Method of manufacturing a cylinder head

Abstract

The invention relates to a method of manufacturing a cylinder head. In particular, the invention relates to a method (3) for manufacturing a cylinder head (2) of an internal combustion engine. In the method (3), a prechamber insert (1) having an internal prechamber (4) is pre-manufactured and arranged in the correct position in a cylinder head mold (11). Then, a casting material is filled into the cylinder head mold (11) with the arranged prechamber insert (1), thereby manufacturing a cylinder head (2) for an internal combustion engine with a material-bonded prechamber insert (1). The invention also relates to a cylinder head (2) and a prechamber insert (1).

Description

Technical Field

[0001] This invention relates to a method for manufacturing a cylinder head. The invention also relates to a cylinder head and a pre-combustion chamber insert for the cylinder head. Background Technology

[0002] In an internal combustion engine, fuel is ignited in the combustion chamber by a spark plug located in the cylinder head. Typically, a pre-combustion chamber is also formed in the cylinder head and positioned between the spark plug and the combustion chamber. A portion of the fuel is then ignited in the pre-combustion chamber and injected into the combustion chamber through a nozzle. The remaining fuel in the combustion chamber is then ignited by the injected portion. The pre-combustion chamber requires a complex overall geometry and must be precisely positioned within the cylinder head. Using current manufacturing methods, it is disadvantageous to achieve such a complex geometry. Particularly problematic is the alignment of the individual nozzles, which directly affects ignition in the combustion chamber. Summary of the Invention

[0003] Therefore, the object of the present invention is to provide a method for manufacturing a cylinder head, wherein the aforementioned disadvantages are overcome.

[0004] This objective is achieved through the technical solution of the present invention.

[0005] The general concept upon which this invention is based is to pre-manufacture a pre-combustion chamber for a cylinder head having all the desired internal features, and then cast the pre-combustion chamber into the cylinder head. The method according to the invention provides a method for manufacturing a cylinder head for an internal combustion engine. In this method, a pre-combustion chamber insert having an internal pre-combustion chamber is pre-manufactured and positioned correctly in a cylinder head mold. Thereafter, casting material is filled into the cylinder head mold having the positioned pre-combustion chamber insert, thereby casting a cylinder head for an internal combustion engine with a material-bonded pre-combustion chamber insert.

[0006] In an internal combustion engine, the combustion chamber is not part of the cylinder head, but is partially confined externally by the cylinder head. However, the location of the combustion chamber can be seen on the cylinder head, so refer to the combustion chamber here and thereafter.

[0007] In the method according to the invention, the pre-combustion chamber insert can be manufactured independently of the cylinder head, possessing all the necessary internal and external features. As a result, the pre-combustion chamber can incorporate a construction of virtually any complexity. In particular, the nozzles leading from the pre-combustion chamber to the combustion chamber can be asymmetrical in shape and / or of different sizes and / or shapes. Furthermore, the nozzle orientation can be adjusted as needed. Overall, this improves the ignition of the internal combustion engine. Moreover, the pre-combustion chamber insert is material-bonded to the cylinder head, thereby optimizing heat transfer between the cylinder head and the pre-combustion chamber. As a result, the temperature within the pre-combustion chamber can be better controlled. The method according to the invention is applicable to manufacturing cylinder heads for internal combustion engines with various designs incorporating pre-combustion chambers.

[0008] Advantageously, the pre-combustion chamber insert can be prefabricated using 3D printing. 3D printing can be used for both passive and active applications. Therefore, a usable pre-combustion chamber insert can be manufactured, avoiding further post-processing, such as that required for creating the internal features of the pre-combustion chamber. Furthermore, the nozzles leading from the pre-combustion chamber to the combustion chamber can be asymmetrically formed and / or have different sizes and / or shapes. Additionally, the nozzle orientation can be adjusted as needed using 3D printing. Alternatively, the pre-combustion chamber insert can be prefabricated using casting methods. Regardless of the manufacturing method, the pre-combustion chamber insert can be made of steel or non-ferrous materials.

[0009] In one embodiment of the method, it may be specified that during the pre-manufacturing of the pre-combustion chamber insert, at least one opening closed to the outside by means of a protective region is pre-manufactured. After the pre-combustion chamber insert is material-bonded into the cylinder head, the protective region is removed, and said at least one opening is opened to the outside. The protective region can thus protect the pre-combustion chamber from the penetration of casting material during the casting of the cylinder head.

[0010] For example, the protective region can be manufactured integrally with the pre-combustion chamber insert. Specifically, this can be achieved by manufacturing the pre-combustion chamber insert using 3D printing. Alternatively, the protective region can be manufactured separately from the pre-combustion chamber insert and can be attached to the pre-manufactured pre-combustion chamber insert by material bonding (preferably by welding). In this case, the protective region can be pre-manufactured in the form of a cover. The cover can be made of the same material as the pre-combustion chamber insert or a different material.

[0011] The following lists possible embodiments of at least one opening. In principle, in one or more embodiments, one or more openings may be formed in the pre-combustion chamber insert. Therefore, the embodiments and number of each opening can vary as needed. It should be understood that this list is not exhaustive.

[0012] The at least one opening can be prefabricated as a gas recirculation opening for introducing recirculated exhaust gas. The at least one opening can also be prefabricated as a purge opening for introducing purge air into the pre-combustion chamber. The at least one opening can be prefabricated as a fuel opening for introducing gaseous or alternative auxiliary fuel. To form the above openings, a hole with a valve system can be formed in the pre-combustion chamber insert. The valve system can then allow passive or active introduction of exhaust gas, purge air, or auxiliary fuel. Alternatively or additionally, the at least one opening can be prefabricated as an instrument opening for accommodating at least one additional instrument. Preferably, the at least one instrument can be a temperature sensor and / or a pressure sensor and / or a combustion air ratio sensor. The at least one opening can be prefabricated as a nozzle leading to the combustion chamber at the combustion chamber-facing end of the pre-combustion chamber insert. Therefore, multiple nozzles can be prefabricated, wherein these nozzles can differ from each other in shape and / or size and / or orientation. For example, these nozzles can have different tilt angles relative to the longitudinal central axis of the pre-combustion chamber insert and / or different diameters and / or cylindrical or conical or other shapes. The at least one opening can be pre-fabricated in the form of a spark plug opening at the end of the pre-combustion chamber insert opposite to the combustion chamber. The spark plug can then be inserted into the pre-combustion chamber through the spark plug opening.

[0013] In an advantageous embodiment of the method, it can be specified that filler material is filled into the inner pre-combustion chamber during the pre-manufacturing of the pre-combustion chamber insert. After the pre-combustion chamber insert has been material-bonded into the cylinder head, the filler material is removed from the inner pre-combustion chamber. The filler material can be filled into the pre-combustion chamber during pre-manufacturing, and the pre-combustion chamber can be sealed with the aforementioned protective area. Preferably, the filler material is inert and does not affect the manufacturing of the cylinder head. After removing the corresponding protective area, the filler material can be removed through the at least one opening thereby opened. The filler material can protect the pre-combustion chamber insert from internal pressure during casting, or at least reduce the internal pressure during casting.

[0014] During the pre-manufacturing of the pre-combustion chamber insert, at least one rotationally asymmetrical positioning unit can be manufactured on the outer side of the pre-combustion chamber insert. In this respect, the positioning unit can be manufactured at the combustion chamber-facing end of the pre-combustion chamber insert, or at the combustion chamber-removing end. When the pre-combustion chamber insert is arranged in the cylinder head mold, it can be positioned correctly in the cylinder head mold using the at least one rotationally asymmetrical positioning unit. In particular, it is conceivable to provide at least two positioning units at each end of the pre-combustion chamber insert. Advantageously, the at least one positioning unit can be formed in or as a protective area, and can be removed after the pre-combustion chamber insert has been material-bonded into the cylinder head.

[0015] In an advantageous embodiment of the method, it may be specified that at least one additional element is integrally manufactured onto the pre-combustion chamber insert during the pre-manufacturing of the pre-combustion chamber insert. Possible embodiments of this element are listed below. In principle, the several elements listed below can be combined in the pre-combustion chamber insert as needed. It should be understood that this list is not exhaustive.

[0016] During the pre-manufacturing of the pre-combustion chamber insert, an ignition source retainer for receiving the auxiliary ignition source of the combustion chamber can be integrally manufactured onto the pre-combustion chamber insert. During the pre-manufacturing of the pre-combustion chamber insert, an injector retainer for receiving the fuel injector of the combustion chamber can also be integrally manufactured onto the pre-combustion chamber insert. Furthermore, a cooling channel unit having a passage for cooling guidance can be integrally manufactured onto the pre-combustion chamber insert. During the pre-manufacturing of the pre-combustion chamber insert, a preheating channel unit having a passage for preheating the pre-combustion chamber can also be integrally manufactured onto the pre-combustion chamber insert. In principle, the cooling channel unit and the preheating channel unit can be implemented as a single unit or a combined unit. The cooling channel unit and the preheating channel unit are capable of cooling and preheating the pre-combustion chamber independently of the cylinder head. Furthermore, during the pre-manufacturing of the pre-combustion chamber insert, at least one external retaining unit can be integrally manufactured onto the pre-combustion chamber insert. In this respect, the retaining unit may include multiple retaining elements to enhance retention, i.e., enhance the material bonding of the pre-combustion chamber insert in the cylinder head. Furthermore, during the pre-manufacturing of the pre-combustion chamber insert, the holding unit for holding the electric heating element can also be integrally manufactured on the pre-combustion chamber insert.

[0017] By manufacturing the aforementioned components together with the pre-combustion chamber insert, these components can be tightly coupled to each other. The cooling channel unit and / or preheating channel unit, tightly coupled to the pre-combustion chamber and optionally to other components, can significantly improve the cooling and / or preheating of the pre-combustion chamber and optionally the other components. Furthermore, the need for an external housing for these components is reduced. Overall, the manufacturing of the cylinder head is thus simplified.

[0018] The present invention also relates to a cylinder head for an internal combustion engine, wherein the cylinder head is manufactured by the method described above. The present invention further relates to a pre-combustion chamber insert for a cylinder head of an internal combustion engine, wherein the pre-combustion chamber insert is adapted to be manufactured by the method described above.

[0019] Other important features and advantages of the invention will become apparent from the accompanying drawings and the description thereof.

[0020] It should be understood that, without departing from the scope of the invention, the above features and those that will be explained below can be used not only in the combinations indicated in each case, but also in other combinations or individually. Attached Figure Description

[0021] Preferred embodiments of the invention are shown in the accompanying drawings and will be explained in more detail in the following description, wherein the same reference numerals denote the same or similar or functionally identical parts.

[0022] In each case, the accompanying drawings schematically illustrate: Figure 1 This is a cross-sectional view of the pre-combustion chamber insert according to the present invention; Figure 2 This is a cross-sectional view of the pre-combustion chamber insert with a schematically machined protective area according to the present invention; Figure 3 This is a cross-sectional view of a pre-combustion chamber insert having an additional functional opening for passive purging according to the present invention; Figure 4 This is a cross-sectional view of the pre-combustion chamber insert according to the invention in the nozzle region; Figure 5 This is a view of the combustion chamber in the cylinder head according to the method of the present invention; Figures 6 to 9 It is a partial view of a cylinder head mold with different mold core elements installed; Figure 10 and Figure 11 This is a cross-sectional view of a cylinder head according to the invention on a pre-combustion chamber insert having an additional closely connected pre-combustion chamber and cooling passage unit; Figure 12 This is a view of a pre-combustion chamber insert having an ignition source retainer and an injector retainer according to the present invention; Figure 13 and Figure 14 It is based on the present invention Figure 12 Cross-sectional views of the pre-combustion chamber insert in different cross-sectional planes. Detailed Implementation

[0023] Figure 1 A cross-sectional view of the pre-combustion chamber insert 1 for the cylinder head 2 of an internal combustion engine is shown. Figure 6 The lower core of the cylinder head 2 is shown. In method 3, the pre-combustion chamber insert 1 is pre-manufactured and cast into the cylinder head 2, thereby integrating it into the cylinder head 2 in a material bonding manner. The pre-combustion chamber insert 1 can be pre-manufactured, for example, by 3D printing or casting. The pre-combustion chamber insert 1 includes an inner pre-combustion chamber 4 and two ends 1a and 1b opposite each other relative to the longitudinal central axis LA of the pre-combustion chamber insert 1. If the pre-combustion chamber insert 1 is cast into the cylinder head 2 (see...), Figure 10 and Figure 11 The first end 1a faces the combustion chamber and the second end 1b faces away from the combustion chamber.

[0024] At the first end 1a of the pre-combustion chamber insert 1, a plurality of openings 5 ​​are formed in the form of nozzles 6. Each nozzle 6 points outward from the pre-combustion chamber 4 towards the combustion chamber. At the second end 2a, the openings 5 ​​are formed in the form of spark plug openings 7. The spark plug openings 7 are used to insert a spark plug into the pre-combustion chamber 4. Figure 1 In method 3, the two openings 5 ​​are respectively closed by the protected area 8. After the pre-combustion chamber insert 1 has been material-bonded into the cylinder head 2, the protected area 8 is removed. Therefore, the openings 5 ​​are exposed to the outside.

[0025] Positioning units 15 are also formed on each end 1a and 1b of the pre-combustion chamber insert 1. With the aid of positioning units 15, the pre-combustion chamber insert 1 can be positioned correctly in the cylinder head 2. Therefore, positioning units 15 are part of the corresponding protected area 8 in each case, and are also removed when the corresponding protected area 8 is removed.

[0026] Figure 2 A cross-sectional view of the pre-combustion chamber insert 1 according to the present invention is shown. Figure 2 In the image, the cutting line used to remove protected area 8 is marked separately with a solid line.

[0027] Figure 3 A cross-sectional view of the pre-combustion chamber insert 1 with another opening 5 according to the present invention is shown. Here, the other opening 5 may be a purge opening 9a for introducing purge air, or a gas recirculation opening 9b for introducing recirculated exhaust gas, or a fuel opening 9c for introducing gaseous or alternative auxiliary fuel into the pre-combustion chamber 4. A valve system in the form of a check valve 10 is also provided at the opening 5.

[0028] Figure 4 A cross-sectional view of the pre-combustion chamber insert 1 according to the invention is shown in the region of the nozzle 6. The protective region 8 has been removed here, and the nozzle 6 is exposed to the outside. The nozzle 6 of the pre-combustion chamber insert 1 may vary in shape, size, and orientation.

[0029] Figure 5 A view of a cylinder head mold 11 for use in method 3 according to the invention is shown. According to method 3, a pre-manufactured pre-combustion chamber insert 1 is positioned correctly in the cylinder head mold 11. Casting material is then poured into the cylinder head mold 11, thereby casting a cylinder head 2 with the pre-combustion chamber insert 1 material-bonded. The aforementioned protective region 8 protects the pre-combustion chamber 4 from penetration by the casting material and is removed after the pre-combustion chamber insert 1 has been material-bonded into the cylinder head 2.

[0030] Figures 6 to 9 A partial view of the cylinder head mold 11 is shown. Figure 6The cylinder head mold 11 is shown, in which the pre-combustion chamber insert 1 is arranged in the correct position. Figure 7 A cylinder head mold 11 with a water jacket core 12 is shown. Figure 8 A cylinder head mold 11 with an intake core 13 and an exhaust core 14 is shown. Figure 9 A cylinder head mold 11 is shown, in which the various components are aligned with each other, in particular by means of a positioning unit 15.

[0031] Figure 10 A cross-sectional view of the cylinder head 2 according to the invention on the pre-combustion chamber insert 1 is shown. Figure 11 Another cross-sectional view of the cylinder head 2 on the pre-combustion chamber insert 1 in an off-plane is shown. Here, the cylinder head 2 includes a water jacket 12a formed therein by a water jacket core 12, and the pre-combustion chamber insert 1 includes a cooling channel unit 16 formed therein. Therefore, the cylinder head 2 and the pre-combustion chamber 4 can be effectively cooled. The cooling channel unit 16 is arranged very close to the pre-combustion chamber 4 of the pre-combustion chamber insert 1, so that the temperature in the pre-combustion chamber 4 can be better maintained. In addition, the walls of the cooling channel unit 16 can be smaller, thereby enhancing the heat transfer between the cooling channel unit 16 and the cylinder head 2.

[0032] Figure 12 A view of the pre-combustion chamber insert 1 according to the invention is shown. Here, the ignition source retainer 17 and the injector retainer 18 are integrally formed on the pre-combustion chamber insert 1. Here, the ignition source retainer 17 includes an internal receiving space and is provided for receiving an auxiliary ignition source (e.g., another spark plug) for the combustion chamber. The injector retainer 18 similarly includes a receiving space and is provided for receiving a fuel injector for the combustion chamber.

[0033] The receiving space in the ignition source retainer 17, the receiving space in the injector retainer 18, the nozzle 6 at the first end 1a, and the spark plug opening 7 at the second end 1b are sealed by the protective area 8, thereby preventing the penetration of casting material during the casting of the cylinder head 2. After casting, the protective area 8 is removed, and the receiving space, as well as the nozzle 6 and spark plug opening 7, are exposed, i.e., open to the outside. The pre-combustion chamber insert 1 can be filled with filler material here to withstand internal pressure during the casting of the cylinder head 2.

[0034] Figure 13 It shows Figure 12 The cross-sectional view of the pre-combustion chamber insert 1 is shown. Figure 14 It shows Figure 12 Another cross-sectional view of the pre-combustion chamber insert 1 shown. (As in...) Figure 13 and Figure 14 As can be seen particularly clearly, the cooling channel unit 16 extends around the pre-combustion chamber insert 1, thereby improving the cooling of the pre-combustion chamber insert 1.

Claims

1. A method (3) for manufacturing a cylinder head (2) for an internal combustion engine. - The pre-combustion chamber insert (1) with an internal pre-combustion chamber (4) is pre-manufactured and arranged in the correct position in the cylinder head mold (11); - Wherein casting material is filled into the cylinder head mold (11) having a pre-combustion chamber insert (1) arranged thereon, thereby casting the cylinder head (2) for the internal combustion engine having a pre-combustion chamber insert (1) with material bonding. in - During the pre-manufacturing of the pre-combustion chamber insert (1), at least one opening (5) is pre-manufactured, wherein, The at least one opening (5) is closed relative to the outside through the protective area (8); - After the pre-combustion chamber insert (1) material is incorporated into the cylinder head (2), the protective area (8) is removed, and the at least one opening (5) is opened to the outside.

2. The method according to claim 1, Its features are, The pre-combustion chamber insert (1) is pre-manufactured by 3D printing or casting.

3. The method according to claim 1 or 2, Its features are, - The protected area (8) is integrally manufactured with the pre-combustion chamber insert (1); and / or - The protective area (8) is manufactured separately from the pre-combustion chamber insert (1), and the protective area (8) is fastened to the pre-manufactured pre-combustion chamber insert (1) by material bonding.

4. The method according to claim 1 or 2, Its features are, - The at least one opening (5) is pre-formed in the form of a nozzle (6) leading to the combustion chamber at the combustion chamber-facing end (1a) of the pre-combustion chamber insert (1); and / or - The at least one opening (5) is pre-formed in the form of a spark plug opening (7) at the end (1b) of the pre-combustion chamber insert (1) opposite to the combustion chamber; and / or - The at least one opening (5) is prefabricated in the form of a purge opening (9a) for introducing purge air; and / or - The at least one opening (5) is prefabricated in the form of a gas recirculation opening (9b) for introducing recirculated exhaust gas; and / or - The at least one opening (5) is prefabricated in the form of a fuel opening (9c) for introducing gaseous or alternative auxiliary fuel; and / or - The at least one opening (5) is prefabricated in the form of an instrument opening for arranging at least one additional instrument.

5. The method according to claim 1 or 2, Its features are, - During the pre-manufacturing of the pre-combustion chamber insert (1), filler material is filled into the inner pre-combustion chamber (4), and - After the pre-combustion chamber insert (1) material is incorporated into the cylinder head (2), the filling material is removed from the internal pre-combustion chamber (4).

6. The method according to claim 1 or 2, Its features are, - During the pre-manufacturing of the pre-combustion chamber insert (1), at least one rotationally asymmetrical positioning unit (15) is manufactured on the outside of the pre-combustion chamber insert (1) on the end (1a) of the pre-combustion chamber insert (1) facing the combustion chamber or on the end (1b) of the pre-combustion chamber insert (1) facing away from the combustion chamber; and - When the pre-combustion chamber insert (1) is arranged in the cylinder head mold (11), the pre-combustion chamber insert (1) is positioned in the correct position in the cylinder head mold (11) by the at least one rotationally asymmetrical positioning unit (15).

7. The method according to claim 6, Its features are, The at least one positioning unit is formed in or as the protective area (8), and is removed after the pre-combustion chamber insert (1) has been materially bonded to the cylinder head (2).

8. The method according to claim 1 or 2, Its features are, - During the pre-manufacturing of the pre-combustion chamber insert (1), an ignition source retainer (17) is integrally manufactured on the pre-combustion chamber insert (1), the ignition source retainer (17) being used to receive an auxiliary ignition source for the combustion chamber; and / or - During the pre-manufacturing of the pre-combustion chamber insert (1), an injector retainer (18) is integrally manufactured on the pre-combustion chamber insert (1) for receiving fuel injectors for the combustion chamber; and / or - During the pre-manufacturing of the pre-combustion chamber insert (1), a cooling channel unit (16) is integrally manufactured on the pre-combustion chamber insert (1), the cooling channel unit (16) having channels for cooling guidance; and / or - During the pre-manufacturing of the pre-combustion chamber insert (1), a preheating channel unit is integrally manufactured on the pre-combustion chamber insert (1), the preheating channel unit having a channel for preheating the pre-combustion chamber; And / or - During the pre-manufacturing of the pre-combustion chamber insert (1), at least one external retaining unit is integrally manufactured on the pre-combustion chamber insert (1); and / or - During the pre-manufacturing of the pre-combustion chamber insert (1), a retaining unit is integrally manufactured on the pre-combustion chamber insert (1) for retaining the electric heating element.

9. The method according to claim 1 or 2, Its features are, During the pre-manufacturing of the pre-combustion chamber insert (1), the fuel injector seal is arranged in the inner pre-combustion chamber (4).

10. A cylinder head (2) for an internal combustion engine, wherein, The cylinder head (2) is manufactured by the method (3) according to any one of claims 1 to 9.

11. A pre-combustion chamber insert (1) for a cylinder head (2) of an internal combustion engine, wherein, The pre-combustion chamber insert (1) is adapted to produce the cylinder head (2) by the method (3) according to any one of claims 1 to 9.

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