Engine package and cylinder head

Abstract

The invention relates to a core package (1) for casting a cylinder head (2) of an internal combustion engine, comprising a bottom core (3) that defines a bottom surface (11) of the cylinder head (2), a top core (4) that defines a top surface (12) of the cylinder head (2), at least one intake-side outer core (5) that defines at least one section (13) of an intake-side outer surface (14) of the cylinder head (2), at least one exhaust-side outer core (6) that defines at least one section (15) of an exhaust-side outer surface (16) of the cylinder head (2), several intake-side channel cores (7) that define intake channels (28) of the cylinder head (2), several exhaust-side channel cores (8) that define exhaust channels (29) of the cylinder head (2), a cavity core (9) that defines cavities (17) of the cylinder head (2), and at least one water core (10) that defines cooling channels. (18) of the cylinder head (2) limited.Improved manufacturability results when the cavity core (9), the inlet-side outer core (5) and the outlet-side outer core (6) are combined to form a single, connected, one-piece cavity core body (19).

Description

The present invention relates to a core stack for casting a cylinder head of an internal combustion engine according to the preamble of claim 1.A generic core package is known from KR 2009 0 025 656 A and comprises a base core which delimits an underside of the cylinder head, a cover core which delimits an upper side of the cylinder head, at least one inlet-side outer core which delimits at least a portion of an inlet-side outer side of the cylinder head, at least one outlet-side outer core which delimits at least a portion of an outlet-side outer side of the cylinder head, a plurality of inlet-side duct cores which delimit inlet ducts of the cylinder head, a plurality of outlet-side duct cores which delimit outlet ducts of the cylinder head, a cavity core which delimits cavities of the cylinder head, and at least one water core which delimits cooling ducts of the cylinder head. In the known core package, the hollow core is arranged completely between the inlet-side outer core and the outlet-side outer core and forms a separate component in this respect. For proper positioning of the hollow core within the core package, it is therefore usually necessary to fix the hollow core to the cover core, which requires an additional working step. In addition, the manufacturing tolerances of the different cores add up to form a tolerance chain, which has to be compensated for in particular at the transition between the cavities and the cooling channels with large wall thicknesses. Moreover, these completely internal cavities form a comparatively large dead volume for oil which can pass into the cavities of the cylinder head during the operation of a vehicle whose internal combustion engine is equipped with such a cylinder head. However, the cavities are required to avoid large masses in the cylinder head.EP 0 958 076 B1 discloses a one-piece core for producing a cylinder head, wherein hollow spaces are produced by the core for forming inlet lines, outlet lines and water chambers or oil lines.EP 0 280 675 A2 discloses a casting mold for producing a crankcase, in which a plurality of cavities for different channels are produced by a base core.EP 3 925 718 A1 discloses a method for producing cylinder heads.DE 197 35 012 C1 discloses a casting mold for producing a cylinder head, in which a sand core is placed in the casting mold in order to form a water chamber.The present invention is concerned with the problem of specifying an improved embodiment for a core package of the type described above or for a cylinder head produced therewith, which embodiment is distinguished in particular by improved tolerances. It is also intended to reduce the possibility that oil will collect in the cavities during operation of the internal combustion engine.This problem is solved according to the invention by the subject matter of the independent claim. Formula embodiments are the subject of the dependent claims.The invention is based on the general idea of combining the cavity core, the inlet-side outer core and the outlet-side outer core into a single coherent, one-piece cavity core body. Thus, three individual components of a conventional core package are combined to form a single component of the core package according to the invention, which considerably improves the tolerance chain. Furthermore, the positioning of the hollow core in the interior of the core package is simplified as a result, so that it is no longer necessary, for example, to fix the hollow core to the cover core. The improved tolerance chain enables narrower tolerances in the region between the cavity core and the water core, so that smaller wall thicknesses can be realized there between the cavities and the cooling channels. This allows material and weight to be saved. Furthermore, sealing measures between the upper side of the cylinder head and the cavities are also dispensed with.Since the one-piece cavity core body extends from the inlet-side outer core via the cavity core to the outlet-side outer core, the cavity core body also shapes the inlet-side and outlet-side outer sides of the crankcase. As a result, the cavities can be designed open on the inlet side and on the outlet side to the environment of the cylinder head, which on the one hand simplifies the cleaning of the cylinder head after the casting process. On the other hand, more surface is available for radiating heat into the environment, which in particular promotes cooling of the cylinder head during operation of the internal combustion engine.According to an advantageous embodiment, the core package can have two inlet-side outer cores, namely a lower inlet-side outer core which adjoins the bottom core and an upper inlet-side outer core which adjoins the cover core and the lower inlet-side outer core. It can now be expediently provided that the upper inlet-side outer core forms a component of the one-piece hollow core body. The lower inlet-side outer core can still form a separate component of the core package.It can now be expediently provided that the respective inlet-side channel core is positively held between the upper inlet-side outer core and the lower inlet-side outer core, which simplifies the cohesion of the core package for the casting process.Additionally or alternatively, the core package can have two outlet-side outer cores, namely a lower outlet-side outer core which adjoins the bottom core and an upper outlet-side outer core which adjoins the cover core and the lower outlet-side outer core. It can now also be expediently provided here that the upper outlet-side outer core forms a component of the one-piece cavity core body. The lower outlet-side outer core can still form a separate component of the core package. The one-piece configuration of the cavity core with the upper inlet-side outer core and / or with the upper outlet-side outer core simplifies the connection of the one-piece cavity core body to the cover core.It can now be expediently provided that the respective outlet-side channel core is positively held between the upper outlet-side outer core and the lower outlet-side outer core, which simplifies the cohesion of the core package for the casting process.An embodiment is preferred in which the one-piece cavity core body comprises the cavity core, the upper inlet-side outer core and the upper outlet-side outer core.An embodiment is expedient in which the cavities formed with the cavity core body in the cylinder head are open to the surroundings of the cylinder head. The cavities open to the environment no longer have to be charged with lubricating oil, so that they cannot form a dead volume for lubricating oil. Furthermore, the open cavities simplify the cleaning of the cylinder head after the casting process. Likewise, the cavities which are open at the side during operation of the internal combustion engine improve the heat radiation into the environment.According to another embodiment, the cavity core body may be configured to form pillars in the cylinder head that connect a lower portion of the cylinder head configured to connect the cylinder head to an engine block of the internal combustion engine to an upper portion of the cylinder head configured to receive camshafts, particularly for controlling gas exchange valves. With the aid of this one-piece hollow core body, the cylinder head can thus be constructed in a simplified manner, wherein in particular a comparatively large amount of material can be saved, which reduces the costs and the weight of the cylinder head.In the present context, a "configuration" is synonymous with a "configuration" such that the phrase "configured such that" is synonymous with the phrase "configured such that.".According to an advantageous embodiment, the core package can also have a transmission-side outer core which delimits a transmission-side outer side of the cylinder head. An embodiment is now particularly advantageous in which the transmission-side outer core forms a further component of the one-piece hollow-space core body. Accordingly, the transmission-side outer core, the cavity core and the two outer cores are then combined to form the one-piece, contiguous cavity core body. Accordingly, a further separate component within the core package can be dispensed with, which additionally improves the tolerance chain.The core package can also have a further outer core, which delimits an end face of the cylinder head facing away from the transmission-side outer side of the cylinder head. This further outer core can be formed within the core package by a separate core. It is likewise conceivable to integrate this further outer core at least partially into the cover core and / or at least partially into the base core, so that this further outer core is formed at least partially integrally on the cover core and / or at least partially integrally on the base core. It can also be provided particularly advantageously that a section of this further outer core is formed integrally on the hollow core body.The one-piece cavity core body may be made of a single blank, for example. Alternatively, it is also conceivable that the one-piece hollow core body is formed by a single molded sand part.A cylinder head according to the invention, which is suitable for an internal combustion engine, comprises a lower side for connecting the cylinder head to an engine block of the internal combustion engine, an upper side for receiving camshafts, an inlet-side outer side, an outlet-side outer side, a plurality of inlet ducts open on the inlet-side outer side for supplying fresh air to cylinders of the internal combustion engine, a plurality of outlet ducts for removing exhaust gas from the cylinders, a plurality of cavities and a plurality of cooling ducts. The cylinder head according to the invention is characterized in that the cavities on the inlet-side outer side and on the outlet-side outer side are open to the surroundings of the cylinder head. This results in the advantages already described above, namely in particular a reduced dead volume for lubricating oil and improved cooling during operation and simplified cleaning after the casting process.Further important features and advantages of the invention are evident from the dependent claims, from the drawings and from the associated description of the figures with reference to the drawings.It is understood that the features mentioned above and those still to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the invention as defined by the claims. The above-mentioned components of a superordinate unit, such as a device, a device or an arrangement, which are designated separately, can form separate components or components of this unit or can be integral regions or sections of this unit, even if this is illustrated differently in the drawings.Preferred exemplary embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally the same components.They show, in each case schematically, FIG. 1 is a greatly simplified sectional view of a core package, FIG. 2 is an isometric view of a cavity core body, FIG. 3 is an isometric view of a cylinder head as a blank, FIG. 4 is an isometric view of the cylinder head as a finished part, FIG. 5 is an isometric sectional view of the cylinder head in the region of cavities.According to FIG. 1, a core package 1, which is used for casting, in particular for sand casting, a cylinder head 2 of an internal combustion engine, comprises a base core 3, a cover core 4, at least one inlet-side outer core 5, at least one outlet-side outer core 6, a plurality of inlet-side duct cores 7, a plurality of outlet-side duct cores 8, a hollow core 9 and at least one water core 10. The core package 1 forms a casting mold for casting the crankcase 2. the bottom core 3 serves to delimit a bottom side 11 of the cylinder head 2. the cover core 4 serves to delimit an upper side 12 of the cylinder head 2. the respective inlet-side outer core 5 serves to delimit at least one section 13 of an inlet-side outer side 14 of the cylinder head 2. the respective outlet-side outer core 6 serves to delimit at least one section 15 of an outlet-side outer side 16 of the cylinder head. The inlet-side duct cores 7 each delimit an inlet duct 28 in the cylinder head 2. the outlet-side duct cores 8 each delimit an outlet duct 29 in the cylinder head 2. the cavity core 9 delimits cavities 17 in the cylinder head 2 and the respective water core 10 delimits at least one cooling duct 18 in the cylinder head 2.In the core package presented here, two inlet-side outer cores 5 are provided, namely a lower inlet-side outer core 5 uwhich connects to the bottom core 3 and an upper inlet-side outer core 5 owhich connects to the cover core 4 and to the lower inlet-side outer core 5 u. The lower intake-side outer core 5 udefines a lower portion 13 uof the intake-side outer side 14 of the cylinder head 2. the upper intake-side outer core 5 odefines an upper portion 13 oof the intake-side outer side 14. The lower outlet-side outer core 6 uconnects to the bottom core 3. The upper outlet-side outer core 6 oconnects to the cover core 4 and to the lower outlet-side outer core 6 u.In the core package 1 presented here, the cavity core 9, the upper inlet-side outer core 5 oand the upper outlet-side outer core 6 oform a single continuous, one-piece cavity core body 19. This environment 20 can be seen in FIGS. 3 to 5.The cavity core body 19 may be made from a single blank. It is likewise conceivable to form the hollow core body 19 by a single molded sand part.According to the embodiment shown in FIG. 2, the hollow core body 19 can also comprise a transmission-side outer core 21 which delimits a transmission-side outer side 22 of the cylinder head 2 that can be seen in FIGS. 3 to 5. Furthermore, according to FIG. 2, the one-piece hollow core body 19 can have a section 23 of a further outer core, which delimits a section of an end face 24, which can be seen in FIGS. 3 to 5, of the cylinder head 2 which is situated opposite the transmission-side outer side 22. Other sections of this further outer core can form separate components of the core package 1 or can be integrated at least partially into the cover core 4 and / or into the bottom core 3 and / or into the lower outer cores 5 uand 6 u.FIG. 3 shows the cylinder head 2 after the casting process, i.e. as a blank. FIG. 4 shows the cylinder head 2 after its machining and finishing, i.e. as a finished part. For example, the bearing points for camshafts and the like can be seen. In the sectional view of FIG. 5, a plurality of cavities 17 can be seen, which are formed on the cylinder head 2 with the aid of the cavity core body 19 presented here or with the core package 1 shown here. These cavities 17 are open to the environment 20, which simplifies the cleaning of the blank.The cavity core body 19 may also be configured to form pillars 25 in the cylinder head 2 of FIG. 5 that connect a lower portion 26 of the cylinder head 2 to an upper portion 27 of the cylinder head 2. The lower part 26 of the cylinder head 2 serves to connect the cylinder head 2 to an engine block of the internal combustion engine. The upper part 27 of the cylinder head 2 serves for receiving camshafts, which are not shown here and which serve in the usual manner for controlling gas exchange valves, likewise not shown.

Claims

Core package (1) for casting a cylinder head (2) of an internal combustion engine, - with a base core (3) which delimits an underside (11) of the cylinder head (2), - with a cover core (4) which delimits an upper side (12) of the cylinder head (2), - with a plurality of inlet-side duct cores (7) which delimit inlet ducts (28) of the cylinder head (2), - with a plurality of outlet-side duct cores (8) which delimit outlet ducts (29) of the cylinder head (2), - with at least one water core (10) which delimits cooling ducts (18) of the cylinder head (2), characterized in that - a cavity core (9) which delimits cavities (17) of the cylinder head (2), an inlet-side outer core (5) which delimits at least a section (13) of an inlet-side outer side (14) of the cylinder head (2), and an outlet-side outer core (6) which delimits at least one section (15) of an outlet-side outer side (16) of the cylinder head (2), are combined to form a single continuous, one-piece cavity core body (19).Core package (1) according to Claim 1, characterized - in that the core package (1) has two inlet-side outer cores (5), namely a lower inlet-side outer core (5u) which adjoins the base core (3) and an upper inlet-side outer core (5o) which adjoins the cover core (4) and the lower inlet-side outer core (5u), - in that the upper inlet-side outer core (5o) forms a constituent part of the one-piece cavity core body (19).Core package (1) according to Claim 1 or 2, characterized - in that the core package (1) has two outlet-side outer cores (6), namely a lower outlet-side outer core (6u) which adjoins the base core (3) and an upper outlet-side outer core (6o) which adjoins the cover core (4) and the lower outlet-side outer core (6u), - in that the upper outlet-side outer core (6o) forms a constituent part of the one-piece cavity core body (19).Core package (1) according to claims 2 and 3, characterised in - that the cavity core, the upper inlet-side outer core (5o) and the upper outlet-side outer core (6o) are combined to form the one-piece, contiguous cavity core body (19).Core package (1) according to one of the preceding claims, characterized - in that the cavities (17) formed in the cylinder head (2) with the cavity core body (19) are open to the surroundings (20) of the cylinder head (2).Core package (1) according to any of the preceding claims, characterized in - that the cavity core body (19) is configured to form pillars (25) in the cylinder head (2) connecting a lower part of the cylinder head (26) configured for connecting the cylinder head (2) to an engine block of the internal combustion engine to an upper part (27) of the cylinder head (2) configured for receiving camshafts.Core package (1) according to one of the preceding claims, characterized - in that the core package (1) additionally has a transmission-side outer core (21) which delimits a transmission-side outer side (22) of the cylinder head (2), - in that the transmission-side outer core (21) forms a constituent part of the one-piece cavity core body (19).Core package (1) according to one of the preceding claims, characterized - in that the one-piece hollow core body (19) is produced from a single blank.Core package (1) according to one of Claims 1 to 7, characterized - in that the one-piece hollow-space core body (19) is formed by a single sand moulding.A cylinder head (2) for an internal combustion engine, the cylinder head (2) being manufactured with the core stack (1) according to any of the preceding claims, such that the cylinder head (2) comprises: - a bottom side (11) for connecting the cylinder head (2) to an engine block of the internal combustion engine, - a top side (12) for receiving camshafts, - an inlet-side outer side (14), - an outlet-side outer side (16), - a plurality of inlet ducts (28) open on the inlet-side outer side (14) for supplying fresh air to cylinders of the internal combustion engine, - a plurality of outlet ducts (19) for discharging exhaust gas from the cylinders, - a plurality of cavities (17), - a plurality of cooling ducts (18), - wherein the cavities (17) are open on the inlet-side outer side (14) and on the outlet-side outer side (16) to an environment (20) of the cylinder head (2).

Images