The present device relates to a coolant core for a cylinder head in an internal combustion engine. Particularly, the present device relates to a modular coolant core for use in assembling a customized coolant core cylinder head.
The manufacture of cylinder heads for internal combustion engines poses difficult manufacturing problems. The cylinder head of an internal combustion engine, whether for a spark driven gasoline internal combustion engine or a compression ignition diesel engine is a complex article of manufacture with many requirements. A cylinder head generally closes the engine cylinders and contains the many fuel explosions that drive the internal combustion engine, provides separate passageways for the air intake to the cylinders and for the engine exhaust, carries the multiplicity of valves needed to control the air intake and engine exhaust, provides a separate passageway for coolant to remove heat from the cylinder head, and provides separate passageways for fuel injectors and the means to operate the fuel injectors.
The walls forming the complex passageways and cavities of a cylinder head must withstand the extreme internal pressures, temperatures and temperature variations generated by the operation of an internal combustion engine, and must be particularly strong in compression-ignition diesel engines. On the other hand, it is desirable that the internal walls of the cylinder head, particularly those walls between coolant passageways and the cylinder closures, permit the effective transfer of heat from the cylinder head, and it is also important that the cylinder head include minimal metal to reduce its weight and cost.
Some cylinder heads are manufactured by casting them as one piece from iron alloys. The casting of the cylinder head portion that closes the cylinders carries the intake and exhaust valves and fuel injectors and provides the passageways for the air intake, exhaust and coolant requires a mold carrying a plurality of core elements. To provide effective cooling of the cylinder head and effective air intake and exhaust from the cylinder of the internal combustion engine, the passageways for the air intake and exhaust are typically interlaced with the coolant passageways within the cylinder head portion. The cavities for coolant, air intake and exhaust must, of course, be formed by core elements within the mold that can be removed when the casting metal solidifies. Difficulties arise in that a larger core may break during the assembly and casting process.
Countervailing requirements make the manufacture of reliable cylinder head difficult. These complex parts are manufactured by the thousands and assembled into vehicles that must operate reliably under an extreme variety of conditions. Therefore, the manufacture of reliable cylinder heads is particularly important because of the high cost of their replacement. Consequently, the finding efficient and cost-effective ways to manufacture reliable cylinder heads has been the subject of the developmental efforts of engine and automobile manufacturers throughout the world for years.
Currently, generally large, single coolant cores unique to a particular cylinder head are created to cover the specific number of cylinders in that particular head. The present disclosure provides a modular coolant core having a unique geometry, which can be used across multiple engine platforms to create a customized cylinder head. Rather than one water jacket that is only used in a unique cylinder head casting, the modular coolant cores of the present disclosure can be used multiple times depending in a core assembly, essentially customized for the number of cylinders the engine platform using the same core and tooling across many different cylinder head configurations. Because the modular coolant core can be used multiple times, thus replicating the same features and geometry, cooling characteristics such as coolant velocity and heat rejection will be more uniform from cylinder to cylinder. Additionally, because the present modular coolant core is small, it is less prone to cracking during casting and assembly. Thus, the described modular coolant core provides not only ease of use and assembly, by providing a single pattern useful in multiple engines with similar port configurations, but also results in more efficient and consistent cooling performance.
There is disclosed herein an improved modular coolant core for a cylinder head for use in an internal combustion engine. The coolant core had a common structural geometry and unique flow pattern, which avoids disadvantages of prior devices, while affording additional structural and operating advantages.
In an embodiment, a modular structure for assembling a cylinder head for an internal combustion engine, is disclosed. The structure comprises a modular coolant core having an inlet and an outlet, a plurality of passageways within an interior space of the coolant core, the passageways fluidly connecting the inlet and the outlet, and wherein the coolant core has a single pattern geometry for assembling into the cylinder head.
In another embodiment, the plurality of passageways creates a unique flow pattern within each coolant core.
In another embodiment, the flow pattern within each coolant core is substantially identical from coolant core to coolant core.
In yet another embodiment, at least one cylinder is associated with each coolant core.
A modular system for constructing a unique coolant core/cylinder head structure for an internal combustion engine, is disclosed. The modular system comprises a lower water jacket, an upper water jacket fluidly connected to the lower water jacket, a plurality of coolant cores forming the lower water jacket, the coolant cores having an inlet for receiving a coolant, and an outlet for releasing the coolant to the upper water jacket, a flow pattern within an interior space of the coolant core fluidly connecting the inlet and the outlet, a cylinder associated with each coolant core, wherein each coolant core has an identical configuration for customized assembly into a modular cylinder head core box having a predetermined configuration and flow pattern from coolant core to coolant core.
These and other aspects of the present device may be understood more readily from the following description of certain embodiments.
a-1b illustrate a cylinder head highlighting the lower water jacket of the coolant core;
a-2b illustrate a cylinder hear highlighting the upper water jacket of the coolant core;
a-1b and 2a-2b illustrate the core 10 from the modular lower water jacket and the core from the upper water jacket, respectively, in the context of the final cylinder head casting. The coolant core 10 includes the modular lower water or coolant jacket 12 and an upper water or coolant jacket 14. As generally understood, coolant enters the coolant core through a point of entry or inlet 16, in the lower water jacket 12. The coolant flows through a series of passageways 18 within the lower water jacket, through an outlet 22, 24, and into the upper water jacket 14, where it travels through a series of passageways within the upper water jacket. Operation of the cylinder head and coolant core and its association with other engine components is well understood and will not be described in further detail.
Referring to
The modular coolant core 100 of the present disclosure is cast using known methods, such as sand casting. The smaller size of the individual coolant cores 100 means that the core is less likely to break during the casting process and assembly of the cylinder head core box. As illustrated in
Use of the individual modular coolant cores 100 in the cylinder head assembly, also results in a cylinder head with improved structure. In addition, the overall smaller size of the modular coolant core 100 means that it is less prone to breaking during assembly of the cylinder head core box. As shown in
The present disclosure provides a modular coolant core useful in the customized assembly of a cylinder head across a variety of engine platforms. In addition, because the modular core has the same geometry and internal configuration, use of the same core results in an improvement in the overall cooling efficiency across all of the cylinders. Use of the smaller core, compared to the traditional large single cast water jacket, means it is less prone to cracking during casting and assembly. Finally, the assembled coolant cores results in a space between each core, which improves the load distribution and uniform sealing along the head gasket. It should be understood that any number of coolant cores may be used in the assembly of the cylinder head, and any variations in geometry of the coolant cores and internal passageways is permitted, depending the specific requirements of a particular engine platform.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US12/44127 | 6/26/2012 | WO | 00 | 12/17/2014 |