CN112211755A

CN112211755A - Water injection system for an internal combustion engine and injection valve for a water injection system

Info

Publication number: CN112211755A
Application number: CN202010660573.2A
Authority: CN
Inventors: P·诺瓦克; R·马莱茨
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2019-07-10
Filing date: 2020-07-10
Publication date: 2021-01-12
Also published as: DE102019210142A1; KR20210008312A

Abstract

A water injection system for an internal combustion engine, comprising at least one distributor device having at least one tubular distributor pipe and at least one disk-shaped connecting element, at least one injection valve, wherein the injection valve has an annular electromagnetic coil acting on a vertically movable armature, which is connected to the valve element. The injection valve is provided with a hollow cylindrical core, which is surrounded at least in sections by an electromagnetic coil. An inlet connection is formed on the injection valve, via which water from the distributor device can be supplied to the injection valve. The inlet connection piece of the injection valve is inserted into a cup-shaped connecting element of the dispenser device and is thus connected to the dispenser device. It is proposed that the distributor device comprises at least one body which projects from the distributor device into an inlet nipple of the injection valve in the interior of the cup-shaped connecting element, the inlet nipple being penetrated in the axial direction by a through-flow channel which defines an inlet opening for supplying the injection valve with water from the distributor device.

Description

Water injection system for an internal combustion engine and injection valve for a water injection system

Technical Field

The present invention relates to a water injection system for an internal combustion engine. The internal combustion engine may in particular be a gasoline engine.

Background

In order to reduce carbon dioxide emissions, it is necessary to optimize the fuel consumption of the internal combustion engine, for example by increasing the compression or by miniaturization solutions in combination with turbocharging. However, at high engine loads, internal combustion engines are generally unable to operate in an optimum operating point in terms of fuel consumption, since this operation is limited by a tendency to knock and high exhaust gas temperatures. A measure for reducing the tendency to knock and for reducing the exhaust gas temperature is the injection of water, wherein it can be injected directly into the combustion chamber of the internal combustion engine or into the intake system of the internal combustion engine.

In internal combustion engines with water injection devices there is the following risk: the pipes and/or components guiding the water are frozen at low temperatures and damaged due to the ice pressure. To prevent this, the water-conducting lines and/or components are typically drained when the engine is shut down.

DE 102015208472 a1, for example, discloses an internal combustion engine having a water injection system which comprises a water tank for storing water, a pump for delivering water and a water injection valve for injecting water. The pump is connected on the inlet side via a first line to the water tank and on the outlet side via a second line to the water injection valve. To simply empty the pump, the pump is arranged above the water tank so that the emptying can be gravity-driven. Alternatively or additionally, the pump may be operated in the opposite conveying direction.

In order to avoid icing of the injection valves of such injection systems, the injection valves must also be emptied. From published german patent application DE 102015208508 a1, a water injection system for an internal combustion engine is known, which comprises at least two injection valves or water injectors, which are emptied one after the other by reversing the conveying direction of a conveyor assembly. Thus, the injection valve or water injector need not be designed to withstand ice pressure. By emptying the injection valve in sequence, the water present should be reliably removed. The air sucked in via the open injection valve should additionally assist the emptying during the emptying.

Disclosure of Invention

The object on which the invention is based is to specify an injection valve for a water injection system of an internal combustion engine, which injection valve can be emptied particularly simply and/or rapidly in the suck-back operation of the water injection system in order to prevent icing of the injection valve and thus damage to the injection valve.

To solve this task, a water jet system according to the invention is proposed. Advantageous embodiments of the invention are also described below.

According to the invention, a water injection system for an internal combustion engine is proposed. The water spray system includes at least one distributor device having at least one tubular distributor tube and at least one cup-shaped connecting element. The injection system furthermore comprises at least one injection valve, wherein the injection valve has an annular magnet coil for acting on a magnet armature which is movable in a lifting manner and is connected to the valve element, wherein a hollow-cylindrical core is formed on the injection valve, which core is surrounded at least in sections by the magnet coil, wherein an inlet connection is formed on the injection valve, via which inlet connection water from the distributor device can be supplied to the injection valve. In water injection systems, the inlet connection piece of the injection valve is inserted into a cup-shaped connecting element of the distributor device and is thus connected to the distributor device. According to the invention, the distributor device comprises at least one body which projects from the distributor device into the inlet connection of the injection valve in the interior of the cup-shaped connecting element. The body is here traversed in the axial direction by a through-flow channel which defines an inlet opening for supplying the injection valve with water from the distributor device. Here, the dispenser tube, the cup-shaped connecting element and the body form one unit as a dispenser device. The distributor pipe, the cup-shaped connecting element and the body are fixedly connected to one another and form a continuous component.

If the injection valve is inserted into the cup-shaped connecting element when the water injection system is assembled, the body enters into the inlet nipple of the injection valve. The inlet opening of the injection valve is therefore not formed by the inlet connection piece, but by a body inserted into the inlet connection piece. The body thus reduces the free flow cross section available for the water supply of the injection valve. At the same time, the dead volume present in the inlet connection, which must be drained in order to avoid icing of the injection valve, is minimized. I.e. less water has to be sucked back from the injection valve.

The injection valve is therefore supplied with water only via the throughflow channel formed in the body. The through-flow channel extends in an axial direction, preferably coaxially with the longitudinal axis of the injection valve.

Furthermore, the reduced free flow cross section of the flow channel formed in the body also increases the flow speed during the return of water, so that the emptying of the injection valve is at the same time accelerated. In addition, the reduced flow cross section counteracts eddy currents. The result is that, with the same suck-back power of the conveyor assembly used for suck-back, significantly more water is sucked back from the injection valve in the same time. I.e. the risk of ice formation and damage to the injection valve due to ice pressure is significantly reduced when the external temperature is low.

The through-flow channel formed in the body preferably has a cylindrical shape. Furthermore, the diameter of the throughflow channel is preferably selected to be as small as possible in order to achieve as high a flow velocity as possible and to generate an uninterrupted water column during the suck-back. At the same time, the diameter is dimensioned in such a way that a sufficient water supply of the injection valve is also ensured. Preferably, the diameter of the through-flow channel is selected to be smaller than the diameter of the distributor device. The diameter of the through-flow channel may be, for example, 2 to 4 mm. The body forming the through-flow channel preferably has a minimum wall thickness which corresponds to the radius of the through-flow channel or is greater than the radius of the through-flow channel.

The distributor device for supplying water to at least one injection valve is also referred to as a rail. Usually, the rail has at least one cup-shaped connecting element for connecting the injection valve. The connecting element is also referred to as rail cup. The rail cup surrounds the inlet-side end of the injection valve. The dead volume of the rail cup is therefore dependent on the specific configuration of the rail cup and the configuration of the inlet-side end of the injection valve. In the water spray system according to the invention, the body is configured on the distributor device such that, in the case of an injection valve inserted into the cup-shaped connecting element, said body projects into the inlet nipple of the injection valve. Thus, any injection valve, for example a fuel injection valve, can be made as an injection valve for water injection according to the invention by means of the distributor device.

Due to the reduced dead volume in the injection valve and possibly in the cup-shaped connecting element, this connecting element can be emptied more simply and more quickly during the suck-back, so that the risk of icing and thus damage due to ice pressure is significantly reduced. The robustness of the water jet system is also improved accordingly.

According to an advantageous embodiment, it is provided that the body is directly connected to the distributor pipe, in particular welded, and protrudes from the distributor pipe. Thus, a simple and cost-effective construction of the dispenser apparatus can be achieved, and the injection valve can be simply assembled on the dispenser apparatus.

According to an advantageous embodiment, it is provided that the cup-shaped connecting element is directly connected to the body, in particular welded to the body. Thus, a simple and cost-effective construction of the dispenser device can be achieved, and the injection valve can be simply fitted on the dispenser device.

According to an advantageous embodiment, it is provided that the body projects from the distributor pipe and protrudes through the cup-shaped connecting element. In this case, the body can additionally serve to reduce the dead volume which is usually retained in a cup-shaped connecting element of the dispenser device, which connecting element serves to connect the injection valve to the dispenser device. Thus, the amount of water sucked back when emptying the system can be further reduced.

According to an advantageous embodiment, it is provided that the cup-shaped connecting element and the body projecting into the injection valve are of one-piece design. Thus, a simple and cost-effective construction of the dispenser device can be achieved, and the injection valve can be simply fitted on the dispenser device. The body and the cup-shaped connecting element do not have to be subsequently connected to one another, for example welded, but can advantageously be produced in one piece.

According to an advantageous embodiment, it is provided that the body projecting into the inlet connection has a ring, wherein the body contacts the distributor pipe on the ring and/or a cup-shaped connecting element rests on the ring. The body can thus advantageously be well and reliably fixed to the distributor pipe by the collar, for example welded thereto. The support surface of the body, which is formed by the collar on the distributor pipe, advantageously allows a good sealing of the distributor device and a stable fastening of the body on the distributor pipe.

According to an advantageous embodiment, it is provided that the body projecting into the inlet connection has a further collar, wherein the cup-shaped connecting element bears against the further collar. The cup-shaped connecting element can thus advantageously be fixed well and reliably to the body by the further collar, for example by welding to the body on the collar. The support surface formed by the further collar on the cup-shaped connecting element by the body advantageously allows a good sealing of the dispenser device and a stable fastening of the cup-shaped connecting element to the body.

According to an advantageous embodiment, it is provided that the cup-shaped connecting element surrounds the inlet connection of the injection valve and the body inserted into the inlet connection at least in sections.

According to an advantageous embodiment, it is provided that the body projects in a tubular manner into the inlet connection of the injection valve and thus reduces the volume of the supply water in the inlet connection by means of the body.

Preferably, the proposed water injection system further comprises a water tank for storing water and a conveyor train for conveying water. The conveyor assembly is preferably capable of reversing the conveying direction, so that the conveyor assembly can also be used to suck water back from the injection valve. The conveyor unit can be, for example, a motor-driven pump, the conveying direction of which can be reversed in order to be able to suck water back into the water tank.

Drawings

Preferred embodiments of the present invention are explained in detail below with reference to the accompanying drawings. The figures show:

figure 1 is a schematic longitudinal section of an injection system according to the invention according to a first preferred embodiment,

figure 2 is a schematic longitudinal section of a spraying system according to the invention according to a second preferred embodiment,

figure 3 is a schematic longitudinal section of an injection system according to the invention according to a third preferred embodiment,

figure 4 is a schematic longitudinal section of a spraying system according to the invention according to a fourth preferred embodiment,

figure 5 is a schematic longitudinal section of an injection system according to the invention according to a fifth preferred embodiment,

figure 6 is a schematic longitudinal section of a spraying system according to the invention according to a sixth preferred embodiment,

figure 7 is a schematic longitudinal section of a spraying system according to the invention according to a seventh preferred embodiment,

figure 8 is a schematic longitudinal section of a spraying system according to the invention according to an eighth preferred embodiment,

figure 9 is a schematic longitudinal section of an injection system according to the invention according to a ninth preferred embodiment,

FIG. 10 is a schematic view of a water spray system according to the present invention, and

FIG. 11 is a schematic illustration of the injection valves of the water injection system of FIG. 10 on the intake train of an internal combustion engine.

Detailed Description

The water injection system of an internal combustion engine can be seen from fig. 1 to 9. The water injection systems shown in the figures comprise at least one injection valve 1 and a distributor device 7, respectively. The distributor device 7 is also referred to as a rail and serves to distribute water to the different injection valves 1. Thus, water can be distributed to a plurality of injection valves 1, for example to four injection valves 1, by means of a distributor device 7.

The injection valve 1 comprises an annular electromagnetic coil 2 for acting on a lifting armature 3, which is connected to a valve element 4. The valve element 4 is embodied here as a hollow needle and is connected at its end facing away from the armature 3 to a spherical valve closing element 29 for releasing and closing at least one injection opening 30. When the electromagnetic coil 2 is energized, a magnetic field is formed, the magnetic force of which moves the armature 3 together with the valve element 4 and the valve closing element 29 in the direction of the core 5 in order to close the working air gap 31 formed between the core 5 and the armature 3. Here, the spherical valve closing element 29 releases the injection opening 30. If the energization of the electromagnetic coil 2 is subsequently terminated, the armature 3, the valve element 4 and the valve closing element 29 are reset into their initial positions by the spring force of the reset spring 32, so that the valve closing element 29 closes the injection opening 30 again. The core 5 is embodied in the form of a hollow cylinder and is connected via a hollow-cylindrical connecting element 33 to an inlet connection 6 via which the injection valve 1 can be supplied with water from the distributor device 7.

Furthermore, the water jet apparatus also comprises a distributor apparatus 7. The dispenser device 7 is also called a rail. The dispenser device 7 comprises a dispenser tube 40, at least one cup-shaped connecting element 12 and a body 8.

The injection valve 1 of the water jet device is connected with the distributor device 7 via a cup-shaped connecting element 12, also referred to as injector cup holder. The connection may be, for example, a plug connection, a press connection, a clamping connection, a latching connection and/or a screw connection. In this way, the connection of the injection valve 1 to the distributor device 7 can be simplified.

The cup-shaped connecting element 12 surrounds the inlet connection 6 of the injection valve 1 and/or the body 8 inserted into the inlet connection 6 at least in sections. The axial and/or radial gap left between the cup-shaped connecting element 12 and the inlet connection 6 or body 8 can be used to receive a sealing element 13, in particular a sealing ring 13, so that the inlet region of the injection valve 1 is sealed off to the outside.

The cup-shaped connecting element 12 has a shoulder 27, so that the cup-shaped connecting element 12 merges into the distributor device 7 via a section with a reduced inner diameter.

Furthermore, the distributor device 7 comprises a body 8 which projects in the axial direction into the inlet connection 6 of the injection valve 1 and thus reduces the volume in the inlet connection 6 which is supplied with water.

In order to reduce the dead volume in the inlet region of injection valve 1, a body 8 projects into inlet connection 6 of injection valve 1, which body is penetrated by a through-flow channel 9, which defines an inlet opening 10. Thus, the injection valve 1 is supplied with water from the distributor device 7 only via the through-flow channel 9. The outer contour of the body 8 is adapted to the inner contour of the inlet socket 6, for example, such that only a small or no gap remains between the body 8 and the inlet socket 6. Furthermore, the outer contour of body 8 can be adapted to the inner contour of inlet connection 6, so that body 8 reduces the dead volume in the inlet region of injection valve 1. This is not shown in the drawings.

The measures proposed for reducing the dead volume help the injection valve 1 and the cup-shaped connecting element 12 to be emptied quickly by back suction, so that there is no need to worry about damage due to frozen water when the internal combustion engine is shut down and the external temperature is low.

In fig. 2 to 9 different embodiments of the water jet system are shown.

The body 8 can, for example, be directly connected to the distributor pipe 40, in particular welded thereto, and thus project from the distributor pipe 40. This is shown in the embodiments of figures 1 to 7.

A cup-shaped connecting element 12 for receiving the injection valve 1 is connected directly to the body 8 and can be welded thereto. This is shown in the embodiments of figures 1 to 7. In the embodiment of fig. 1 to 4 and 6 to 9, the body 8 projects through the central opening of the cup-shaped connecting element 12 and at the same time projects from the distributor tube 40. The central opening of the cup-shaped connecting element 12 can have a flange, for example. On this flange, the body 8 can contact and be welded with a cup-shaped connecting element 12. The flange may be directed towards the injection valve 1 as shown in the embodiments of fig. 1 and 3, or towards the distributor pipe 40 as shown in the embodiments of fig. 2, 4, 6-9.

In the embodiment shown in fig. 5, the body 8 is not directly connected to the distributor pipe 40. In this exemplary embodiment, the body 8 is formed in one piece with a cup-shaped connecting element 12.

Rings

11a, 11b can be formed on the body 8. In the exemplary embodiment of fig. 1 to 7, a collar 11a is formed on the body 8, on which collar the body 8 rests on the distributor pipe 40 and is welded to the distributor pipe 40 on the collar 11 a. In the embodiment of fig. 6, the cup-shaped connecting element 12 simultaneously bears against the ring 11a from the opposite side.

In the exemplary embodiment of fig. 3 to 5, a further ring 11b is formed on the body 8 in addition to the ring 11 a. In these embodiments, the cup-shaped connecting element 12 rests on the further collar 11 b.

Fig. 8 and 9 show an embodiment in which the distributor pipe 40 is designed as a hose, the body 8 being connected to the distributor pipe 40 designed as a hose, and the cup-shaped connecting element 12 being arranged on the body 8 and being connected thereto. The injection valve 1 is inserted into the cup-shaped connecting element 12. Thus, in the embodiment of fig. 8 and 9, the distributor tube 40, which is configured as a hose, the body 8 and the cup-shaped connecting element 12 also together constitute a distributor device.

From fig. 10 a water injection system with at least one injection valve 1 can be seen. The system shown comprises, for example, four such injection valves 1. The injection valve 1 is connected to a distributor device 7 or rail, to which water is supplied from a water tank 15. Water is supplied to the distributor device 7 by means of the conveyor assembly 16 via the water line 17. The conveyor assembly 16 is currently embodied as a pump which is arranged outside the water tank 15 and can be driven by an electric motor. However, other embodiments of the conveyor assembly 16 are possible. The conveyor assembly 16 can be arranged in the water tank 15 or integrated into the tank bottom. The conveyor assembly 16 is designed in such a way that a reversal of the conveying direction is possible, so that ice-pressure-sensitive lines and/or components of the suck-back emptying system, in particular the injection valve 1, can be passed through.

In order to prevent water from flowing back from the water tank 15 in the direction of the conveyor assembly 16 after emptying, a shut-off element 18, in particular a shut-off valve, can be arranged in the water line 17 upstream of the conveyor assembly 16. Upstream of the shut-off element 18, a filter 19 is arranged, which is intended to prevent harmful particles from entering the conveyor assembly 16 and the injection valve 1.

In the system shown in fig. 10, a return line 22 branches off from the water line 17 downstream of the conveyor assembly 16, which return line ends in the water tank 15. The excess delivery volume of the conveyor assembly 16 can be fed back into the water tank 15 via the return line 22, for example, in order to regulate the pressure in the distributor device 7. For regulating the pressure, a pressure sensor 23 may be provided in the dispenser device 7 or in the water line 17. In order not to suck water from the water tank 15 via the return line 22 during the suck-back process, a check valve 20 is provided in the return line 22. Furthermore, a throttle 21 is upstream of the non-return valve 20, by means of which a blocking pressure can be built up for pressure regulation.

As can be seen from fig. 11, the injection valve 1 is arranged on an intake pipe 24 via which combustion air is supplied to a combustion chamber 25 of the internal combustion engine. Therefore, water injection is performed outside the combustion chamber 25. Water is supplied to the combustion chamber 25 together with the combustion air. Fuel is injected directly into the combustion chamber 25 by means of a fuel injector 26.

As shown in fig. 5 and 6, the body 8 may also extend into the distributor tube 40. Thus, a reservoir may be formed in the dispenser tube 40 around the body 8 in which water remaining in the dispenser tube 40 may collect when the dispenser tube 40 is emptied. Thus, the body 8 projecting into the distributor pipe 40 ensures that water remaining in the distributor pipe 40 cannot flow into the injection valve 1.

Of course, other embodiments and hybrids of the illustrated embodiments are possible.

Claims

1. A water injection system for an internal combustion engine, the water injection system comprising:

at least one dispenser device (7) having at least one tubular dispenser tube (40) and at least one cup-shaped connecting element (12),

at least one injection valve (1), wherein the injection valve (1) has an annular magnetic coil (2) for acting on a vertically movable armature (3) which is connected to a valve element (4), wherein a hollow-cylindrical core (5) is formed on the injection valve (1), which is surrounded at least in sections by the magnetic coil (2), wherein an inlet socket (6) is formed on the injection valve (1), via which inlet socket water from a distributor device (7) can be supplied to the injection valve (1), wherein the inlet socket (6) of the injection valve (1) is inserted into a cup-shaped connecting element (12) of the distributor device (7) and is therefore connected to the distributor device (7),

characterized in that the distributor device (7) comprises at least one body (8) which projects from the distributor device (7) into the inlet nipple (6) of the injection valve (1) in the interior of the cup-shaped connecting element (12), said body being penetrated in the axial direction by a through-flow channel (9) which defines an inlet opening (10) for supplying the injection valve (1) with water from the distributor device (7).

2. The water spray system of claim 1 wherein the body (8) is directly connected, in particular welded, with the distributor pipe (40) and protrudes from the distributor pipe (40).

3. The water jet system according to any one of the preceding claims, characterized in that the cup-shaped connecting element (12) is directly connected with the body (8), in particular welded with the body (8).

4. The water spray system of any one of the preceding claims wherein the body (8) protrudes from the distributor tube (40) and through the cup-shaped connecting element (12).

5. The water injection system according to any one of the preceding claims wherein the cup-shaped connecting element (12) and the body (8) projecting into the injection valve (1) are constructed as one piece.

6. Water spray system according to any one of the preceding claims, characterized in that the body (8) projecting into the inlet nipple (6) has a collar (11a), wherein the body (8) is in contact with the distributor pipe (40) on the collar (11a) and/or the cup-shaped connecting element (12) bears against the collar (11 a).

7. Water spray system according to any one of the preceding claims, characterized in that the body (8) projecting into the inlet nipple (6) has a further collar (11b), wherein the cup-shaped connecting element (12) bears against the further collar (11 b).

8. The water injection system according to any one of the preceding claims, characterized in that the cup-shaped connecting element (12) surrounds at least in sections an inlet nipple (6) of the injection valve (1) and a body (8) inserted into the inlet nipple (6).

9. The water injection system according to any one of the preceding claims, characterized in that the body (8) projects tubular into the inlet connection (6) of the injection valve (1) and thus the volume providing feed water in the inlet connection (6) is reduced by the body (8).

10. A water injection system according to any one of the preceding claims further comprising a water tank (15) for storing water and a conveyor set (16) for conveying water, wherein the conveying direction of the conveyor set (16) is preferably reversible in order to enable sucking water back into the water tank (15).