Cylinder head and method for manufacturing a cylinder head

Abstract

A cylinder head for an internal combustion engine is described, comprising a support structure; a combustion chamber area; an inlet port; an exhaust port, wherein the combustion chamber area includes the inlet valve port and the exhaust valve port; an opening for the inlet of cooling air; air guide structures, fins, cavities and / or channels that direct the cooling air to the combustion chamber area; an opening for the inlet of a second cooling medium; a cooling medium circuit element, wherein the shape and size of the cross-sectional area of ​​the cooling medium circuit element is adapted to produce a substantially turbulent flow of the oil over at least 50% of the length of the cooling medium circuit element in the area to be cooled by the cooling medium circuit element;and a receiving element for receiving a fastening element, wherein the receiving element has a substantially column-like section, and wherein the cylinder head is configured to allow airflow around at least a portion of the substantially column-like section; and wherein the receiving element is configured to receive a nut for the fastening element and to countersink it at least partially therein. Furthermore, a method for manufacturing a cylinder head is described.

Description

Technical field

[0001] The invention relates to cylinder heads for internal combustion engines and a method for manufacturing a cylinder head. In particular, the invention relates to the cooling of a cylinder head for an internal combustion engine and a method for manufacturing a cylinder head with improved cooling. background

[0002] Air, water, or oil, sometimes in combination, are used to cool internal combustion engines. Cooling the cylinder heads is particularly important, as their temperature affects the combustion process and thus the engine's performance.

[0003] These engines are typically manufactured using a casting process. In air / oil-cooled cylinder heads, oil cooling is achieved through a cast-in cooling jacket. However, due to the casting technique and the necessary rigidity of the cylinder head, air-side cooling is usually limited. Another disadvantage of cylinder heads with three or four valves is the reduced cross-section for air cooling, resulting from the larger area of ​​the intake and exhaust ports.

[0004] Adequate cylinder head cooling contributes to the performance of the internal combustion engine. Efficient cylinder head cooling is crucial for both the performance and lifespan of an engine. The cylinder head is subjected to high thermal stresses because it seals the combustion chamber and houses the valves. In doing so, the cylinder head absorbs a large portion of the combustion heat. Effective cooling ensures that this heat is dissipated to prevent overheating. Overheating of the cylinder head can lead to problems such as burnt valves, cracks, and deformation, ultimately resulting in engine failure. In particular, the aluminum alloys commonly used for manufacturing cylinder heads often only withstand higher temperatures for a few hours. An optimal combustion chamber temperature is also essential for efficient combustion.Good cooling helps ensure that the fuel-air mixture burns optimally, resulting in better performance and lower fuel consumption.

[0005] Therefore, the object of the present invention is to provide a cylinder head with improved cooling and a method for manufacturing a cylinder head with improved cooling. Summary

[0006] The invention therefore comprises a cylinder head for an internal combustion engine and a method for manufacturing a cylinder head for an internal combustion engine.

[0007] According to the embodiments described herein, a cylinder head for an internal combustion engine, in particular a boxer engine, is described. The cylinder head according to the invention comprises a support structure for supporting the structure of the cylinder head; a combustion chamber area which, in the assembled state, faces the combustion chamber of the internal combustion engine and closes it off; at least one intake port for the intake of an air-fuel mixture or air for the combustion of the fuel in the cylinder of the internal combustion engine; and at least one exhaust port for the exhaust of the combustion process in the cylinder of the internal combustion engine, wherein the combustion chamber area comprises the at least one intake valve port and the at least one exhaust valve port.The cylinder head according to the invention further comprises at least one first opening for the inlet of cooling air; air guide structures, ribs, cavities and / or channels which are fluidically connected to the first opening and which are designed to guide the first cooling fluid within the cylinder head to the combustion chamber area of ​​the cylinder head; at least one second opening for the inlet of a second cooling medium, wherein the second cooling medium is in particular oil; and a cooling medium circuit element, in particular a cooling oil circuit element, wherein the shape and size of the cross-section of the cooling medium circuit element is adapted to cause a substantially turbulent flow of the oil over at least 50% of the length of the cooling medium circuit element in the area to be cooled by the cooling medium circuit element.The cylinder head according to the invention further comprises at least one receiving element for receiving a fastening element for attaching the cylinder head to the housing of the internal combustion engine, wherein the receiving element for the fastening element has a mounting shaft with a substantially column-like section, and wherein the cylinder head is designed to allow an airflow around at least a part of the substantially column-like section, and wherein the receiving element for the fastening element is designed to receive a nut for the fastening element and to at least partially countersink it therein.

[0008] According to the embodiments described herein, a cylinder head for an internal combustion engine is described. The cylinder head comprises a support structure for supporting the cylinder head structure; a combustion chamber area which, in the assembled state, faces and closes off the combustion chamber of the internal combustion engine; at least one intake port for the intake of an air-fuel mixture or air for the combustion of the fuel in the cylinder of the internal combustion engine; and at least one exhaust port for the exhaust gas of the combustion process in the cylinder of the internal combustion engine. The combustion chamber area comprises the at least one intake port and the at least one exhaust port. The cylinder head according to the invention further comprises at least one first opening for the intake of cooling air; and at least one receiving element for receiving a fastening element for attaching the cylinder head to the housing of the internal combustion engine.The receiving element for the fastening element comprises a mounting shaft with a substantially column-like section, wherein the cylinder head is configured to allow airflow around at least a portion of the substantially column-like section; and wherein the receiving element for the fastening element is configured to receive a nut for the fastening element and to at least partially countersink it therein.

[0009] Furthermore, a cylinder head for an internal combustion engine is described according to the embodiments described herein. The cylinder head according to the invention comprises a support structure for supporting the cylinder head structure; a combustion chamber area which, in the assembled state, faces the combustion chamber of the internal combustion engine and closes it off; at least one intake port for the intake of an air-fuel mixture or air for the combustion of the fuel in the cylinder; and at least one exhaust port for the exhaust gas of the combustion process in the cylinder of the internal combustion engine. The combustion chamber area comprises the at least one intake valve port and the at least one exhaust valve port.The cylinder head according to the invention further comprises at least one first opening for the inlet of cooling air; at least one second opening for the inlet of a second cooling medium, wherein the second cooling fluid is in particular oil; and a cooling medium circuit element, in particular a cooling oil circuit element, wherein the shape and size of the cross-section of the cooling medium circuit element is adapted to cause a substantially turbulent flow of the cooling medium over at least 50% of the length of the cooling medium circuit element in the area to be cooled by the cooling medium circuit element.

[0010] The cylinder head according to the embodiments described herein features improved cooling compared to known cylinder heads. This allows for an increase in engine performance. Furthermore, the cylinder head cooling protects the engine from damage caused by overheating. Proper cooling prevents cracks, deformation, and other problems that can lead to power loss and costly repairs. Typically, the cylinder head gasket seals the combustion chamber. A cylinder head gasket that leaks due to overheating, cracks, deformation, or the like can lead to a loss of power and even engine damage. The cylinder head according to the invention can prevent such damage through improved cooling.

[0011] According to one embodiment, the cylinder head has a receiving element for a countersunk nut for attaching the cylinder head to the engine housing. The concept of the nut being located in the receiving element increases the flow cross-section in the cylinder head, thereby improving cooling performance. The receiving element for a countersunk nut and the corresponding area of ​​the cylinder head are designed such that cooling air can flow around (and especially above) the receiving element (particularly also with the nut installed). This allows for the cooling of an additional area of ​​the cylinder head that is poorly or not at all reached by a cooling system in conventional cylinder heads. Cooling the area around the receiving element for the nut is particularly advantageous because this area is located close to the combustion chamber area of ​​the cylinder head and therefore absorbs a particularly large amount of heat from the combustion chamber.

[0012] According to the embodiments described herein, a receiving element for receiving a fastening element can be understood as a structure that can at least partially receive a fastening element, such as a nut, screw, bolt, or the like. The receiving element, and in particular the mounting shaft of the receiving element, and typically also the substantially column-like section, can, for example, at least partially or section by section have the shape of a column (in particular a hollow column), a channel, a tube, a shaft, a pillar, or the like. In one embodiment, the receiving element can be part of the support structure or be connected to it. The cylinder head according to the invention is designed to allow an airflow around at least a part of a substantially column-like section of the receiving element.This can be achieved, for example, by a clear (unobstructed or unobstructed) immediate surroundings of the column-like section, an air duct running close to it, one or more air guide elements (such as air deflectors or the like) between the first opening and the column-like section, or similar measures. The "immediate" surroundings can be understood as the area directly adjacent to the column-like section.

[0013] According to the embodiments described herein, the receiving element is configured to receive a nut for the fastening element and to countersink it at least partially. In one embodiment, the receiving element may also be configured to countersink part of the bolt for fastening the cylinder head within the receiving element. Partially countersinking the nut (and typically the bolt) within the receiving element can be understood to mean that, in the assembled state, the nut (and typically the bolt) does not protrude, or protrudes only slightly, beyond the edge of the receiving element (plus any washer), for example, up to 30% of the nut length. Typically, the receiving element may be designed with a channel or passage, and a correspondingly adapted cross-section and length for this purpose.

[0014] In some embodiments, the cylinder head has a cooling medium circuit element according to the invention, which causes turbulent flow at least in one area to be cooled. Typically, the cooling medium circuit element comprises one or more channels. According to the embodiments described herein, a "circulation element" can be understood as a part, section, component, or segment of a circuit. For example, a "cooling medium circuit element" can typically be understood as an element that comprises channels. Typically, the cooling medium circuit element can have an inlet and an outlet for the cooling medium, also called a cooling medium inlet and a cooling medium outlet.In particular, the cooling medium circuit element can be connected to other elements of a cooling circuit, especially to other elements located outside the cylinder head or the engine, and furthermore, especially via the inlet and outlet. For example, the other elements of a cooling medium circuit can include pumps, additional channels, heat exchangers, and / or radiators to which the cooling medium circuit element can be connected. In some embodiments described herein, the cooling medium circuit element is designed to run substantially within the cylinder head according to the invention. The term "substantially within" can be understood here as running to a large (or even greater) extent within the cylinder head.For example, the cooling medium circuit element can be designed to typically extend at least 60%, or typically at least 70%, or typically at least 80% within the cylinder head according to the invention.

[0015] According to the embodiments described herein, the shape and size of the cross-section of the cooling medium circuit element can be adapted to produce a substantially turbulent flow of the cooling medium. The substantially turbulent flow (i.e., exhibiting at least partially turbulent or laminar components) can, in some embodiments, be produced, for example, by the design of the shape and size of the cross-section of the channel(s) of the cooling medium circuit element, by the surface properties of the material of the channel(s) of the cooling medium circuit element, by structures within the channel(s) of the cooling medium circuit element, and / or by the choice of the cooling medium, such as oil.The essentially turbulent flow enables significantly improved heat dissipation in the areas of the cylinder head according to the invention that require cooling, and particularly in areas of the cylinder head where air cooling is difficult or impossible. Designing the channels of the cooling medium circuit element in such a way that turbulent flow is generated with the selected (or given) cooling medium is an effective measure to increase the heat absorption of the cooling medium. The design of the geometry of the cylinder head according to the invention is a parameter that enables the corresponding design of the channels of the cooling medium circuit element. For example, such a design of the cylinder head can be achieved by a 3D printing manufacturing process.

[0016] Typically, the area to be cooled by the cooling medium circuit element can include at least the area of ​​the combustion chamber center between an intake port and an exhaust port. Typically, an intake port as described herein in embodiments can be understood as a channel in the cylinder head designed to accommodate an intake valve. Similarly, an exhaust valve port can be understood as a channel in the cylinder head designed to accommodate an exhaust valve. A channel as used herein can, in some embodiments, be understood as a tubular connecting passage or passage. In some embodiments, the area to be cooled by the cooling medium circuit element can also include other areas, such as the spark plug dome area and the exhaust port area of ​​the cylinder head, as will be explained in more detail below.

[0017] Typically, a substantially turbulent flow of the cooling medium is induced over at least 50% of the length of the cooling medium circuit element in the area to be cooled by the cooling medium circuit element. Alternatively, a substantially turbulent flow of the cooling medium is induced over at least 50% of the length of the cooling medium circuit element. A substantially turbulent flow can be understood as a flow that is largely turbulent (i.e., at least 50%, typically at least 60%, and typically at least 70%), but may also exhibit laminar components.

[0018] According to the embodiments described herein, the cylinder head according to the invention provides air guide structures, ribs, cavities and / or channels (in particular through its geometry and design) which are fluidically connected to the first opening for the intake of cooling air and which are designed to guide the first cooling fluid (e.g., cooling air) within the cylinder head to the combustion chamber area of ​​the cylinder head. For example, the air guide structures and ribs can contribute to forming the cavities and channels that are connected to the first opening for the intake of cooling air. The term "fluidically connected" can be understood in particular as the connection of an arrangement of structural elements by a flow.In particular, the fluidically interconnected structural elements can allow the exchange of fluids, permit flow between the structural elements, and / or permit a continuous flow originating from the opening. Specifically, the air guide structures, ribs, cavities, and / or channels of the cylinder head according to the invention are designed and configured to direct the first cooling fluid within the cylinder head to the combustion chamber area, and in particular to an area above the combustion chamber area in the cylinder head. The cooling air can thus be directed, in particular, to one of the hottest areas of the cylinder head and effect heat exchange. Typically, the geometry of the cylinder head is designed such that cooling channels, cavities, and ribs are created that guide the cooling air accordingly.Being able to efficiently reach one of the hottest areas of the cylinder head with a cooling medium without compromising the stability of the cylinder head significantly influences the cooling performance and thus the performance of the engine.

[0019] In one embodiment, the cylinder head includes a support structure for supporting the cylinder head structure. Typically, the support structure can comprise, or consist essentially of, vertical elements. These essentially vertical elements can provide the cylinder head with support, dimensional stability, and rigidity. For example, a provided support structure can make it possible to adapt the remaining geometry of the cylinder head to the requirements of improved cooling. Typically, the separation of the "support" and "cooling" functions in the cylinder head according to the invention results in several design possibilities that lead to improved cooling. In one embodiment, for example, the structures that conduct the cooling air (e.g., walls, partitions, guide structures, etc.) can be...The cylinder head's internal structure can be designed to be thinner than in known systems due to the existing support structure of the cylinder head. Thinner structures offer improved heat transfer within the cylinder head.

[0020] In one embodiment, which can be combined with other embodiments described herein, the combustion chamber area of ​​the cylinder head is arranged on a combustion chamber plate and, in particular, is enclosed by the combustion chamber dome, the mean material thickness of which is s < 1 / 10 * D1, where D1 is the combustion chamber diameter. This relatively thin material thickness, which thus offers high heat transfer, can be achieved through the support structure and the stiffness provided by the support structure.

[0021] Typically, the essentially vertical support structure can also serve for heat conduction. Furthermore, the support structure requires very little cooling surface area on the combustion chamber plate or for stiffening elements. This allows for effective air cooling through aerodynamically optimized channels leading to the hot combustion chamber plate, located outside the support structure.

[0022] In one embodiment, the support structure can be a substantially continuous structure of walls that provides support and rigidity to the cylinder head. In one example, the support structure can extend inside the cylinder head. Typically, the support structure can consist of substantially vertical walls. In another example, the support structure can be a substantially continuous structure of substantially vertical walls that defines an inner region within the support structure and an outer region outside the support structure. In particular, the support structure can form an X-shaped shape, a curved X shape, a cross-shaped shape, a star-shaped shape, a trefoil-shaped shape, a triangular shape, a quadrilateral shape, and / or a polygonal shape. The walls of the support structure can typically extend over the height, or a portion thereof, of the cylinder head.In particular, the support structure extends to a sufficient height to absorb the forces caused by the combustion pressure.

[0023] In one embodiment, which can be combined with other embodiments, the support structure can at least partially encompass the outer walls of the cylinder head. For example, the outer walls of the cylinder head can be designed to be particularly high (especially compared to existing cylinder heads).

[0024] According to one embodiment described herein, which can be combined with other embodiments, the support structure can represent a type of partition, on the two sides of which different cooling fluids are used to cool the cylinder head. For example, air can be used as the primary cooling medium on one side of the support structure and oil as the secondary cooling medium on the other side of the support structure. In particular, cooling can be performed with oil inside the support structure and with air outside the support structure.

[0025] The support structure, which runs particularly between the cylinder head bolts and the center of the combustion chamber, allows the intake and exhaust ports as well as the combustion chamber floor to be manufactured with thin walls, since they contribute only marginally to the rigidity of the cylinder head according to the invention. This results in a largely separate inner and outer area.

[0026] In one embodiment, the cylinder head also includes at least one second opening for a second cooling medium, in particular oil. The second opening for the second cooling medium is typically adapted to be connected to the cooling medium circuit element of some of the embodiments described herein. In particular, the cooling medium circuit element includes one or more cooling medium channels. Cooling with two different cooling media enables improved cooling of the cylinder head, and especially cooling in different areas of the cylinder head that cannot be reached and cooled, or can only be reached and cooled poorly, by a single cooling medium.

[0027] As mentioned above, the support structure, with its high rigidity, allows for thin-walled construction of the areas to be cooled (especially the combustion chamber floor and exhaust port), which significantly improves heat dissipation. The cooling medium channels can be positioned very close to the critical zones (especially compared to known cylinder heads). The cooling medium circuit element of the present invention, typically in conjunction with the turbulent flow cross-sections of the cooling medium channels, results in significantly improved heat dissipation in the critical zones, i.e., in the hottest areas of the cylinder head.

[0028] According to one embodiment, which can be combined with other embodiments, the cooling medium circuit element is designed to generate substantially turbulent flow in the spark plug dome area, the combustion chamber center area, and the exhaust port area of ​​the cylinder head. Typically, an area can be understood as a surface or volume extending around the corresponding region. The "combustion chamber center" region, for example, can be understood as a surface and / or volume encompassing the geometric center of the cylinder head's combustion chamber and the surface and / or volume surrounding the geometric center of the combustion chamber. The "spark plug dome" region, for example, can be understood as a volume encompassing the spark plug dome of the cylinder head and the volume surrounding the spark plug dome. The same applies to the exhaust port area.Typically, the area or volume surrounding the corresponding element can be up to four times the size of the element itself. In the case of the combustion chamber center, for example, the area can encompass a radius around the geometric center of the combustion chamber, typically extending up to two-thirds of the radius, or even more, of the combustion chamber area. The turbulent flow of the cooling medium circuit element, at least in these areas, provides effective cooling in particularly heat-stressed regions. By precisely routing the cooling medium channels of the cooling medium circuit element, the areas where turbulent flow is required can be reduced, thus simplifying the generation of turbulent flow in the area of ​​the cylinder head to be cooled.

[0029] In one embodiment, the cooling medium circuit element extends for at least 50% of its total length within or inside the support structure of the cylinder head according to the invention. This allows for good access to the area to be cooled by the cooling medium and also enables efficient distribution between different cooling media. The support structure can advantageously act as a divider between the areas to be cooled by different cooling media. The total length of the cooling medium circuit element can be understood, in particular, as the length that the cooling medium travels from an inlet of the cooling medium circuit element or from the point where the cooling medium circuit element enters the cylinder head, until it reaches the outlet of the cooling medium circuit element or exits the cylinder head at another location.

[0030] According to one embodiment, which can be combined with other embodiments described herein, the cross-section of a channel of the cooling medium circuit element is at least partially substantially oval, substantially elliptical, and / or substantially a flat rectangle. This promotes turbulent flow with a suitable cooling medium and is a cost-effective and efficient way to provide turbulent flow in a portion of the cooling medium circuit element. Typically, a shape described as "substantially" may have deviations of up to 30%, still typically up to 20%, and still typically up to 10% from the exact geometric figure.

[0031] Typically, the cooling medium circuit element comprises at least one substantially annular section that surrounds an exhaust port. The cylinder head typically includes two exhaust ports, with the cooling medium circuit element having two substantially annular sections, each surrounding an exhaust port. Furthermore, the cooling medium circuit element typically has a meandering section that leads to a cooling medium outlet. A meandering section of a cooling medium circuit element can be understood as a section that includes twists, loops, bends, curves, arcs, serpentines, and / or a series of changes in direction of the cooling medium circuit element's tubing.Typically, these coils, loops, bends, curves, arcs, serpentines, and / or successive changes of direction are arranged in close succession, so that the cooling effect of the cooling medium circuit element is increased by the larger surface area of ​​the circuit element. In one embodiment, which can be combined with other embodiments, the meandering section leads from the ring-shaped area(s) for cooling the outlet channels past the spark plug dome to the cooling medium outlet. The geometry according to the invention allows for increased cooling capacity, particularly in areas subjected to high thermal stress and in areas where air cooling achieves no or only poor results.

[0032] In one embodiment, the cylinder head comprises two intake ports and two exhaust ports in the combustion chamber area, wherein the cylinder head's cooling medium circuit element is designed to cool the area of ​​the combustion chamber center between the intake ports and the exhaust ports. Typically, at least the area of ​​the combustion chamber center containing the intake ports and the exhaust ports is designated as the area to be cooled by the cooling medium circuit element. This arrangement enables efficient cooling within the available space.

[0033] According to one embodiment, the cylinder head further comprises a combustion chamber side encompassing the combustion chamber area, a top surface substantially opposite the combustion chamber side, two longitudinal side walls, and two transverse side walls. In particular, the cylinder head is designed such that, when assembled with the nut and optionally a washer, the receiving element for the fastening element extends over a maximum of approximately 70% of the height of a longitudinal side wall. The height of a longitudinal side wall is measured from the combustion chamber side to the top surface of the cylinder head. Specifically, the height of a longitudinal side wall described herein is the maximum height of a longitudinal side wall. In another embodiment, the receiving element for the fastening element, when assembled with the nut and optionally a washer, extends over a maximum of approximately 60% of the height of a longitudinal side wall.In another embodiment, the receiving element for the fastening element, when assembled with the nut and optionally a washer, extends over a maximum of approximately 50% of the height of a longitudinal side wall. The relatively small footprint of the receiving element together with the fastening element in the vertical direction of the cylinder head allows for cooling above (in the vertical direction) the receiving element, or a flow of cooling air above the receiving element that is not interrupted or obstructed by protruding parts. In particular, the relatively small height of the receiving element with the fastening element and nut can be used to arrange an air duct for the flow of cooling air above the receiving element. This can, for example, increase the cooling capacity in the cylinder head.

[0034] In one embodiment, the cylinder head is designed such that, above the receiving element for the fastening element in the assembled state with the nut and optionally a washer, an air duct for cooling air is arranged, which is connected to the first opening. This enables cooling in the cylinder head, which in known systems is blocked or interrupted by parts protruding into the cooling flow. The cooling performance is thus improved in known areas and made possible in some areas of the cylinder head for the first time. Typically, an air duct can be understood as a space that allows the inflow or flow of air.

[0035] According to one embodiment, which can be combined with other embodiments, the receiving element for the fastener is designed to accommodate a nut for the fastener substantially over its entire length. The nut does not protrude substantially, or only to a small extent (typically up to 30%, or typically up to 20% of its total length), beyond the receiving element (plus any washer, if present). For example, only the nut head protrudes from the receiving element. This allows for more space for the flow of cooling air to increase cooling performance. In particular, the receiving element has a bearing surface for a nut and / or a washer. This ensures a secure fit of the nut and fastener and allows for correct and easy installation of the nut in the receiving element.

[0036] In one embodiment, the cylinder head also includes a nut for the fastening element and, optionally, a washer, wherein the nut is at least partially countersunk in the receiving element for the fastening element. "At least partially" can typically be understood to mean that at least 60%, or typically at least 70%, or typically at least 80% of the nut can be countersunk in the receiving element. As described above, the at least partially countersunk nut increases the cooling capacity in the cylinder head.

[0037] According to one embodiment, the cylinder head according to the invention can further comprise air guide structures, ribs, cavities, and / or channels designed to direct cooling air from the first opening to an area above the combustion chamber area of ​​the cylinder head. This directs the cooling air into a zone that experiences significant heat generation during combustion. The term "above the combustion chamber area" can be understood as the area in the cylinder head that is adjacent to the combustion chamber area. In one example, the area above the combustion chamber area in the cylinder head can extend up to one-third of the height of the cylinder head. Typically, the area above the combustion chamber area can extend beyond the extent of the combustion chamber area in the plane perpendicular to the height of the cylinder head and typically occupies an area approximately twice the size of the combustion chamber area itself.

[0038] Additionally, the air cooling system can be designed for optimized airflow. For example, aerodynamically designed inlets and cooling ducts, in conjunction with flow-optimized fins and internal components (such as air deflectors, channels, ribs, etc.), can increase airflow with a moderate pressure drop, thus improving cooling. The design of cooling fins, spring retainer mounts, spark plug domes, and other downstream components can also be optimized for aerodynamics.

[0039] According to one embodiment, which can be combined with other embodiments described herein, the cylinder head according to the invention is manufactured by a 3D printing process, in particular a laser bed fusion process. Typically, the 3D printing process enables the production of the cylinder head structures described herein. In particular, the guide for the cooling medium circuit element, the support structure, the receiving element, and / or the air guide elements can be realized by a 3D printing process. In some embodiments, the airflow for cooling can also be guided more precisely and closer to the critical areas through the cylinder head due to the cylinder head geometries made possible by a 3D printing process. In cylinder heads where cooling is achieved by means of a cast-in cooling jacket, air-side cooling is usually limited due to the casting technique and the necessary rigidity.Furthermore, in conventional cylinder heads, the airflow can only be directed away from the hot zones. Additionally, due to the cross-sections required for casting, the flow of a second cooling medium is limited to laminar flow, also due to the viscosity of the cooling medium. If the cooling medium channels in conventional cylinder heads are mechanically machined, only a minimal cooling effect is possible because it is not possible to access the hotspots closely and over a sufficiently large area. Therefore, the manufacturing process according to the invention, using a 3D printing method, allows for several improvements in the cooling of the cylinder head according to the invention.

[0040] Some of the structures described herein can be particularly well realized using 3D printing to the extent described. For example, the cooling channels used for oil cooling in the internal area can advantageously be manufactured using 3D printing and precisely routed around the hotspots. Typically, the narrow cross-sections made possible by 3D printing promote turbulent flow. The largely exposed areas outside the support structure can typically be subjected to a large flow of cooling air. Furthermore, the design of cooling fins, spring retainer mounts, spark plug domes, and other downstream components can be aerodynamically optimized using 3D printing, thus avoiding the limitations of a casting process.

[0041] Typically, the cylinder head exhibits a combination of the features described above.

[0042] One aspect of the present invention relates to a method for manufacturing a cylinder head according to the embodiments described herein. In particular, the method comprises a 3D printing process, especially a laser bed fusion process. Typically, the method according to the invention includes applying the material to be processed in powder form in thin layers onto a base plate. The powdered material is then selectively melted by means of laser radiation and, after solidification, forms a solid layer of material. These steps are repeated. Several of these solidified layers form the cylinder head according to the invention. The above steps of the method are repeated until the cylinder head according to the invention has been produced. Brief description of the drawings Fig. Figure 1 shows a schematic perspective top view of the cylinder head according to the invention from the combustion chamber side according to some embodiments described herein; Fig. Figure 2 shows a schematic perspective top view of the cylinder head according to the invention in a view from a side wall of the cylinder head according to some embodiments described herein; Fig. Figure 3a shows a schematic section of the cylinder head according to the invention in the area of ​​the receiving element according to some embodiments described herein; Fig. Figure 3b shows a schematic view of a nut for the receiving element of the cylinder head according to some embodiments described herein; Fig. Figures 4a to 4c show sectional views of the cylinder head according to the invention in the area of ​​the receiving element according to some embodiments described herein; Fig. Figure 5a shows a schematic top view of a cylinder head according to the invention with a support structure according to the embodiments described herein; Fig. Figure 5b shows a schematic sectional view of a support structure in a cylinder head according to the embodiments described herein; Fig. Figure 6a shows a schematic front view of a cooling medium circuit element for a cylinder head according to the invention in accordance with some embodiments described herein; Fig. Figure 6b shows a schematic side view of a cooling medium circuit element for a cylinder head according to the invention in accordance with some embodiments described herein; Fig. Figure 7 shows a section of a cooling medium circuit element for a cylinder head according to the invention with a sectional view through one of the pipes of the cooling medium circuit element according to some embodiments described herein; and Fig. Figure 8 shows a flowchart of a process for manufacturing a cylinder head according to the invention.

[0043] Unless otherwise stated, the drawings given herein serve to illustrate features of embodiments of the disclosure. These features are assumed to be applicable to many different cylinder heads. As such, the drawings are not to be understood as showing all conventional features known to those skilled in the art that are necessary for the application of the embodiments disclosed herein. Description

[0044] Embodiments of the present disclosure and certain features, advantages, and details thereof are explained in detail below with reference to the non-limiting examples illustrated in the accompanying drawings. Descriptions of generally known materials, processing techniques, etc., have been omitted to avoid obscuring the disclosure with unnecessary details. However, it should be understood that the detailed description and specific examples, while indicating embodiments of the present disclosure, are provided for illustrative purposes only and not for limitation. Various substitutions, modifications, additions, and / or arrangements within the scope and / or extent of the underlying concepts of the invention will be obvious to those skilled in the field from this disclosure.

[0045] Fig. Figure 1 shows a perspective top view of the cylinder head 1 according to the invention, as seen from the combustion chamber side 10. The combustion chamber side 10 has the combustion chamber area 3, which closes off the combustion chamber. The combustion chamber area 3 typically has a combustion chamber center 16, which in turn can be described as an area containing the exact geometric center of the combustion chamber area. The combustion chamber area 3 can, for example, Fig. As shown in Figure 1, the combustion chamber area is essentially round. The combustion chamber area has a diameter of at least D1. Furthermore, in the combustion chamber area, Figure 3 of the Fig. 1. Two intake ports 4 and two exhaust ports 5 are arranged. The intake and exhaust ports are typically designed and configured to accommodate the intake and exhaust valves of the cylinder head, respectively.

[0046] In conjunction with Fig. Figure 2, which shows a perspective side view of a part of the cylinder head 1 according to the invention, shows the cylinder head 1 having a top side 11 opposite the combustion chamber side 10, two longitudinal sides 12 and 13, and two transverse sides 14 and 15.

[0047] The cylinder head 1 according to the invention also has a first opening 6 on each side, which represents an inlet for cooling air. The cooling air is directed from and through the first opening 6 into the interior of the cylinder head 1. Fig. Figure 1 shows further air inlets 61 next to the first opening 6. Inside the cylinder head 1, ribs, air guides, channels, and the like are typically arranged to direct the cooling air within the cylinder head 1. For example, in the cylinder head 1 according to the invention, the cooling air can be directed to an area above the combustion chamber area in the cylinder head to ensure that the cooling air reaches one of the hottest areas of the cylinder head. The features of the cylinder head according to the invention described herein, such as the comparatively small thickness of the combustion chamber side (1 / 10 * D1), the support structure, and the manufacturing process using 3D printing, contribute to efficient cooling by the cooling air.

[0048] The cylinder head 1 according to the invention comprises a receiving element 7 having a column-like area or section 72. The receiving element 7 serves to receive a fastening element for attaching the cylinder head 1 according to the invention to the engine housing. Typically, the cylinder head 1 has more than one receiving element, for example, two or four receiving elements 7, two of which are located in the Fig. 1 and Fig. Figure 2 shows the receiving element 7, which can typically accommodate part of the fastening element and the nut for the fastening element.

[0049] Fig. Figure 3a shows a detailed view of the cylinder head 1 according to the invention. In the detailed view, the receiving element 7 and the column-like section 72 of the receiving element can be seen. Fig. Figure 3a shows two receiving elements 7, one on the left and one on the right. A mounted nut 8 can be seen in the receiving element 7 shown on the left. The nut 8 is typically partially countersunk in the column-like area 72 of the receiving element 7. In the Fig. In the receiving element 7 shown on the left (3a), the nut 8 is countersunk except for a small portion. The receiving element 7 has, by way of example, a bearing surface 73. The bearing surface 73 of the receiving element 7 is typically designed to provide a support for a nut or a washer. In the example shown in Fig. No nut is mounted on the receiving element 7 shown on the right in 3a.

[0050] The mother could, for example, be a mother 8, as seen in Fig. 3b is shown. For example, the nut described herein can have a nut head 81 and a nut shank 82. In some embodiments, where the nut is at least partially recessed in the receiving element, the nut shank 82 is substantially completely recessed in the receiving element, while the nut head 81 protrudes from the receiving element. The in Fig. The nut 8 shown in 3b has, according to some embodiments described herein, an internal toothing 83. The internal toothing 83 of the nut shown in Fig. The example shown in 3b allows for space-saving installation of the nut, e.g., using a thin tool. The space-saving installation of nut 8, in turn, makes it possible to provide space for an air duct and air guide elements, which would not fit with a conventional installation.

[0051] The cylinder head according to the invention is designed to allow airflow around at least part of the column-like section 72. For example, an air duct or air shaft 76 can lead around at least part of the receiving element 7 to allow cooling air to flow around the column-like section. According to some embodiments, and as shown in the Fig. As shown in Figure 3a, the air duct 76 is open at the front (i.e., on the side of the longitudinal side 12), which further facilitates the flow of cooling air around the receiving element 7 or the column-like section 72. Typically, the air duct 76, which at least partially surrounds the column-like section 72 of the receiving element, is connected to the first opening 6 for the supply of cooling air. Such a design can be realized and / or simplified, for example, by features such as the support structure, the 3D printing process, and / or other features described herein.

[0052] Fig. Figure 4a is a sectional view of a section of the cylinder head according to the invention, wherein the section shows the receiving element 7. In the sectional view of the Fig. Figure 4a shows the passage 74 of the receiving element 7, into which part of the fastening element and the nut can be inserted or countersunk. The mounted nut 8 and the washer 9 are also visible in the sectional view.

[0053] Fig. 4b shows the same section view as Fig. 4a the air duct 76, which directs an airflow around the column-like section 72 of the receiving element 7, as well as another air duct 75 above the receiving element 7. By means of the recessed nut, an air duct can be formed in the cylinder head above the receiving element 7, through which cooling air can flow to cool the cylinder head. Typically, the air duct 75 is connected to the first opening 6 for the intake of cooling air. In Fig. 4b shows that the recessed nut does not block or obstruct the flow of cooling air in the space above the receiving element 7, thus enabling the creation of an air duct. Fig. 4b shows the airflow in the air shaft 76 schematically represented by arrows.

[0054] The term “above” the receiving element can be understood as above in a direction that extends essentially perpendicularly from the combustion chamber side 10 to the opposite top 11.

[0055] In one embodiment, the cylinder head 1 is configured such that the receiving element 7 with the nut 8 (and, if present, the washer 9) extends, in the assembled state, over a maximum of approximately 70% of the maximum height of a longitudinal side wall 12 or 13. The height runs, in particular, essentially vertically from the combustion chamber side 10 to the opposite upper surface 11 of the cylinder head.

[0056] Fig. Figure 4c shows a detailed view of the sectional views of the Fig. 4a and Fig. 4b. The nut 8 projects only partially (or preferably not at all) into the air duct 76 above the receiving element. For example, the nut 8 projects only about 30% of its length beyond the bearing surface 73 of the receiving element 7 and the washer 9. In some embodiments, the nut may project more than 30%, such as up to about 50% of its length, beyond the bearing surface 73 of the receiving element 7 and the washer 9. In other embodiments, the nut may project less than 30%, such as about 20% or 15% of its length or less, beyond the bearing surface 73 of the receiving element 7 and the washer 9. Typically, the nut head protrudes from the receiving element, while the remainder of the nut is substantially recessed within the receiving element.According to the embodiments described herein, the recessed part of the nut is measured from the contact surface between the nut and the bearing surface of the receiving element, or, if present, from the contact surface between the nut and the washer.

[0057] Fig. Figure 5a shows a simplified top view of the cylinder head 1 according to the invention. Fig. Figure 5a shows the support structure 40 of the cylinder head according to the invention. According to some embodiments, the support structure 40 can consist of one or more substantially vertical structures. "Vertical" here refers to the extension in the vertical direction of the cylinder head according to the invention, in particular substantially perpendicular to the combustion chamber side 10 and / or the top surface 11 of the cylinder head. Fig. Figure 5b shows a perspective sectional view of the support structure 40 inside the cylinder head 1. Fig. 5b shows the essentially vertical orientation of the walls of the support structure in the height direction of the cylinder head 1. The support structure is designed to support and / or ensure the rigidity and dimensional stability of the cylinder head 1 according to the invention.

[0058] The support structure 40 of the Fig. 5a and Fig. 5b has an X-shaped or cloverleaf-shaped form. In some embodiments, the support structure can also be configured as a cross-shaped, star-shaped, triangular, quadrilateral, or polygonal shape, or as a curved X. The exemplary X-shaped support structure 40 of Fig. 5a and Fig. Section 5b divides the cylinder head into essentially five areas 41, 42, 43, 44, and 45. According to some embodiments described herein, the support structure can divide the cylinder head into areas located outside the support structure and (one or more) areas located inside the support structure. Typically, areas 41, 42, 43, and 44 can be described as being located in the cylinder head outside the support structure 40. Area 45 can be described as being located in the cylinder head inside the support structure 40. According to embodiments described herein, areas 41, 42, 43, and 44, i.e., the areas located in the cylinder head outside the support structure, can be accessed and cooled by air cooling. According to the invention, area 45 located in the cylinder head inside the support structure is accessed and cooled by a second cooling medium (such as oil).The support structure 40 can, in the example, represent a separation between the two cooling media used for cooling in the cylinder head according to the invention.

[0059] In an embodiment that can be combined with other embodiments, the area 45, which lies within the support structure, can also be referred to as the combustion chamber center area.

[0060] The support structure 40 in the cylinder head according to the invention serves to stiffen the combustion chamber and thereby enable a thin-walled design of the remaining structures of the cylinder head 1. The support structure can be connected externally to the screw points of the receiving element according to the invention (in the Fig. 5a and Fig. 5b (indicated by the smaller circles on the outside of the support structure) to ensure the flow of force. The thin walls of the cylinder head, made possible by the support structure, allow heat to pass through more easily.

[0061] Fig. 6a and Fig. Figure 6b shows an embodiment of a cooling medium circuit element 17. Fig. 6a shows a top view, while Fig. Figure 6b shows a perspective view from the side and from above. Typically, the cooling medium circuit element is a cooling oil circuit element. As described above, the cooling medium circuit element, along with the second cooling medium, can be used, for example, in area 45 within the support structure to cool the area within the support structure. The cooling medium circuit element described herein typically consists of one or more channels through which the cooling medium can flow. In particular, the cooling medium circuit element is adapted to be connected to a pump or the like to ensure flow of the cooling medium within the cooling medium circuit element.

[0062] The one in the Fig. 6a and Fig. The cooling medium circuit element 17 shown in Figure 6b comprises areas for cooling the exhaust port (or ports) and / or the intake port (or ports). Typically, the areas for cooling the exhaust ports of the cylinder head 1 are ring-shaped, as shown in Figure 6b. Fig. 6a and Fig. The ring-shaped areas 20 shown in Figure 6b typically guide the cooling medium circuit element 17 around the exhaust ports of the cylinder head to cool them. Furthermore, the cooling medium circuit element 17 of the cylinder head 1 according to the invention has a meandering area 21 that can cool the area located within the support structure 40 in a substantially vertical direction. Typically, the meandering area 21 is designed to cool the area of ​​the exhaust port and the center of the combustion chamber. For this purpose, the cooling medium circuit element according to the invention can lead upwards to the exhaust port in loops or similar configurations.

[0063] Typically, the cooling medium circuit element 17 comprises a cooling medium inlet 22 and a cooling medium outlet 23. According to some embodiments, further elements of a cooling medium circuit can be connected to the cooling medium inlet 22 and / or the cooling medium outlet 23, such as further channels, pumps, heat exchangers, coolers, etc.

[0064] Fig. Figure 7 is a detailed view of the cooling medium circuit element 17 according to the invention, as it is used, for example, in Fig. Figure 6a shows a channel of the cooling medium circuit element in a cutaway view, revealing the cross-section 18 of a channel of the cooling medium circuit element. The Fig. The exemplary cross-section 18 shown in Figure 7 can be described as essentially elliptical or oval. It has two diameters, D2 and D3, which essentially determine its shape. Typically, the first diameter, D2, of the cross-section 18 is larger than the second diameter, D3. In particular, the diameters D2 and D3 of the elliptical cross-section 18 can have a ratio of approximately 3:1, approximately 4:1, approximately 5:1, or more.

[0065] According to the embodiments described herein, the cross-section of the cooling medium circuit element is designed, at least in some sections, to promote turbulent flow within the cooling medium circuit element, particularly considering the cooling medium used, such as oil. The large surface area of ​​the channel compared to its volume (and thus, in particular, the comparatively narrow cross-section) contributes to increasing heat transfer.

[0066] Even if only this one section of the cooling medium circuit element is in Fig. As shown in section 7, other or all sections of the cooling medium circuit element may also have such a cross-section 18.

[0067] Advantageously, the cylinder head according to the invention can be manufactured by a 3D printing process. The method 50 according to some embodiments is described in Fig.Figure 8 is shown in a flowchart. Typically, the cylinder head according to the invention can be manufactured by laser bed fusion or selective laser melting. In some embodiments, the cylinder head according to the invention is manufactured by applying the material to be processed in powder form in thin layers onto a base plate in box 51. The powdered material is then selectively remelted in box 52 using laser radiation and forms a solid layer of material after solidification. These steps are repeated. Several of these solidified layers form the cylinder head according to the invention. In particular, the structures and features according to the invention, such as the support structure, the cooling medium circuit element, the air ducts, especially around and above the receiving element, and others, can thus be manufactured with particular precision and efficiency.

[0068] This written description uses examples to disclose the invention and to enable any person skilled in the art to implement it, including the manufacture and use of any devices or systems and the performance of any methods contained therein. The patentable scope of the invention is defined by the claims and may include other examples that might occur to a person skilled in the art. Such other examples shall fall within the scope of the claims if they have structural elements that do not differ from the literal wording of the claims or if they contain equivalent structural elements with insignificant differences from the literal wording of the claims. Reference symbol list: 1 cylinder head 2 Support structure 3 Combustion chamber area 4 Inlet channel 5 Outlet channel 6 First Opening 61 air inlets 7 Recording element 72 column-like section 73 Contact area 74 Pass of the recording element 75, 76 air channels around the receiving element 8 Mother 81 Nut head 82 Maternity 83 Internal teeth of the nut 9 Washer 10 Combustion chamber side 11 Top 12, 13 Longitudinal side walls 14, 15 transverse side walls 16 Area combustion chamber center 17 Cooling medium circuit element 18 Cross section 20 ring-shaped area 21 Meandering area 22 Cooling medium inlet 23 Cooling medium outlet 31 Combustion chamber plate D1 combustion chamber diameter D2 Dimension of a pipe cross-section D3 Dimension of a pipe cross-section

Claims

[1] Cylinder head (1) for an internal combustion engine, comprising: A support structure (40) to support the structure of the cylinder head (1); A combustion chamber area (3) which, in the assembled state, faces the combustion chamber of the internal combustion engine and closes it off; At least one inlet port (4) for the inlet of an air-fuel mixture or air for the combustion of the fuel in the cylinder of the internal combustion engine; At least one exhaust port (5) for the exhaust of the combustion process in the cylinder of the internal combustion engine; wherein the combustion chamber area (3) comprises the at least one inlet valve channel (4) and the at least one exhaust valve channel (5); At least one first opening (6) for the inlet of cooling air; Air guide structures, ribs, cavities and / or channels that are fluidically connected to the first opening and are designed to direct the cooling air within the cylinder head to the combustion chamber area (3) of the cylinder head (1); at least one second opening for the inlet of a second cooling medium, wherein the second cooling medium is in particular oil; a cooling medium circuit element (17), in particular a cooling oil circuit element, wherein the shape and size of the cross-section (18) of the cooling medium circuit element is adapted to produce a substantially turbulent flow of the oil over at least 50% of the length of the cooling medium circuit element (17) in the area to be cooled by the cooling medium circuit element; and at least one receiving element (7) for receiving a fastening element for attaching the cylinder head to the housing of the internal combustion engine; wherein the receiving element (7) for the fastening element has a mounting shaft with a substantially column-like section (72), and wherein the cylinder head (1) is configured to allow an airflow around at least a part of the substantially column-like section (72); and wherein the receiving element (7) is designed to receive a nut (8) for the fastening element and to at least partially countersink it therein. [2] The cylinder head according to one of the preceding claims, wherein the cooling medium circuit element (17) is designed to generate a substantially turbulent flow in the area of ​​the spark plug dome, in the area (16) of the combustion chamber center and in the area of ​​the exhaust valve channel (5) of the cylinder head (1); and / or wherein the cooling medium circuit element (17) extends within the support structure (40) for at least 50% of its total length. [3] The cylinder head according to one of the preceding claims, wherein the cross-section (18) of the cooling medium circuit element (17) is at least partially substantially oval, substantially elliptical and / or substantially in the shape of a flat rectangle. [4] The cylinder head according to one of the preceding claims, wherein the cooling medium circuit element (17) has a substantially ring-shaped area (20) that leads around an outlet channel and further has a meandering area (21) that leads to a cooling medium outlet (23). [5] The cylinder head according to one of the preceding claims, wherein the support structure (40) comprises substantially vertical walls, and wherein these substantially vertical walls form an X-like, a cross-like, a star-like, a cloverleaf-like, a triangular, a quadrilateral, and / or a polygonal shape. [6] The cylinder head according to one of the preceding claims, wherein the cylinder head (1) is manufactured by a 3D printing process. [7] The cylinder head according to one of the preceding claims, wherein the combustion chamber area (3) is arranged on a combustion chamber plate (31) whose mean material thickness s< 1 / 10 *D1 is, where D1 is the combustion chamber diameter. [8] The cylinder head according to one of the preceding claims, wherein the receiving element (7) for the fastening element is configured to receive a nut (8) for the fastening element substantially over the entire length of the nut; and where the cylinder head (1) further comprises in particular a nut (8) for the fastening element, and optionally a washer (9), wherein the nut (8) is at least partially recessed in the receiving element for the fastening element. [9] The cylinder head according to any of the preceding claims, wherein the cylinder head further comprises: a combustion chamber side (10) encompassing the combustion chamber area (3), a top (11), which is essentially opposite the combustion chamber side (10), two longitudinal side walls (12; 13) and two transverse side walls (14; 15); and wherein the cylinder head is designed such that above the receiving element (7) for the fastening element in the assembled state with the nut (8), and optionally the washer (9), an air duct for cooling air is arranged which is connected to the first opening (6). [10] Method for manufacturing a cylinder head according to any one of claims 1 to 9. [11] The method according to claim 10, wherein the method comprises a 3D printing method, in particular a laser bed fusion method.

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