Method and device for emptying a water line on an internal combustion engine as needed

Abstract

Method for emptying, as needed, a water line which, on an internal combustion engine of a motor vehicle, supplies water to an addition device for the combustion air flow supplied to the combustion chambers of the internal combustion engine, characterized in that, in conjunction with a shutdown of the motor vehicle, at least as needed, the water still present in a wide area of the water line is conveyed by means of a conveying device which, when the internal combustion engine is in operation, can convey the water from a storage container to the addition device, by conveying air through the addition device into a component which carries the combustion air flow, and wherein an open-pore storage structure for conveyed water is provided in the component which carries the combustion air flow.

Description

The invention relates to a method for emptying a water line as required, which leads water on an internal combustion engine of a motor vehicle to an addition device for the combustion air flow supplied to the combustion chambers of the internal combustion engine. The invention further relates to an advantageous apparatus for carrying out the method according to the invention.The publication DE 10 2014 222 463 A1 shows the prior art. In future, there will be an increasing number of vehicle internal combustion engines in which water is added to the combustion of fuel at least at certain operating points. This is preferably taken from a storage container carried along and conveyed by means of a conveying device to at least one injection valve which injects a specific amount of water, for example, into the air intake system of the internal combustion engine or into (in each case) one of its combustion chambers. The present invention relates to such a system, wherein the water injection into the air intake system of the internal combustion engine takes place via a so-called addition device, which can be designed in a wide variety of ways.If the motor vehicle is shut down for a period of several hours after operation in the cold season, water which is still located in a feed line or in the water line to the addition device could freeze, as a result of which water supply to the air intake system of the internal combustion engine would not be possible for a relatively long period of time after the internal combustion engine has been restarted. Also, said water conduit itself could be damaged by ice pressure.To demonstrate a remedy for these described problems is the object of the present invention.The solution to this object is characterized for a method according to the preamble of claim 1, in that, in conjunction with the motor vehicle being shut down, at least as required, the water still located in a wide region of the water line is conveyed by means of a conveying device, which during operation of the internal combustion engine can convey the water from a storage container to the addition device, by conveying air through the addition device into a component which conducts the combustion air stream. A corresponding device for carrying out the method according to the invention is the subject matter of the dependent claims.It is proposed to convey the water (as a liquid at risk of freezing) from the water line mentioned after the vehicle has been shut down, at least in the cold season, into a component through which the combustion air flow is guided during operation of the internal combustion engine. This is done by means of an air stream, wherein advantageously the said addition device is also freed from water present therein, i.e. flushed with air. This air or this air flow is advantageously conveyed by the same conveying device, which also conveys the water as required during operation of the internal combustion engine. For this purpose, a suitably controllable changeover valve is provided in an intake line of this conveying device, which is in particular designed as a pump, so that this conveying device can selectively convey water from the storage container or air from the environment.By discharging the water discharged from the water line into the air intake system of the internal combustion engine, this water advantageously does not reach the environment in an uncontrolled manner, so that there is no risk of the vehicle user being misconfirmed. Preferably, the discharged water either passes from individual air intake pipes into a so-called combustion air collector, into which alternatively to a water injection into individual air intake pipes the aforementioned addition device can also open, i.e. into which during operation of the internal combustion engine the water can also be injected if necessary. In such a combustion air collector, from which a plurality of combustion chambers of the multi-cylinder internal combustion engine are supplied with combustion air, there is no such large air throughput at all in part load operating points of the internal combustion engine that water located therein would be entrained immediately and completely into a single combustion chamber, so that after the internal combustion engine is restarted, a uniformly and temporally extended water discharge from this combustion air collector is ensured. In particular, the water discharged in connection with a shutdown of the motor vehicle into the combustion air collector (or into the structural element carrying a combustion air flow of the internal combustion engine) will collect at the lowest point of this combustion air collector, viewed in the direction of gravity.There or generally in the component guiding the combustion air flow, however, the water accumulated there could freeze. Depending on the geometric shape and shape, smaller separate ice particles could then form, which could later be disadvantageously entrained into the combustion chambers as a larger frozen water mass. In order to prevent this, it is further proposed to provide an open-pored storage structure for the water conveyed in according to the invention in the combustion air collector or generally in the structural element guiding the combustion air flow. This storage structure can be a sponge or designed in the manner of such a sponge, for example an open-pored mat made of plastic or stainless steel. The water brought in in conjunction with parking the motor vehicle collects in this open-pore structure and then freezes in this structure.

Claims

Method for emptying a water line, as required, which leads water on an internal combustion engine of a motor vehicle to an addition device for the combustion air stream fed to the combustion chambers of the internal combustion engine, characterized in thatthe water still located in a wide region of the water line is conveyed, at least as required, by means of a conveying device, which can convey the water from a storage container to the addition device during operation of the internal combustion engine, by conveying air through the addition device into a structural element which conducts the combustion air stream, and wherein an open-pored storage structure for conveyed water is provided in the structural element which conducts the combustion air stream.Device according to claim 1, wherein the sponge-like storage structure is provided lying below within the structural element which is designed as a combustion air collector and conducts the combustion air stream, as viewed in the direction of gravity.