The present invention relates to a pre-assemblable constructional unit of a fresh air system for an internal combustion engine, in particular of a motor vehicle. The invention furthermore relates to a fresh air system equipped with at least one such constructional unit.
Internal combustion engines, in particular in motor vehicles, have a fresh air system that, as a rule, has a distribution chamber from which lead individual fresh air canals to combustion chambers of cylinders of the internal combustion engine. Furthermore, modern internal combustion engines have a fuel injection assembly that inject fuel, by means of injection nozzles, directly into the combustion chambers of the cylinder or into the previously-mentioned fresh air canals that lead to the combustion chambers. Electrical cabling is required to actuate the injection valves or injection nozzles, which electrical cabling comprises the power supply lines and/or signal lines for controlling or for operating electric coils and the like. The assembly of internal combustion engine is comparably expensive, in particular when individual components are intended to be accessible or easily de-assembled for maintenance purposes.
The present invention addresses the problem of demonstrating a way for a simplified construction of an internal combustion engine that is characterised by an economical manufacturability and/or simple maintenance.
This problem is solved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.
The invention is based on the general concept of equipping a fresh air system for an internal combustion engine with a separately manufacturable, pre-assemblable constructional unit that comprises both an electrical unit as well as a fuel unit. The electrical unit has an electric coil for each of the plurality of cylinders of the internal combustion engine in order to actuate a fuel injection valve. Furthermore, the electrical unit comprises an electrical cabling for actuating the coils. It has a plurality of insertion openings that are oriented parallel to one another that respectively penetrate the coils coaxially. Moreover, the electrical unit has a plastic body that is injection moulded onto the coils and onto the cabling. In contrast thereto, the fuel unit has a tubular connecting piece associated with each coil for receiving an injection valve. Furthermore, the fuel unit comprises a distributor housing that contains a fuel distribution chamber that has connection openings and to which the connecting pieces are welded or soldered in such a manner that they are directed toward one another in a parallel fashion and are furthermore connected to the distributor chamber in a communicating manner. Moreover, the fuel unit and the electrical unit are coordinated with one another in such a manner that for the purposes of assembly, the connecting pieces of the fuel unit can be coaxially inserted into the insertion openings of the electrical unit. By means of the suggested method of construction, both the electric components are combined into the electrical unit, while the fuel components are assembled into the fuel unit. By means of the connecting pieces and the insertion openings, the units, which are respectively independent of one another and are separately pre-assemblable, can be combined into a constructional unit that then comprises the electric components and the fuel components and that is furthermore completely pre-assemblable independent of the fresh air system. By the targeted grouping and assembling of different components of the internal combustion engine, the assembly process can be simplified as a whole.
An embodiment, which is particularly advantageous, is one in which the electrical unit has a tubular body for each coil, said tubular body being arranged coaxially to each respective coil, and said tubular body, when in the assembled state, furthermore protrudes with one end section of the plastic body on one side facing away from the fuel unit, and finally said tubular body forms a section of the associated insertion opening. Advantageously, the connecting pieces are dimensioned in such a manner that in the assembled state, they extend through the respective insertion opening and, in particular, protrude over the end section of the respective tubular body. This special method of construction makes if possible for no sealings to be required between the fuel unit and the electrical unit or between the individual connecting pieces and the corresponding insertion openings since the fuel arrives directly into the respective injection chamber from the connecting pieces by means of the injection valves inserted into the connecting pieces, the constructional unit and, in particular, the electrical unit being installed on said injection chamber. In the assembled state, thus only one sealing is required between the electrical unit and a housing of the fresh air system or between the protruding end sections of the tubular bodies and the housing of the fresh air system in the region of the fuel injection openings. In this manner, a sufficient sealing can be realised with reduced expenditure, which sealing particularly prevents an emission of fuel into the surroundings of the internal combustion engine.
Additional important features and advantages of the invention can be found in the dependent claims, in the drawings, and in the pertinent description of the figures with reference to the drawings.
It is understood that the features described above and those to be described in what follows can be used not only in the particular cited combination; but also in other combinations or independently without departing from the scope of the present invention.
Preferred embodiments of the invention are shown in the drawings and are described in more detail in the following description, the same reference numerals referring to components which are the same or functionally the same or similar.
It is schematically shown in
Corresponding to
For a plurality of cylinders of the internal combustion engine that are not shown here, the electrical unit 3 has respective electric coils 5 by means of which a fuel injection valve, which is not shown here, can respectively be activated. In the example, the electrical unit 3 comprises four coils 5. However, this number is random and results from the number of cylinders. The electrical unit 3 furthermore comprises an electrical cabling 6, by means of which the coils 5 can be actuated. The cabling 6 comprises for this purpose a plurality of lines 7 and advantageously a shared electric plug and socket connection 8. The electrical unit is moreover equipped with a plastic body 9, which is represented as transparent in
The fuel unit 4 has a tubular connecting piece 12 for each coil 5, said connecting piece being configured to respectively receive an injection valve. The fuel unit 4 furthermore has a distributor housing 13 that contains or encloses a fuel distribution chamber 14 that is recognisable in the cross sectional representation of
In the assembled state that is a recognisable in
The electrical unit 3 moreover comprises seat regions 20 integrally formed on or configured on the plastic body 9. Said seat regions are respectively arranged coaxially to one of the insertion openings 10. If, as is shown in
The tubular bodies 17 of the electrical unit 3 can, corresponding to the preferred embodiment shown here, be respectively arranged coaxially to one of the seat regions 20. Furthermore, they carry on their protruding end section a ring sealing 25. For example, the respective end section 19 can be equipped with a radially protruding, circumferential flange 26. The respective ring sealing 25 in the assembled state dips into the counter seat region 21 and effects there a radial sealing between the injection canal 23 and the end section 19. In this manner, both an intake of unmetered air and an emission of fuel can be prevented.
In the embodiment shown here, the tubular body 17 is respectively configured in such a manner that it has a supporting section 27, which is arranged in the interior of the plastic body 9 and which encloses the respective coil 5. At the same time, electrical connections can be configured on this supporting section 27, said electrical connections electrically contacting coils 5 that are arranged in the interior of the supporting section 27 and furthermore electrically contacting lines 7 running outside the supporting section 27.
Corresponding to
The constructional unit 1 can, for example, be attached to the housing 18 of the exhaust gas system 2 by means of webs 29. For example, these webs 29 have through-openings that make it possible for the constructional unit 1 to be screw-connected on the housing 18. In the shown preferred example, the webs 29 are attached to the fuel unit 4, and namely preferably on its distributor housing 13, being welded or soldered thereon, for example. It is notable that the electrical unit 3 rests solidly on the housing exclusively by means of a plug and socket connection, however it is not directly attached thereto. Furthermore, the fuel unit 4 rests solidly on the electrical unit 3 by means of a plug and socket connection, however is not directly attached thereto. A fastening of the fuel unit 4 on the housing 18 is achieved by means of the webs 29 by means of which a fastening of the fuel unit 4 onto the electrical unit 3 as well as a fastening of the electrical unit 3 onto the housing 18 is also indirectly realised.
The connecting pieces 12 can, corresponding to
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP08/54276 | 4/9/2008 | WO | 00 | 3/19/2010 |
Number | Date | Country | |
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60910885 | Apr 2007 | US |