Cylinder head with integrated turbocharger
11692505 · 2023-07-04
Assignee
Inventors
- Michael P Schmidt (Highland, MI, US)
- Douglas Trudeau (Lake Orion, MI, US)
- Constantin Hagiu (Windsor, CA)
- Brian Jacobs (Romeo, MI, US)
Cpc classification
F01N13/10
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F02F1/243
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01M13/028
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F02M35/10144
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F02F1/36
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Y02T10/12
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
F01M2013/027
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F02F1/24
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N13/008
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F02M35/10157
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F02B37/183
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Y02T10/40
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
F02F2200/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F02F1/4264
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F02F1/40
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F02M35/10222
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F02F1/42
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01M13/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N13/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01N13/10
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F02B37/18
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F02F1/36
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A cylinder head assembly includes a cast cylinder head and a turbocharger housing integrally cast with the cylinder head. The integrated cylinder head and turbocharger housing includes: (i) a compact low wetted area to provide an uninterrupted flow path pointed directly at a catalyst face to facilitate achieving cold start emissions targets, (ii) a casting core assembly with specific core geometry and steps for assembly to enable core assembly while meeting all cylinder head and integrated turbine housing functional requirements, (iii) an oxygen sensor disposed pre-turbine in an integrated exhaust manifold, and (iv) a fully integrated PCV make-up air system.
Claims
1. A cylinder head assembly for an internal combustion engine, comprising: a cast cylinder head; and a turbocharger housing integrally cast with the cylinder head, wherein the integrally cast cylinder head and turbocharger housing comprises: a turbine inlet duct configured to receive exhaust gas from an integrated exhaust manifold and direct exhaust gas to a turbine disposed within the turbocharger housing; a wastegate inlet duct configured to receive exhaust gas from the exhaust manifold and bypass exhaust gas around the turbine; a fully integrated PCV make-up air system configured to supply make-up air to the cylinder head for positive crankcase ventilation; and a compressor inlet shroud coupled to the turbocharger housing, wherein the integrated PCV make-up air system is integrated into the compressor inlet shroud and the turbocharger housing.
2. The cylinder head assembly of claim 1, wherein the PCV make-up air system includes an MUA passage having a first passage formed in the compressor inlet shroud, and a second passage formed in the turbocharger housing.
3. The cylinder head assembly of claim 1, where the PCV make-up air system does not have an external connection for the make-up air.
4. A cylinder head assembly for an internal combustion engine, comprising: a cast cylinder head; and a turbocharger housing integrally cast with the cylinder head, wherein the integrally cast cylinder head and turbocharger housing comprises: a compact low wetted area to provide an uninterrupted flow path pointed directly at a catalyst face to facilitate achieving cold start emissions targets.
5. The cylinder head assembly of claim 4, further comprising an oxygen sensor disposed at least partially within an integrated exhaust manifold and configured to sense an oxygen content of exhaust gas flowing through a turbine inlet duct and/or a wastegate inlet duct.
6. The cylinder head assembly of claim 5, further comprising a water jacket cast into the integrally cast cylinder head and turbocharger housing, wherein the water jacket is configured to cool the oxygen sensor so as to enable placement of the oxygen sensor at least partially within the integrated exhaust manifold.
7. The cylinder head assembly of claim 5, wherein the oxygen sensor is configured to be utilized pre-turbine in full Lambda 1 engine operation.
8. The cylinder head assembly of claim 5, further comprising an oxygen sensor port formed in a collector of the integrated exhaust manifold, wherein the oxygen sensor is disposed in the oxygen sensor port upstream of both the turbine inlet duct and the wastegate inlet duct.
9. The cylinder head assembly of claim 4, further comprising a core assembly system for forming the cylinder head assembly, the system comprising: a turbo top core; a top core; an oil gallery core; an upper water jacket core; an intake scroll core; an exhaust port core; an exhaust side core; an intake port core; an intake side core; and a lower water jacket core.
10. A method of forming the cylinder head assembly of claim 7 with the core assembly system, the method comprising: coupling the intake scroll core to the exhaust port core; and coupling the exhaust side core to the exhaust port core.
11. The method of claim 10, further comprising: providing the lower water jacket core; subsequently placing the intake side core with the lower water jacket core; placing the intake port core at least partially into the intake side core and the lower water jacket core; and lowering the joined intake scroll core, exhaust port core, and exhaust side core into the water jacket core, thereby allowing a hyper-elliptical shaped volute core to pass by the lower water jacket core and upper water jacket core during assembly to allow the location of a water jacket to be close to an exhaust volute for cooling thereof.
12. The method of claim 10, further comprising: positioning the lower water jacket core; assembling the exhaust port core; positioning the exhaust port core by placing a chamber end into the lower water jacket, and lowering the exhaust port core such that an exhaust port volute passes by the lower water jacket core; and positioning the upper water jacket core such that it passes by the exhaust port volute.
13. The cylinder head assembly of claim 4, further comprising a fully integrated PCV make-up air system configured to supply make-up air to the cylinder head for positive crankcase ventilation.
14. The cylinder head assembly of claim 4, wherein the turbocharger housing further includes a wastegate housing defining a wastegate passage and a valve seat with a wastegate inlet.
15. The cylinder head assembly of claim 14, further comprising a wastegate system coupled to the turbocharger housing and having a wastegate valve assembly and a wastegate valve actuator assembly.
16. The cylinder head assembly of claim 15, wherein the wastegate valve actuator assembly is a direct drive actuator configured to open the wastegate valve assembly such that a wastegate valve is completely out of the wastegate flow path through the wastegate inlet such that the exhaust flow can be flowed directly onto the catalyst face.
17. The cylinder head assembly of claim 16, wherein the wastegate valve is rotated from a sealed position over the wastegate inlet to greater than 90° to be completely out of the wastegate flow path.
18. The cylinder head assembly of claim 16, wherein the wastegate valve is further rotated to at least 90° from the sealed position to increase wastegate flow by blocking exducer flow of a turbine wheel rotatably disposed within the turbocharger housing with a backside of the wastegate valve.
19. The cylinder head assembly of claim 4, further comprising; an integrated exhaust manifold; a turbine inlet duct configured to receive exhaust gas from the exhaust manifold and direct exhaust gas to a turbine disposed within the turbocharger housing; a wastegate inlet duct configured to receive exhaust gas from the exhaust manifold and bypass exhaust gas around the turbine; and an oxygen sensor disposed at least partially within the exhaust manifold and configured to sense an oxygen content of the exhaust gas flowing through the turbine inlet duct and/or the wastegate inlet duct.
20. A cylinder head assembly for an internal combustion engine, comprising: a cast cylinder head; and a turbocharger housing integrally cast with the cylinder head, wherein the integrally cast cylinder head and turbocharger housing comprises: (i) a compact low wetted area to provide an uninterrupted flow path pointed directly at a catalyst face to facilitate achieving cold start emissions targets, (ii) a casting core assembly wherein an intake scroll core is coupled to an exhaust port core and an exhaust side core is coupled to the exhaust port core, (iii) an oxygen sensor disposed pre-turbine at least partially within an integrated exhaust manifold, (iv) a fully integrated PCV make-up air system, (v) a water jacket cast into the integrally cast cylinder head and turbocharger housing, wherein the water jacket is configured to cool the oxygen sensor so as to enable placement of the oxygen sensor at least partially within the integrated exhaust manifold, and (vi) a wastegate housing defining a wastegate passage and a valve seat with a wastegate inlet.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION
(14) Described herein are systems and methods for integrally casting features or components into the cylinder head of an internal combustion engine. Typically, an internal combustion engine is a compact mix of hardware often required to fit in very tight underhood spaces. When components with high mass and density, such as turbocharger systems, are bolted externally to an engine, the resulting structure can potentially affect NVH, dynamics, packaging, decking, durability, etc.
(15) In order to reduce or prevent such issues in the present disclosure, the turbocharger housing is integrated (e.g., cast) into an aluminum cylinder head, which is advantageously configured to reduce engine cost, improve packaging, simplify assembly, reduce number of assembly steps, improve catalyst light off emissions, reduce turbocharger noise (e.g., wastegate resonances, flow noise, rotor group unbalance whine, etc.), improve engine warm up, and improve fuel economy.
(16) Further, the disclosed system is optimized for cold start emissions, CARB compliance, and water cooling. One potential issue with water-cooled turbochargers is the potential loss of enthalpy to the cooling system, which can impact thermodynamic performance as well as cold start catalyst light off. However, the disclosed design includes a reverse rotating turbocharger with a wastegate position to direct the exhaust flow directly on the exhaust catalyst brick face, thereby significantly improving catalyst light off.
(17) Further, traditional turbocharger housings are made of steel, which convects heat from the hot exhaust gasses to the ambient air. The steel mechanical properties are such that it achieves the required durability. Since in some examples of the present disclosure the turbocharger housing is integrated into an aluminum cylinder head, in order to maintain durability, water cooling passages and water flow rates are provided to properly maintain the aluminum material within temperatures that allow its strength to achieve the required durability. Thus, the water jacket is optimized to keep the metal temperature below the target value at any point in the turbine housing.
(18) In one specific example, the water cooling passages maintain a turbine tongue of the turbocharger below a predetermined temperature to ensure no cylinder head cracks propagate to the water jacket. This is accomplished by providing a turbine housing layout that allows the coolant as close as possible to the tongue to enable adequate cooling while still manufacturing with conventional sand cast methods. In the example, the turbine housing is designed with a hyper-elliptical volute shape “squashing” to allow the volute core to pass by the water jacket cores during assembly. This provides a desired rectangular cross-sectional shape of the exhaust volute at the closes point of core pass-by to each the upper and lower water jacket
(19) In some examples, the disclosed design is configured to cool the turbocharger housing's aluminum exhaust passages by providing turbocharger housing water jackets. The water jackets include an upper and lower water jacket connected at multiple points including cup plugs and drilled holes. In one example, coolant from the block water jacket is metered by the head gasket into the cylinder head lower water jacket at both the intake and exhaust valve bridges. Water flow streams merge above the combustion chambers, and subsequently flow below the integrated exhaust port passages toward the integrated turbine housing.
(20) The upper water jacket flows in parallel and receives water from the lower water jacket directly above the combustion chambers. The upper water jacket flows coolant around the exhaust valve guides, over the integrated exhaust port passages, and then above the integrated turbine housing. After wrapping around the turbine housing, the water jacket flow streams merge together to form a common water outlet, high in elevation to prevent trapping air during operation. The coolant flow targets critical areas of the turbine (e.g., volute, tongue, wastegate), yet is selective in are areas to limit the overall heat rejection of the system. In this way, the water flow passages above and below the turbine housing minimize heat rejection, achieve water velocity and metal temperature targets, and achieve structural targets for low cycle fatigue.
(21) In additional examples of the present disclosure, due to the water cooled turbine, one or more oxygen sensors may be utilized pre-turbine when the engine is controlled in full Lambda 1 operation as the water jacket also cools critical components of the oxygen sensor. In this way, the oxygen sensor can be vertically oriented and centered in the integrated exhaust manifold collector before the wastegate channel and volute. Lambda 1 refers to an engine operating state where lambda=1, which means stoichiometric engine/combustion operation. With this stoichiometric operation, after combustion there should not be excess oxygen or unburnt fuel in the exhaust gases.
(22) In additional examples of the present disclosure, a PCV make-up air system is fully integrated into the turbocharger housing and cylinder head, thus obviating the need for external tubes or hoses, which can require an active onboard diagnostics monitoring for disconnection of the tubes/hoses.
(23) Accordingly, the systems described herein provide a cast cylinder head with an integrally cast turbocharger housing that includes (i) a very compact low wetted area to provide an uninterrupted flow path pointed directly at the catalyst face to achieve cold start emissions targets, (ii) a casting core assembly with specific core geometry and steps for assembly to enable core assembly while meeting all cylinder head and integrated turbine housing functional requirements, (iii) an oxygen sensor disposed pre-turbine, for use in full Lambda 1 engine operation, vertical and centered in the integrated exhaust manifold, (iv) a fully integrated PCV make-up air system, (v) a water jacket cast into the integrally cast cylinder head and turbocharger housing, wherein the water jacket is configured to cool the oxygen sensor so as to enable placement of the oxygen sensor at least partially within the integrated exhaust manifold, and (vi) a wastegate housing defining a wastegate passage and a valve seat with a wastegate inlet.
(24) With reference now to
(25) With continued reference to
(26) As described herein in more detail, the cartridge opening 26 is configured to receive cartridge assembly 32 therein, followed by a compressor inlet shroud 38, to define a compressor inlet 40, as shown in
(27) In the example embodiment, the turbocharger housing 12 includes an integrated (cast-in) turbine inlet duct 50 and wastegate inlet duct 52 (see also
(28) As shown in
(29) The bushing 154 is inserted through the wastegate actuator bore 66 and includes an upper end configured to couple to the coupling 156, and a lower end configured to receive and couple to a shaft 160 of the wastegate valve 158. The wastegate valve 158 is inserted into the wastegate passage 60 for subsequent coupling to the bushing 154. In one example, the shaft 160 is splined to the bushing 154, however it will be appreciated that various couplings are envisioned.
(30) Moreover, in the illustrated example, the coupling 156 is one side of an Oldham coupling 162, which includes an intermediate member 164 disposed between first coupling 156 and a second coupling 176 of the wastegate valve actuator assembly 152. In this way, the Oldham coupling 162 is configured to operably couple the wastegate valve actuator assembly 152 to the wastegate valve assembly 150. However, it will be appreciated that wastegate system 16 may have any suitable coupling between the wastegate valve actuator assembly 152 and the wastegate valve assembly 150 that enables system 16 to function as described herein.
(31) In the example embodiment, the wastegate valve actuator assembly 152 is a direct drive actuator and generally includes a housing 170 for housing a motor 172 having an output shaft 174, which is configured to couple to coupling 176. The direct drive actuator advantageously enables opening of the wastegate beyond the typical 30° maximum to beyond 90° as far as is needed to fully bypass the wastegate inlet duct 52. In some examples, the wastegate is opened beyond 180° to increase wastegate flow by blocking exducer flow of the turbine wheel 116 with a backside 166 of the wastegate valve 158.
(32) Additionally, in some examples, the turbocharger housing 12 includes a reverse rotation configuration (e.g., rotates counter clockwise as shown in
(33) As shown in
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(35) The water jacket systems 18 are shown as a water jacket core 300 that, after casting, represents a space or void cast into the cylinder head 10 and integrated turbocharger housing 12. The void subsequently defines one or more passages to receive a flow of coolant for cooling the cylinder head 10 and turbocharger housing 12. As such, in the illustrated example, the volume for coolant flow is represented in solid.
(36) In the example embodiment, the water jacket core 300 generally includes a cylinder head water jacket portion 302 and a turbocharger housing water jacket portion 304. The cylinder head water jacket portion 302 is integrated (cast) into the cylinder head 10, and the turbocharger housing water jacket portion 304 is integrated (cast) into the turbocharger housing 12. In the illustrated example, the cylinder head water jacket portion 302 is fluidly coupled to the turbocharger housing water jacket portion 304, and water jacket portions 302, 304 are formed by an upper water jacket 306 and a lower water jacket 308.
(37) The upper water jacket 306 defines an upper turbocharger housing water jacket 310 integrated (e.g., fluidly coupled) with an upper cylinder head water jacket 312, and the lower water jacket 308 defines a lower turbocharger housing water jacket 314 integrated with a lower cylinder head water jacket 316. The upper and lower cylinder head water jackets 312, 316 each define a plurality of passages 318 (shown in solid, not all labeled) to enable coolant to flow therethrough and provide cooling to various cylinder head components including the exhaust manifold 57. Similarly, the upper and lower turbocharger housing water jackets 310, 314 define a plurality of passages 322 (shown in solid, not all labeled) for flowing coolant around the integrated turbocharger housing 12 for cooling thereof, including a turbine exhaust flow and a wastegate exhaust flow such as, for example, exhaust flow 68 (
(38) As shown, the upper and lower turbocharger housing water jackets 310, 314 merge (fluidly connect) at an end coupling 328 of the turbocharger housing 12. Similarly, the upper and lower cylinder head water jackets 312, 316 merge at end couplings 330, 332, and the upper cylinder head water jacket 312 includes a coolant outlet 334 to a thermostat (not shown). In the illustrated arrangement, flow of coolant can begin in the lower cylinder head water jacket 316 and flow through passages 318 to the lower turbocharger housing water jacket 314 to cool the turbocharger housing 12. The flow then passes to upper turbocharger housing water jacket 310 via end coupling 328, further cools turbocharger housing 12, and finally flows through coolant outlet 334. Additionally, flow from the lower cylinder head water jacket 316 passes through end couplings 330, 332 into upper cylinder head water jacket 312, through passages 318, and finally through coolant outlet 334. It will be appreciated, however, that various other flow control arrangements are contemplated depending on various design considerations (e.g., materials, packaging requirements), desired temperature and flow characteristics, etc.
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(40) In a third step, the joined intake scroll core 410, exhaust port core 412, and exhaust side core 414 are lowered into the lower water jacket core 420, as shown in
(41) With reference now to
(42) Turning now to
(43) It will be understood that the mixing and matching of features, elements, methodologies, systems and/or functions between various examples may be expressly contemplated herein so that one skilled in the art will appreciate from the present teachings that features, elements, systems and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise above. It will also be understood that the description, including disclosed examples and drawings, is merely exemplary in nature intended for purposes of illustration only and is not intended to limit the scope of the present disclosure, its application or uses. Thus, variations that do not depart from the gist of the present disclosure are intended to be within the scope of the present disclosure.