Discoloration protection

Abstract

A device is provided for protecting at least one metallic surface against discolorations under the action of heat. The device includes a metallic surface with a lacquer applied a lacquer applied thereto to the metallic surfaces and then stoving the metallic surface while sealing the metallic surface against oxygen contact to form a permanently effective oxygen barrier.

Claims

1. A device for discharging exhaust gases and waste heat of an internal combustion engine of a vehicle, the device comprising: a covering for an engine space in which the internal combustion engine is arranged; at least one exhaust tract branching off from the internal combustion engine and connected from the internal combustion engine upward to the covering over substantially a shortest possible distance so that the exhaust gases are dischargeable into surroundings of the vehicle via the covering, wherein the covering has a first surface on a first metallic material above the internal combustion engine and a second surface on a second metallic material disposed above the first metallic material, at least part of the first metallic material being substantially impermeable to air and moisture and at least parts of the second metallic material being formed with a plurality of openings therethrough for permitting an upward flow of heat away from the engine, a lacquer applied to the first and second metallic surfaces and sealing the first and second metallic surface against oxygen contact and the sealed metallic surface with the lacquer thereon being stoved to form a permanently effective oxygen barrier that prevents the first and second metallic materials from discoloring when exposed to the exhaust gas and the heat of the internal combustion engine.

2. The device of claim 1, wherein the lacquer is a clear lacquer stoved at a stoving temperature of 450 C.

3. The device of claim 2, wherein the clear lacquer is a NANO-X clear lacquer with an oxygen barrier.

4. A vehicle comprising: an internal combustion engine that produces a heated exhaust gas; an exhaust system component that accommodates a flow of the heated exhaust gas from the internal combustion engine and directs the heated exhaust gas from the vehicle in a direction up and away from a road on which the vehicle is disposed; a covering disposed at least partially above the internal combustion engine and the exhaust system component and being integrated into an outer body area of the vehicle, the covering having a first surface on a first metallic material above the internal combustion engine and a second surface on a second metallic material disposed above the first metallic material, at least part of the first metallic material being substantially impermeable to air and moisture and at least parts of the second metallic material being formed with a plurality of openings therethrough for permitting an upward flow of the heated exhaust gas away from the engine having an array of orifices therethrough that permit the heated exhaust gas and heat from the internal combustion engine to flow up and escape from the vehicle through the orifices and into ambient surroundings, the covering having a clear lacquer applied to the first and second metallic surfaces, the clear lacquer having an oxygen barrier therein for sealing the first and second metallic surface from oxygen contact thereby forming a permanently effective oxygen barrier that prevents the first and second metallic surfaces from discoloring when exposed to the heated exhaust gas and the heat of the internal combustion engine.

5. The vehicle of claim 4, wherein the exhaust system component extends along substantially a shortest possible distance from the internal combustion engine to the covering.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an overall illustration of a possible embodiment of the device.

(2) FIG. 2 is an exploded drawing with respective components of the device of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(3) A covering 1 illustrated in FIG. 1 covers or protects an exhaust system or an engine space comprising an exhaust system and an internal combustion engine against external influences.

(4) The covering 1 absorbs exhaust gases emerging from the internal combustion engine or the exhaust system. For this purpose, the exhaust gases generated by the internal combustion engine flow over the covering, which discharges them into the respective surroundings.

(5) Furthermore, the covering 1 functions to remove heat from the internal combustion engine. Orifices 3 are formed in the covering 1 for heat removal and preferably are in the form of hexagonal holes. The orifices 3 allow air exchange between the engine space located under the covering and the surroundings. Air heated by the internal combustion engine rises up in the direction of the covering 1, passes through the covering 1 via the orifices 3 and is discharged into the surroundings. At the same time, the discharge of the heated air causes an ingress of cold ambient air into the engine space.

(6) The covering 1 makes it possible to arrange an exhaust system in a vehicle so that the exhaust gases are expelled up and away from the road. The covering therefore is configured to be connected to a respective exhaust system and to absorb exhaust gases emerging from the respective exhaust system and to discharge them into the surroundings.

(7) The exhaust gases delivered by the exhaust system usually are very hot. Accordingly, at least those parts of the covering 1 that contact the exhaust gases are formed from a temperature-resistant material so that the heat can be absorbed and discharged. The corresponding parts of the covering 1 preferably are pretreated by blasting with blasting stock and, if appropriate, by subsequent electropolishing. The covering 1 may be treated initially with what is known as an INOX SPECTRAL method. In this known electrochemical process, the metallic surface of the covering acquires coloring due to the build-up of a chromium oxide layer. It was shown, surprisingly, that this effect hardens the metallic surface against oxygen contact in such a way that the subsequent stoving of the clear lacquer no longer has to take place under a protective nitrogen atmosphere. The clear lacquer used may be a clear nano-lacquer with an oxygen barrier, such as a NANO-X clear lacquer, for example a NANO-X clear lacquer AFP 1563. This lacquer then is stoved at a stoving temperature of approximately 450 C.

(8) Insofar as an oxygen barrier is not generated by a corresponding method, such as the INOX spectral method, before the application of the clear lacquer, the clear lacquer is stoved under a protective atmosphere, such as, for example, nitrogen, preferably at a temperature of 450 C.

(9) The heat-resistant layer also may be formed solely by application of a nano-clear lacquer with an oxygen barrier on a respective part of the covering and subsequent stoving under a protective atmosphere. Moreover, a PVD layer (physical vapor deposition) also may be provided as a heat-resistant layer. The type of layer selected depends on the relevant part of the covering and also on its desired visual impression.

(10) The overview, illustrated in FIG. 2, of the components of the covering 1 affords a possibility for a detailed explanation of the construction of the covering 1.

(11) A basic skeleton composed of an inner panel 2 and an outer panel 4 carries further components. The outer panel 4 initially is treated by the INOX SPECTRAL method, using an embodiment of the method of the invention, and subsequently is painted with a clear lacquer. The inner panel 2 is painted only with a clear lacquer. The outer panel 4 subsequently is stoved under an air atmosphere in a stoving furnace, while the inner panel 2 treated only with clear lacquer is stoved under a protective atmosphere of nitrogen at approximately 450 C. in a stoving furnace. The clear lacquer preferably is a nano-clear lacquer, in particular a nano-clear lacquer with an oxygen barrier.

(12) The further components include paired diaphragms 6 of the exhaust system, only one of which is illustrated for reasons of clarity. Ring diaphragms 8, 18 are inserted into each diaphragm 6, and a covering 10 for a catalytic converter of the exhaust system is arranged centrally on the outer panel 4. The covering 10 for the catalytic converter is delimited downward by a service cover (not illustrated). The service cover conceals access or ingress formed by orifices 13 to the internal combustion engine arranged beneath the covering 10. The inner panel 2 carries two inner covers 5 that are impermeable to air and moisture and shield respective regions beneath the inner covers against, for example, climatic influences. Both the diaphragms 6 of the exhaust system and the covering 10 for the catalytic converter may be composed of ceramic or of a composite ceramic material.

(13) Parts of the covering, such as the diaphragms 6, that contact the exhaust gases are configured to discharge the exhaust gases or an exhaust gas jet thereof into the surroundings in a defined direction, for example opposite to the direction of travel.

(14) The covering 1 enables an efficient reduction of heating of the engine space and therefore of an entire vehicle caused by operation of the internal combustion engine. A temperature lowering or stabilization achieved thereby may be important for the use of heavy-duty accumulators, since these often attain optimal efficiency in the range of 20 to 40 C. Thus, the covering of the invention enables the engine space to be used as a storage space for accumulators, for example, for a hybrid drive.

(15) The method of the invention provides vehicle components that are resistant to high temperature and that also have a desirable outwardly visible appearance.