Manufacturing method for cylinder heads for internal combustion engines

Abstract

To provide a method of manufacturing a cylinder head for an internal combustion engine that is light in weight and sufficiently durable in a flame deck region.SOLUTION: A method of manufacturing a cylinder head for an internal combustion engine includes the steps of: splitting a cylinder head (1) into a main portion (2) where a flame deck configuring a crown of each cylinder exists and an operation portion (3) where a housing of valve control means exists; making at first a single main portion (2) of the cylinder head (1) by a casting process within a mold (5); and making subsequently an operation portion (3) of the cylinder head (1) by an additional makeup of adding a layer on top of a layer beginning from the previously-made main portion (2) of the cylinder head (1).SELECTED DRAWING: Figure 1

Description

Cross - reference to related applications

[0005] ,

[0001] This patent application claims priority to the specification of Italian Patent Application No. 102020000014458 filed on June 17, 2020, the entire disclosure of which is incorporated herein by reference.

Technical Field

[0002] The present invention relates to a method for manufacturing a cylinder head for an internal combustion engine.

Background Art

[0003] An internal combustion engine generally comprises an engine block in which a plurality of cylinders are obtained, each cylinder comprising a respective combustion chamber and a respective piston mechanically connected to a crankshaft in order to transmit the force generated by combustion to the crankshaft. The engine block is provided with at least one cylinder head, which forms the crown of the cylinder (i.e., the upper closure of the cylinder) and is designed to house the intake and exhaust valves and the corresponding control means (i.e., return springs and camshaft).

[0004] Cylinder heads are currently made of steel (when the importance of weight reduction is low) or lightweight aluminum alloys (when higher performance engines requiring lighter weights are concerned).

[0005] Various techniques are available for manufacturing partially completed cylinder heads made of lightweight aluminum alloy, and conventional solutions (as described, for example, in International Publication No. 2005084851, German Patent Application Publication No. 102009021471, U.S. Patent Application Publication No. 2008017346 and German Patent Application Publication No. 102014204859) are melting processes, such as gravity casting or low-pressure casting processes (which can be die casting or sand casting), but recently additive manufacturing has also been proposed as a possible solution, as it allows manufacturers to obtain particularly complex and lightweight internal shapes (i.e., those with particularly thin wall thicknesses).

[0006] However, the use of additive manufacturing to produce partially finished cylinder heads made of lightweight aluminum alloy has proven unsatisfactory due to its long manufacturing time (and therefore high manufacturing cost) resulting from the considerable dimensions of the cylinder head, and the low mechanical resistance of the cylinder head, which tends to break particularly in areas close to the flame deck.

[0007] Patent application international publication 2014165734 describes a method for manufacturing a piston for an internal combustion engine, the piston comprising two parts, which are joined together by a joint, one manufactured by casting or forging and the other by an additive manufacturing process. [Overview of the project]

[0008] The object of the present invention is to provide a method for manufacturing a cylinder head for an internal combustion engine, thereby enabling manufacturers to produce a cylinder head that is lightweight and sufficiently durable (especially in the flame deck area).

[0009] According to the present invention, a method for manufacturing a cylinder head for an internal combustion engine is provided as described in the appended claims.

[0010] The attached claims describe preferred embodiments of the present invention and form an integral part of the description. [Brief explanation of the drawing]

[0011] Next, the present invention will be described with reference to the accompanying drawings illustrating non-limiting embodiments thereof. [Figure 1] This is a schematic perspective view of the cylinder head of an internal combustion engine according to the present invention. [Figure 2] Figure 1 is a schematic perspective exploded view of the cylinder head. [Figure 3] Figure 1 is a schematic diagram of the manufacturing unit where the cylinder head is produced. [Modes for carrying out the invention]

[0012] In Figure 1, number 1 represents the cylinder head of an internal combustion engine as a whole.

[0013] The cylinder head 1 constitutes the crown of the cylinders of the internal combustion engine (i.e., the upper closure of the cylinders) and therefore has a flame deck that constitutes the crown of each cylinder. Furthermore, the cylinder head 1 is designed to house intake and exhaust valves and corresponding control means (i.e., return springs and camshafts), and therefore, within the cylinder head 1 there are housings for the intake and exhaust valves and housings for the valve control means.

[0014] As shown in Figure 2, during the preparation phase (i.e., the design phase), the cylinder head 1 is divided into a main section 2 containing the flame decks that form the crowns of each cylinder, and an operating section 3 containing the housings for the valve control means. In the cylinder head 1, the two sections 2 and 3 are permanently and inseparably connected to each other; that is, the two sections 2 and 3 cannot be separated unless the cylinder head 1 is destroyed or cut.

[0015] The main part 2 of the cylinder head 1 contains the combustion chamber region, and following mechanical processing, the final surface must face the region where combustion occurs; therefore, the locally required mechanical and stress resistance characteristics of the material must be very high.

[0016] The working part 3 of the cylinder head 1 contains the camshaft region, and the design of its components typically includes cavities and circuits with specific shapes required by the lubrication and cooling circuits. Therefore, the essential features of the working part 3 of the cylinder head 1 are lightness and geometric complexity.

[0017] In Figure 3, number 4 represents the production plant as a whole, designed to manufacture cylinder head 1.

[0018] Production plant 1 includes a casting station S1 equipped with a casting bench (i.e., die-casting machine) having a mold 5, which can be opened to negatively reproduce the shape of the sole main part 2 of the cylinder head 1. At casting station S1, the sole main part 2 of the cylinder head is manufactured by a casting process, for example, gravity or low-pressure casting into the mold 5, i.e., a supply device supplies a predetermined amount of molten metal into the mold 5, which hardens within the mold 5 to produce the main part 2 of the cylinder head 1. Subsequently, after the molten metal hardens, the mold 5 is opened to remove the main part 2 of the cylinder head 1 in a partially completed state. After the partially completed main part 2 of the cylinder head 1 is removed from the mold 5, excess parts are removed (i.e., casting process residues such as risers and burrs).

[0019] The production plant 1 includes a processing station S2 equipped with an industrial furnace 9, and performs hot quenching and aging treatment on the main part 2 of the cylinder head 1 (before starting the production of the working part 3 of the cylinder head 1 by additive manufacturing, as described below).

[0020] The production plant 1 is equipped with a processing and installation station S3, and the main part 2 of the partially completed cylinder head 1 is mechanically processed by a machine tool 6 (the mechanical processing is performed after thermal processing at the processing station S2). In particular, first the lower surface 7 (shown in Figure 2) of the main part 2 is flattened by chip removal machining so that the lower surface 7 can obtain a predetermined surface roughness, and then the upper surface 8 (shown in Figure 2) of the main part 2 (parallel to and opposite to the lower surface 7) is flattened by chip removal machining so that the upper surface 8 can obtain a predetermined surface roughness.

[0021] Before commencing the manufacturing of the working part 3 of the cylinder head 1 by additive manufacturing, the lower surface 7 of the main part 2 is flattened by chip removal machining (e.g., by milling), as described below, to enable the lower surface 7 to obtain a predetermined surface roughness that is relatively low.

[0022] According to a preferred embodiment, during machining of the main part 2, the machining and mounting station S3 enables the acquisition of a geometric reference (e.g., a hole or screw hole penetrating the lower surface 7 of the main part 2) in the main part 2.

[0023] When the machining of the lower surface 7 of the main part 2 (including the creation of geometric references) is completed, the main part 2 of the cylinder head 1 is coupled to the adjusted support plate 10, which constitutes a positioning reference for subsequent additive manufacturing. That is, the main part 2 of the cylinder head 1 is placed and restrained at a predetermined position on the support plate 10. Obviously, the lower surface 7 of the main part 2 is in direct contact with the support plate 10. Therefore, the lower surface 7 of the main part 2 preferably (by the previously performed machining) must be smooth in order to make the connection between the main part 2 and the support plate 10 more stable. According to a possible embodiment, the support plate 10 has a striker body, which projects perpendicularly from the support plate 10 and is designed to engage with a corresponding (either matching or not matching the previously created geometric references) cavity available in the main part 2 of the cylinder head 1 (i.e., the cavity can be manufactured specifically for the connection to the support plate 10 or can naturally exist in the main part 2). In this way, a better and more stable connection between the main part 2 and the support plate 10 is ensured.

[0024] The geometric references obtained in the main part 2 (especially through the lower surface 7 of the main part 2) facilitate and improve (make more accurate) the connection of the main part 2 to the support plate 10.

[0025] Once the main part 2 is attached onto the support plate 10 and before starting the manufacturing of the operating part 3 of the cylinder head 1 by additive manufacturing as described below, the upper surface 8 of the main part 2 is flattened by chip removal machining (e.g., by milling) to enable the upper surface 8 to obtain a relatively low predetermined surface roughness. The surface roughness may or may not be small in order to improve the subsequent adhesiveness of the operating part 3 of the cylinder head 1. That is, generally speaking, since the lower surface 7 must adhere firmly to the support plate 10, the surface roughness of the upper surface 8 is greater than that of the lower surface 7. On the other hand, the operating part 3 of the cylinder head 1 must be printed on the upper surface 8 by additive manufacturing.

[0026] That is, between the machining of the lower surface 7 of the main part 2 and the machining of the upper surface 8 of the main part 2, the main part 2 is attached to the support plate 10 by placing the lower surface 7 of the main part 2 on the support plate 10. According to another embodiment, both the machining of the lower surface 7 of the main part 2 and the machining of the upper surface 8 of the main part 2 are performed before attaching the main part 2 on the support plate 10 by placing the lower surface 7 of the main part 2 on the support plate 10 (clearly, correct flatness needs to be ensured for the subsequent printing process by additive manufacturing).

[0027] The production plant 1 comprises a measuring station S4 provided with a three-dimensional scanner 11, and the three-dimensional scanner executes a three-dimensional scan of the main part 2 (attached to the support plate 10) in order to obtain the actual three-dimensional profile of the main part 2 (before starting the manufacture of the operating part 3 of the cylinder head 1 by additive manufacturing, as will be described below), that is, thanks to the three-dimensional scan, the actual dimensions and shape of the main part 2 can be reconstructed except for the construction tolerances. The design of the operating part 3 is preferably adjusted (for example, heated and / or deformed) according to the actual three-dimensional profile of the main part 2, clearly, the adjustment is limited to less than a few millimeters, but in any case, they then enable an almost perfect coupling between the main part 2 of the cylinder head 1 and the operating part 3 of the cylinder head 1.

[0028] The production plant 1 includes a filling station S5, in which the main part 2 (attached to a support plate 10) is inserted into a cup-shaped container 12 having an open top and a more or less parallelepiped shape, the support plate 10 preferably forming the base of the container 12 (partitioning the container 12 at the bottom), i.e., the container 12 is obtained by connecting the support plate 10 to four vertical side walls. The container 12 is sized to accommodate the main part 2 inside with a small gap, i.e., to minimize the volume that remains free inside the container 12 after the main wall 2 is inserted. Subsequently, before the production of the working part 3 of the cylinder head 1 is started by additive manufacturing, all holes or cavities that open through the top surface 8 of the main part 2 are filled with metal powder 13, which is the same metal powder 13 that will be used in subsequent additive manufacturing, as described later, and the function of the container 12 is to laterally contain the metal powder 13 used to fill all holes or cavities that open through the top surface 8 of the main part 2.

[0029] Basically, there is a powder bed 13 (on the same plane as the upper surface 8 of the main section 2) immediately outside the filling station S5, and layers can be deposited on it by additive manufacturing.

[0030] According to a possible embodiment, filling with powder 13 at the filling station is carried out in a controlled (modified) atmosphere in which air is replaced by an inert gas (e.g., argon).

[0031] Production plant 1 operates according to an additive manufacturing process called PBF ("powder bed fusion"), and therefore includes an additive manufacturing station S6 equipped with an additive manufacturing machine 14 that uses thermal energy to melt specific points within a previously deposited layer of metal powder 13, in particular the thermal energy generated by a laser source which melts the metal powder 13 and solidifies it by cooling, thereby manufacturing each part of the working unit 3. Thus, the working unit 3 is manufactured starting from layer design using a process that is repeated layer by layer to obtain the final shape. After layer (level) fusion, a construction platform housing a support plate 10 is lowered, a recoater deposits a new layer of metal powder 13, and the procedure is repeated.

[0032] To manufacture the working part 3 of the cylinder head 1 by additive manufacturing, the main part 2 of the cylinder head 1 (mounted on a support plate 10, housed in a container 12, and filled with powder 13) is inserted into an additive manufacturing machine 14. Additive manufacturing starts from the previously manufactured main part 2 of the cylinder head 1 and adds layers on top of the layers of metal powder 13; that is, the working part 3 of the cylinder head 1 is constructed in layers directly on top of the main part 2 (which was previously manufactured by casting). In this regard, it should be noted that the additive manufacturing process called PBF cannot add powder layers 13 on voids; therefore, all holes and cavities penetrating the upper surface 8 of the main part 2 are temporarily filled in advance with metal powder 13, so that the main part 2 has a (temporarily) solid and flat surface, and the working part 3 of the cylinder head 1 can be constructed in layers.

[0033] The container 12 may have filling elements that protrude from the support plate 10 or side wall (i.e., protrude inward into the container 12) and negatively reproduce the outer shape of the main part 2 of the cylinder head 1, in order to reduce the amount of powder 13 required to fill the container 12 (the best scenario for completely eliminating the filling of metal powder 13 before the start of the additive manufacturing process). These filling elements (attached to the support plate 10 or side wall of the container 12) may also be movable (in a single direction or in different directions perpendicular to each other) to move toward / away from the main part 2 of the cylinder head 1 located inside the container 12, and the movement of the filling elements serves both to allow the main part 2 to be inserted into / removed from the container 12 (i.e., the filling elements move away to form the necessary "maneuvering space" to move the main part 2) and to compensate for the structural tolerances of the main part 2 (i.e., to adjust the main part 2 to be slightly larger or slightly smaller than the nominal dimensions).

[0034] It should be noted that the main part 2 of the cylinder head 1 can be designed to avoid (or at least limit) the presence of holes or cavities opening through the top surface 8, in order to simplify the subsequent construction of the operating part 3.

[0035] In the preferred but unbonded embodiment shown in the attached drawings, an additive manufacturing process called PBF is used, which requires the use of metal powder 13. In other embodiments, other additive manufacturing processes that do not require the use and presence of metal powder 13 can be used, such as an additive manufacturing process called BIM ("Binder Injection Molding"), an additive manufacturing process called MIM ("Metal Injection Molding"), or an additive manufacturing process called LC ("Laser Cladding"). Obviously, since the additive manufacturing process called PBF is no longer used, the presence of the container 12 and the metal powder 13 (and therefore the presence of the filling station S5 and the washing station S7) is no longer required.

[0036] The production plant 1 includes a cleaning station S7 equipped with a cleaning machine 15. Once the manufacturing of the working unit 3 is complete, the completed cylinder head 1 is removed from the container 12, removed from the support plate 10, and inserted into the cleaning machine 15 for cleaning. This cleaning is performed in particular by removing the powder 13 accumulated for printing on the working unit 3, and by removing the powder 13 previously used to temporarily close all holes or cavities that penetrate and open through the top surface 8 of the main unit 2. The cleaning machine 15 removes the powder 13 using suction, but the final cleaning of the cylinder head 1 can also be performed by sandblasting, ultrasonic or chemical cleaning. Obviously, any possible printing supports must be removed (manually or automatically) before performing linear (sandblasting) of the cylinder head 1.

[0037] The production plant 1 may also include a processing station S8 equipped with an industrial furnace 16 in which the cylinder head 1 (which here includes both parts 2 and 3) undergoes thermal stress relief treatment.

[0038] After processing station S8 (if possible), head 1 is ready for further machining required to obtain different quality control and final results.

[0039] According to possible embodiments, before initiating the production of the working part 3 of the cylinder head 1 by additive manufacturing (in particular, immediately before the filling station, i.e., before adding the powder 13 to the main part 2), there may be a chemical treatment to deoxidize the upper surface 8 of the main part 2, i.e., to remove all surface oxides from the upper surface 8 of the main part 2. The deoxidation of the upper surface 8 of the main part 2 is intended to improve the adhesion of the initial layer of the working part 3 to the upper surface 8 of the main part 2.

[0040] According to a possible embodiment, before manufacturing the working part 3 of the cylinder head 1 by additive manufacturing (especially if the main part 2 is already inside the additive manufacturing machine 14), the upper surface 8 of the main part 2 can be heated, for example, using an infrared lamp, and the heating of the upper surface 8 of the main part 2 is intended to improve the adhesion of the initial layer of the working part 3 to the upper surface 8 of the main part 2.

[0041] According to possible embodiments, the main part 2 of the cylinder head 1 is manufactured by gravity casting using a first metal alloy (typically an aluminum-based alloy, e.g., A354 or A356 alloy), while the working part 3 of the cylinder head 1 is manufactured by additive manufacturing using a second metal alloy (typically an aluminum-based alloy, e.g., A6061, AlSi9Cu3, or AlSi10Mg alloy) that, unlike the first metal alloy, is compatible with the first metal alloy (i.e., can be firmly bonded to the first metal alloy and has the same thermal expansion as the first metal alloy in use). In this way, each metal alloy can be optimized for the stresses it will experience in use, and indeed, the main part 2 of the cylinder head 1 is subjected to high mechanical and thermal stresses resulting from combustion occurring in the cylinder during use (the main part 2 of the cylinder head 1, including the flame deck, constitutes the crown of the cylinder), while the working part 3 of the cylinder head 1 is subjected to much lower mechanical and thermal stresses during use. According to different embodiments, both parts 2 and 3 of the cylinder head 1 are manufactured from the same metal alloy (typically an aluminum-based alloy).

[0042] For this reason, the embodiments described herein can be combined with one another without exceeding the scope of protection of the present invention.

[0043] The above manufacturing method has different advantages.

[0044] First, the manufacturing method described above allows the manufacturer to obtain a cylinder head 1 that is extremely lightweight and extremely durable. This result is achieved because the main part 2 of the cylinder head 1 is manufactured by a conventional casting process that ensures high durability (in addition, the main part 2 of the cylinder head 1 must resist high mechanical and thermal stresses and therefore must have thick walls and must not have overly complex geometric shapes, so it does not particularly benefit from being manufactured by additive manufacturing), whereas the working part 3 of the cylinder head 1 is manufactured by additive manufacturing, which allows for very complex shapes and thin thicknesses in order to maximize lightness.

[0045] Furthermore, the fact that the casting process is used to manufacture a significantly smaller part than usual (i.e., the main sole portion 2 of the cylinder head 1, which is slightly more than half the total volume of the cylinder head 1) generates greater mechanical resistance than usual in the main portion 2 of the cylinder head 1, and in fact, by reducing the amount of molten metal supplied to the mold 5, the solidification time is reduced, and therefore the final mechanical resistance is increased.

[0046] In other words, the above manufacturing method better combines the best aspects (i.e., a strong pair) of the two manufacturing techniques (casting and additive manufacturing) and eliminates the worst aspects (i.e., weaknesses) of the two techniques.

[0047] In fact, casting is an ideal manufacturing technique for producing the main part 2 of the cylinder head 1 because it guarantees high mechanical properties even under high temperatures. On the other hand, additive manufacturing is an ideal manufacturing technique for producing the working part 3 of the cylinder head 1 because it ensures complex and lightweight shapes compared to conventional designs, as well as casting walls of different cores with very limited thicknesses and which are difficult to obtain. Furthermore, obtaining these shapes during the casting process is complex and problematic, requiring activities known as "mold making" and "core assembly," namely the activities of filling and extracting sand molds from equipment, and these shapes are then assembled to obtain the "negative" of the desired shape.

[0048] Furthermore, by manufacturing the single operating part 3 of the cylinder head 1 by additive manufacturing (a slow manufacturing technique where the larger the part being manufactured, the slower the technology becomes), the manufacturing of the cylinder head 1 requires more time compared to manufacturing by single casting, but this time extension is not excessive.

[0049] The working unit 3 manufactured by additive manufacturing is preferably designed from the outset with the aim of lightening and optimizing the printing process (the so-called "design for additive manufacturing"), thereby reducing printing time, lowering the overall weight of the article, and optimizing the manufacturing process. In fact, by designing the working unit 3 with additive manufacturing in mind, it is possible from the outset to minimize the support required for the printing process that constitutes the lost molten powder (i.e., the material that is discarded and removed during the article cleaning stage).

[0050] Finally, the manufacturing method described above is easy to implement and economical because it uses only commercial manufacturing and processing techniques. [Explanation of Symbols]

[0051] 1 Cylinder head 2 Main parts 3. Operating part 4 Production Plant 5. Mold 6 Machine tools 7 Bottom side 8 Top side 9 Industrial Furnaces 10 Support plate 11. 3D scanner 12 containers 13 powder 14 Additive manufacturing machines 15 Washing machine 16 Industrial Furnaces S1 Casting Station S2 Processing Station S3 Machining and Installation Station S4 Measurement Station S5 Filling Station S6 Additive Manufacturing Station S7 Washing Station S8 Processing Station

Claims

1. A method for manufacturing a cylinder head (1) for an internal combustion engine, The aforementioned manufacturing method is In the preparation stage (i.e., during the design stage), the cylinder head (1) is divided into a main part (2) in which the flame deck constituting the crown of each cylinder is located, and an operating part (3) in which the housing of the valve control means is located. First, the single main part (2) of the cylinder head (1) is manufactured by a casting process in a mold (5), Next, the process involves manufacturing the operating part (3) of the cylinder head (1) by an additive manufacturing process called PBF, which involves adding a layer on top of the layer of metal powder (13) that starts from the main part (2) of the cylinder head (1) that was manufactured earlier. Before commencing the manufacture of the operating part (3) of the cylinder head (1) by additive manufacturing, the step of filling all holes or cavities opening in the upper surface (8) of the main part (2) by using the same metal powder (13) used in the additive manufacturing, A manufacturing method that includes this.

2. The manufacturing method according to claim 1, further comprising the step of manufacturing the operating part (3) of the cylinder head (1) by additive manufacturing, and then removing the metal powder (13) remaining on the main part (2) of the cylinder head (1) and the metal powder (13) that has accumulated during the subsequent printing process.

3. The manufacturing method according to claim 1 or 2, further comprising the step of inserting the main part (2) into a cup-shaped container (12) with an open top and filling all holes or cavities opening in the upper surface (8) of the main part (2) by using the metal powder (13) before commencing the manufacture of the operating part (3) of the cylinder head (1) by additive manufacturing.

4. The manufacturing method according to claim 3, further comprising the step of placing the main part (2) on a support plate (10) and coupling it thereto, before commencing the manufacture of the operating part (3) of the cylinder head (1) by additive manufacturing, wherein the support plate is a position reference for the additive manufacturing and partitions the container (12) at its bottom.

5. The manufacturing method according to claim 3 or 4, wherein the container (12) comprises at least one filling element, the filling element protruding inward from the container (12) to reduce the amount of powder (13) required to fill the container (12) and negatively reproducing the outer shape of the main part (2) of the cylinder head (1).

6. The manufacturing method according to claim 5, wherein the filling element is movable relative to the container (12) so as to approach or move away from the main part (2) of the cylinder head (1) which is located inside the container (12).

7. A method for manufacturing a cylinder head (1) for an internal combustion engine, The aforementioned manufacturing method is In the preparation stage (i.e., during the design stage), the cylinder head (1) is divided into a main part (2) in which the flame deck constituting the crown of each cylinder is located, and an operating part (3) in which the housing of the valve control means is located. First, the single main part (2) of the cylinder head (1) is manufactured by a casting process in a mold (5), Next, the process involves manufacturing the operating part (3) of the cylinder head (1) by additive manufacturing, which involves adding layers to the layers of the cylinder head (1) that begin with the previously manufactured main part (2). A manufacturing method comprising the step of flattening the upper surface (8) of the main part (2) by chip removal machining before commencing the manufacture of the operating part (3) of the cylinder head (1) by additive manufacturing, thereby enabling the upper surface (8) to obtain a predetermined surface roughness.

8. The manufacturing method according to claim 7, further comprising the step of deoxidizing the upper surface (8) of the main part (2) before commencing the manufacture of the operating part (3) of the cylinder head (1) by additive manufacturing.

9. The manufacturing method according to claim 7 or 8, further comprising the step of heating the upper surface (8) of the main part (2) before commencing the manufacture of the operating part (3) of the cylinder head (1) by additive manufacturing.

10. Before starting the manufacturing of the operating part (3) of the cylinder head (1) by additive manufacturing, To obtain the actual 3D profile of the main part (2), the steps include: performing a 3D scan of the main part (2); The steps include adjusting the design of the operating unit (3) to the actual 3D profile of the main unit (2), and A manufacturing method according to any one of claims 7 to 9, including

11. A method for manufacturing a cylinder head (1) for an internal combustion engine, The aforementioned manufacturing method is In the preparation stage (i.e., during the design stage), the cylinder head (1) is divided into a main part (2) in which the flame deck constituting the crown of each cylinder is located, and an operating part (3) in which the housing of the valve control means is located. First, the single main part (2) of the cylinder head (1) is manufactured by a casting process in a mold (5), Next, the process involves manufacturing the operating part (3) of the cylinder head (1) by additive manufacturing, which involves adding layers to the layers of the cylinder head (1) that begin with the previously manufactured main part (2). A further step, before commencing the production of the operating part (3) of the cylinder head (1) by additive manufacturing, includes placing and joining the main part (2) of the cylinder head (1) onto a support plate (10), wherein the support plate is a position reference for the additive manufacturing, A method for manufacturing the support plate (10) having a striker body that protrudes vertically from the support plate (10) and is designed to engage with a corresponding cavity present in the main part (2) of the cylinder head (1).

12. The manufacturing method according to claim 11, further comprising the step of flattening the lower surface (7) of the main part (2) of the cylinder head (1) by chip removal machining before placing and joining the main part (2) of the cylinder head (1) on the support plate (10), thereby enabling the lower surface (7) to obtain a predetermined surface roughness.

13. The manufacturing method according to claim 11 or 12, further comprising the step of forming geometric criteria in the main portion (2) of the cylinder head (1) that are used to connect the main portion (2) to the support plate (10), in particular a hole or screw hole opening to the lower surface (7) of the main portion (2).

14. A method for manufacturing a cylinder head (1) for an internal combustion engine, The aforementioned manufacturing method is In the preparation stage (i.e., during the design stage), the cylinder head (1) is divided into a main part (2) in which the flame deck constituting the crown of each cylinder is located, and an operating part (3) in which the housing of the valve control means is located. First, the single main part (2) of the cylinder head (1) is manufactured by a casting process in a mold (5), Next, the process involves manufacturing the operating part (3) of the cylinder head (1) by additive manufacturing, which involves adding layers to the layers of the cylinder head (1) that begin with the previously manufactured main part (2). A manufacturing method comprising the step of the main part (2) of the cylinder head (1) undergoing heat quenching and aging treatment before commencing the manufacture of the operating part (3) of the cylinder head (1) by additive manufacturing.

15. The manufacturing method according to claim 14, further comprising the step of manufacturing the operating part (3) of the cylinder head (1) by additive manufacturing, and then subjecting the cylinder head (1) to a thermal stress relief treatment.

16. The manufacturing method according to claim 14 or 15, wherein the main part (2) of the cylinder head (1) is manufactured by casting using a first metal alloy, and the operating part (3) of the cylinder head (1) is manufactured by additive manufacturing using a second metal alloy different from the first metal alloy.

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