure in the exhaust pipe greatly exceeds the pressure f in the cleaning system immediately after the opening of the exhaust valve 9, which gives a positive pressure difference. This pressure differential is used according to the present invention to drive fuel gas into the fuel gas outlet system and further into the fuel gas recirculation circuit that terminates somewhere in the cleaning gas system by the inlet. It should be noted here that if the throttle device according to the present invention is not present, the shape of the curve c is e because of the relatively large volume that is compressed immediately after the exhaust valve is actuated directly downstream of the exhaust valve. Will be much flatter and only a smaller maximum pressure value will be obtained.

  The emphasis on g is that the cleaning gas pressure f for cleaning exceeds the actual pressure in the exhaust pipe and the following exhaust gas exhaust system. During this phase, if the cleaning inlet is open towards the combustion chamber, there is a positive pressure difference transmitted through the cylinder volume between the cleaning system and the exhaust gas exhaust system, so cleaning is This leads to the inflow of the cleaning gas into the cylinder volume through the inlet and the simultaneous extrusion of fuel gas (Herausdraengen) by the open exhaust valve.

  The illustrated embodiments can be changed and modified within the scope of the present invention.

  For example, the valve rotation mechanism is not compulsory for the function of the recirculation control, but may be provided in the embodiment shown in FIGS. On the other hand, when such a valve rotation mechanism is lacking, the throttle device and the exhaust pipe are arranged even if the throttle device is in the form of a baffle, a slide sleeve, or a step protruding from the valve head. It is also possible to have a completely different geometry than the portion that has been made. However, in the illustrated embodiment, the baffle, the slide sleeve, or the step protruding from the valve head is formed symmetrically with respect to the valve stem in all radial directions, such as the portion where the exhaust pipe is disposed. ing.

  Obviously, according to the present invention, the exhaust valve may be formed from one part, i.e. as one piece, or may be constructed by assembling a plurality of parts. Here, additional components such as the rotating blade ring 25 or additional components may be fixed to the exhaust valve. What is important is that the exhaust valve is always controlled and moved as a whole. The cylinder head can also be assembled as an assembly from individual members. The members can be specially adapted to achieve their respective functions and / or internal spaces. For example, a water-cooled annular conduit 24. In addition, in all embodiments, an actively controlled or passive return valve can be provided in the fuel gas outlet or recirculation conduit.

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Combustion chamber 3 Piston 4 Inlet slit 5 Supply pipe 6 Distribution pipe 7, 107, 307 Valve rod 8, 108, 308 Valve head 9, 109, 309 Exhaust valve 10, 110, 310 Throttle device 10, 110 Throttle protrusion 310 Throttle stage 11 Exhaust pipe 12 Exhaust gas collection pipe 13 Exhaust gas conduit 14 Turbine 15 Compressor 14, 15 Exhaust turbocharger 16 Supercharged air conduit 17 Supercharged air cooler 18, 118a, 118b, 318, 318a, 418, 418a Fuel Gas outlet pipe 19 Recirculation gas collection space 20 Fuel gas exhaust port 21 Recirculation gas processing unit 22 Diameter enlarged portion 23 Return valve 24 Water-cooled annular conduit 25 Valve rotating blade ring

1 is a schematic view of an internal combustion engine according to a first embodiment of the present invention. FIG. 2 is a partial cross-sectional view of a combustion chamber exhaust port of the internal combustion engine shown in FIG. 1 when an exhaust valve is closed. FIG. 3 is a view corresponding to FIG. 2 when the exhaust valve opens in a fuel gas outflow opening region. FIG. 6 is a schematic view of a region of a combustion chamber exhaust port according to a further embodiment of the present invention when the exhaust valve opens in a fuel gas outflow opening region. FIG. 5 is a view corresponding to FIG. 4 when the exhaust valve opens in an exhaust gas discharge opening region. The present invention of an internal combustion engine when the exhaust valve is closed but not grasped by the present invention FIG. 6 is a schematic view showing a region of a combustion chamber exhaust port in a cylinder head that is not grasped depending on the purpose of explanation. FIG. 7 is a view corresponding to FIG. 6 when the exhaust valve opens in the fuel gas outflow opening region. FIG. 8 is a view corresponding to FIGS. 6 and 7 when the exhaust valve opens in an exhaust gas outflow opening region. It is a schematic view of a combustion chamber outlet region plus slightly modified with respect to variation shown in FIGS. 6-8. It is a diagram of the pressure transition displayed through the crank angle. It is a diagram of the flow product displayed through the crank angle.

Claims (29)

An internal combustion engine, in particular a two-cycle large diesel engine, having at least one combustion chamber (2) defined by a cylinder (1) and a piston (3) cooperating with a crankshaft, each said combustion chamber comprising: At least one fuel gas outlet (20; 120; 320; 420) formed between the valve head (8; 108; 308) of the exhaust valve (9; 109; 309) and the disposed valve seat. And at least one supercharged air inlet (4), wherein the exhaust valve (9; 109; 309) is operable between an open position and a closed position, and the fuel The gas exhaust (20; 120; 320; 420) has at least one exhaust pipe (11) and at least one fuel gas outlet pipe (18; 118a, 118b; 318, 318a; 418, 418a). Are connected, for example by it, part of the fuel gas generated during combustion in an internal combustion engine sent back the supercharged air inlet (4),
A throttle device (10; 110; 310) fixed to the exhaust valve (9; 109; 309) or integrally formed with the exhaust valve (9; 109; 309) is provided, The throttling device is configured so that the fuel gas flows in the fuel gas outflow opening region of the exhaust valve (9; 109; 309) from the closed position of the exhaust valve (9; 109; 309) to the desired opening degree. It is prevented from flowing into the exhaust pipe (11), or at least in the exhaust gas discharge opening region of the exhaust valve (9; 109; 309) from the larger opening degree to the opening position. In the exhaust gas discharge opening region, the throttle device (10; 110; 310) preferably does not throttle the flow of fuel gas into the exhaust pipe (11) at all or little. The throttle device (10; 110; 310) and the branch portion on the exhaust port side of the fuel gas outlet pipe (18; 118a, 118b; 318, 318a; 418, 418a) The throttle device (10; 110; 310) causes the flow of fuel gas into the fuel gas outlet pipe (18; 118a, 118b; 318, 318a; 418, 418a) in the fuel gas outlet opening region, Internal combustion engines characterized in that they are arranged with respect to each other, preferably not at all, or at least not unnecessarily.   The exhaust valve (9; 109; 309) is at a piston position in the down stroke, which is a minimum 1 ° and a maximum 40 ° crankshaft angle above the piston position where the opening of the supercharged air inlet (4) begins. The internal combustion engine according to claim 1, wherein the internal combustion engine is controlled so as not to open before reaching.   The throttle device and the exhaust port side branch of the fuel gas outlet pipe prevent or at least throttle the fuel gas from flowing into the fuel gas outlet pipe in the exhaust gas discharge opening region, and / or A return valve is provided in the fuel gas outflow pipe, and the return valves are arranged relative to each other so as to prevent or at least restrict the inflow of fuel gas into the fuel gas outflow pipe in the exhaust gas discharge opening region. The internal combustion engine according to claim 1 or 2, wherein the internal combustion engine is provided.   The throttle device (10; 110) has a throttle protrusion (10; 110) protruding in a radial direction from the valve stem (7; 107) of the exhaust valve (9), preferably one round, When the exhaust valve (9; 109) is open in the fuel gas outflow opening region, the protrusion (10; 110) is formed at a branch portion on the exhaust port side of the fuel gas outflow pipe (18; 118a; 118b). In the region of the valve stem (7; 107) present in the region of the exhaust pipe (11) placed downstream in the direction of flow, the exhaust pipe is preferably cylindrical in this region The internal combustion engine according to any one of claims 1 to 3, wherein the internal combustion engine is formed.   The fuel gas outlet pipe (18) is separated from the fuel gas exhaust port (20) and branches in the exhaust pipe (11), and the throttle protrusion (10) is an exhaust valve in the exhaust gas discharge opening region. When (9) is open, it is provided in the region of the valve stem (7) located approximately at the height of the branch portion of the fuel gas outflow pipe (18) in the exhaust pipe (11). The exhaust pipe (11) has an annular diameter enlarged portion in the region of the branch portion of the fuel gas outflow pipe (18). ) Is open in the exhaust gas discharge opening region, preferably the fuel gas does not throttle at all into the exhaust pipe (11), or at least the exhaust valve (9) flows out of the fuel gas. It is characterized by squeezing weaker than when opening in the open area. Internal combustion engine according to claim 4,.   The throttle protrusion (110) is present in the region of the valve stem (107) existing in the combustion chamber (2) when the exhaust valve (109) is opened in the exhaust gas discharge opening region. The branch portion of the fuel gas outlet pipe (118a; 118b) is preferably present in the valve seat or in a region directly connected to the valve seat of the exhaust pipe (11). The internal combustion engine according to claim 4.   The diameter of the valve stem (7; 107) is curved in the region of the throttle projection (10; 110), at least on the side of the throttle projection (10; 110) facing the valve head (8; 108). The squeezing projection (10; 110) transitions to the largest radially outer dimension, and the squeezing projection (10; 110) is preferably rounded at its radially outer edge. Item 7. The internal combustion engine according to any one of Items 4 to 6.   The exhaust pipe has an exhaust cylinder placed in the fuel gas exhaust port in the flow direction, and at the outer periphery thereof, at least one exhaust conduit and at least one fuel gas outlet pipe are branched, The branch portion of the exhaust conduit is provided downstream of the branch portion of the fuel gas outflow pipe, and the throttle device may include a slider that is slidably received in the axial direction in the exhaust cylinder. Preferably, the slider is firmly connected to the exhaust valve, so that when the exhaust valve opens in the fuel gas outflow opening region, a branch portion of the exhaust conduit, preferably the exhaust valve is the exhaust gas discharge opening. The internal combustion engine according to any one of claims 1 to 3, wherein when the fuel gas outlet pipe is open in a region, the branch portion of the fuel gas outlet pipe is at least partially covered.   The slider is configured as a cylindrical slide sleeve, which is connected, for example through a radial strut, preferably to the valve stem of a rotatable exhaust valve, which is likewise cylindrical. Preferably, the exhaust conduit is provided with a plurality of branches distributed around the circumference of the exhaust cylinder, and / or the exhaust conduit is provided with a ring of the exhaust conduit that opens annularly with respect to the exhaust cylinder. The internal combustion engine according to claim 8, wherein a branch portion is provided.   The exhaust pipe (11) has a preferably cylindrical exhaust cylinder that is placed in the fuel gas exhaust port (420) in the flow direction, and the throttle device (310) includes the valve head ( 308) on the side facing away from the combustion chamber (2), preferably in the axial direction of the valve stem (307), or at least with a protruding step (310) with an axial element, the exhaust cylinder The step portion closes or at least narrows the exhaust cylinder when the exhaust valve (309) is open in the fuel gas outflow opening region. The fuel gas outflow pipes (318, 318a; 418, 418a) branch in a branch region located radially outside the step portion (310), and when the exhaust valve (309) is closed, the valve Head (308) The fuel gas outflow pipes (318, 318a; 418, 418a) are covered with the combustion chamber (2) and extend radially outward from the branch region. 2), and the branch region is preferably in a region connected radially outward to the step (310), or at least near the outer periphery of the step (310) When the exhaust valve (309) is closed, the valve seat on the side facing the combustion chamber (2) of the valve head (308) extends radially outward from the branch region. The internal combustion engine according to any one of claims 1 to 3, wherein:   The fuel gas outflow pipe (18; 318, 318a; 418, 418a) branches at a fuel gas exhaust port through a branch portion (22; 318a; 418a) that is annularly opened toward the exhaust cylinder, The branches are preferably bead-like open into the material and / or the fuel gas outlet pipe (118a, 118b) has a plurality of branches (118a, 118b) distributed over the circumference of the exhaust cylinder. The internal combustion engine according to claim 1, wherein the internal combustion engine is provided.   The region of the fuel gas outlet (420) is provided with a coolant conduit (24) at least partly surrounding the material of the combustion chamber wall, in particular the material behind the valve seat. The internal combustion engine according to any one of claims 1 to 11. Combustion defined by an internal combustion engine, in particular a two-cycle large diesel engine, in particular an internal combustion engine according to any one of claims 1 to 12, defined by a cylinder (1) and a piston (3) cooperating with a crankshaft. An exhaust valve (9; 109; 309) for opening and closing a fuel gas exhaust port (20; 120; 320; 420) of the chamber (2), the exhaust valve (9; 109; 309) being disposed A valve stem (7; 107; 307) through which the exhaust valve is opened to form the fuel gas outlet (20; 120; 320; 420) with the valve seat An exhaust valve (9; 109; 309) having a valve stem operable between the valve stem and a closed position and a valve head (8; 108; 308) connected to the valve stem;
A throttle device (10; 110; 310) fixed to the exhaust valve (9; 109; 309) or integrally formed with the exhaust valve (9; 109; 309) is provided, The throttling device is configured so that the fuel gas flows in the fuel gas outflow opening region of the exhaust valve (9; 109; 309) from the closed position of the exhaust valve (9; 109; 309) to the desired opening degree. Inflow to the exhaust pipe (11) is prevented, or at least in the exhaust gas discharge opening region of the exhaust valve (9; 109; 309) from the larger opening degree to the opening position. In the exhaust gas discharge opening region, the throttle device (10; 110; 310) preferably does not restrict the flow of fuel gas into the exhaust pipe (11) at all. Or An exhaust valve, characterized in that not squeezed least is very strong (9; 109; 309).   The throttle device (10; 110) projects radially from the valve stem (7; 107) of the exhaust valve (9), is spaced from the valve head (8; 108), and preferably extends around the throttle projection ( 10; 110), and the diameter of the valve stem (7; 107) is at least in the region of the throttle projection (10; 110) the valve head (8; 10) of the throttle projection (10; 110). 108) curving and transitioning to the largest radially outer dimension of the throttle projection (10; 110), the throttle projection (10; 110) being preferably at its radially outer edge. 14. Exhaust valve (9; 109) according to claim 13, characterized in that it is rounded.   The throttle device (310) has at least an axial element on the side of the valve head (308) facing away from the combustion chamber (2), preferably in the axial direction of the valve stem (307). When the exhaust valve (309) is closed, the region of the valve head (308) connected to the step (310) on the outer side in the radial direction when the exhaust valve (309) is closed The exhaust valve (309) according to claim 13, wherein the exhaust valve (309) is mounted on a side of the valve head (308) facing away from the combustion chamber (2).   The throttle device is capable of moving in the axial direction in the exhaust cylinder, and is slidably received especially on the inner periphery of the exhaust cylinder, and a slider separated from the valve head, particularly in the form of a cylindrical sleeve. The exhaust valve according to claim 13, wherein the slider is connected to the valve stem of the exhaust valve through a radial strut.   The exhaust valve according to any one of claims 13 to 16, wherein the valve stem (307) is further provided with a valve rotating blade ring (25).   A non-contact readable identification mark is provided in an end region facing the combustion chamber of the valve stem, and the identification mark is provided between the fuel gas outflow opening region and the exhaust gas discharge opening region. At least one axial extension corresponding to the path of the valve to reach the transition position, the identification mark preferably extending around the periphery of the valve stem The exhaust valve according to any one of claims 13 to 17. 13. Internal combustion engine, in particular according to any one of claims 1 to 12, having at least one combustion chamber (2) defined by a cylinder (1) and a piston (3) cooperating with a crankshaft. In particular, a cylinder head for a two-cycle large diesel engine, in which an exhaust valve (9; 109; 309) opens and closes a fuel gas exhaust (20; 120; 320; 420) in the cylinder head. For the valve head (8; 108; 308), the fuel gas outlet (20; 120; 320; 420) having at least one exhaust pipe (11) and at least one fuel. Connected to the gas outlet pipe (18; 118a, 118b; 318, 318a; 418, 418a), for example, thereby during combustion Some without fuel gas, the cylinder head is returned to the charge air inlet (4),
An exhaust valve (9; 109; 309) according to any one of claims 13 to 18 is provided, the throttle device (10; 110; 310) and the fuel gas outlet pipe (18; 118a, 118b; 318, 318a; 418, 418a) is a branch portion on the exhaust port side where the throttle device (10; 110; 310) has the fuel gas outflow pipe (18) of the fuel gas in the fuel gas outflow opening region. 118a, 118b; 318, 318a; 418, 418a), preferably arranged in relation to each other so that they do not squeeze at all or at least unnecessarily, preferably further non-contact A cylinder head, characterized in that it is provided with a reader for an identification mark that operates in the above. A two-cycle large diesel engine having at least one combustion chamber (2) defined by a cylinder (1) and a piston (3) cooperating with a crankshaft, each of which is an exhaust valve (9; 109; 309) at least one fuel gas outlet (20; 120; 320; 420) formed between the valve head (8; 108; 308) and the disposed valve seat, and at least one In a method for manufacturing a two-cycle large diesel engine having a supercharged air inlet (4), in particular a two-cycle large diesel engine according to any one of claims 1 to 12,
A method for producing a two-cycle large diesel engine, wherein the exhaust valve (9; 109; 309) according to any one of claims 13 to 18 is attached. A two-cycle large diesel engine having at least one combustion chamber (2) defined by a cylinder (1) and a piston (3) cooperating with a crankshaft, each of which is an exhaust valve (9; 109; 309) at least one fuel gas outlet (20; 120; 320; 420) formed between the valve head (8; 108; 308) and the disposed valve seat, and at least one In a method for manufacturing a two-cycle large diesel engine having a supercharged air inlet (4), in particular a two-cycle large diesel engine according to any one of claims 1 to 12,
A method for manufacturing a two-cycle large diesel engine, wherein the cylinder head according to claim 19 is attached.   The method according to claim 20 or 21, wherein the two-cycle large diesel engine is manufactured for the first time.   22. A method according to claim 20 or 21, wherein the two-cycle large diesel engine continues to be in a more operable state.   20. Installation of an exhaust valve (9; 109; 309) according to any one of claims 13 to 18 replaces other conventional exhaust valves or installation of a cylinder head according to claim 19. The conventional two-cycle heavy-duty diesel engine that does not have the feature of any one of claims 1 to 12 is described in any one of claims 1 to 12, because other conventional cylinder heads are replaced by 24. The method of claim 23, wherein the apparatus is changed to the two-cycle large diesel engine described.   Use of an internal combustion engine according to any one of the preceding claims in structures used on water, in particular ships, whose legal operating permit depends on the legal operating permit of the internal combustion engine. Operating internal combustion engine, in particular a two-cycle large diesel engine, in particular having at least one combustion chamber (2) defined by a cylinder (1) and a piston (3) cooperating with a crankshaft, in particular 1 to 12 4. The internal combustion engine according to claim 1, wherein each of the combustion chambers is disposed between a valve head (8; 108; 308) of an exhaust valve (9; 109; 309) and a valve seat disposed. The exhaust valve (9; 109; 309) having at least one fuel gas outlet (20; 120; 320; 420) and at least one supercharged air inlet (4) formed. Is operable between an open position and a closed position, wherein the fuel gas outlet (20; 120; 320; 420) has at least one exhaust pipe (11) and at least one fuel gas outlet pipe. (18 118a, 118b; 318, 318a; 418, 418a), for example during operation in which part of the fuel gas generated during combustion is returned to the supercharged air inlet (4) In the method of flowing out fuel gas in the internal combustion engine of
In the fuel gas outflow opening region of the exhaust valve (9; 109; 309) from the closed position of the exhaust valve (9; 109; 309) to the desired opening degree, the exhaust valve (9; 109; 309) or the throttle device (10; 110; 310) formed integrally with the exhaust valve (9; 109; 309) allows fuel gas to flow into the exhaust pipe (11). The fuel gas is prevented or at least throttled more strongly in the exhaust gas discharge opening region of the exhaust valve (9; 109; 309) from the larger opening degree to the opening position. In the outflow opening region, the throttle device (10; 110; 310) causes the fuel gas outflow pipe (18; 118a, 118b; 318, 318a; 418, 418a) of the fuel gas. Or inflow preferably not at all restricted, or, wherein the not throttled at least unnecessary.   In the exhaust gas discharge opening region, inflow of fuel gas into the fuel gas outflow pipe is prevented by an active controllable or passive return valve provided in the throttle device and / or the fuel gas outflow pipe or 27. The method of claim 26, wherein the method is at least squeezed.   28. A method according to claim 26 or 27, characterized in that in an electronically operated exhaust valve, the control time of the throttle device is continuously corrected.   28. A method according to claim 26 or 27, wherein in an exhaust valve operated by a camshaft, the outflow of fuel gas is controlled by an actively controllable return valve in the fuel gas outflow tube.

Images