阅读说明：本技术 内燃机的水喷射装置 (Water jet device for internal combustion engine ) 是由 P·格拉代尔 I·布拉克 P·申克 于 2018-05-30 设计创作，主要内容包括：本发明涉及一种内燃机(2)的水喷射装置,包括用于储存水的水箱(5),用于将水喷射到所述内燃机(2)中的至少一个水喷射器(6),用于将水从所述水箱(5)输送到所述水喷射器(6)中的输送元件(3),提出,所述水喷射装置(1)还包括截止元件(11),所述截止元件布置在所述水箱(5)和所述输送元件(3)之间,并且所述截止元件设置为用于将所述截止元件(11)和所述水喷射器(6)之间的系统压力保持在一定水平上,以避免处于所述水箱(5)和所述输送元件(3)之间的水蒸发。(The invention relates to a water injection device for an internal combustion engine (2), comprising a water tank (5) for storing water, at least one water injector (6) for injecting water into the internal combustion engine (2), a conveying element (3) for conveying water from the water tank (5) into the water injector (6), it is proposed that the water injection device (1) further comprises a shut-off element (11) which is arranged between the water tank (5) and the conveying element (3) and which is provided for maintaining a system pressure between the shut-off element (11) and the water injector (6) at a level such that evaporation of water between the water tank (5) and the conveying element (3) is avoided.)

1. A water injection device of an internal combustion engine (2), comprising:

-a water tank (5) for storing water,

-at least one water injector (6) for injecting water into the internal combustion engine (2),

-a conveying element (3) for conveying water from the water tank (5) into the water injector (6),

characterized in that the water jet device (1) further comprises a shut-off element (11) arranged between the water tank (5) and the conveying element (3) and arranged for maintaining the system pressure between the shut-off element (11) and the water jet (6) at a level to avoid evaporation of water between the water tank (5) and the conveying element (3).

2. The water jet device according to claim 1, characterized in that the shut-off element (11) is configured as a shut-off valve (11 a).

3. Water jet device according to any one of the preceding claims, characterized in that the shut-off element (11) is provided for keeping the system pressure between the shut-off element (11) and the water jet (6) greater than 3 x 10 ⁵Pa, preferably greater than 5X 10 ⁵Pa is less than 10X 10 ⁵Pa level.

4. The water jet device according to any one of the preceding claims, characterized in that the shut-off element (11) is provided for being brought into the open position, in particular by energization, upon activation of the water jet.

5. Water jet device according to any one of the preceding claims, characterised in that the shut-off element (11) is arranged to be closed in the absence of current.

6. The water jet device according to any one of the preceding claims, characterized in that a pressure reservoir (14) is provided between the conveying element (3) and the water jet (6).

7. A water injector device as claimed in any one of the foregoing claims, characterized in that the water injector device (1) comprises a return line (15), wherein the return line (15) is provided for leading water from the area between the conveying element (3) and the water injector (6) back into the water tank (5).

8. A water monitor according to claim 7 wherein a check valve (16) is arranged in the return line (15).

9. The water spray device according to any one of the preceding claims characterized in that the water spray device (1) comprises a plurality of water sprays (6) connected to a distributor (9), wherein the distributor (9) is arranged between the shut-off valve (11) and the water sprays (6).

10. The water jet device according to any one of the preceding claims, characterized in that the shut-off element (11) is provided for being brought into the open position, in particular by energization, when the direction of travel of the conveying element (3) is changed.

11. An internal combustion engine comprising a water injection device (1) according to any of the preceding claims for injecting water.

Technical Field

The present invention relates to a water jet device for an internal combustion engine and to such an internal combustion engine.

Background

Due to the increasing demand for reduced carbon dioxide emissions, internal combustion engines are increasingly being optimized with regard to fuel consumption. However, known internal combustion engines cannot be operated optimally with regard to consumption in operating points with high load, since the operation is limited by a tendency to knock and high exhaust gas temperatures. One possible measure for reducing the tendency to knock and for reducing the exhaust gas temperature is to inject water. Here, there is usually a separate water injection system in order to be able to achieve the water injection. Thus, for example, a water injection system for an internal combustion engine is known from DE 102015208476 a 1.

In water injection systems for internal combustion engines, a water tank is usually provided so that water is available at any time for injection into the intake tract or combustion chamber of the internal combustion engine. In addition, in such water injection systems, water can be taken from the exhaust gas system of an internal combustion engine in the motor vehicle or from the surroundings of the motor vehicle, for example, by means of a water intake device and supplied, for example, also to a water tank. Water can be delivered, for example, by means of a pump from a water tank via a distributor device to an injection valve, through which the water is then injected, for example, into the intake manifold or combustion chamber of an internal combustion engine. For this purpose, as in injection systems for fuel, a distributor device can be provided for storing and distributing water to a plurality of injection valves, through which water can then be injected.

Between operating points where the water injection system is activated, the pump for delivering water is turned off. I.e., the water is stationary in the hydro jet and piping of the hydro jet system. Due to the high temperature of the part of the internal combustion engine near the water injection system, the standing water can be heated and possibly evaporate. This effect is exacerbated where the vehicle is traveling at high altitudes where air pressure is lower. A functional impairment may occur when the water injection system is restarted due to steam formation, since the system pressure can only build up with a delay due to steam. Thus, the water jet system is delayed in preparation for operation. Due to this delayed operational readiness, temperature peaks in the exhaust gas and knocking events in the combustion can occur in the event of rapid load jumps.

Disclosure of Invention

According to the invention, a water injection system for an internal combustion engine is proposed. The water injection device comprises a water tank for storing water, at least one water injector for injecting water into the internal combustion engine, a conveying element for conveying water from the water tank into the water injector. According to the invention, the water injector further comprises a shut-off element which is arranged between the water tank and the conveying element and which is provided for maintaining the system pressure between the shut-off element and the water injector at a level such that evaporation of water situated between the water tank and the conveying element is avoided.

Compared with the prior art, the water injection device of the internal combustion engine has the following advantages: the stop member may be closed when the area between the stop member and the hydro jet is filled with water. An enclosed area is formed between the shut-off member and the hydro jet by closing the shut-off member. Thus, the system pressure in this region between the shut-off element and the water injector can also be kept above the steam pressure of the water in the deactivated phase of the water injection device. Thus, steam formation of water is avoided and a short pressure build-up time and a fast spray release are ensured. The maintenance of the system pressure can be assisted here, for example, by an additional pressure accumulator and/or by an elastic element in the water jet system which operates as a pressure accumulator.

The shut-off element can also advantageously be opened when the vehicle is parked, in order to be able to empty the water in the region between the shut-off valve and the water injector by means of the return delivery of the delivery element, so that the water injector and the lines are protected against damage by frozen and expanding water.

Since a shut-off valve is arranged between the water tank and the conveying element, the conveying element can advantageously be protected from flooding by water by closing the shut-off element after emptying the region between the shut-off element and the water injector. The connection from the conveying element to the water tank can advantageously be interrupted by closing the shut-off element, so that the conveying element is not flooded by water from the water tank. Thereby, the pump can also be arranged, for example, below the level of the water in the water tank, without the pump being flooded by water from the water tank. Therefore, a higher degree of freedom can be achieved at the time of vehicle assembly. This is important in particular if a system with a water tank and a conveying element is present in the rear of the vehicle, since the installation space available in the vertical direction is very limited.

Further advantageous embodiments and developments of the invention are possible by the features specified in the dependent claims.

According to an advantageous embodiment, it is provided that the shut-off element is designed as a shut-off valve. The shut-off valve ensures that water is located in the area between the shut-off valve and the hydro jet.

According to an advantageous embodiment it is provided that said shut-off valve is arranged for keeping the system pressure between the shut-off valve and the water injector above 3 x 10 ⁵Pa, preferably greater than 5X 10 ⁵Pa, particularly preferably greater than 5X 10 ⁵Pa is less than 10X 10 ⁵Pa level. Thus, on the one hand, the formation of steam in the region between the shut-off element and the water injector can be avoided, and on the other hand, when water is injected into the intake passage of the internal combustion engine, wetting of the wall surface of the water on the intake passage can be avoided. During water spray activation, components of the water spray system are cooled by replenishing influent water from the tank. However, in the presence of high temperature and quiescent medium water in the water spray system, the temperature rises until steam is formed. This effect is exacerbated at high altitudes, such as when driving in mountainous areas, due to the reduced air pressure and the concomitant reduced evaporation temperature. If the system pressure between the stop member and the water jet is greater than 3X 10 ⁵Pa, preferably greater than 5X 10 ⁵Pa is less than 10X 10 ⁵At the level of Pa, the steam formation effect is counteracted and the steam formation can also be prevented without activating the water injection, since the evaporation temperature of the water rises to 140 ℃.

According to an advantageous embodiment, it is provided that the blocking element is provided for being brought into the open position when the water jet is activated, in particular by being energized. The shut-off valve is preferably designed as an electrically operated shut-off valve, which can be controlled in a simple and precise manner by the control unit. In case of activation of the water spray, the shut-off valve is energized and thus enables water delivery from the water tank into the water spray. In the case of non-activated water injection, the shut-off valve is also switched currentless and thus maintains the system pressure at a sufficient pressure level so that the heated water does not evaporate.

According to an advantageous embodiment, it is provided that the blocking element is closed when no current is present. Thus, the blocking element can be closed, for example, by a restoring force caused by a spring element. The advantage thereby results in that the pressure in the area between the shut-off valve and the water injector can be maintained without activating the water injection. In operation with activated water injection, the shut-off valve can be energized and thereby opened in order to enable the delivery of water from the water tank. In the case of parking the vehicle after emptying the region between the shut-off element and the water jet, the shut-off element is closed currentless and thus provides protection against flooding for the conveying element.

According to an advantageous embodiment, a pressure accumulator is provided between the conveying element and the water injector. Such a pressure accumulator can advantageously assist in maintaining the system pressure by closing the shut-off element.

According to an advantageous embodiment it is provided that the water injector comprises a return line, wherein the return line is provided for leading water from the region between the conveying element and the water injector back into the water tank. The return line here serves as a bypass for water, through which water can flow from the region between the delivery element and the hydro jet, bypassing the delivery element and the shut-off valve, back into the water tank.

According to an advantageous embodiment, a check valve is arranged in the return line. The check valve allows water to flow in only one direction from the area between the delivery member and the hydro jet to the water tank. The system pressure between the shut-off valve and the hydro jet can advantageously be determined by the design of the check valve, i.e. for example by the pressure required for opening the check valve.

According to an advantageous embodiment, it is provided that the water injector device comprises a plurality of water injectors which are connected to a distributor, wherein the distributor is arranged between the stop element and the water injectors.

According to an advantageous embodiment, it is provided that the blocking element is configured to be brought into the open position when the direction of travel of the conveying element is changed, in particular by being energized. Thus, water can be supplied back to the water tank by a simple control of the shut-off element.

Furthermore, an internal combustion engine comprising a water injection device for injecting water according to the invention is advantageous. Here, the advantages obtained in connection with the water jet device according to the invention are also obtained. Particularly preferably, the internal combustion engine operates on the otto principle and on gasoline. The following internal combustion engines may be understood as internal combustion engines operating according to the otto principle: in the internal combustion engine, the combustion of gasoline or a gasoline-air mixture is effected by an external ignition device in the form of a spark plug. Since the ignition time is precisely predetermined by ignition from an external source in such an internal combustion engine, the advantages described in connection with the water injection device according to the invention can be utilized to a full extent. By the short pressure build-up time and the rapid spray release of the water spray device according to the invention, the tendency to knock can also be avoided in the event of rapid load jumps.

Drawings

Embodiments of the invention are illustrated in the drawings and are explained in detail in the following description. The figures show:

figure 1 is a very simplified schematic view of an internal combustion engine with a water injection arrangement according to a first embodiment of the invention,

figure 2 is a simplified schematic view of a water jet assembly according to a first embodiment,

FIG. 3 is a simplified schematic view of a water jet assembly according to a second embodiment of the present invention.

Detailed Description

The water jet device 1 of the internal combustion engine 2 is explained in detail according to a first embodiment with reference to fig. 1 and 2. The internal combustion engine 2 is operated in particular according to the otto principle and with direct gasoline injection.

In fig. 1 is schematically shown an internal combustion engine 2 having a plurality of cylinders, and a part of a water injection device 1 according to the invention. Each cylinder of the internal combustion engine 2 comprises a combustion chamber 20 in which a piston 21 can reciprocate. Furthermore, each cylinder of the internal combustion engine 2 has an intake passage 22, and air is supplied to the combustion chamber 20 via the intake passage 22. The exhaust gas is discharged via the exhaust passage 23. For this purpose, an intake valve 25 is arranged on the intake channel 22 and an exhaust valve 26 is arranged on the exhaust channel 23. Further, reference numeral 24 designates a fuel injection valve.

Furthermore, a water injector 6 is arranged on the intake channel 22, which water injector injects water into the intake channel 22 of the internal combustion engine 2 via the control unit 10. In this embodiment, one water injector 6 is provided per cylinder. Alternatively, for better preparation or to increase the maximum amount of water that can be injected per combustion cycle, two water injectors may be arranged per cylinder.

Furthermore, the water jet device 1 has a conveying element 3, which is designed as a pump, for example, and an electric drive 4 for driving the conveying element 3. As can be seen from fig. 1 and 2, a water tank 5 for storing water is also provided, which is connected to the conveying element 3 via a first line 7. The second conduit 8 connects the conveying element 3 with a distributor 9 or rail to which a plurality of hydro jets 6 are connected.

Between the water tank 5 and the feed element 3, a shut-off element 11 is arranged, which divides the first line 7 into a first line section 7a and a second line section 7b and which is controlled by a control unit 10.

The shut-off element 11 is arranged to maintain the system pressure between the shut-off element 11 and the water injector 6 at a level at which the water between the water tank 5 and the conveying element 3 does not evaporate. The shut-off element 11 can be, for example, a shut-off valve 11a, for example, an electrically actuated shut-off valve 11 a. The shutoff valve 11a is, for example, a two-position two-way selector valve.

The stop element 11 is especially arranged for positioning between the stop element 11 and the water jet 6The system pressure in the region of (a) is maintained at greater than 3 x 10 ⁵Pa, preferably greater than 5X 10 ⁵Pa level. In order to be able to achieve an optimized water injection and thus an optimized combustion, the shut-off valve 11a is arranged in such a way that the system pressure in the region between the shut-off element 11 and the water injector 6 is kept at less than 10 × 10 ⁵Pa。

The shut-off valve 11a is in particular designed such that it is closed without current, for example by the closing force of the spring element 12. In the case of inactive water injection, the shut-off valve 11a is closed currentless and thus the system pressure is maintained at a level sufficient for avoiding steam formation (first switching state of the shut-off valve 11 a). In case the water spray is activated, the shut-off valve 11a is energized and thus the delivery of water from the water tank 5 to the water sprayer 6 is enabled (second switching position of the shut-off valve 11 a).

Furthermore, the shut-off valve 11a is provided for being opened by energization in the event of a change in the direction of operation of the conveying element 3, i.e. for example in the event of a change in the direction of rotation of the pump (in which water is supplied back into the water tank 5) (second switching position of the shut-off valve 11 a).

The water jet device 1 includes a plurality of water jets 6. For this purpose, a distributor 9, for example a water rail, is provided in the water jet device 1, to which a plurality of water jets 6 can be connected and which distributes the water onto the water jets 6.

In fig. 2, the shut-off valve 11a is in a first switching position, i.e. a closed position.

The formation of steam in the water jet device 1 in the area between the shut-off element 11 and the conveying element 3 can be prevented and avoided by providing the shut-off element 11 between the water tank 5 and the conveying element 3. Thus, the water injection device 1 is ready to operate in the deactivated operating point and can be quickly put into use when the combustion of the internal combustion engine 2 requires water injection.

Furthermore, the water jet device 1 comprises in this embodiment a pressure reservoir 14. The pressure accumulator 14 is provided for equalizing pressure fluctuations and can assist in this to maintain the system pressure in the region between the shut-off element 11 and the water injector 6 with the shut-off valve 11 closed. For this purpose, a pressure reservoir 14 may be arranged, for example, between the conveying element 3 and the water injector 6. However, the resilient member in the water jet device 1, such as the resilient portion of the distributor tube 9, may also function as the pressure reservoir 14.

The second embodiment of the water jet arrangement 1 according to the invention of fig. 3 differs from the first embodiment in that a return line 15 is provided in the second embodiment of the water jet arrangement 1. Water can flow from the area between the conveying element 3 and the water injector 6 back into the water tank 5 via a return line 15. In this embodiment, a check valve 16 is arranged in the return line 15. The check valve 16 allows water to flow back into the water tank 5 from the area between the conveying element 3 and the water injector 6, but at the same time prevents flow in the other direction. The check valve 16 is arranged for being opened currentless (open position of the check valve 16) by the water pressure in the area between the conveying element 3 and the water injector 6, which acts against the force of e.g. the spring element 13. The check valve 16 closes (closed position) when the pressure in the area between the conveying element 3 and the hydro jet 6 can no longer overcome the force of the spring element 13. In fig. 3, the check valve 16 is in the closed position.

Of course, further embodiments and mixed forms of the embodiments shown are also possible.