Patent Application
20170350277
The present application claims priority to German Patent Application No. 102016209951.5, filed on Jun. 7, 2016. The entire contents of the above-referenced application are hereby incorporated by reference in its entirety for all purposes.
The combustion gases of an internal combustion engine naturally have a high level of thermal energy. The exhaust gas flow which is created as a result of the thermal energy of the combustion gases is greatest directly downstream of the cylinder heads or the engine manifold. Located at this point is the turbocharger, the function of which is to convert some of the thermal energy and therefore to re-utilize it for the combustion process. The turbocharger comprises on the one hand a compressor and on the other hand a turbine that are intercoupled via a shaft. The compressor compresses the intake air for the combustion process and therefore supplies the energy which is converted by the turbocharger to the combustion process.
The turbine comprises a turbine wheel having a housing which encloses the turbine wheel in a spiral profile, a flow inlet duct and a flow outlet duct. The path of the exhaust gas flow of the combustion gases of an internal combustion engine extends through the flow inlet passage, through the turbine wheel and continues through the flow outlet duct. On account of the close position of the turbocharger to the cylinder heads or to the engine manifold, the temperature of the exhaust gas flow is very high. The inner walls of the turbine housing are very heavily exposed to the thermal stresses which are caused by the exhaust gas flow. Furthermore, the high temperatures on the walls of turbine housing lead to thermal bridges which could compromise, damage, or even destroy the elements outside of the turbine housing. It is therefore an aim of the engine manufacturer to reduce the thermal bridges of the turbine housing of a turbocharger. In the prior art, different approaches are disclosed.
Disclosed in U.S. Pat. No. 9,097,121 B2 is an insulation for a turbocharger which on the one hand protects the inner walls of the flow inlet duct and on the other hand protects the inner walls of the flow outlet duct against the hot exhaust gas flow of the internal combustion engine. The insulation consists of two sleeves. The first sleeve is introduced into the flow inlet duct and the second sleeve is introduced into the flow outlet duct. Both sleeves in this case protect only the inner walls of the flow inlet duct and of the flow outlet duct against the high temperatures of the exhaust gas flow. The flow inlet duct and the flow outlet duct are typically not directly interconnected. Therefore, the two sleeves do not cover any of the fully closed regions inside the turbine housing. The region between the two sleeves is not separately protected against the high temperatures of the exhaust gas flow. In particular, the turbine wheel housing which encloses the turbine wheel in a spiral profile is exposed to the high temperatures of the exhaust gas flow of the internal combustion engine. Furthermore, the introduction of the sleeves takes place after production of the turbine housing. In this case, the sleeves are not connected in a positive-locking manner to the individual ducts.
Further documents of the prior art refer to just the outer insulation of a turbine housing. The outer insulation of a turbine housing of a turbocharger aims above all at heat insulation of the turbine housing itself. The quantity of heat which is emitted to the turbine housing by the exhaust gas flow can compromise, damage or even destroy elements in the surrounding region of the turbocharger. An outer insulation is in this case helpful and reduces the outwardly emitting quantity of heat. With this type of insulation, however, the inner walls of the individual ducts, especially of the flow inlet duct, of the flow outlet duct and the inner region of the turbine wheel housing which encloses the turbine wheel in a spiral-like manner are not protected against the high temperatures of the exhaust gas flow. Examples of an outer insulation of a turbine housing are to be gathered from documents U.S. Pat. No. 7,074,009 B2, DE 100 22 052 A1, U.S. Pat. No. 4,300,349 A, WO 2016/010847 A1 and CN 2835566Y.
Turbine housings of a turbocharger are for the most part stamped out in one piece. U.S. Pat. No. 7,074,009 B2 and DE 100 22 052 A1 in each case disclose a turbine housing which consists of a plurality of layers. In U.S. Pat. No. 7,074,009 B2, the turbine housing is first of all assembled and in the second step the insulating lining is applied from the outside. The insulating lining is in this case fitted to the turbine housing is a positive-locking manner. In DE 100 22 052 A1, the turbine housing is assembled from a plurality of metal sheets. The individual metal sheets in this case can be coated with heat insulating effect.
The inventors have recognized the aforementioned drawbacks and facing these challenges developed an exhaust gas turbine. The exhaust gas turbine includes a first turbine housing part having insulating material extending along an interior surface and a second turbine housing part having insulating material extending along an interior surface, the second turbine housing part coupled to the first turbine housing part to form a volute directing exhaust gas to a turbine wheel. An exhaust gas turbine designed with a two part housing enables insulating material to be efficiently applied to internal surfaces of the housing to improve the thermal properties of the turbine.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
Further features, characteristics and advantages of the present invention are gathered from the following description of exemplary embodiments with reference to the attached figures.
At least
The present description relates to a turbine housing for a turbocharger and to a method for its production. In one example, an advantageous turbine housing is provided, made from cast metal, for a turbocharger. In another example, a method for producing a turbine housing is provided.
The turbine housing, made from cast metal, for a turbocharger, may be provided with an insulating material for protection against high temperatures of an exhaust gas flow. The turbine housing may include a flow inlet duct, a turbine wheel housing which encloses a turbine wheel and may be connected to the flow inlet duct, and a flow outlet duct which may be connected to the turbine wheel housing. With this, an exhaust gas flow path extends through the flow inlet duct, through the turbine wheel housing and through the flow outlet duct. In this case, the exhaust gas flow path may have a wall which is adjacent to the exhaust gas flow. The turbine housing may include at least two interconnected housing parts. A region of the exhaust gas flow path may be formed in each housing part. In this case, each exhaust gas flow path region may include a section of the wall which is adjacent to the exhaust gas flow. The insulating material may be provided along the exhaust gas flow path (e.g., entire exhaust gas flow path) on the side of the wall which faces the exhaust gas flow. The at least two housing parts may be interconnected along a surface which intersects the exhaust gas flow path perpendicularly to the flow direction of the exhaust gas. Additionally or alternatively, the at least two housing parts may be interconnected along a surface which is parallel to the flow direction of the exhaust gas in the exhaust gas path. A curved progression of the intersecting surface is also possible in this case.
Due to the fact that the turbine housing may include at least two interconnected housing parts, wherein an exhaust gas flow path region is formed in each housing part, wherein each exhaust gas flow path region may include a section of the wall which is adjacent to the exhaust gas flow, the regions (e.g., all of the regions) of the wall in the exhaust gas flow path can be made easily accessible for introducing the insulating material so that attaching the insulating material along the entire flow path becomes possible, if desired. The advantage of a turbine housing which includes at least two parts therefore lies in the fact that an insulating material can be applied to all the inner walls of the turbine housing. In this case, the regions of the inner walls which are exposed to the high temperatures of the exhaust gas flow may be of importance.
According to one example, the turbine wheel housing may enclose the turbine wheel in a spiral profile. The spiral-like stamping of the turbine wheel housing which encloses the turbine wheel leads to a channeling of the exhaust gas flow and therefore to a higher effectiveness of the energy conversion or to a higher level of efficiency.
According to another example, the exhaust gas flow path may have at least one branch. In particular, it may have a branch in the flow inlet duct and a branch in the flow outlet duct, wherein the branch in the flow inlet duct is fluidically connected to the branch in the flow outlet duct, bypassing the turbine wheel housing. The fluidic connection between the flow inlet duct and the flow outlet duct, bypassing the turbine wheel housing, may be designed as a waste-gate passage. This connection may also be referred to as a bypass.
According to another example, the turbine housing may include cast steel, cast aluminum, or gray cast iron. For instance, the turbine housing may be produced or constructed from cast steel, cast aluminum, and/or gray cast iron. Specifically in one example, the turbine housing may be produced from gray cast iron. For the reduction of weight of a turbocharger, the turbine housing may be produced from cast aluminum, in another example. In another example, a turbocharger may be used in conjunction with a high performance engine, for instance, the turbine housing may be produced from cast steel.
According to another example, the at least two housing parts may be interconnected in a positively locking, frictionally locking, or materially bonding manner. The positively locking connection can for example be produced by means of connecting flanges and at least one clamping ring. Frictionally locking or materially bonding connections may be preferred, in one example. In the case of the frictionally locking connection, screw fastening and/or riveting may be used, and in the case of the materially bonding connection welding may be used.
The turbine housing discussed herein may be produced by means of a method. For this, a method which interconnects the at least two housing parts of the turbine housing is provided. The section of the wall which is adjacent to the exhaust gas flow and located in the exhaust gas flow path region of the respective housing part may be provided, before the connecting, with an insulating material for protection against high temperatures of the exhaust gas flow. For example, the wall which is adjacent to the exhaust gas flow may be provided with the insulating material by means of coating. However, inserting pre-manufactured insulating elements is also possible, in some examples.
According to one example, the housing parts may be interconnected in a positively locking, frictionally locking, or materially bonding manner. The housing parts of the turbine housing may be interconnected in a frictionally locking manner by means of screwing fastening or riveting or in a materially bonding manner by means of welding.
Described below, with reference to the figures, are exemplary embodiments for a turbine housing with an insulating lining for protection of the inner walls against high temperatures of the exhaust gas flow of an internal combustion engine.
In another example, the turbine housing 2 may be produced from aluminum or from gray cast iron. The turbine housing 2, which in the present exemplary embodiment is designed as a two-part turbine housing 2 with two housing parts 2a, 2b, includes a flow inlet duct 3, a turbine wheel housing 4 and a flow outlet duct 5. The flow inlet duct 3 may be a volute providing exhaust gas flow to a turbine wheel 112 configured to convert the exhaust gas flow into rotational energy. The turbine wheel 112 is schematically depicted in
An exhaust gas flow path 110 extends from the flow inlet duct 3 along the turbine wheel housing 4 up to the flow outlet duct 5. The division of the two-part turbine housing 2 is carried out along the flow inlet duct 3 and therefore parallel to a flow direction 146 of the exhaust gas, in the depicted embodiment. Specifically,
Shown in
Shown in
Shown in
At 602 the method includes manufacturing a first turbine housing part. In one example, manufacturing the first turbine housing part may including casting the first turbine housing part. Additionally or alternatively, manufacturing the first turbine housing part may include machining the first turbine housing part.
At 604 the method includes manufacturing a second turbine housing part. Similar to the first turbine housing part, the second turbine housing part may be manufactured by casting and/or machining the part, in some examples. In other examples, different techniques may be used to manufacture the first and second turbine housing parts. For instance, one part may be cast while the other may be machined or vice versa.
At 606 the method includes providing the first and second turbine housing parts with insulating material on interior surfaces of the turbine housing parts. For instance, an interior surface of each of the first and second turbine housing parts may be coated with an insulating material.
At 610 the method includes interconnecting the first and second turbine housing parts. Interconnecting the turbine housing parts may include welding the first and second housing parts. Additionally or alternatively, interconnecting the turbine housing parts may include attaching the first and second turbine housing parts with fastening devices. The method 600 enables efficient manufacturing of a turbine housing with improved insulation. As a result, the thermal properties of the turbine are improved while reducing the turbine housing's manufacturing cost.
The present invention, for illustration purposes, has been explained based on a number of exemplary embodiments. A person skilled in the art, however, recognizes that deviations from the individual exemplary embodiments are possible and that features of individual exemplary embodiments can be combined with each other. Therefore, the turbine housing 2 can, for example, be divided into more than two housing parts 2a, 2b in order to then connect these in a positively locking, frictionally locking or materially bonding manner, as a result of which the accessibility of exhaust gas flow path regions which are to be provided with an insulation can be further improved.
The described exemplary embodiments refer to a turbine housing 2 for a turbocharger. However, the features of the present invention can also be used for other turbines. Furthermore, the intersecting surfaces can intersect the exhaust gas flow path 110 at an optional angle. In the case of a higher number of housing parts 2a, 2b, a plurality of intersecting surfaces and different angles are also possible. The invention is therefore not intended to be limited exclusively to the described exemplary embodiments but only by the attached claims.
The subject matter of the present disclosure is further described in the following paragraphs. According to one aspect, a method for producing a turbine housing made from cast metal is provided. The method includes during the production of the turbine housing, providing a first and second turbine housing parts with insulating material on a section of a wall which is adjacent to exhaust gas flow and located in the exhaust gas flow path region of the respective housing part and interconnecting the first and second turbine housing parts.
In another aspect, an exhaust gas turbine is provided. The exhaust gas turbine includes a first turbine housing part having insulating material extending along an interior surface and a second turbine housing part having insulating material extending along an interior surface, the second turbine housing part coupled to the first turbine housing part to form a volute directing exhaust gas to a turbine wheel.
In any of the aspects described herein or combinations of the aspects, the housing parts may be interconnected in a positively locking, frictionally locking or materially bonding manner.
In any of the aspects described herein or combinations of the aspects, the first and second housing parts may be coupled along a surface which is parallel to a flow direction of exhaust gas in the volute.
In any of the aspects described herein or combinations of the aspects, the first and second housing parts are coupled along a surface which is perpendicular to a flow direction of exhaust gas in the volute.
In any of the aspects described herein or combinations of the aspects, the insulating material in the first and second turbine housing parts may extend along the interior surface from an inlet to a turbine wheel housing.
In any of the aspects described herein or combinations of the aspects, the insulating material in each of the first and second turbine housing parts may extend along the interior surface from a flow inlet duct to a flow outlet duct.
In any of the aspects described herein or combinations of the aspects, the insulating material in each of the first and second turbine housing parts may be an insulating coating.
In any of the aspects described herein or combinations of the aspects, the first and second turbine housing parts may be constructed out of aluminum.
In any of the aspects described herein or combinations of the aspects, the first and second turbine housing part may be coupled by a weld.
It will further be appreciated by those skilled in the art that although the invention has been described by way of example with reference to several embodiments it is not limited to the disclosed embodiments and that alternative embodiments could be constructed without departing from the scope of the invention as defined in the appended claims.
Note that the example manufacturing method included herein can be used with various engine and/or vehicle system configurations. As such, various acts, operations, or functions illustrated may be performed in the sequence illustrated, in parallel, or in some cases omitted. Likewise, the order of the method steps may not necessarily required to achieve the features and advantages of the example embodiments described herein, but is provided for ease of illustration and description. One or more of the illustrated acts or functions may be repeatedly performed depending on the particular method being used.
It will be appreciated that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. For example, the above technology can be applied to V-6, I-4, I-6, V-12, opposed 4, and other engine types. Further, one or more of the various system configurations may be used in combination with one or more of the described methods. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, and other features, functions, and/or properties disclosed herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102016209951.5 | Jun 2016 | DE | national |
