Exhaust duct for a motor vehicle and method for forming an exhaust duct

Abstract

Exhaust duct for motor vehicle air (10) with an air outlet housing (38) that can be inserted into a bumper (14) of a motor vehicle (10), a first channel half (28) connected to the air outlet housing (38) to limit a section of the exhaust air flow path and a second channel half (30) adjoining the first channel half (28) to limit a section of the exhaust air flow path, wherein the second channel half (30) is formed by a heat shield for thermal covering of a part of an exhaust system (24) of the motor vehicle (10), wherein the second channel half (30) is designed three-dimensionally on an outer side (32) facing the first channel half (28) to limit the flow path, and wherein the second channel half (30) has at least two side walls (34) connected to each other via a bottom (36) to limit the flow path, at least in a partial area of ​​the flow path.

Description

[0001] The invention relates to an outlet duct for exhaust air of a motor vehicle and to a method for forming an outlet duct, with the aid of which, in particular, heated cooling air from an intercooler for cooling a turbocharger can be expelled into the environment.

[0002] From DE 37 29 477 C3 a motor chain saw with an exhaust silencer is known, in which an outer heat shield of the exhaust silencer can be cooled from the inside with cooling air intended for an internal combustion engine.

[0003] From DE 10 2008 045 596 A1 an outlet duct for cooling air heated by a charge air cooler is known, which is formed partly between a rear panel and a housing of an exhaust system and runs to an outlet opening provided in an underbody.

[0004] A motor vehicle can be provided with an exhaust system through which exhaust gases from a motor vehicle engine can be released into the environment. In particular, in a motor vehicle designed as a sports car, the exhaust system can provide an exhaust outlet in both a right-hand rear area and a left-hand rear area of ​​the motor vehicle, which are connected to one another within the motor vehicle via the exhaust system. To protect a rear bumper from the effects of the hot exhaust gases, the exhaust system can be provided with a heat shield at the rear. In particular, if the motor vehicle has a turbocharger for charging fresh air for the motor vehicle engine, which is to be cooled with the aid of an intercooler, it is necessary to provide an additional air outlet for the intercooler in the motor vehicle.

[0005] There is a constant need to be able to exhaust air from a motor vehicle in a cost-effective and space-saving manner.

[0006] The object of the invention is to provide measures that enable a cost-effective and space-saving discharge of exhaust air from a motor vehicle.

[0007] The object is achieved according to the invention by an outlet channel having the features of claim 1 and a method having the features of claim 10. Preferred embodiments of the invention are specified in the subclaims and the following description, which may each individually or in combination represent an aspect of the invention.

[0008] According to the invention, an outlet duct for exhaust air of a motor vehicle, in particular for heated cooling air of a charge air cooler for cooling a turbocharger, is provided with an air outlet housing which can be inserted into a bumper of a motor vehicle, a first duct half connected to the air outlet housing for delimiting a section of the flow path of the exhaust air and a second duct half adjoining the first duct half for delimiting a section of the flow path of the exhaust air, wherein the second duct half is formed by a heat protection shield for thermally covering a part of an exhaust system of the motor vehicle, wherein the second duct half is designed three-dimensionally on an outer side facing the first duct half for delimiting the flow path, and wherein the second duct half, at least in a partial region of the flow path, has at least two, in particular rib-like projecting, connected to one another via a base,has side walls to limit the flow path.,

[0009] The heat shield originally intended for the exhaust system can thus simultaneously be used to limit the exhaust air flow path. This allows an existing component to fulfill an additional function, eliminating the need for a component that would otherwise be required for this function. This makes it possible, in particular, to provide the at least one exhaust outlet, preferably the at least two exhaust outlets, of the exhaust system, as well as an additional air outlet opening of the exhaust duct, intended, for example, for heated cooling air from a charge air cooler, in a rear area of ​​the motor vehicle, without the various flows and the ducts limiting the flows interfering with one another.It is even possible that the air in the exhaust duct and the first half of the duct can provide thermal insulation as an additional heat shield layer, thereby further improving the thermal insulation of the exhaust system. By using the heat shield already provided for the exhaust system as part of the exhaust duct that restricts further flow, a corresponding separate component can be eliminated, thus enabling cost-effective and space-saving exhaust air discharge from a motor vehicle.

[0010] The second duct half used as a heat shield for the exhaust system can be made of a suitable temperature-resistant material, for example cast iron. It can be taken into account that temperatures of approximately 750°C, which the heat shield is intended to shield, can occur in the exhaust system, and that a surface temperature of approximately 410°C can be expected for the heat shield. Compared to the second duct half used as a heat shield, the first duct half can be made of a material, for example sheet steel, which is designed for significantly lower temperatures, for example approximately 120°C. Preferably, upstream of the first duct half and the second duct half, there is another flow duct for the exhaust air, which only needs to be designed for the significantly lower temperature, for example approximately 120°C.The air outlet housing can, in particular, be connected directly to the first duct half, forming a common structural unit. Furthermore, it is possible for the air outlet housing to be connected directly or indirectly to the second duct half. If necessary, the first duct half can be fastened to the second duct half, preferably via a seal arranged therebetween. The first duct half and the second duct half, in particular, have a dividing plane extending in the direction of flow, so that the first duct half and the second duct half form the boundary of the flow path in the manner of juxtaposed shells.

[0011] The second duct half is not flat on its outer side facing away from the exhaust system, but rather is adapted to the geometry of the first duct half, which is attached to the second duct half. The second duct half, used as a heat shield, is thus not merely a formed sheet, but a three-dimensional body. Especially when the second duct half is made of cast iron, the three-dimensional shape can be incorporated into the casting process. This simplifies the geometry of the first duct half and optimizes it for easy assembly.

[0012] Preferably, the flow path defined by the first duct half and the second duct half is oriented substantially only in the vertical direction and / or along the direction of travel of the motor vehicle. Flow perpendicular to the direction of travel is thereby avoided. This prevents the flow of exhaust gas in the exhaust system, shielded by the heat shield, and the flow of exhaust air in the exhaust duct from flowing parallel. Instead, the flows of the exhaust system and the exhaust duct can run substantially at right angles to each other, so that the exhaust air does not heat up excessively via the second duct half.

[0013] Particularly preferably, the second duct half is designed to thermally cover an exhaust gas flow flowing essentially in a horizontal direction transverse to the direction of travel of the motor vehicle, wherein the second duct half is shaped to shield thermal radiation radiated in a horizontal direction and to shield thermal radiation radiated in at least one vertical direction, wherein the second duct half has a curved base on an outer side facing the first duct half to delimit the flow path. The second duct half can partially encompass the exhaust system in its function as a heat shield, for example in an angular range of 45° to 90°. The flow path of the exhaust duct can follow this particularly curved configuration of the second duct half, wherein in particular the flow cross-section can remain essentially constant.In particular, if the exhaust duct is connected to a charge air cooler, a significant portion of the flow path can be formed through the second duct half.

[0014] In particular, the air outlet housing delimits an air outlet opening for the exhaust air, wherein the air outlet housing has a cover that differs from the visual impression of a base formed on an outer side of the second duct half, wherein the cover, starting from the air outlet housing, essentially completely covers a section of the base of the second duct half along the flow path. This makes it possible for the second duct half to be invisible from outside the motor vehicle through the air outlet opening of the air outlet housing. Instead, only the cover is visible. This makes it possible to improve the visual appearance by designing the cover in a visually appealing manner that fits into the visual design of the motor vehicle.The second half of the channel can thus be optimized for its function as a heat shield without having to accept any impairment of the heat shield function for the sake of the visual appearance.

[0015] The air outlet housing preferably has a support frame, in particular one that defines an air outlet opening for the exhaust air. The support frame has a first fastening means for fastening to a bumper and a second fastening means for fastening to a component of the motor vehicle that has an exhaust system. The outlet duct can thus be pre-assembled to the bumper via the support frame and, during assembly of the bumper, also fastened to the component that has the exhaust system, whereby the intended relative position of the first duct half to the second duct half can be achieved automatically.

[0016] The invention further relates to a rear assembly for the rear of a motor vehicle, comprising an exhaust system for discharging hot exhaust gases from a motor vehicle engine into the environment, an outlet duct, which can be designed and developed as described above, for discharging exhaust air, wherein the second duct half at least partially covers the exhaust system. By using the heat shield provided for the exhaust system anyway as part of the outlet duct restricting further flow, a corresponding separate component can be eliminated, thus enabling cost-effective and space-saving expulsion of exhaust air from a motor vehicle.

[0017] In particular, the exhaust system has an exhaust flow duct extending substantially horizontally transversely to the direction of travel of the motor vehicle, wherein the second duct half covers the exhaust flow duct over a large part of its horizontal extent, wherein, in particular, the exhaust flow duct connects a right exhaust outlet provided in a right rear region with a left exhaust outlet provided in a left rear region of the motor vehicle. The flow directions of the flow in the exhaust system and the flow in the exhaust duct may not be parallel but substantially perpendicular to each other, thus avoiding unnecessarily strong heating of the exhaust air in the exhaust duct.

[0018] The invention further relates to a motor vehicle, in particular a sports car, with a rear assembly, which can be designed and developed as described above, and a charge air cooler for cooling a turbocharger for charging fresh air for a motor vehicle engine, wherein the exhaust duct is connected to the charge air cooler for discharging cooling air. By using the heat shield provided for the exhaust system anyway as part of the exhaust duct restricting further flow, a corresponding separate component can be eliminated, thus enabling cost-effective and space-saving expulsion of exhaust air from a motor vehicle.

[0019] The invention further relates to a method for forming an exhaust duct, which can be designed and further developed as described above, in a motor vehicle, which can in particular be designed and further developed as described above, comprising the steps of providing a bodyshell of the motor vehicle having an exhaust system, attaching the second half of the duct to the bodyshell as a heat shield for the exhaust system, attaching the air outlet housing and the first half of the duct to a bumper of the motor vehicle, and connecting the bumper to the bodyshell to form the exhaust duct. The exhaust duct can be formed automatically when the bumper is connected to the bodyshell, thus ensuring cost-effective assembly.By using the heat shield provided for the exhaust system anyway as part of the outlet duct that limits further flow, a corresponding separate component can be saved, so that a cost-effective and space-saving discharge of exhaust air from a motor vehicle is possible.

[0020] The invention will be explained below by way of example with reference to the accompanying drawings using preferred embodiments, wherein the features presented below can represent an aspect of the invention both individually and in combination. They show: Fig. 1: a schematic rear view of a motor vehicle, Fig. 2: a schematic perspective view of the motor vehicle from Fig. 1 from the bottom, Fig. 3: a schematic sectional view of a rear assembly of the motor vehicle from Fig. 1, Fig. 4: a schematic perspective exploded view of an exhaust duct of the rear assembly of Fig. 3 and Fig. 5: a schematic perspective view of the outlet channel from Fig. 4 in the assembled state.

[0021] The Fig. 1 and Fig. The motor vehicle 10 shown in Figure 2, configured as a sports car, has a rear assembly 12 with a bumper 14. A left exhaust outlet 18 is provided in a left rear area 16, and a right exhaust outlet 22 is provided in a right rear area 20. The left exhaust outlet 18 and the right exhaust outlet 22 are part of an exhaust system 24.

[0022] As in Fig. 3, the bumper 14 opens into a Fig. 4 and Fig.5, which in the illustrated embodiment defines two separate flow paths. The outlet channel 26 has a first channel half 28 and a second channel half 30, which define the flow paths. The second channel half 30 simultaneously serves as a heat shield for the exhaust system 24. The second channel half 30 has, on its upper side 32 facing the first channel half 28, rib-like protruding side walls 34, which are connected to one another via a base 36 to form a three-dimensional design for defining the flow paths of the outlet channel 26.

[0023] The first duct half is connected to an air outlet housing 38. The air outlet housing 38 has a support frame 42 forming an air outlet opening 40, which can be connected to the bumper 14 and to the first duct half 28. A cover 44 is connected to the support frame 42, which extends into the interior of the outlet duct 26 and covers a portion of the second duct half 30 that would otherwise be visible above the air outlet opening 40.

Claims

[1] Outlet duct for exhaust air of a motor vehicle (10) with an air outlet housing (38) insertable into a bumper (14) of a motor vehicle (10), a first duct half (28) connected to the air outlet housing (38) for delimiting a section of the flow path of the exhaust air and a second duct half (30) adjoining the first duct half (28) for delimiting a section of the exhaust air flow path, wherein the second channel half (30) is formed by a heat shield for thermally covering a part of an exhaust system (24) of the motor vehicle (10), wherein the second channel half (30) is designed three-dimensionally on an outer side (32) facing the first channel half (28) to delimit the flow path, and wherein the second channel half (30) has, at least in a partial region of the flow path, at least two side walls (34) connected to one another via a base (36) to delimit the flow path. [2] Outlet channel according to claim 1 characterized by that the flow path delimited by the first channel half (28) and the second channel half (30) is oriented substantially only in the vertical direction and / or along the direction of travel of the motor vehicle (10). [3] Outlet channel according to one of claims 1 to 2 characterized byin that the second channel half (30) is designed for thermally covering an exhaust gas flow flowing essentially in a horizontal direction transversely to the direction of travel of the motor vehicle (10), wherein the second channel half (30) is shaped for shielding thermal radiation radiated in a horizontal direction and for shielding thermal radiation radiated in at least one vertical direction, wherein the second channel half (30) has a curved bottom (36) for delimiting the flow path on an outer side (32) facing the first channel half (28). [4] Outlet channel according to one of claims 1 to 3 characterized bythat the air outlet housing (38) delimits an air outlet opening (40) for the exhaust air, wherein the air outlet housing (38) has a panel (44) which is different from the optical impression of a floor (36) formed on an outer side of the second duct half (30), wherein the panel (44) starting from the air outlet housing (38) essentially completely covers a section of the floor (36) of the second duct half (30) along the flow path. [5] Outlet channel according to one of claims 1 to 4 characterized by in that the air outlet housing (38) has a holding frame (42), wherein the holding frame (42) has a first fastening means for fastening to a bumper (14) and a second fastening means for fastening to a structural unit of the motor vehicle (10) having an exhaust system (24). [6] Rear assembly for a rear of a motor vehicle, with an exhaust system (24) for discharging hot exhaust gases of a motor vehicle engine to the environment, an outlet duct (26) according to one of claims 1 to 5 for discharging exhaust air, wherein the second duct half (30) at least partially covers the exhaust system (24). [7] Rear assembly according to claim 6 characterized by in that the exhaust system (24) has an exhaust gas flow channel running essentially in a horizontal direction transverse to the direction of travel of the motor vehicle, wherein the second channel half (30) covers the exhaust gas flow channel over a large part of its horizontal extent, wherein the exhaust gas flow channel connects a right exhaust gas outlet (22) provided in a right rear region (20) to a left exhaust gas outlet (18) provided in a left rear region (16) of the motor vehicle (10). [8] Rear assembly according to claim 6 or 7 characterized bythat the bumper (14) is provided, wherein the air outlet housing (38) is inserted in the bumper (14). [9] Motor vehicle with a rear assembly (12) according to one of claims 6 to 8 and a charge air cooler for cooling a turbocharger for charging fresh air for a motor vehicle engine, wherein the outlet duct (26) is connected to the charge air cooler for discharging cooling air. [10] Method for forming an outlet channel (26) according to one of claims 1 to 5 in a motor vehicle (10), comprising the steps Providing a shell of the motor vehicle (10) having an exhaust system (24), Attaching the second half of the duct (30) to the shell as a heat shield for the exhaust system (24), Fastening the air outlet housing (38) and the first duct half (28) to a bumper (14) of the motor vehicle (10) and Connecting the bumper (14) to the body shell to form the exhaust duct (26).

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