Injector arrangement for metering a fluid into an exhaust system

Abstract

Injector arrangement for metering a fluid, in particular a reducing agent, into an exhaust system (9) of an internal combustion engine, comprising - an injector (2), - a housing (3) with a main body (30) and a cover (31), - wherein a first opening (5) is provided in the cover (31), through which a fluid connection (4) for supplying the fluid to the injector (2) is arranged, - wherein a second opening (6) is further provided in the cover (31), through which a cable for electrical connection to the injector (2) is passed, - wherein the fluid connection (4) is fixed to the first opening in a fluid-tight manner by means of a first caulking connection (11), and - wherein the cable (10) is fixed fluid-tight to the second opening (6) by means of a second caulking connection (12).

Description

Prior ArtThe present invention relates to an injector arrangement for metering a fluid, in particular a reducing agent, into an exhaust system of an internal combustion engine, and to an internal combustion engine having an injector arrangement according to the invention.To reduce exhaust emissions in internal combustion engines, reducing agents, e.g., urea, are injected into an exhaust system of the internal combustion engine. This is done by means of an injector. Since very high temperatures normally prevail in the exhaust system, elevated requirements are to be placed on such urea injectors. Such an injector is known, for example, from DE 10 2013 205 309 A1. In order to reduce the temperatures of the injector, a cooling circuit is provided here, which is routed around the injector. An electrical connection of the injector is guided through the housing by a bushing made of an elastomer. However, in urea injectors of this type, a further problem arises which can result from the occurrence of highly reactive vapours, for example ammonia, which can occur in the exhaust gas tract or in the feed line and attack elastomers and plastics in particular. Such vapors may significantly reduce a lifetime of the injector assembly. Furthermore, DE 10.2009 029 348 A1 is known from the prior art.Disclosure of the InventionThe injector arrangement according to the invention for metering a fluid, in particular a reducing agent, into an exhaust system of an internal combustion engine has the advantage, in contrast, that the injector arrangement is resistant to possibly emerging, highly reactive vapors of the fluid to be injected, the vapors cannot emerge from an injector housing in an uncontrolled manner, and furthermore that the injector arrangement does not damage at high temperatures. This is achieved according to the invention in that the injector arrangement comprises an injector and a housing in which the injector is arranged. The housing is formed in two parts with a main body and a cover. The main body is preferably provided in the shape of a pot. The cover further includes first and second openings. A fluid port for supplying the fluid to the injector is passed through the first opening, and a cable for an electrical terminal of the injector is passed through the second opening. In this case, the fluid connection is fixed to the first opening in a fluid-tight manner by means of a first caulking connection, and the cable is fixed to the second opening in a fluid-tight manner by means of a second caulking connection. Thus, both connections can be fixed in the cover in a fluid-tight manner by means of caulking connections, so that elastomers or other sealing materials, which can be attacked by reactive vapors that may possibly occur, can be dispensed with in particular. Since the injector arrangement is arranged on the exhaust system of the internal combustion engine, high temperatures also occur in this case. In this case, the caulking connections are temperature-resistant, so that damage cannot occur. The caulking connections also have the advantage that even in the event of vibrations or shaking movements, no unintentional loosening of the connections occurs.The dependent claims show preferred developments of the invention.The cover is preferably made of a metal material, in particular aluminum. Further preferably, the main body is also made of a metal material, preferably stainless steel.According to a further preferred embodiment of the invention, the injector arrangement comprises a third fluid-tight caulking connection which is provided between the cover and the main body of the housing. As a result, the cover can also be connected to the main body in a fluid-tight manner in a simple and cost-effective manner.The injector arrangement preferably has a first sleeve through which the cable is passed for electrical contacting. In this case, a fluid-tight seal is provided between the cable and the sleeve, for example by means of a heat-resistant plastic. The second caulking connection is provided between the first sleeve and the cover. This makes it possible to avoid damage to the cable during the caulking process.Further preferably, the injector arrangement comprises a second sleeve with a radially outwardly directed collar. The second sleeve is arranged at the first opening and the fluid connection is passed through the second sleeve. The fluid connection is fixed to the second sleeve in a fluid-tight manner, preferably by means of a welded connection or a caulked connection. The first caulking connection is provided between the cover and the second sleeve, preferably on the collar.Particularly preferably, an injector connection is provided on the injector, which is connected to the second sleeve.Further preferably, the injector arrangement comprises a welded connection between the second sleeve and the fluid connection.Particularly preferably, the injector arrangement is designed in such a way that only caulking connections are provided on the cover for sealing the closed housing. As a result, a housing for the injector arrangement that is particularly cost-effective and simple to produce can be provided.Furthermore, the present invention comprises an internal combustion engine comprising an injector arrangement according to the invention which is arranged on an exhaust system of the internal combustion engine. The injector arrangement is in particular an arrangement for injecting a reducing agent, in particular a urea-water solution.DRAWINGA preferred embodiment of an injector assembly according to the present invention will be described in detail below. In the drawing, the following is: FIG. 1 shows a schematic sectional view of an injector arrangement according to a preferred exemplary embodiment of the invention.Preferred Embodiment of the InventionAn injector arrangement 1 according to a preferred exemplary embodiment of the invention is described in detail below with reference to FIG. 1.As can be seen from FIG. 1, the injector arrangement 1 comprises an injector 2 which is arranged in a housing 3. The injector 2 is configured to meter a fluid, in particular a reducing agent such as a urea-water solution, into an exhaust line 9 of an internal combustion engine.The housing 3 is made of a metallic material, for example stainless steel, and is provided in two parts in this exemplary embodiment. The housing 3 comprises a pot-shaped main body 30 and a cover 31 closing the pot-shaped main body 30.The lid 31 is preferably made of aluminum and the main body 30 is preferably made of stainless steel.As can be seen from FIG. 1, the cover 31 has a first opening 5 and a second opening 6. The first opening 5 serves to receive a fluid connection 4, via which the fluid to be injected is supplied to the injector 2. The second opening 6 serves for the passage of a cable 10 for an electrical contacting of the injector 2. the injector 2 comprises an electrical connection 20 (only indicated schematically in FIG. 1 ) which is connected to the cable 10. In this case, a welded connection 22 is formed between the cable 10 and the electrical connection 20.As can be seen from FIG. 1, the cable 10 is passed through a first sleeve 7. The first sleeve 7 is likewise made of a metallic material, preferably of aluminum. A region between the sleeve 7 and the cable 10 is sealed in a fluid-tight manner, for example by means of a plastic.As can be further seen from FIG. 1, the fluid connection 4 does not open directly on the injector 2, but rather in a second sleeve 8, which in turn is fixed on a tubular injector connection 21. The second sleeve 8 has a radially outwardly directed collar 80. A second welded joint 15 is provided between the second sleeve 8 and the injector port 21.For sealing at the first opening 5 in the cover 31, a first caulking connection 11 is provided between the cover 31 and the second sleeve 8 on the collar 80. A second caulking joint 12 is provided between the first sleeve 7 through which the cable 10 is passed and the cover 31. A third caulking joint 13 is provided between the lid 31 and the main body 30. Furthermore, a welded connection 14 is provided between the fluid connection 4 and the second sleeve 8.Consequently, only caulking connections are provided on the cover 31, so that a temperature-resistant, fluid-tight seal is ensured on the cover 31. Since caulking connections can be produced relatively easily and quickly, production costs can also be significantly reduced. Since the temperatures are relatively high in the region of the exhaust line 9, it is not necessary according to the invention to use elastomer seals or the like which could be damaged due to the high temperatures.Furthermore, according to the invention, the injector 2 can be mounted last in the housing 3, so that for a mounting sequence, free accessibility for contacting the cable 10 at the electrical connection 20 of the injector is possible. Short production times can thereby be achieved and in particular a secure electrical contacting of the electrical connection 20 can be made possible, which does not have to take place in a housing or the like which is difficult to access.It should be noted that alternatively the fluid connection 4 could also be arranged directly on the injector connection 21 and the first caulking could be carried out between the fluid connection 4 and the cover 31. The second sleeve 8 can then be dispensed with.Since a radially outward collar 80 is provided on the second sleeve 8, the first caulking joint 11 can be formed between the collar 80 and the lid 31, whereby damage to the fluid port 4 during the caulking process can be prevented.

Claims

Injector arrangement for metering a fluid, in particular a reducing agent, into an exhaust line (9) of an internal combustion engine, comprising - an injector (2), - a housing (3) having a main body (30) and a cover (31), - wherein a first opening (5) is provided in the cover (31), through which a fluid connection (4) for supplying the fluid to the injector (2) is arranged, - wherein a second opening (6) is further provided in the cover (31), through which a cable for electrical connection to the injector (2) is passed, - wherein the fluid connection (4) is fixed in a fluid-tight manner to the first opening by means of a first caulking connection (11), and - wherein the cable (10) is fixed in a fluid-tight manner to the second opening (6) by means of a second caulking connection (12).Arrangement according to Claim 1, characterized in that the cover (31) is produced from a metal material, in particular from aluminium.An assembly according to any preceding claim, characterised bya third fluid tight caulking connection (13) between the cover (31) and the main body (30) of the housing.Arrangement according to one of the preceding claims, characterized bya first sleeve (7) through which the cable (10) is passed, wherein a fluid-tight seal is provided between the cable (10) and the first sleeve (7) and the second caulking connection (12) is provided between the first sleeve (7) and the cover (31).Arrangement according to one of the preceding claims, characterized bya second sleeve (8) having a radially outwardly directed collar (80), wherein the fluid connection (4) opens out on the second sleeve (8) and is fixed to the second sleeve (8) in a fluid-tight manner, wherein the first caulking connection (11) is provided between the cover (31) and the second sleeve (8).Arrangement according to Claim 5, characterized in that the injector (2) comprises an injector connection (21) which is connected to the second sleeve (8).Arrangement according to claim 5 or 6, characterised bya welded connection between the second sleeve (8) and the fluid connection (4).Arrangement according to one of the preceding claims, characterized in that only caulking connections are provided on the cover (31).Internal combustion engine, comprising an injector arrangement according to one of the preceding claims, which is arranged on an exhaust system (9) of the internal combustion engine.

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