EP2832980A1 - Engine housing of a combustion engine and combustion engine equipped with the same - Google Patents

Abstract

The invention relates to a motor housing (4) with a cylinder block (6) and a cylinder head unit (5) which is formed from a head section (8) and at least one integral hollow cylinder section (9) with internal piston running surface (11). The hollow cylinder section (9) of the cylinder head unit (5) can be pushed into the cylinder block (6) at least partially in the axial direction of the hollow cylinder section (12). In addition, the cylinder head unit (5) can be prestressed against the cylinder block (6) by means of at least one fastening element (23) in the axial direction of the hollow cylinder section (12).

Description

The invention relates to a motor housing of an internal combustion engine, as well as an engine equipped with this engine housing, as indicated in the claims 1 and 16.

From the US 4,708,105 A an internal combustion engine in monobloc design is known in which at least one hollow cylinder with an inner raceway for a piston is designed together with at least one cylinder head as a one-piece casting or forms an integral cylinder head unit. The engine or cylinder block of the internal combustion engine is divided in a vertical plane along the in-line cylinder, whereby the cylinder block is formed of two half-shells with a vertical separation or joining plane. These half shells are dimensioned such that the cylinder head unit supporting or partially receiving, upper portion of the cylinder block, as well as the crankshaft housing forming, lower portion of the cylinder block are each defined in half by the two half-shells of the cylinder block construction. The mutual support between the cylinder head unit and the cylinder block is accomplished via two mutually spaced in the piston movement direction support zones. A first support zone is positioned approximately at the level of the cylinder bottom of the cylinder head unit, the cylinder head unit being supported on the half shells of the cylinder block via a horizontal support surface and an intermediate seal. A cooling channel for flowing through with a cooling medium is sealed by means of this seal against the external environment of the internal combustion engine. Another support zone with a further sealing element is formed in the immediate vicinity of the open end of the hollow cylinder of the cylinder head unit. In addition, a circumferential projection or a rib-like extension is formed on the outer wall of the hollow cylinder. This extension engages positively in a corresponding, groove-shaped recess on the inner sides of the two half-shells of the cylinder block. In the condition of use, the two half-shells of the cylinder block are joined together and clamped to each other via transverse to the cylinder axis glands. Due to the positive engagement between the rib-like projections on the hollow cylinder and the groove-like depressions on the inner sides of the half-shells of Cylinder block, the cylinder head unit is fixed in the axial direction of the hollow cylinder relative to the cylinder block.

In the from the GB 2 425 570 A known monobloc engine is a cylinder head unit formed from a one-piece casting, in which a bushing for slidably guiding the piston is pressed. In this cylinder head unit all inlet and outlet channels for the combustion air and for the exhaust gases and insertion openings for a spark plug or an injector are implemented. Furthermore, a cooling passage for passing a cooling medium is formed in the cylinder head unit. A crankshaft housing for receiving and supporting the crankshaft comprises in the lower end portion a circumferential holding web for connection to an oil sump forming the lower end of the engine. The crankshaft housing is closed in the downward direction, in particular designed as a hollow cylinder, wherein the cylinder axis is horizontal. When assembling the motor housing, the cylinder head unit is placed on the exclusively upwardly open crankcase and then biased against the crankshaft housing with a lying in the piston movement direction and reaching through the entire engine housing fitting, the screw heads are supported on the bottom closed bottom portion of the crankcase.

From the WO 2004/111418 A1 is another monobloc design is known in which at least one hollow cylinder and at least one cylinder head are formed as a one-piece casting and thus are united to form a cylinder head unit. Per hollow cylinder, a piston liner is pressed into the cylinder head unit. The cylinder or engine block is a casting which comprises at least an upper portion of the crankshaft housing and on which crankshaft housing side walls are formed, which are pulled up to a plane above the cylinder head unit and form at least one bearing for at least one overhead camshaft for valve control. In these laterally raised walls cooling channels are integrated, which are flowed through by a cooling fluid. The installation of the cylinder head unit in the cylinder block unit is carried out by axial insertion in the piston movement direction.

The in the US 4,708,105 A described embodiment has the disadvantage that bolted by the vertically divided crankcase this transverse to the direction of movement of the piston must become. Furthermore, it is disadvantageous in this embodiment that the seal between the cylinder head unit and the cylinder block is problematic or subject in the long term to the risk of leaks. In addition, there is a rigid, positive connection between the cylinder head unit and the cylinder block, which may lead to different thermal expansion and thus to mechanical stresses between the cylinder block and the cylinder head unit due to temperature differences within the engine block or due to different thermal expansion coefficients. A disadvantage is in the embodiment according to the GB 2 425 570 A , as well as in the WO 2004/111418 A1 in that additionally at least one bushing has to be pressed into the cylinder head unit. Furthermore, it is disadvantageous in these embodiments that the cooling channels are self-contained integrated in each case a cast block and thus an internal casting core for the preparation of these parts is necessary. Furthermore, the proposed constructions place high demands on the casting technique. By made in the known embodiments space or space distribution between the cylinder head unit and the cylinder block unit, it is also hardly possible to produce the engine as possible weight-saving and cost-efficient.

The present invention has for its object to provide a motor housing, which eliminates or reduces these quality and cost disadvantages and the risk of engine damage by occurring internal stresses. Another object of the invention is that the engine housing or an internal combustion engine equipped with it is functional for as long as possible and can achieve long service life.

This object of the invention is achieved by the measures according to claim 1, in particular by an engine housing with a cylinder block and a cylinder head unit, which cylinder head unit is formed from a head portion and at least one integrally mitgegossenen hollow cylinder portion with internal piston running surface, wherein the hollow cylinder portion of the cylinder head unit at least partially in the cylinder block in the axial direction of the hollow cylinder portion is inserted, and wherein the cylinder head unit by means of at least one fastening element in the axial direction of the hollow cylinder portion is prestressed against the cylinder block. As a result, an optimized structural unit or an improved motor housing is formed, which represents a good basis for an internal combustion engine according to claim 16.

In other words, therefore, a motor housing is provided with a cylinder block and a cylinder head unit, which cylinder head unit is formed from a head portion and at least one integrally mitgegossenen hollow cylinder portion with internal piston tread. The hollow cylinder portion of the cylinder head unit is in this case at least partially inserted into the cylinder block in the axial direction of the hollow cylinder section. The hollow cylinder portion forms on the inside thereof directly the sliding surface for a piston oscillating therein, so that an independent piston liner is obsolete. In addition, the cylinder head unit can be prestressed against the cylinder block with at least one fastening element in the axial direction of the hollow cylinder section.

An advantage of the design according to the invention is that there is no separating or joining surface between the head section of the cylinder head unit and the one-piece cast hollow cylinder section, and therefore no cylinder head gasket is required to seal the combustion chamber. A particular advantage of the embodiment of the invention is that a simple motor mounting is possible by the Relativverschiebbarkeit the hollow cylinder section in the axial direction with respect to the cylinder block. In addition, relative displacements, which occur due to temperature changes at the contact surfaces or transition interfaces between the cylinder block and hollow cylinder section, can be compensated to a great extent, so that mechanical stresses in the motor housing are prevented or minimized as much as possible. Especially when the cylinder head unit and the cylinder block at least partially receiving the cylinder block are formed of different materials with different thermal expansion coefficients, the specified structure is of particular advantage. It is also advantageous that due to the pretensionability of the cylinder head unit in the axial direction of the hollow cylinder section against the cylinder block, the cylinder head unit is precisely defined in its position relative to the cylinder block. In addition, the main forces occurring in the course of fuel combustion are intercepted in the motor housing in the main direction. By the so-called "wet cylinder liner" or by the "wet piston guide bushing, in which the outer surface of the hollow cylinder can be directly in contact with the cooling medium, a good or rapid heat transfer to the cooling medium can be carried out, which also under high loads Internal combustion engine ensures good heat dissipation and cooling, so that a long service life and a good reliability of operation can be achieved. The provided in the subject invention redundancy of separate liners for the pistons, which bushings would be pressed into the hollow cylinder, thus favors the cooling performance and the cooling behavior relative to the engine cylinders and beyond a cost-effective design of the motor housing can be achieved.

Furthermore, it may be expedient that between the cylinder head unit and the cylinder block at least one cooling channel for the passage of a cooling medium is formed, which cooling channel is sealed by means of at least one sealing element at a first interface between the head portion and the cylinder block relative to the outside of the motor housing, and by means at least one further sealing element is sealed at a further transition interface between the hollow cylinder portion and the cylinder block relative to a crankshaft housing for receiving a crankshaft. The advantage here is that the cooling channel is not an internal chamber, which is integrated in one of the two castings. Thus, internal mandrels, i. so-called lost mold cores, which are technically problematic and expensive, are unnecessary or reduced for the casting process. According to the stated construction, the cooling passage is formed immediately around the skirt portion of the hollow cylinder portion from the geometry or boundary surfaces of adjacent portions of the cylinder head unit and the cylinder block. By structurally independent sealing elements a long-term reliable sealing of the cooling channel between the adjacent parts can be achieved. A particular advantage lies in the fact that heat-related Relativverschiebungen or thermal expansion due to temperature differences have no or only marginal influence on the tightness of the cooling channel and so a reliable seal can be achieved.

Furthermore, it can be provided that the at least one sealing element is arranged at the further transition interface between the hollow cylinder section and the cylinder block offset by a height distance relative to a further sealing element of a adjacent hollow cylinder section. It is advantageous in this measure that the space or the distance between the individual hollow cylinder sections, ie the distance or the so-called cylinder gauge between the cylinders, can be made relatively small or narrow. As a result, the overall length of internal combustion engines with cylinders in series can be kept as short as possible. This is achieved by making the punctures for the Include sealing rings in the individual cylinders have a height offset to the punctures for receiving sealing rings in a neighboring cylinder. In addition, the punctures in the individual juxtaposed cylinders can thereby be made sufficiently deep, without causing excessive material weakening due to excessive constrictions of the gutter between immediately adjacent wooden cylinders. The height offset between punctures of adjacent cylinder parts can be chosen to be large enough to ensure a minimum thickness of material in the groove-shaped recesses in the gutter.

In addition, it may be provided that transition surfaces at the first transition interface between the head section and the cylinder block and transition surfaces at the further transition interface between the hollow cylinder section and the cylinder block are aligned at an angle, in particular at right angles to each other. It is advantageous here that the corresponding parts are easy to produce in the course of the manufacturing process and a favorable mutual support or load transfer is achieved.

Also advantageous is an embodiment according to which in the head portion of the cylinder head unit leading into the combustion chamber inlet and outlet channels, and at least one introduction opening for an injection nozzle or a spark plug are provided. Of particular benefit in this case, if the material recesses are already taken into account during the casting process, and thus in the course of a machining finish, the required material removal remains low.

According to a particular embodiment, it is possible that the fastening element, with which the cylinder head unit can be prestressed against the cylinder block in the axial direction of the hollow cylinder section, is provided or formed in addition to the application of a prestressing force to a bearing shell of a crankshaft bearing. The advantage here is that with reference to the vertical axis of the engine those parts which are highly loaded due to the internal combustion pressures in the engine, screwed together with as few screw or biased to each other, and thus results in a favorable force or absorption of the forces occurring. In addition, the assembly times for the motor housing can be kept as low as possible, so that a good basis for a cost-effective production is created. In particular, at least one is Bolt formed, which screws together the bearing shell for a main bearing of the crankshaft, the cylinder block and the cylinder head unit and joins together to form a one-piece assembly. The at least one fastening element is preferably anchored or screwed in the cylinder head section, while the screw head is supported on the bearing shell. The cylinder block is penetrated via a through hole from the shaft of the at least one fastening element.

Furthermore, it can be provided that an axial length of the hollow cylinder section of the cylinder head unit is between 50% and 200%, in particular between 80% and 110%, preferably approximately 100%, of a wall height of the cylinder block. The advantage here is that the cylinder block occupies the highest possible volume or material content of the engine design, so that when selecting a cylinder block material with relatively low density, such as aluminum, the total mass of the motor housing can be reduced or can be relatively low.

Furthermore, it can be provided that the hollow cylinder section in the region of its further transition interface to the cylinder block has an approximately cylindrical or conical outer circumferential surface and is accommodated without play in the cylinder block. It is advantageous that the hollow cylinder portion can be inserted in the axial direction in the cylinder block and positioned as scheduled or fixed. Furthermore, it is advantageous that due to the axial displaceability of the hollow cylinder portion relative to the cylinder block any relative displacements due to temperature-induced different thermal expansions can be compensated relatively free of tension.

Furthermore, it is expedient that the cylinder head unit has a shoulder surface running normal to the axial direction of the hollow cylinder section, via which the cylinder head unit is supported on the cylinder block and can be pretensioned against the cylinder block. The advantage here is that by the alignment of this shoulder or support surface a simple processing is possible. Furthermore, it is advantageous that by biasing the two parts to each other in this shoulder surface optimum power transmission for receiving the engine forces is produced. In particular, at a right angle to the shoulder surface force application Spreiz- or wedge forces are avoided.

According to an advantageous development, it can be provided that an upper end face of the cylinder block in the axial direction of the hollow cylinder section lies approximately at the level of a plane receiving a cylinder bottom of the cylinder head unit. The advantage here is that the cylinder block occupies the highest possible volume or proportion of construction on the engine design, so that by a low material density of the cylinder block material, such as aluminum, the total mass of the motor housing can be reduced.

In particular, it can be advantageous that the cylinder head unit is formed from a first material having a first material density, and that the cylinder block is formed from a further material having a different material density than the first material. This can ensure that those material properties can be selected which are considered optimal for the respective functional part of the engine. The cylinder head unit with the directly molded or integrally formed hollow cylinder section for immediate implementation of the piston liner can for example be formed from a material which is sufficiently resilient and wear-resistant, has good sliding properties and also optimally withstands the high combustion temperatures and high pressures inside the combustion chamber , Furthermore, this can be used in terms of costs and technical requirements as optimized as possible casting process for the processing of aluminum or gray cast iron.

According to an expedient development it can be provided that the material of the cylinder head unit has a higher material density than the material of the cylinder block. It is advantageous here that the total weight of the engine design can be reduced by having a comparatively low density in mechanically and thermally comparatively lightly stressed parts, such as the cylinder block, at least a large part of the installed volume of material. Above all, the material for the formation of the cylinder head unit, which is exposed to relatively high mechanical and thermal loads, is expediently made of a material which has a comparatively high density and thereby better meet the thermal and mechanical requirements.

In particular, according to an expedient embodiment, it can be provided that the cylinder head unit is formed by gray cast iron and directly forms the piston running surface, and that the cylinder block is formed by aluminum or cast aluminum. It is advantageous here that gray cast iron has a relatively good wear resistance and a comparatively high temperature resistance. In addition, aluminum or aluminum casting in the course of the casting process is easy to handle. The use of aluminum for the cylinder block also has the advantage that it compared to gray cast iron has a significantly low density, thereby allowing a relatively lightweight construction of the motor housing is possible.

According to an expedient measure, it is provided that a cooling channel for the passage of a coolant in an end-side end section of the motor housing is bounded on the one hand by the first material of the cylinder head unit and on the other hand by the different, different material of the cylinder block. As a result, a so-called "wet piston guide bushing" is created, which achieves a good cooling behavior or a high cooling capacity for the cylinders of the engine housing. In addition, a material pairing is made possible, which optimally exploits the advantages of the respective material properties.

Finally, it can be provided that the cylinder block forms at least a partial section of a crankshaft housing in its end section opposite the receiving opening for the cylinder head unit. It is advantageous here that by forming the largest possible, coherent functional units they can be cast in one piece. Thus, parting planes are avoided, which on the one hand gives the advantage that sealing material is saved. On the other hand, the number of components required in the course of assembly of the motor housing can be drastically reduced, whereby the assembly or construction costs can be kept low.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

Fig. 1

einen vertikalen Längsschnitt durch eine Brennkraftmaschine entlang der Achse der Kurbelwelle;

Fig. 2

einen Schnitt durch einen Zylinder der Brennkraftmaschine nach Fig. 1 mit einer Schnittebene normal zur Kurbelwellenachse, insbesondere gemäß den Linien II-II in Fig. 1;

Fig. 3

einen Schnitt parallel zur Befestigungsanordnung bzw. parallel zu den Befestigungsmitteln für die Hauptkomponenten der Brennkraftmaschine nach Fig. 1, mit einer Schnittebene normal zur Kurbelwellenachse, insbesondere gemäß den Linien III-III in Fig. 1.

In each case, in a highly simplified, schematic representation:

Fig. 1

a vertical longitudinal section through an internal combustion engine along the axis of the crankshaft;

Fig. 2

a section through a cylinder of the internal combustion engine after Fig. 1 with a sectional plane normal to the crankshaft axis, in particular according to the lines II-II in Fig. 1 ;

Fig. 3

a section parallel to the mounting arrangement or parallel to the attachment means for the main components of the internal combustion engine according to Fig. 1 , with a sectional plane normal to the crankshaft axis, in particular according to the lines III-III in Fig. 1 ,

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component names, wherein the disclosures contained in the entire description can be mutatis mutandis to the same parts with the same reference numerals or component names. Also, the location information chosen in the description, such as top, bottom, side, etc. related to the immediately described and illustrated figure and these position information in a change in position mutatis mutandis to transfer to the new location.

Fig. 1 shows a section through an internal combustion engine 1 along an axis 2 of the crankshaft 3. The engine 1 partially shown in this figure comprises a motor housing 4 with a cylinder head unit 5 and a cylinder block 6. Furthermore, at least one piston 7 and a crankshaft 3 are housed in the motor housing 4 , The illustrated cylinder head unit 5 is composed of a head section 8 and at least one hollow cylinder section 9. The head portion 8 and the hollow cylinder portion 9 are made in one piece, in particular formed from a single casting. There is the possibility that per cylinder 10 or per hollow cylinder section 9, a cylinder head unit 5 is formed, which consists of a head section 8 and a hollow cylinder section 9. However, it is also possible that a cylinder head unit 5 forms a plurality of cylinders 10, which accordingly consists of a head section 8 and a plurality of hollow cylinder sections 9. The head section 8 in each case fulfills the function of the valve mounting or valve control with respect to the combustion chamber of the internal combustion engine 1 Fig. 1 shown embodiment, an internal combustion engine 1 is shown, which has three cylinders 10 and piston 7. The cylinder head unit 5 consists in the illustrated embodiment of a one-piece contiguous head portion 8 and three integrally formed thereon Hollow cylinder sections 9, which are provided for slidable guidance of each one of the pistons 7.

The hollow cylinder section 9 forms directly on its inner wall or inner surface a piston running surface 11, along which the piston 7 is movable in an oscillating manner in the axial direction 12 of the hollow cylinder section 9. The defined by the material of the cylinder head unit 5 piston tread 11 forms a sufficiently stable and precise guidance for the piston 7. For a sufficient sealing between the piston running surface 11 and the piston 7 guided therewith, a plurality of piston rings 13 supported on the lateral surface of the piston 7 ensure that the combustion chamber 14 is sufficiently sealed to reduce the pressure arising in the combustion chamber 14 during the combustion of fuel into an oscillating movement to convert the piston 7 and if possible no combustion gases in the direction of the crankshaft 3 and to flow toward the crankcase 39.

The combustion chamber 14 is limited by a plurality of surfaces. On the one hand by the cylinder bottom 15, which is defined by the cylinder head unit 5 and a fictitious separation or transition surface between the head portion 8 and the hollow cylinder portion 9 represents. Furthermore, the combustion chamber 14 can be defined by the piston running surface 11 of the hollow cylinder section 9. In addition, the combustion chamber 14 is limited by the piston head 16, which typically extends into a combustion bowl, which is located on the side facing away from the connecting rod 17 side of the piston 7.

The hollow cylinder section 9 is defined by a relatively thin-walled, hollow cylinder element, wherein at least a partial section of the outer jacket surface 18 of the hollow cylinder section 9 forms a boundary surface of the cooling channel 19. The hollow cylinder portion 9 is molded directly to the head portion 8, or manufactured in a casting with this.

Due to the rapid relative movements between the piston 7 and hollow cylinder section 9 11 high demands are placed on the piston tread. In particular, their surface condition, their temperature resistance, their wear resistance and their manufacturing tolerances must meet increased requirements in order to avoid excessive wear on the sliding parts or surfaces. In addition, must the surfaces in contact ensure the best possible mutual sealing.

The outer circumferential surface 18 of the hollow cylinder section 9 is designed predominantly cylindrical. It can be provided that the outer circumferential surface 18 of the hollow cylinder section 9 is conical or frustoconical in the end section facing away from the head section 8 and / or has a shoulder.

The head section 8 of the cylinder head unit 5 comprises inlet and outlet channels 20 for gas exchange in the combustion chamber 14 and at least one introduction opening 21 for, for example, an injection nozzle, a glow plug or a spark plug. Especially useful appears in the Fig.1 to 3 illustrated embodiment of the motor housing 4 for a diesel fuel-powered internal combustion engine 1. In the inlet and outlet ports 20 valve seats are mounted, in which the valves, which are responsible for a regulated gas exchange in the combustion chamber 14, are recorded. The main body of the cylinder head unit 5 described above is made of a first material 22 and is integrally molded by a casting method. This first material 22 has a relatively high strength or surface hardness compared to the material for the cylinder block 6. Furthermore, it is advantageous if this first material 22 has good wear properties for the cylinder head unit 5 and is resistant to the high temperatures and pressures in the combustion chamber 14.

The cylinder head unit 5 is fastened by means of at least one fastening element 23 on the motor housing 4 or on the cylinder block 6 and also biased in the direction of the cylinder block 6. It is expedient if the cylinder head unit 5 is connected to the cylinder block 6 via a plurality of fastening elements 23, in particular in the form of screws. It is practical to provide for each main bearing for the crankshaft 3 two helical fasteners 23 - Fig. 3 -, So that in the illustrated embodiment of a 3-cylinder internal combustion engine 1 - Fig. 1 a total of eight fastening elements 23 for fastening the cylinder head unit 5 on the cylinder block 6 and at the same time for rotatably supporting the crankshaft 3 on the cylinder block 6 or in the crankshaft housing 39 are formed.

The already mentioned cooling channel 19 or the cooling channels 19 around the cylinder 10 are predominantly formed between inner surfaces of the cylinder block 6 and the outer surfaces of the cylinder head unit 5 adjacent thereto. Thus, two boundary surfaces of the cylinder head unit 5 and the cylinder block 6 meet, which must be sealed to prevent leakage of the cooling liquid. A first transition interface 24 between the cylinder head unit 5 and the cylinder block 6 is located approximately at the level of the cylinder bottom 15, wherein the corresponding separation or joining plane is arranged horizontally and by an upper end face 25 of the cylinder block 6, and by a shoulder surface 26 of the Cylinder head unit 5 is formed. For sealing the cooling channel 19, a sealing element 27 is arranged between these two surfaces 25, 26. This sealing element 27 may be, for example, a simple, flat plastic seal. However, it is also possible to perform the sealing element 27, for example, as a metal layer seal, wherein the core of the seal is made of spring steel and the surfaces are formed of thin elastomer layers.

A further transition interface 28 between the cylinder head unit 5 and the cylinder block 6 is located in the end section of the hollow cylinder section 9 facing away from the head section 8. This transition interface 28 is sealed by at least one further sealing element 29. The sealing element 29 used in this case is preferably formed by at least one sealing ring, in particular by at least one O-ring, which is held in a corresponding Einstechnut 30 of the cylinder block 6. Those Einstechnuten 30, which are located on the outer cylinders 10 of the motor housing 4, are introduced on the inside of jacket walls 31 of the cylinder block 6. If a plurality of cylinders 10 are arranged in an internal combustion engine 1, then further recesses 30 for the sealing elements 29 are located opposite centrally arranged cylinders 10 in at least one intermediate web 32 of the cylinder block 6.

According to the embodiment Fig. 1 an internal combustion engine 1 is shown, which has a plurality of cylinders 10. In order to keep the axial distance 33 or the so-called cylinder pitch between the individual cylinders 10 as low as possible, the wall thickness 34 of the intermediate webs 32 is made as low as possible. By the Einstechnuten 30 for the sealing elements 29, the intermediate webs 32 are additionally weakened. Would you now two increments 30 of adjacent cylinders 10 at the same height level, ie perform exactly opposite, so the gutter 32 would be weakened by the both sides arranged Einfüguten 30 to a large extent. In order to keep this weakening of the intermediate web 32 as low as possible, the recesses 30 of adjacent cylinders 10 are ideally not executed at the same height or not at the same height level, but these are arranged offset by a certain height distance 35 to each other. Thus, it can be ensured that the intermediate web 32 can be executed with the thinnest possible wall thickness 34 and still has sufficient strength or stability.

At the in Fig. 1 illustrated embodiment, the axial length 36 of the hollow cylinder section 9 is about 100% of the wall height 37 of the cylinder block 6. This ratio can be constructively set between about 50% to 200%. If one chooses this value rather high, then a higher proportion of first material 22 must be used to create the motor housing 4, this first material 22 is typically heavier or has a higher material density, as a first material 22 different, further material 38th for the cylinder block 6. If the value is selected low, the outer jacket walls 31 of the cylinder block 6 are to be pulled relatively far upwards.

The cylinder block 6 is preferably formed of a further material 38, which is lighter or has a lower density than the material of the cylinder head unit 5. This further material 38 must have at least such a high strength that the resulting forces in the motor housing 4 without a Damage to the material structure can be recorded. An example of such a material 38 is the execution of the cylinder block 6 in cast aluminum.

In Fig. 2 the internal combustion engine 1 is shown in a cross section, which runs through the cylinder center of a cylinder 10 and is normal to the axis 2 of the crankshaft 3. In this section, arranged in the crankcase 39 components of the internal combustion engine 1 are shown. In particular, it can be seen that the bearing shell 40 of a crankshaft bearing, in particular a crankshaft main bearing, by means of a pair of fastening means 23 with the cylinder block 6 and also or simultaneously with the cylinder head unit 5 is screwed. The bearing shell 40 is partially of a balancing mass 41 of the crankshaft 3 covered. A the lower end of the crankshaft housing 39 forming sump has not been shown for the sake of clarity.

Furthermore are in Fig. 2 a recess 42 for the camshaft, and a recess 43 for plunger for valve actuation visible. However, the camshaft and tappets are not shown in this figure. In the illustrated embodiment of the internal combustion engine 1, the actuation of the valves operates such that the camshaft lying laterally to the cylinders 10 transmits an actuating force to the vertically extending plungers. The plungers then in turn pass the appropriate actuating movement to an overhead rocker arm, which then actuates the valves.

In this illustration, it is also readily apparent that a shoulder surface 44 is formed on the cylinder head unit 5 in the transition region between the head section 8 and the hollow cylinder section 9. This shoulder surface 44 rests against the end face 25 of the cylinder block 6 and can thus absorb the preload force which is built up by the at least one fastening element 23 or transmit it to the cylinder block 6.

Fig. 3 shows a section through the internal combustion engine 1 in the plane of a pair of fasteners 23. Clearly visible is a bearing shell 40 of the crankshaft bearing 45, which bearing shell 40 is connected via two helical fasteners 23 with the cylinder block 6, said fasteners 35 subsequently with are bolted to the head portion 8 of the cylinder head unit 5 and anchored in the head portion 8. Thus, the cylinder block 6 is effectively clamped between at least one bearing shell 40, which completes a crankshaft bearing 45, and the head portion 8 of the cylinder head unit 5.

Furthermore, it can be seen that the fastening elements 23 are designed as screws which extend from the back of the bearing shell 40 into the cylinder head unit 5. In this case, the bearing shell 40 and the cylinder block 6 simple through holes, through which the shaft of the fasteners 23 is passed. In the cylinder head unit 5, a threaded bore is formed per fastening element 23, into which the fastening elements 23 are screwed. By the fasteners 23 is a sufficient biasing force on the contact surfaces or transition interface 24 between the cylinder head unit 5 and the cylinder block 6, and applied to the contact surfaces between the cylinder block 6 and the bearing shells 40. Between the at least one bearing shell 40 and the cylinder block 6, the crankshaft bearing 45 is defined, which receives the crankshaft 3 rotatably.

The embodiments show possible embodiments of the motor housing 4, wherein it should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but also various combinations of the individual embodiments are possible with each other and this possibility of variation due to the teaching of technical action representational invention in the skill of those skilled in this technical field.

Furthermore, individual features or combinations of features from the different exemplary embodiments shown and described can also represent independent, inventive or inventive solutions.

The task underlying the independent inventive solutions can be taken from the description.

All statements of value ranges in the present description should be understood to include any and all sub-ranges thereof, e.g. is the statement 1 to 10 to be understood that all sub-areas, starting from the lower limit 1 and the upper limit 10 are included, ie. all sub-areas begin with a lower limit of 1 or greater and end at an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

Above all, the individual in the Fig. 1 to 3 shown embodiments form the subject of independent solutions according to the invention. The relevant objects and solutions according to the invention can be found in the detailed descriptions of these figures.

For the sake of order, it should finally be pointed out that, for a better understanding of the structure of the motor housing 4, this or its components have been shown partly unevenly and / or enlarged and / or reduced in size.

REFERENCE NUMBERS

1 Internal combustion engine 31 shell wall 2 axis 32 gutter 3 crankshaft 33 Wheelbase 4 motor housing 34 Wall thickness 5 Cylinder head unit 35 height distance 6 cylinder block 36 axial length 7 piston 37 wall height 8th header 38 further material 9 Hollow cylinder section 39 crankcase 10 cylinder 40 bearing shell 11 Piston tread 41 Leveling compound 12 axially 42 Recess for the camshaft 13 piston ring 43 Recess for the plunger 14 combustion chamber 44 shoulder surface 15 cylinder base 45 crankshaft bearing 16 piston crown 17 connecting rod 18 outer jacket surface 19 cooling channel 20 Inlet and outlet channels 21 introduction opening 22 first material 23 fastener 24 first transition interface 25 face 26 shoulder surface 27 sealing element 28 further transition interface 29 another sealing element 30 Einstechnut

Claims (16)

Motor housing (4) with a cylinder block (6) and a cylinder head unit (5), which cylinder head unit (5) consists of a head section (8) and at least one integrally cast hollow cylinder section (9) with an inner piston running surface (11), characterized in that the hollow cylinder section (9) of the cylinder head unit (5) is at least partially insertable into the cylinder block (6) in the axial direction (12) of the hollow cylinder section (9), and in that the cylinder head unit (5) is secured in the axial direction (12) by means of at least one fastening element (23) ) of the hollow cylinder portion (9) against the cylinder block (6) is prestressed. Motor housing according to claim 1, characterized in that between the cylinder head unit (5) and the cylinder block (6) at least one cooling channel (19) for the passage of a cooling medium is formed, which cooling channel (19) by means of at least one sealing element (27) at a first Transition interface (24) between the head portion (8) and the cylinder block (6) relative to the outside of the motor housing (4) is sealed, and by means of at least one further sealing element (29) at a further transition interface (28) between the hollow cylinder section (9) and the cylinder block (6) relative to a crankshaft housing (39) is sealed for receiving a crankshaft. Motor housing according to claim 2, characterized in that the at least one further sealing element (29) at the further transition interface (28) between the hollow cylinder portion (9) and the cylinder block (6) by a height distance (35) relative to a further sealing element (29) of adjacent hollow cylinder section (9) is arranged offset. Motor housing according to claim 2, characterized in that transition surfaces on the first transition interface (24) between the head section (8) and the cylinder block (6) and transition surfaces on the further transition interface (28) between the hollow cylinder section (9) and the cylinder block (6). angular, in particular at right angles to each other. Motor housing according to one of the preceding claims, characterized in that in the head portion (8) of the cylinder head unit (5) in the combustion chamber (14) leading inlet and outlet channels (20) and at least one introduction opening (21) for an injection nozzle or a spark plug provided are. Motor housing according to one of the preceding claims, characterized in that the fastening element (23), with which the cylinder head unit (5) in the axial direction (12) of the hollow cylinder section (9) against the cylinder block (6) is prestressed, in addition to applying a biasing force on a Bearing shell (40) of a crankshaft bearing (45) is formed. Motor housing according to one of the preceding claims, characterized in that an axial length (36) of the hollow cylinder section (9) of the cylinder head unit (5) between 50% and 200%, in particular between 80% and 110%, preferably about 100%, of a wall height ( 37) of the cylinder block (6) is. Motor housing according to one of the preceding claims, characterized in that the hollow cylinder portion (9) in the region of its further transition interface (28) to the cylinder block (6) has a cylindrical or conical outer surface (18) and is received without play in the cylinder block (6). Motor housing according to one of the preceding claims, characterized in that the cylinder head unit (5) has a normal to the axial direction (12) of the hollow cylinder section (9) extending shoulder surface (44), via which the cylinder head unit (5) on the cylinder block (6) is supported and can be prestressed against the cylinder block (6). Motor housing according to one of the preceding claims, characterized in that an upper end face (25) of the cylinder block (6) in the axial direction of the hollow cylinder section (9) is approximately at the level of a cylinder bottom (15) of the cylinder head unit (5) receiving plane. Motor housing according to one of the preceding claims, characterized in that the cylinder head unit (5) from a first material (22) is formed with a first material density, and that the cylinder block (6) of a further material (38) with a compared to the first Material (22) of different material density is formed. Motor housing according to claim 11, characterized in that the material (22) of the cylinder head unit (5) has a higher material density than the material (38) of the cylinder block (6). Motor housing according to claim 11 or 12, characterized in that the cylinder head unit (5) is formed by gray cast iron and immediately forms the piston running surface (11), and that the cylinder block (6) is formed by aluminum or cast aluminum. Motor housing according to one of claims 11 to 14, characterized in that a cooling channel (19) for passing a cooling liquid in an end-side end portion of the motor housing (4) on the one hand from the first material (22) of the cylinder head unit (5) and on the other hand from the other, further Material (38) of the cylinder block (6) is limited. Motor housing according to one of the preceding claims, characterized in that the cylinder block (6) forms at least a partial section of a crankcase (39) in its end section opposite the receiving opening for the cylinder head unit (5). Internal combustion engine (1) comprising a motor housing (4) with a cylinder head unit (5) and a cylinder block (6), in which motor housing (4) at least one piston (7) and at least one crankshaft (3) are accommodated, characterized in that Motor housing (4) is designed according to one or more of the preceding claims.

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