EP1775455B1 - Autoignition engine with combustion chambers for high pressure ignition - Google Patents

Description

The invention relates to a self-igniting internal combustion engine with combustion chambers for high ignition pressures according to the preamble of claim 1.

In today customary vehicle engines, especially engines for commercial vehicles, ignition pressures are in use which already make very high demands on the sealing of the combustion chambers and expose the combustion chamber limiting components, in particular the cylinder head very high thermal and mechanical loads. As a result of these high loads, the cooling effect which can be provided via the cooling passages in the cylinder head on the combustion chamber ceiling is often insufficient for adequate cooling, in particular in the areas between the valves. As a result, so-called web breaks between the valve openings in the cylinder head can adjust and destroy the cylinder head and thus the engine.

Parallel to this existing problem, it is essential to achieve the future required exhaust emissions on the one hand and the ever-increasing demands on the liter performance of the internal combustion engine while reducing the weight, inevitably the ignition pressures in the order of up to 300 bar, which is almost a doubling equals the usual standard today. Such requirements can not be met with reasonable effort in terms of the use of materials with today common engine designs.

Based on this prior art, it is an object of the invention to provide an internal combustion engine, which has grown with reasonable design effort very high ignition pressures.

The problem is solved by the characterizing features of claim 1, advantageous embodiments are characterized in the subclaims.

The invention is based on the assumption that the combustion chamber seal usual today must be taken over by the underside of the cylinder head in future engines with greatly increased ignition pressures of a separate component. It is a arranged between the combustion chamber and the cylinder head the top surface of the combustion chamber forming separate, with the crankcase and / or the cylinder liner positively and gastight connected cooled plate in which the valve seats at least one inlet valve and at least one outlet valve are arranged and the is penetrated by the at least one injection valve. The advantage of such a component is, on the one hand, that the positive connection of the cooled plate with the crankcase and / or the cylinder liner can be made directly to the combustion chamber boundary, whereby the deflection under pressure already considerably minimized compared to today's standard cylinder heads due to the much smaller spans On the other hand, the use of this separate from the crankcase, cylinder head and possibly the cylinder liner component opens up completely new possibilities in terms of material selection. The cooling of the cooled plate is carried out by the cooling medium provided for the cooling of the crankcase and the cylinder head, so that the cooled plate can be advantageously integrated into the existing cooling system.

A further advantage of the cooled plate according to the invention is that, due to the better accessibility for the mechanical processing, cooling channels can be introduced into the cooled plate which permit a significantly improved cooling of the combustion chamber roof and the valve seats compared to conventional cylinder heads. The cooling channels can be advantageously formed as outgoing from the peripheral side of the cooled plate holes, which advantageously extend in the cooled plate that they cut other holes and form a connected system of holes. In this case, at least some of the bores are reclosed towards the peripheral side in order to simplify advantageously the inflow and outflow of the coolant.

The supply of the cooled plate with coolant can be done easily and thus advantageously so that in the peripheral side and / or in the protruding edge region of the top surface of the combustion chamber forming flat side of the cooled plate and / or the top surface opposite flat side of the cooled plate inflow and / / or outflow openings are provided and the supply of the cooled plate with coolant directly and / or via the crankcase and / or via the cylinder head. This opens up the possibility of optimally adapting the coolant flow to the respective structural conditions.

The cooled plate according to the invention can be used both in bushing-free combustion chambers and in combustion chambers which have a sleeve arranged in a cylinder bore. When using a socket, it is particularly advantageous to use one which has a collar which is supported on a balcony in the cylinder bore.

To supply the cooled plate with the coolant, it is further advantageous to form the inflow and outflow openings in the cooled plate as bores corresponding to corresponding openings in the cylinder head or in the collar of the bush or in the crankcase or in a separate coolant manifold and the cooling channels in Connect the cooled plate to the coolant chambers in the cylinder head, crankcase or separate coolant manifold. For this purpose, sealing means can be provided in each case in the crossing area, which reliably prevent leakage of the cooling medium.

By independent of the crankcase and cylinder head separate version of the cooled plate opens up the possibility of free choice of material, so that for the cooled plate high strength metal alloys are used, their use for the cylinder head or the crankcase for cost reasons or for constructive reasons would ban. The freedom in material selection also opens up the possibility in which the valve seats are advantageously incorporated in the one-piece cooled plate.

For Brennraumabdichtung it is also advantageous to provide the cooled plate with a cylindrical extension, the outer diameter of the inner diameter of the Combustion chamber substantially corresponds to the cylindrical projection is in the assembled state in the interior of the cylinder bore or the socket, so that the cooled plate surrounds the upper edge of the combustion chamber angle. It is particularly conducive to the seal to choose the diameter of the cylindrical projection so that there is an interference fit between it and the combustion chamber diameter. In addition, it may be advantageous for sealing the combustion chamber to provide a seal between the combustion chamber overlapping part of the cooled plate and the crankcase or the Buchsenbund.

The connection of the cooled plate with the crankcase or, if present, the bushing collar is advantageously accomplished by screwing the cooled plate to the crankcase or the bushing collar by means of screws, the screws are advantageous as close to the combustion chamber edge to arrange the deflection of the cooled plate during the Minimize ignition events. Alternatively to this type of attachment, it is possible for combustion chambers having a socket, by means of an internal thread on the upper edge of the sleeve and an external thread on the circumference of the cylindrical extension to screw the cooled plate to the socket, so that the connection between the socket and the cooled plate in particularly favorable manner takes place directly on the combustion chamber edge. Another simple and therefore cheap way to connect the cooled plate with the socket consists of welding these two components together.

To improve the efficiency of the internal combustion engine and / or the wear on the valve seats, the cooled plate may be provided on its side facing the combustion chamber with a coating of low thermal conductivity and / or high wear resistance, wherein the coating with low thermal conductivity minimizes the heat loss of the combustion chamber gas and thus advantageously increases the efficiency and a wear-reducing coating on the valve seats positively influences the service life.

In order to produce different material properties in the cooled plate in different planes, it may be advantageous to construct the cooled plate in layers of parallel plates with different material properties, wherein at least one of the inner parallel plate having recesses connected to the cooling system of the internal combustion engine. By the construction of a package of parallel plates, both the cooling channels and the coolant supply and coolant discharges can be particularly simple and therefore advantageous by z. B. create cutouts on one or more of the parallel plates. To increase the bending stiffness of the composite, it is provided to connect adjacent plates of the plate pack together.

The cylinder head, which adjoins the cooled plate on the side facing away from the combustion chamber, can be designed as a cylinder head assigned to a cylinder or as a continuous cylinder head assigned to several or all cylinders and contains, in addition to the gas exchange channels, at least one injection valve and the guides for the inlet cylinder head. and exhaust valves. To further minimize the deflection of the cooled plate during ignition, the cylinder head is advantageously configured to pressurize the cooled plate at least in the region of its center. In order to make the cylinder head advantageously as rigid as possible, the coolant chambers are divided, extending at least perpendicular to the flat side of the cooled plate bulkheads, which derive particular occurring in the center of the cooled plate forces in the cylinder head fasteners in the crankcase. The use of the cooled plate according to the invention opens up possibilities of material selection with respect to the cylinder head, which did not exist in conventional internal combustion engines for commercial vehicles for reasons of strength, then light metal alloys can be used for the cylinder head, which reduce the weight in an advantageous manner and have much better properties with respect to the Heat transport have.

For controlling and actuating the gas exchange valves and the injection valves, a control and actuation module is provided which extends over a plurality of cylinders, preferably over all cylinders of a series engine or over all cylinders of a cylinder bank of a V-engine and which contains at least one camshaft and the actuators for the gas exchange valves and encloses the actuators for the injectors. The control and actuation module is connected to the lubricant circuit and has a housing cover, via which the actuators for the gas exchange valves and the injectors are accessible. Also with regard to the control and actuation module fastened by means of detachable connections to the cylinder head or the cylinder heads, the construction detached from the cylinder head offers new possibilities in the choice of material. A complete or at least partial execution in plastic allows an advantageous weight reduction and simplifies the production as a plastic injection molded part. In the control and actuation module can advantageously an all combustion chambers or integrated all the combustion chambers of a cylinder bank common charge air pipe.

Fig. 1

Ein Brennraum einer Brennkraftmaschine in Teildarstellung, geschnitten und schematisch dargestellt

Fig. 2

der Brennraum aus Fig. 1 in Seitenansicht von außen

Fig. 3

der Brennraum aus Fig. 1 in Draufsicht von außen

Fig. 4

einen Schnitt durch den Brennraum entlang der Linie B - B

Fig. 5

einen Schnitt durch die den Brennraum nach oben abschließende gekühlte Platte entlang der Linie C - C

Fig. 6

eine erste Detaildarstellung der Verbindung zwischen gekühlter Platte und Buchse

Fig. 7

eine zweite Detaildarstellung der Verbindung zwischen gekühlter Platte und Buchse

Fig. 8

eine dritte Detaildarstellung der Verbindung zwischen gekühlter Platte und Buchse

Fig. 9

eine Detaildarstellung einer Kühlmittelverbindung zwischen Kurbelgehäuse und gekühlter Platte

Fig. 10

eine zweite Detaildarstellung einer Kühlmittelverbindung zwischen Kurbelgehäuse und gekühlter Platte

Fig. 11

eine Detaildarstellung der Kühlmittelverbindung zwischen Zylinderkopf und gekühlter Platte

Fig. 12

eine Schnittdarstellung durch den Brennraum entlang der Linie D - D

Fig. 13

eine Schnittdarstellung durch den Brennraum entlang der Linie E - E

Fig. 14

eine Schnittdarstellung durch den Brennraum mit einer beschichteten gekühlten Platte entlang der Linie F - F

Fig. 15

eine Schnittdarstellung durch eine gekühlte Platte mit Schichtaufbau entlang der Linie G - G

Fig. 16

eine Schnittdarstellung durch eine gekühlte Platte mit Schichtaufbau entlang der Linie H - H

Fig. 17

die Darstellung des Brennraums aus Fig. 1 mit aufgesetztem Steuerungs- und Betätigungsmodul

Example of the arrangement according to the invention are explained in more detail below with the aid of the drawings, in which:

Fig. 1

A combustion chamber of an internal combustion engine in partial view, cut and shown schematically

Fig. 2

the combustion chamber off Fig. 1 in side view from the outside

Fig. 3

the combustion chamber off Fig. 1 in plan view from the outside

Fig. 4

a section through the combustion chamber along the line B - B

Fig. 5

a section through the combustion chamber upwards final cooled plate along the line C - C

Fig. 6

a first detail of the connection between the cooled plate and socket

Fig. 7

a second detail of the connection between the cooled plate and socket

Fig. 8

a third detail of the connection between the cooled plate and socket

Fig. 9

a detailed view of a coolant connection between the crankcase and cooled plate

Fig. 10

a second detail of a coolant connection between the crankcase and cooled plate

Fig. 11

a detailed representation of the coolant connection between the cylinder head and cooled plate

Fig. 12

a sectional view through the combustion chamber along the line D - D

Fig. 13

a sectional view through the combustion chamber along the line E - E

Fig. 14

a sectional view through the combustion chamber with a coated cooled plate along the line F - F.

Fig. 15

a sectional view through a cooled plate with layer structure along the line G -

Fig. 16

a sectional view through a cooled plate with layer structure along the line H - H

Fig. 17

the representation of the combustion chamber Fig. 1 with attached control and actuation module

The concept of an internal combustion engine for high ignition pressures is based on the basic idea that the sealing of the combustion chambers must be functionally separated from the cylinder head in order to create more favorable geometric conditions for the sealing and to open up new possibilities with regard to the materials that can be used. It is therefore proposed an independent component which lies between the combustion chamber and the cylinder head and whose exclusive function is to complete the combustion chamber to the cylinder head and seal. A combustion chamber which follows the above-mentioned concept, is in Fig. 1 shown schematically in a sectional view, the course of the cutting plane is from the Fig. 3 removable and labeled there with AA.

Fig. 1 shows a combustion chamber 1 of a self-igniting internal combustion engine, which consists of a cylinder liner 2, a piston 3 and a cooled plate 4. The cylinder liner 2 is arranged in a known manner in the crankcase 5 and surrounded in the region of the combustion chamber 1 by coolant leading rooms 6 for cooling the combustion chamber walls. The piston 3 acts via a connecting rod 7 on a crankshaft 8, which is mounted in the crankcase 5 is (not shown). Towards the top, the combustion chamber 1 is closed by the cooled plate 4, which essentially has the outer diameter of a bushing collar 9 arranged on the cylinder head end of the cylinder liner 2. On the cooled plate 4, a cylindrical projection 10 is arranged to the combustion chamber 1, the diameter of which substantially corresponds to the inner diameter of the cylinder liner 2, so that the cooled plate 4, the cylinder head side edge of the cylinder liner 2 engages angularly.

Inside the cooled plate 4 cooling channels 11 are arranged, in which a cooling medium circulates. The cooled plate 4 is positively and gas-tightly connected to the cylinder liner 2. Furthermore, in the cooled plate 4 valve seats (in Fig. 1 not visible), which cooperate with the valve plates 12 of the gas exchange valves 13. The fuel supply takes place via an opening 20, which passes through the cooled plate 4 in its center from the side facing away from the combustion chamber 1 in the direction of the combustion chamber 1 and in which an injection valve (in Fig. 1 not shown) is arranged. The arrangement of the injection valve in the opening 20 is made such that the injection valve, possibly with the interposition of a sealant, the combustion chamber gas-tight and with its injection nozzle opening (not shown) projects into it. Held is the injection nozzle in the cylinder head 14, which adjoins the cooled plate 4 on the side facing away from the combustion chamber 1 and this completely covered with its side facing the cooled plate 4 and projects beyond this. The cylinder head 14 is fastened in a conventional manner by means of screws (not shown) which project through the cylinder head 14 in the direction of the crankcase 5 and fix it on the crankcase 5. The gas channels (not shown) for intake air or the combustion gases, the valve guides (not shown) for the valve stems 15 of the gas exchange valves 13 and a coolant chamber 16 for cooling the cylinder head 14 or its built-in parts are arranged in the cylinder head 14 in a known manner. By perpendicular to the cooled plate 4 extending first bulkheads 17 and parallel to the cooled plate 4 extending second bulkheads 18, the space in the cylinder head 14 is divided into a cellular structure, on the one hand by connecting holes 21 allows targeted coolant management and on the other hand, has a high rigidity, the a deflection of the cooled plate 4 counteracts in the ignition phase.

An external view of the cylinder liner 2 with attached cooled plate 4 show Fig. 2 in side view and Fig. 3 in plan view. The cooled plate 4 is screwed to the bushing collar 9 by means of screws 19, and corresponds in diameter to the outer diameter By the connection of the bushing collar 9 with the cooled plate 4 at the combustion chamber boundary, the possible deflection of the cooled plate 4 is reduced to a minimum. In the cooled plate 4 are, as already to Fig. 1 executed, arranged the gas exchange valves 13 and the opening 20 for the injection valve.

A section through the combustion chamber along the line BB ( Fig. 3 ) shows Fig. 4 , Also in this illustration, the cooled plate 4 is screwed to the bushing collar 9 of the cylinder liner 2 by means of the screws 19. In the cooled plate 4, starting from the circumference of the cooled plate 4, cooling channels 11 extend toward the center of the cooled plate 4. The course of the cooling channels 11 in the cooled plate 4 is exemplified in FIG Fig. 5 shown. The Fig. 5 shows a section along the line CC in Fig. 2 , Starting from opposite sides of the circumference of the cooled plate 4, bores 11.1, 11.2, 11.5, 11.6, which form two pairs of bores, extend toward each other, each of the pairs of bores forming an "X", ie, intersecting the bores of a pair of bores. The arrangement of the bore pairs relative to the arrangement of the openings for the gas exchange valves 13, whose centers essentially form the vertices of a square, is made such that the intersection of a pair of holes between two adjacent openings for the gas exchange valves 13. The holes 11.1, 11.2, 11.5, 11.6 of each pair of holes extend from the respective points of intersection viewed in the direction of the center of the cooled plate 4 again apart and intersect the holes of the respective opposing hole pair on a line through the center of the cooled plate 4th A single bore 11.3, 11.4, which likewise starts from the circumference of the cooled plate and is offset by 90 ° relative to the X-shaped bore pairs between two adjacent openings of the gas exchange valves 13, strikes these two points of intersection of the bore pairs. The so-forming network of connected holes 11.1 - 11.6 forms the cooling channels 11 which, as will be explained in more detail below, can be connected in different ways with the cooling system of the internal combustion engine. By the selected course of the holes 11.1 - 11.6 an efficient cooling of the critical areas between the openings for the gas exchange valves 13 and between them and the opening 20 is achieved for the injection valve, so that so-called barges can be reliably avoided.

The above in connection with the FIGS. 1 to 5 described screwing the cylinder liner 2 with the cooled plate 4 is in a detailed representation in Fig. 6 shown cut. The cooled plate 4 is located, the combustion chamber 1 in the direction of the cylinder head 14 (in Fig. 6 not shown) finally, in the region of the bushing collar 9 on the cylinder liner 2 and surrounds the inner edge of the bushing collar 9 angle-shaped. Through a through hole 22, the screw 19 cooperates with a corresponding thread 23 in the bushing collar 9 and sets the cooled plate 4 on the bushing collar 9. For sealing the combustion chamber 1, the diameter of the cylindrical projection 10 of the cooled plate 4 in conjunction with the inner diameter of the cylinder liner 2 can be designed so that there is an interference fit. Additionally or alternatively, it is of course possible to provide between bushing collar 9 and cooled plate 4, a sealant. With regard to the screws 19 used different designs of the screw head are conceivable in the screws 19 shown with protruding screw head 19.1 are corresponding recesses in the cylinder head 14 (FIGS. Fig. 1 ). If countersunk screws are used, however, the side of the cylinder head 14 adjacent to the cooled plate 4 can be made smooth in the area of the screws 19. Preferably, the screws 19 are mutually equally spaced along the circumference of the cooled plate 4 and the bushing collar 9 are arranged.

The above in connection with the FIGS. 1 to 6 described example of a combustion chamber for high ignition pressures uses a cylinder liner 2 as part of the combustion chamber, this is of course not mandatory. The arrangement shown in the figures and described above can of course also be carried out without a cylinder liner, the combustion chamber is then formed by the cylinder bore, the cooled plate 4 and the piston 3. Both FIGS. 1 to 6 If, in the case of a linerless version, one has to imagine the cylinder liner designated by 2 and the bushing collar designated 9 as an integral component of the crankcase 5, moreover nothing changes in terms of arrangement and function.

Other ways to connect the cooled plate 4 with the bushing collar 9 of the cylinder liner 2 show the detailed representations in the FIGS. 7 and 8 , According to the sectional drawing in Fig. 7 the connection of the cooled plate 4 with the bushing collar 9 by welding. For this purpose, a continuous or over the circumference repeatedly interrupted, for example punctiform weld seam 24 along the outer circumference of the joint between the cooled plate 4 and bushing collar 9 is provided. A punctiform welded connection minimizes the heat input and thus the risk of distortion of the cylinder liner 2. The cylindrical projection 10 of the cooled plate 4 can also in this example form a press fit together with the inner diameter of the bushing collar 9, which takes over the seal in the case of an interrupted weld.

The sectional view according to Fig. 8 shows another way to screw the cooled plate 4 with the bushing collar 9, to the cylindrical projection 10 of the cooled plate 4, an external thread 25 is provided which cooperates with an internal thread 26 on the cylinder head side edge of the bushing collar 9. By screwing the cooled plate 4 with the bushing collar 9 via the screw 25, 26, the connection between these components takes place at the lowest in terms of minimizing possible deflections of the cooled plate 4 geometric location, namely directly to the combustion chamber boundary. With regard to the sealing of the combustion chamber 1, the screw connection 25, 26 also acts like a labyrinth seal.

Of course, those discussed above in connection with the FIGS. 6 to 8 described compounds between the cooled plate 4 and the cylinder liner only examples, it can be with the skilled person available resources many different connections between these two components, but especially between the cooled plate and the crankcase, in an embodiment of the combustion chamber without cylinder liner realize.

In connection with the description of the cooling channels 11 forming holes 11.1-11.6 has already been mentioned that they are connected to the cooling system of the internal combustion engine. This connection can be done in different ways. Some ways to feed the cooling channels 11 in the cooled plate 4 with coolant or dissipate coolant from them, show by way of example the detailed representations in the FIGS. 9-11 ,

The sectional drawing in Fig. 9 Simplifies the already known arrangement of cooled plate 4 and cylinder liner 2. The cylinder liner 2 is located in the cylinder bore in the crankcase 5, wherein for cooling the walls of the combustion chamber 1 coolant leading spaces 6 between the crankcase 5 and cylinder liner 2 are formed. The cooled plate 4 has a bore 11 forming a cooling channel which extends from the peripheral side 27 of the cooled plate 4 radially inwardly. To the peripheral side 27 towards the cooling channel 11 is closed by means of a pressed ball 28. The connection of the cooling channel 11 to the cooling system of the internal combustion engine is through a supply bore 29 accomplished, which passes through the bushing collar 9 of the cylinder liner 2 and is aligned with a connection bore 30 in resting on the bushing collar 9 edge region of the cooled plate 4, wherein the connection bore 30 opens into the cooling channel 11. Of course, similar feed bores and thus aligned connection bores may be provided at several points of the cooled plate 4 and cooperate with corresponding cooling channels to ensure efficient cooling.

Another way, from the crankcase 5 to supply coolant to the cooled plate 4 shows schematically in a sectional drawing, Fig. 10 , Again, the already described arrangement of cylinder liner 2 and cooled plate 4 is shown. This arrangement is enclosed on the one hand by the crankcase 5 and the other hand arranged on the crankcase 5 cylinder head 14. In the crankcase 5 runs a connecting channel 31 from a arranged in the crankcase 5 coolant passage 32 to the dividing line between the cylinder head 14 and crankcase 5 and goes there in a cylinder head 14 arranged connection channel 33 via, in turn, via a connection opening 34 in the analog for example Fig. 9 in the cooled plate 4 arranged cooling channel 11 opens. To seal the transition between the crankcase 5 and cylinder head 14 on the one hand and the cylinder head 14 and cooled plate 4 on the other hand, sealing means 35 are provided. Also in this example, similar coolant supply to the cooled plate 4 may be provided at several points.

The sectional drawing in Fig. 11 Finally, in simplified form, shows a coolant supply of the cooled plate 4 from the cylinder head 14 of the internal combustion engine. The arrangement shown also in this case comprises a cylinder liner 2 with which the cooled plate 4 is connected in one of the ways described above. The combination of cylinder liner 2 and cooled plate 4 superimposed in a cylinder bore in the crankcase 5, such that the cylinder head side flat side of the cooled plate 4, with the cylinder head 14 adjacent side of the crankcase 5 is aligned. For coolant supply, a connection between the coolant chamber 16 and the cooling channel 11 in the cooled plate 4 is provided by the coolant chamber 16 arranged in the cylinder head 14 via a connection opening 36 to be cooled on the cooled plate 4, which is in alignment with a coolant connection 37 in the cooled plate 4 created. The cooling channel 11 formed from the peripheral side of the cooled plate 4 and formed in the form of a bore is, as in the examples described above, by a pressed ball 28 near the peripheral side locked. To seal the joint between the cylinder head 14 and the cooled plate 4, a sealing means 35 is arranged around the coolant connection 37. As already to the examples after the FIGS. 9 and 10 executed, can also in the example after Fig. 11 a plurality of similar connections between the coolant chamber 16 in the cylinder head 14 and cooling channels 11 may be provided in the cooled plate 4.

For the examples described above according to the FIGS. 9-11 It is common that, of course, the coolant discharge from the cooled plate 4 to the crankcase 5 or the cylinder head 14 may be formed similar to the coolant supply lines described in the examples, so that can be dispensed with a separate representation of the coolant discharges. Furthermore, it is of course conceivable to use different types of coolant supply or the coolant discharge in the coolant supply of a cooled plate 4 in combination for use, also here, a separate presentation is unnecessary. The above-described principles of the coolant supply of the cooled plate 4 are of course equally suitable for internal combustion engines with cylinder liners and bushingless internal combustion engines. In the case of Buchsenlosen internal combustion engines, it has in the examples after the FIGS. 9-11 to present the illustrated cylinder liner 2 only as an integral part of the crankcase 5, so that even with regard to this aspect can be dispensed with a separate presentation and description.

A connection of the cooled plate 4 according to the training according to Fig. 5 to the cooling system in an arrangement according to Fig. 1 is below using the sectional drawings in the FIGS. 12 and 13 explained in more detail. It shows Fig. 12 a section along the line DD ( Fig. 5 ) and Fig. 13 a section along the line EE ( Fig. 5 ). After the arrangement above in connection with the FIGS. 1 and 5 has already been described in detail, will be discussed below only on the connection between the coolant chamber 16 in the cylinder head 14 and the cooling channels 11 forming holes 11.1 - 11.6.

Fig. 12 shows, starting from a first coolant chamber 16.1, which is part of the coolant chamber 16 in the cylinder head 14, an inlet bore 38 which connects the first coolant chamber 16.1 with the bore 11.1 in the cooled plate 4. The bore 11.1 which is closed to the narrow side of the cooled plate 4 through a ball 28, cuts at the point X, the bore 11.2 whose further course to the point Y in the sectional view is. At point Y, the bore 11.2 cuts the bore 11.6 whose course in the right half of Fig. 12 is shown. The bore 11.6 cuts at the point Z the bore 11.5 and is closed on the narrow side of the cooled plate 4 with a pressed-in bore 11.6 ball 28. Via a drain hole 39, a connection between the bore 11.6 and a second coolant chamber 16.2 is made in the cylinder head 14, which is located downstream of the first coolant chamber 16.1 and also part of the coolant chamber 16.

One of the presentation in Fig. 12 in parts deviating in Fig. 5 with EE marked cutting course shows Fig. 13 , After the cutting process with the cutting in the Fig. 12 is identical to the point of intersection Y, this is to the above description Fig. 12 directed. At point Y, the bore 11.2 intersects both the bore 11.6 and the bore 11.3, whose course in the right half of Fig. 13 is shown. The bore 11.3 is also closed near the peripheral side with a ball 28. For discharging the coolant from the cooled plate 4, a further drain hole 40 is provided which connects the bore 11.3 with a third coolant chamber 16.3 which is also part of the coolant chamber 16 and downstream of the coolant chamber 16.1.

Analogous to that in connection with the FIGS. 12 and 13 described connection of the coolant chamber 16 to the cooling channels 11 in the cooled plate 4 is also the connection of the rest in Fig. 5 It should only be noted that the bores 11.1 and 11.2 coolant supply lines and the bores 11.3, 11.4, 11.5, 11.6 are coolant discharges and accordingly the supply of the coolant supply lines of parts of the coolant chamber 16 takes place in the cylinder head 14, which are upstream of the parts of the coolant chamber 16 in which the coolant discharges are returned.

Regarding the interpretation of in conjunction with the FIGS. 1 . 5 . 12, 13 It should be noted that the connections 21 between the individual parts of the coolant space 16 (FIGS. Fig. 1 ) and the connections between the coolant chamber 16 and the cooling channels 11 are designed so that a staggered according to the heat load of the cooled plate 4 and cylinder head 14 heat dissipation, while the heat load and thus the heat dissipation at the combustion chamber boundary is greatest and increases increasing distance from the combustion chamber.

On the above in connection with the FIGS. 1 . 5 . 12, 13 described example, it should also be noted that the connection of the cooled plate 4 with the bushing collar or with the crankcase with bushing internal combustion engines conditional that the valve seats of the gas exchange valves 13 are associated with the crankcase 5 in the mounted state, the valve guides, however, are in the cylinder head 14. This constellation results in increased demands on the assembly accuracy of the cylinder head 14 to the crankcase 5. In particular, cumulative manufacturing tolerances lead to that no continuous cylinder heads should be used at least for large-volume engines for commercial vehicles, but those which include one or two cylinders.

For the exact mounting of the cylinder head relative to the cooled plate 4 or the cooled plates 4, if the cylinder head comprises a plurality of cylinders, fitting measures, e.g. Dowel pins required.

With regard to the choice of material, the separation of the combustion chamber seal from the cylinder head results in completely new possibilities. The cooled plate 4 may be made of a high strength metal alloy e.g. high-strength forged steel exist that could not be used for conventional cylinder heads for structural, manufacturing and financial reasons. The cylinder head, on the other hand, is made of simpler materials, such as, for example, because of the low stress experienced by conventional cylinder heads. Aluminum can be produced, which in addition to cost advantages also bring weight advantages.

With a suitable choice of material, the valve seats for the gas exchange valves 13 can be incorporated directly into the cooled plate, so that can be dispensed with the pressing of valve seat rings. This eliminates four components per cylinder in a four-valve engine in use today, ie 24 components in a 6-cylinder engine, but in particular the stresses caused by the press-fitting of the valve seat rings in conventional cylinder heads are avoided. These stresses, which are exacerbated by the heat input during the combustion process, contribute to a considerable extent to the emergence of the already mentioned Stegrisse.

The separation of the combustion chamber seal from the cylinder head also allows or simplifies wear-reducing and / or efficiency-increasing measures on the combustion chamber roof.

Such a measure is in Fig. 14 shown in a partial view a section along the line FF in Fig. 3 shows. Also in this illustration is assumed by a bolted to the bushing collar 9 a cylinder liner 2 cooled plate 4, wherein cylinder liner 2 cooled plate 4 and piston 3 ( Fig. 1 ) form the combustion chamber 1. On the one hand to reduce the combustion caused by the heat input into the cooled plate 4 and on the other hand to minimize the caused by the closing operations of the valve plate 12 at the valve seats 41 wear is provided, the combustion chamber 1 covering the side of the cooled plate 4 with a ceramic coating 42 to provide. Such ceramic coatings can be applied in many different ways; the methods used for this purpose are known to the person skilled in the art. Of course, other than ceramic coatings are conceivable.

To achieve different material properties in different levels of the cooled plate consists, as in Fig. 15 in a partial view along the line GG ( Fig. 16 ), the possibility of constructing the cooled plate 4 from layers. In this case, a first package of two layers 45 is provided, the two layers 45 consisting of metal plates which form a rigid composite and contain both inflow openings 43 and outflow openings 44, via which the cooling liquid from the cylinder head 14 analogously to the example Fig. 11 flow or can flow to this. To the two layers 45 is followed in the direction of the combustion chamber 1, a third layer 46, the recesses 47, for example in the form of free distances. The recesses 47 correspond to the feed openings 43 and the discharge openings 44 and form the cooling channels of the cooled plate 4. In the choice of material of the third layer 46 may be geared to a good workability, because this layer 46 anyway because of the recesses 47 to the flexural rigidity of the Can contribute together. The fourth layer 48 in the direction of the combustion chamber 1, like the first two layers 45, consists of a material of high flexural stiffness, while the fifth layer 49 in the direction of the combustion chamber has high hardness and low thermal conductivity. In this fifth layer 49 are the valve seats of the gas exchange valves (in Fig. 15 not shown) incorporated. The connection of the parallel plates 45, 46, 48, 49 to each other in the example shown by welds 50 along the circumference of the parallel plates 45, 46, 48, 49, but there are also other possibilities conceivable, the parallel plates to a cooled plate to summarize the forming package. The formation of the cooled plate as a stack of parallel In addition to the possibility of realizing certain material properties in certain planes of the cooled plate, plates have the further advantage that the coolant channels can be produced particularly easily, even in complicated shapes and over several levels of the cooled plate, for example by simple free punching. An example with coolant channels 11 punched out of the layer 46 shows Fig. 16 in a section through the said layer 46 along the line HH ( Fig. 15 ). As can be seen in the illustration, the coolant channels 11 are arranged at valve holes 51 spaced slightly in the region of the valve webs 51.1 and optimize the cooling effect in this area. In addition to the above-described free-dancing of the coolant channels, they can also be recessed in relief in the parallel plates.

As already mentioned above, especially in connection with Fig. 1 described, either a common all combustion chambers common or more each at least one combustion chamber associated cylinder heads are provided, wherein the cylinder head or the cylinder heads includes only the gas exchange channels, the cooling channels, the guides for the gas exchange valves and the receptacle for the injectors. The control and operating mechanisms for the gas exchange valves and for the injection valves, which are usually contained in the cylinder head or in the cylinder heads in conventional engine designs, are, as in Fig. 17 in a sectional drawing along the line AA ( Fig. 2 ), arranged in a control and actuation module which is common to all combustion chambers. After the presentation in Fig. 17 from the representation in Fig. 1 only differs by the control and actuation module 52, which adjoins on the side facing away from the combustion chamber 1 of the cylinder head 14 to this, only these deviating parts of the illustration will be described below. Regarding the rest also in the reference numerals with the Fig. 1 identical parts of the presentation will be added to the description Fig. 1 directed.

The control and actuation module 52 has a common to all combustion chambers and thus also all cylinder heads 14 carrier 53 on which in a trough-shaped portion 54, a camshaft 55 is rotatably mounted. The drive of the camshaft 55 is effected in a conventional manner by a driven via the crankshaft 8, not shown in the diagram gear assembly, it may be a gear drive, a chain or a toothed belt. The camshaft 55 acts in a known manner via its cams 56 on roller rocker arm 57, which rotatably on a common carrier 53 mounted axis 58 are arranged, such that the cams 56 of the camshaft 55 act on the cam-side ends 57.1 of the rocker arm 57. As a result of this admission actuate the valve-side ends 57.2 of the roller rocker arm 57 via valve bridges 59, the gas exchange valves 13 and thereby open or close on the valve plate 12, the gas exchange channels (not shown).

The combustion chambers are supplied with fuel via injection valves 60 arranged in the cylinder head 14, which are connected via pipe connections (not shown) to an injection system (not shown). The injection system may be e.g. to trade a common rail injection system. The actuation of the injectors via an electronic control (not shown) by electrical means, as is common in common rail injection systems. To supply the lubrication points a central lubricant bore 61 is provided, which is supplied by the lubricant circuit of the internal combustion engine (not shown) with lubricant and in turn with the lubrication points in the control and actuation module 52 via lubricant channels (not shown) is directly or indirectly ally. Excess lubricant is collected in the common carrier 53 and returned via a return line (not shown) in the oil pan of the internal combustion engine (not shown).

For encapsulation of the components arranged on the common carrier 53, a cover 62 is provided, which is screwed to the common carrier 53 and closes the interior of the control and actuation module 52 with respect to the surrounding atmosphere. The attachment of the cover 62 on the common carrier 53 by means of screws (not shown), the common carrier 53 in turn is fixed by means of screws (not shown) on the cylinder head 14 and to the cylinder heads 14.

Of course, the above description of the mechanisms for actuating the gas exchange valves and the injectors is to be understood as exemplary only. The actuation arrangement for the gas exchange valves may of course also be an electronically controlled arrangement which actuates the gas exchange valves individually via actuators actuated electrically or hydraulically. Likewise, the common rail injection system described is only one possible embodiment, it may of course also be a pump-nozzle system or a pump-line-nozzle system.

Also in connection with the control and actuation module described above open up by the separation of the cylinder head new possibilities in the choice of material. It is conceivable, for example, to produce the common carrier 53 made of light metal or a fiber-reinforced plastic as an injection-molded part, which in addition to weight advantages also brings about a considerable simplification of production.

Depending on the material used for the common carrier or the manufacturing method used, moreover, further functional parts can be made in one piece with it. Thus, it is conceivable to integrate the charge air pipe and / or coolant pipes for connecting the cylinder head or the cylinder heads to the cooling system of the internal combustion engine in the common carrier.

The above in connection with the Fig. 17 Of course, the control and actuation module 52 described does not necessarily have to be separated from the cylinder head 14, the functionality of the control and actuation module can of course also be integrated into the cylinder head under certain conditions. Thus, in a lower camshaft, ie plunger actuated rocker arms and single cylinder heads integration of the actuator assembly for the gas exchange valves in the cylinder heads would be advantageous, as is customary in such constructions.

Deviating from the example described above, numerous modifications and embodiments are conceivable, which can be derived from the basic approach with knowledge available to a person skilled in the art. The arrangements described above are therefore only exemplary character.

Claims (31)

1. Auto-ignition internal combustion engines having combustion chambers for high ignition pressures, wherein the combustion chambers (1) are composed in each case of a cylinder bore arranged in the crankcase (5) of the internal combustion engine or of a cylinder liner (2) arranged in the cylinder bore, of a piston (3) guided in the cylinder bore or in the cylinder liner (2), and of a cylinder head (14) arranged opposite the piston (3), and wherein

   - coolant-conducting chambers (6) are arranged in the crankcase (5) such that coolant flows around parts of the wall of the cylinder bore or of the cylinder liner (2) on the side facing away from the combustion chamber (1),

   - the cylinder head (14) is assigned one or more combustion chambers (1) and likewise has coolant chambers (16) through which coolant flows,

   - gas exchange valves, at least one injection valve and guides for at least one inlet valve and at least one outlet valve are arranged in the cylinder head (14) for each combustion chamber (1),

   and wherein, between the combustion chamber (1) and the cylinder head (14), there is arranged a separate, cooled plate (4) which forms the top surface of the combustion chamber (1) and which is connected in positively locking and gas-tight fashion to the crankcase (5) and/or to the cylinder liner (2) and in which the valve seats of at least one inlet valve and of at least one outlet valve are arranged and through which the at least one injection valve projects,
   characterized
   in that cooling ducts (11) extend through the cooled plate (4) such that bores (11.1, 11.2, 11.5, 11.6), which form two pairs of bores, run toward one another from opposite sides of the circumference of the cooled plate (4), wherein the bores (11.1, 11.2, 11.5, 11.6) of a pair of bores intersect in x-shaped fashion such that the point of intersection of a respective pair of bores lies between two adjacent openings for gas exchange valves (13), and
   in that the bores (11.1, 11.2, 11.5, 11.6) of each pair of bores run, from their respective points of intersection, in diverging fashion again as viewed in the direction of the centre of the cooled plate (4), and intersect the bores of the respectively opposite pair of bores, wherein the two points of intersection of the bores of the opposite pairs of bores are intersected by a respective single bore (11.3, 11.4) which likewise extends from the circumference of the cooled plate (4) and which runs, offset through 90° with respect to the X-shaped pairs of bores, between two adjacent openings of gas exchange valves (13), and
   in that the cooled plate (4) is manufactured from a high-strength metal alloy, with the valve seat being machined into the cooled plate (4).
2. Internal combustion engine according to Claim 1, characterized in that the connection of the cooled plate (4) to the crankcase (5) and/or to the cylinder liner (2) is realized as close as possible to the combustion chamber edge.
3. Internal combustion engine according to Claim 2, characterized in that the cooled plate (4) is cooled by means of coolant.
4. Internal combustion engine according to one of the preceding claims, characterized in that at least some of the bores (11.1 - 11.6) which extend from the circumferential side of the cooled plate (4) are closed off again toward the circumferential side.
5. Internal combustion engine according to one of the preceding claims, characterized in that inflow openings and/or outflow openings for the coolant are provided in the circumferential side and/or in the protruding edge region of that flat side of the cooled plate (4) which forms the top surface of the combustion chamber (1) and/or of that flat side of the cooled plate (4) which is situated opposite the top surface, and the inflow of coolant takes place directly into the cooled plate (4) and/or into the cooled plate (4) via the cylinder head (14) and/or into the cooled plate (4) via the crankcase (5), and in that the outflow of coolant takes place directly out of the cooled plate (4) and/or out of the cooled plate (4) into the cylinder head (14) and/or out of the cooled plate (4) into the crankcase (5).
6. Internal combustion engine according to one of the preceding claims, characterized in that the cylinder liner (2) has, at its end facing toward the cylinder head (14), an encircling liner collar (9) which is supported on the upper edge of the cylinder bore or on an encircling balcony in the cylinder bore.
7. Internal combustion engine according to one of the preceding claims, characterized in that the inflow openings and outflow openings are bores in the cooled plate (4) which correspond with corresponding openings in the cylinder head (14) or in the lining collar (9) of the cylinder liner (2) or in the crankcase (5) or in a separate coolant distributor pipe and which connect the cooling ducts (11) in the cooled plate (4) to the coolant chambers (16) in the cylinder head or to coolant-conducting chambers (6) in the crankcase (5) or to the coolant distributor pipe.
8. Internal combustion engine according to Claim 7, characterized in that sealing means (35) are provided in the respective region in which the coolant passes over between cooled plate (4) and cylinder head (14) or cooled plate (4) and lining collar (9) or cooled plate (4) and crankcase (5) or cooled plate (4) and coolant distributor pipe.
9. Internal combustion engine according to one of the preceding claims, characterized in that the cooled plate (4) has, on its side facing toward the combustion chamber (1), a cylindrical projection (10) whose external diameter substantially corresponds to the internal diameter of the combustion chamber (1), wherein the cylindrical projection (10) is, in the mounted state of the cooled plate (4), situated in the interior of the cylinder bore or of the cylinder liner (2), such that the cooled plate (4) engages annularly around the upper inner edge of the cylinder bore or of the cylinder liner (2).
10. Internal combustion engine according to Claim 9, characterized in that the external diameter of the cylindrical projection (10) is selected relative to the internal diameter of the cylinder bore or of the cylinder liner (2) so as to generate an interference fit.
11. Internal combustion engine according to one of the preceding claims, characterized in that a combustion chamber seal is arranged between that part of the cooled plate (4) which overlaps the combustion chamber wall and that part of the crankcase (5) and/or of the cylinder liner (2) which faces said part of the cooled plate.
12. Internal combustion engine according to one of the preceding claims, characterized in that the cooled plate (4) is screwed to the crankcase (5) or to the cylinder liner (2) by means of screws (19).
13. Internal combustion engine according to Claim 12, characterized in that the screws (19) are arranged concentrically with respect to the combustion chamber axis and are substantially equably spaced apart from one another as viewed in the circumferential direction.
14. Internal combustion engine according to Claim 9, characterized in that the cooled plate (4) is screwed to the cylinder liner (2) by way of an internal thread (26) on the upper edge of the liner collar (9) and an external thread (25) on the circumference of the cylindrical projection (10).
15. Internal combustion engine according to one of Claims 1 to 10, characterized in that the cooled plate (4) is welded to the cylinder liner (2).
16. Internal combustion engine according to one of the preceding claims, characterized in that, if a cylinder liner (2) with liner collar (9) is used, the cooled plate (4) has an external diameter which substantially corresponds to the external diameter of the liner collar (9) of the cylinder liner (2).
17. Internal combustion engine according to one of the preceding claims, characterized in that the cooled plate (4) has, on its surface which delimits the combustion chamber (1), a coating (42) with low thermal conductivity and/or high wear resistance.
18. Internal combustion engine according to one of the preceding claims, characterized in that the cooled plate (4) is constructed from a multiplicity of layers (45, 46, 48, 49) which run parallel to the combustion chamber roof and which in turn are of plate-like form, thus giving rise to a plate pack, wherein at least one parallel plate situated in the interior of the plate pack has recesses (47) which are situated over coolant supply points and coolant discharge points in the coolant circuit of the internal combustion engine, and wherein the parallel layers (45, 46, 48, 49) of the plate pack are connected to one another.
19. Internal combustion engine according to one of the preceding claims, characterized in that at least one of the parallel layers (45, 46, 48, 49) has material characteristics that differ from those of the other parallel layers (45, 46, 48, 49).
20. Internal combustion engine according to one of the preceding claims, characterized in that multiple cylinder heads (14) are provided, wherein each cylinder head (14) is assigned at least one combustion chamber (1).
21. Internal combustion engine according to one of the preceding claims, characterized in that one cylinder head (14) is provided to which all of the combustion chambers (1) are jointly assigned.
22. Internal combustion engine according to one of the preceding claims, characterized in that the cooled plate (4) is subjected to pressure by the cylinder head (14) at least in the centre thereof.
23. Internal combustion engine according to one of the preceding claims, characterized in that partitions (17, 18) which divide up the coolant chambers (16) are arranged in the interior of the cylinder head (14) at least perpendicularly to the flat side of the cooled plate (4), thus giving rise to a structure which is flexurally rigid in the direction of the combustion chamber (1).
24. Internal combustion engine according to one of the preceding claims, characterized in that the cylinder head (14) or the cylinder heads (14) are manufactured from a light metal alloy.
25. Internal combustion engine according to one of the preceding claims, characterized in that that side of the cylinder head (14) or of the cylinder heads (14) which faces away from the combustion chambers (1) is adjoined by at least one control and actuation module (52), wherein the control and actuation module (52) is assigned to a multiplicity of combustion chambers (1) and, on a common carrier (53), comprises at least the actuation devices for the inlet and outlet valves and the injection nozzles for said combustion chambers (1).
26. Internal combustion engine according to Claim 25, characterized in that the common carrier (53) comprises at least one camshaft (55).
27. Internal combustion engine according to either of Claims 25 and 26, characterized in that, on the common carrier (53), there is arranged a cover (62) via which the actuation and/or control elements are accessible.
28. Internal combustion engine according to one of Claims 25 to 27, characterized in that a lubricating oil supply port and a lubricating oil return port are arranged on the common carrier (53).
29. Internal combustion engine according to one of Claims 25 to 28, characterized in that the control and actuation module (52) is fastened to the cylinder head (14) or to the cylinder heads (14) by means of detachable connections.
30. Internal combustion engine according to one of Claims 25 to 29, characterized in that the control and actuation module (52) is at least partially manufactured from plastic.
31. Internal combustion engine according to one of Claims 25 to 30, characterized in that a charge-air pipe which is common to all of the combustion chambers (1) is arranged on the control and actuation module (52).

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