DE102020205582A1 - Injection valve for a water injection system of an internal combustion engine and water injection system with such an injection valve - Google Patents

Abstract

For an injection valve (1) for a water injection system (50) of an internal combustion engine (100), comprising an annular magnetic coil (2) for acting on a liftable armature (3) which is connected to a valve member (4), further comprising a hollow cylindrical core (5), which is at least partially surrounded by the magnetic coil (2) and is formed on an inlet connector (6) or is connected to an inlet connector (6), wherein the injection valve (1) can be supplied with water via the inlet connector (6), it is proposed that a body (8) is inserted into the inlet connector (6) through which a flow channel (9) passes in the axial direction (a), the flow channel (9) formed in the body (8) having an inlet opening ( 10) for supplying the ice injection valve (1) with water, the body (8) being pressed into a receptacle (60) of the inlet connector (6).

Description

State of the art

The invention relates to an injection valve for a water injection system of an internal combustion engine with the features of the preamble of claim 1. The internal combustion engine can in particular be a gasoline engine. The invention also relates to a water injection system for an internal combustion engine with an injection valve according to the invention.

To reduce carbon dioxide emissions, it is important to optimize the fuel consumption of internal combustion engines, for example by increasing compression or through downsizing concepts in combination with turbocharging. With a high engine load, however, the internal combustion engine can generally not be operated at an operating point that would be optimal with regard to fuel consumption, since the operation is limited by the tendency to knock and high exhaust gas temperatures. Measures for reducing the tendency to knock and / or lowering the exhaust gas temperatures provide for the injection of water, it being possible for the injection to take place directly into a combustion chamber of the internal combustion engine or into an intake tract of the internal combustion engine.

In internal combustion engines with water injection, there is a risk that pipes and / or components carrying water will freeze at low temperatures and be damaged by ice pressure. To prevent this, the water-carrying lines and / or components are usually emptied when the engine is switched off.

the DE 10 2015 208 472 A1 shows an example of an internal combustion engine with a water injection device which comprises a water tank for storing water, a pump for conveying the water and a water injection valve for injecting water. On the inlet side, the pump is connected to the water tank via a first line and on the outlet side to the water injection valve via a second line. For easy emptying of the pump, it is arranged above the water tank so that it can be emptied by gravity. Alternatively or in addition, the pump can be operated in the opposite direction of delivery.

To prevent the injection valves of such an injection system from icing up, they must also be emptied. From the published patent application DE 10 2015 208 508 A1 a water injection device 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 conveying element. The injection valves or water injectors therefore do not have to be designed to be resistant to ice pressure. The fact that the injection valves are emptied one after the other should ensure that any water present is safely removed.

Disclosure of the invention

According to the invention, an injection valve for a water injection system of an internal combustion engine is proposed. The injection valve comprises an annular magnetic coil for acting on a stroke-movable armature which is connected to a valve member. The injection valve further comprises a hollow cylinder-shaped core, which is at least partially surrounded by the magnetic coil and is formed on an inlet connector or is connected to an inlet connector, wherein the injection valve can be supplied with water via the inlet connector. According to the invention, a body is inserted into the inlet connector through which a flow channel passes in the axial direction, the flow channel formed in the body defining an inlet opening for supplying the ice injection valve with water, the body being pressed into a receptacle of the inlet connector.

Advantages of the invention

Compared to the prior art, the injection valve for a water injection system of an internal combustion engine has the advantage that the injection valve can be emptied particularly easily and quickly through the body in the inlet port when the water injection system is sucked back. In this way, icing of the injection valve and thus damage to the injection valve can advantageously be prevented. The injection valve is supplied with water, for example, exclusively via the flow channel formed in the body. This extends in the axial direction, preferably coaxially to a longitudinal axis of the injection valve. The reduced free flow cross-section of the flow channel formed in the body also increases the flow speed when water is sucked back, so that the emptying of the injection valve is accelerated at the same time. In addition, the reduced flow cross-section counteracts turbulence. As a result, significantly more water can be sucked back out of the injection valve in the same time with the same sucking back performance of a conveying element used for sucking back. This means that the risk of icing up and damage to the injection valve due to ice pressure is significantly reduced at low outside temperatures.

Thus, in the case of the injection valve according to the invention, the inlet opening of the injection valve is not through the inlet port, but rather through the formed in the inlet port inserted body. The body thus reduces the free flow cross-section available for supplying water to the injection valve. At the same time, a dead volume present in the inlet connector, which has to be emptied to avoid icing up of the injection valve, is minimized. This means that less water has to be sucked back out of the injection valve. The body can therefore preferably be inserted into the inlet connector in such a way that no cavity remains between the body and the inlet connector that is directly or indirectly in fluid connection with the flow channel formed in the body. Thus any injection valve, for example a fuel injection valve, can advantageously be upgraded to an injection valve according to the invention for water injection in an advantageously simple manner through the body inserted into the inlet connector.

Because the body is pressed into the receptacle of the inlet connector, the body is advantageously firmly connected to the injection valve. In addition, the pressing-in ensures that no cavity remains between the body and the inlet connector which is in fluid connection directly or indirectly with the flow channel formed in the body. It can thus advantageously be ensured that the free flow cross-section available for the water supply to the injection valve is reduced to the flow channel and thus dead volume present in the inlet connector is minimized. Furthermore, pressing the body into the inlet connector represents an advantageously simple and inexpensive method of fastening the body. The body is designed, for example, as a press-fit socket.

Further advantageous refinements and developments of the invention are made possible by the features specified in the subclaims.

According to an advantageous embodiment it is provided that the body has a pine cone profile in the area in which the body is in direct contact with the receptacle of the inlet connector. Due to the pine cone profile, the body can advantageously be fixed firmly and well in the receptacle of the inlet connection. For example, the body can also be hooked into the receptacle due to the pine cone profile. The body is thereby fixed in the injection valve.

According to an advantageous embodiment, it is provided that the pine cone profile is designed to run around the body. By means of such a pine cone profile that encircles the body, the body can advantageously be firmly fixed all around in the receptacle of the inlet connector and, for example, also be hooked into the receptacle of the inlet connector at several points around the body. The body is thereby fixed in the injection valve.

According to an advantageous embodiment, it is provided that the pine cone profile is hooked in the receptacle, in particular on an inner jacket of the receptacle of the inlet connector. The body can therefore not be removed again from the connecting piece without being destroyed. The body is thus advantageously and permanently fixed in the injection valve.

According to an advantageous embodiment it is provided that at least one slot is formed in the body. Due to the design of the slot, the press-in forces that are required to press the body into the receptacle of the inlet connector can be selected in such a way that a permanent connection occurs without any possible cold welding or chip formation on the receptacle of the inlet connector during the press-in process.

According to an advantageous embodiment it is provided that the at least one slot is formed in the body at the end of the body facing away from the valve member. With slots of this type, the press-in forces can advantageously be controlled well through the design of the slots.

According to an advantageous embodiment it is provided that the slot in the body extends along the axial direction of the body. A slot formed in this way advantageously extends in the same direction as, for example, the flow channel. At the same time, the slot extends in the same direction in which the body is pressed into the receptacle, so that the body is advantageously stable when it is pressed in. By selecting the length of the slot, the necessary press-in forces can thus advantageously be well controlled.

According to an advantageous embodiment, it is provided that the body is at least partially formed from a closed-cell material. The closed-cell material can be, for example, a foam or a metal foam. The closed-cell material is elastically deformable. If the body is formed from such a closed-cell material, the body can also absorb a force in the case of a freezing medium. In this way, permanent deformation or a negative influence on the function of the injection valve can be prevented. If water freezes in the injection valve, especially in the body, and expands, the closed-pore material of the body can deform elastically. The elastically deformed body can thus provide the water with the additional space it needs when it freezes. If the water liquefies again, the body can expand again and return to its original shape. The closed-pore press-fit bushing thus both reduces the volume in the inlet connection through the flow channel and at the same time can absorb transverse forces that occur in the event of the medium freezing without adversely affecting the function of the injection valve.

According to an advantageous embodiment, it is provided that an inner diameter of the flow channel formed in the body is less than 3.0 millimeters, preferably less than 2.5 millimeters, in particular preferably less than 2.1 millimeters. The inside diameter is thus designed so that a sufficient amount of water can be injected and at the same time the dead volume of the injector is minimized.

According to an advantageous embodiment it is provided that a water injection system for an internal combustion engine comprises an injection valve, the water injection system further comprising a water tank for storing water and a conveying element for conveying water from the water tank to the injection valve.

Figure list

• 1 einen schematischen Längsschnitt durch ein erstes Ausführungsbeispiel des Einspritzventils,
• 2 eine vergrößerte Darstellung des Längsschnitts durch das erste Ausführungsbeispiel des Einspritzventils aus 1,
• 3 eine dreidimensionale Schnittdarstellung des ersten Ausführungsbeispiels des Einspritzventils aus 1,
• 4 eine vergrößerte Darstellung des Bereichs zwischen dem Körper und dem Einlassstutzen des ersten Ausführungsbeispiels des Einspritzventils,
• 5 einen schematischen Längsschnitt durch ein zweites Ausführungsbeispiel des Einspritzventils,
• 6 eine dreidimensionale Darstellung des zweiten Ausführungsbeispiels des Einspritzventils aus 5,
• 7 einen schematischen Längsschnitt durch ein drittes Ausführungsbeispiel des Einspritzventils,
• 8 eine schematische Darstellung eines Ausführungsbeispiels eines Wassereinspritzsystems,
• 9 eine schematische Darstellung eines Ausführungsbeispiels eines Verbrennungsmotors mit einem Einspritzventil.

Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it

• 1 a schematic longitudinal section through a first embodiment of the injection valve,
• 2 an enlarged view of the longitudinal section through the first embodiment of the injection valve 1 ,
• 3 a three-dimensional sectional view of the first embodiment of the injection valve 1 ,
• 4th an enlarged illustration of the area between the body and the inlet port of the first embodiment of the injection valve,
• 5 a schematic longitudinal section through a second embodiment of the injection valve,
• 6th a three-dimensional representation of the second embodiment of the injection valve 5 ,
• 7th a schematic longitudinal section through a third embodiment of the injection valve,
• 8th a schematic representation of an embodiment of a water injection system,
• 9 a schematic representation of an embodiment of an internal combustion engine with an injection valve.

Embodiments of the invention

Of the 1 is an injection valve 1 for a water injection system 50 of an internal combustion engine 100 can be seen that an annular solenoid 2 to act on a lifting armature 3 includes which with a valve member 4th connected is. The valve member 4th is in the present case designed as a hollow needle and on its the anchor 3 remote end with a spherical valve closing element 29 for opening and closing at least one injection opening 30th tied together. When the magnet coil is energized 2 a magnetic field is formed, the magnetic force of which affects the armature 3 including the valve member 4th and the valve closing element 29 towards a core 5 moved to one between the core 5 and the anchor 3 trained working air gap 31 close. The spherical valve closing element 29 gives the injection opening 30th free. Then the solenoid is energized 2 finished, become the anchor 3 , the valve member 4th and the valve closing element 29 by means of the spring force of a return spring 32 returned to their original position, so that the valve closing element 29 the injection port 30th closes again.

The core 5 is designed as a hollow cylinder and has a hollow cylinder-shaped connecting part 33 with an inlet port 6th connected through which the injector 1 can be supplied with water from a distribution line, not shown, for example a rail. The inlet port 6th is encompassed, for example, by a cup-shaped connection element of the distribution line, a rail cup, with between the cup-shaped connection element and the inlet nozzle 6th a sealing ring 13th can be arranged. The inlet area can thus be sealed off from the outside.

To reduce a dead volume in the inlet area of the injection valve 1 is in the inlet port 6th of the injector 1 a body 8th pressed in. The body 8th is designed as a press-fit socket for this purpose. The body 8th is from an inlet direction of the injector 1 in the axial direction a in the recording 60 of the inlet port 6th pressed in. The body 8th is designed essentially as a hollow cylinder. The body 8th is in the axial direction a from a flow channel 9 interspersed. The flow channel 9 defines an inlet opening 10 . The supply of the injector 1 with water from the distribution line therefore takes place exclusively over the flow channel 9 . An outer jacket 81 of the body 8th is also attached to an inner jacket 61 the recording 60 of the inlet port 6th adjusted so that the body 8th the dead volume in the inlet area of the injector 1 reduced. So is the body 8th an at least partially cylindrical outer jacket 81 formed on an at least partially cylindrical inner jacket 61 the recording 60 of the inlet port 6th is flat. Because the body 8th in the recording 60 of the inlet port 6th is pressed in, the outer jacket presses 81 of the body 8th in the radial direction on the inner jacket 61 the recording 60 of the inlet port 6th . The radial direction is perpendicular to the axial direction a .

The one in the body 8th trained flow channel 9 preferably has a cylindrical shape. The diameter d of the flow channel 9 is furthermore preferably chosen as small as possible in order to achieve the highest possible flow velocity during back suction and to generate a water column that does not tear off. At the same time is the diameter d of the flow channel 9 dimensioned in such a way that there is still an adequate water supply to the injection valve 1 is ensured. The diameter is preferred d of the flow channel 9 selected to be smaller than the diameter of the distribution line, for example the rail. The diameter d of the flow channel 9 can be, for example, less than 3.0 millimeters, preferably less than 2.5 millimeters, particularly preferably less than 2.1 millimeters. In this embodiment, the diameter is d of the flow channel 9 two millimeters. The diameter d of the flow channel is in a radial direction perpendicular to the axial direction a of the flow channel 9 measured. The body 8th in which the flow channel 9 is formed, preferably has a minimum wall thickness that corresponds to the radius of the flow channel 9 equals or is above.

By reducing the dead volume due to the in the receptacle 60 of the inlet port 6th press-fit body 8th can the injector 1 can be quickly emptied by sucking back, so that damage from freezing water when the combustion engine is switched off 100 and low outside temperatures are not to be feared

In the 2 , 3 and 4th are various representations of a first embodiment of the body 8th shown. In the first embodiment of the body 8th is on the body 8th a pine cone profile 82 educated. The pine cone profile 82 is as a structure on the outer jacket 81 of the body 8th educated. The outer jacket 81 is in the area of the pine cone profile 82 in direct contact with the inner jacket 61 the recording 60 . The pine cone profile 82 is preferably the body 8th on the outer jacket 81 trained all around. 4th shows an enlarged sectional view of the pine cone profile 82 . On the outer jacket 81 a plurality of bumps are formed. The elevations can be on the inner jacket 61 the recording 60 to be hooked. The elevations of the pine cone profile 82 can for example be designed like scales and thus together form a structure similar to that of a pine cone. The elevations can, for example, be the body 8th also surrounded all around.

The 5 and 6th are two representations of a second exemplary embodiment of the injection valve 1 to infer that it differs from that of the 2 until 4th only through the specific design of the in the inlet port 6th pressed-in body 8th differs. In the second embodiment, there are slots 40 in the body 8th educated. In this embodiment, for example, there are four slots 40 in the body 8th educated. The four slots 40 are each spaced at angles of 90 ° around the axial direction a arranged around. The slots 40 are in this embodiment as incisions in the body 8th educated. The slots 40 run as incisions in the body 8th in the axial direction a of the injector 1 and thus in the direction from which the body is 8th in the recording 60 is pressed in. The slots 40 are on one of the closing elements 29 of the injector 1 remote side of the body 8th educated. The slots 40 preferably have a length I of 3 mm to 7 mm. The length I of the slots is in the axial direction a measured. The slots 40 extend as incisions from that of the valve member 4th facing away, for example ring-shaped top 85 of the body 8th along the axial direction a over the length I of the slots 40 .

Another embodiment of the injection valve 1 is in 7th shown. In this embodiment, the body 8th made of a porous material. The material has closed pores, so that no medium can escape from the flow channel 9 can penetrate into the pores of the material. Due to the pores in the material, the material is compressible and, for example, elastically deformable. The closed-cell material can be, for example, a foam or a metal foam. Due to the closed-cell material, the body can 8th also in the case of freezing medium in the flow channel 9 absorb a force. Freezes water in the lazy river 9 and expands in the process, so the closed-pore material of the body can expand 8th , for example, elastically deform in the radial direction. Thus, the elastically deformed body can 8th provide the water with the additional space it needs when it freezes. If the water then liquefies again, the body can 8th expand again and into his return to its original shape. The body 8th can be used in the cold as well as in the warm state 60 of the connecting piece 6th be introduced. When the body is pressed in 8th In the warm state, the press-in forces required for press-in decrease advantageously. A hardening of the body 8th can be beneficial in the inclusion 60 take place. The body 8th can be designed in one piece or in several parts. Furthermore, the body can 8th in the recording 60 of the inlet port 6th be formed by placing a potting compound in the receptacle at the end of production 60 of the injector 1 is poured. This can then be the body 8th form and, for example, also be designed with closed pores.

In 8th is a water injection system 50 with injectors 1 shown. The water injection system 50 is for an internal combustion engine 100 provided and comprises at least one distribution line 7th and at least one injection valve 1 . One of the supply of the injectors 1 distribution line serving with water 7th also becomes rail 7th called. The water injection system shown 50 includes, for example, four such injection valves 1 . The injectors 1 are on a distribution line 7th connected.

Usually has a distribution line 7th at least one cup-shaped connection element for connecting an injection valve 1 on. The injector 1 is connected to the distribution line via the cup-shaped connection element 7th tied together. The connection can be, for example, a plug-in, press-fit, clamp, snap-in and / or screw connection. This connection element is also called a rail cup. The rail cup engages around the inlet end of the injection valve 1 in the area of the inlet port 6th . One between the cup-shaped connection element and the inlet port 6th or the body 8th Any remaining axial and / or radial gap can be used to accommodate a sealing element, in particular a sealing ring, so that the inlet area of the injection valve 1 is sealed to the outside. The sealing ring can be arranged on the outer circumference of the body or surround the body in sections so that it seals radially. As an alternative or in addition, the sealing ring can be on an annular end face of the body 8th be axially supported so that it seals axially.

The dead volume of the rail cup depends on the specific design of the rail cup and the design of the inlet end of the injection valve 1 away. To minimize the dead volume in the rail cup or the cup-shaped connection element, the can be inserted into the inlet nozzle 6th inserted body 8th this in the axial direction a and / or protrude in the radial direction. For example, the body can 8th have an annular collar, which the inlet port 6th protrudes in the axial and radial directions. The annular collar can also be used to support the injection valve 1 on a cup-shaped connection element of the distribution line 7th be used. The injection valve can via the annular collar 1 be supported axially and / or radially on the cup-shaped connection element.

The distribution line 7th or the rail 7th becomes from a water tank 15th is supplied with water. The water becomes the distribution line 7th with the help of a conveyor element 16 via a water pipe 17th fed. The conveyor element 16 is present as outside of the water tank 15th arranged, electric motor driven pump executed. Other designs of the conveyor element 16 but are also possible. In particular, the conveying element 16 in the water tank 15th be arranged or integrated in the tank bottom. The conveyor element 16 can be designed in such a way that it enables the conveying direction to be reversed in order to avoid the ice pressure-sensitive lines and / or components of the system, in particular the injection valves 1 to be able to empty by sucking back.

To allow water to flow back out of the water tank after emptying 15th in the direction of the conveying element 16 can prevent in the aqueduct 17th upstream of the conveying element 16 a shut-off element 18th , in particular a check valve, be arranged. Upstream of the shut-off element 18th is in the present case a filter 19th arranged that the entry of harmful particles into the conveying element 16 and the injectors 1 prevented.

The one in the 8th system shown branches downstream of the conveying element 16 a return line 22nd from the water pipe 17th from that in the water tank 15th ends. Via the return line 22nd can be an excess delivery rate of the conveying element 16 in the water tank 15th be fed back, for example, to the pressure in the distribution line 7th to regulate. To regulate the pressure, in the distribution line 7th or in the water pipe 17th a pressure sensor 23 be provided. So via the return line 22nd no water from the water tank during the suction process 15th is sucked in is in the return line 22nd a check valve 20th intended. The check valve 20th is also a throttle 21 upstream, with which a dynamic pressure can be built up to implement the pressure control.

Again 9 can be seen, are the injectors 1 on a suction pipe 24 arranged over which a combustion chamber 25th of the internal combustion engine 100 is supplied with combustion air. The water injection therefore takes place outside the combustion chamber 25th through the injector 1 into the suction pipe 24 the internal combustion engine 100 . The water becomes the combustion chamber 25th supplied together with the combustion air. The fuel is injected by means of a fuel injector 26th directly into the combustion chamber 25th injected.

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

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102015208472 A1 [0004]
• DE 102015208508 A1 [0005]

Claims (10)

Injection valve (1) for a water injection system (50) of an internal combustion engine (100), comprising an annular magnetic coil (2) for acting on a liftable armature (3) which is connected to a valve member (4), further comprising a hollow cylindrical core (5) ), which is surrounded at least in sections by the magnetic coil (2) and forms on an inlet connector (6) or is connected to an inlet connector (6), wherein the injection valve (1) can be supplied with water via the inlet connector (6), characterized in that that a body (8) is inserted into the inlet connector (6) through which at least one flow channel (9) passes in the axial direction (a), the flow channel (9) formed in the body (8) having an inlet opening (10 ) for supplying the ice injection valve (1) with water, the body (8) being pressed into a receptacle (60) of the inlet connector (6). Injector after Claim 1 , characterized in that the body (8) has a pine cone profile (82) in the area in which the body (8) is in direct contact with the receptacle (60) of the inlet connector (6). Injector after Claim 2 , characterized in that the pine cone profile (82) is designed to run around the body (8). Injector after Claim 2 or 3 , characterized in that the pine cone profile (82) is hooked in the receptacle (60), in particular on an inner jacket (61) of the receptacle (60) of the inlet connector (6). Injection valve according to one of the preceding claims, characterized in that at least one slot (40) is formed in the body. Injector after Claim 5 , characterized in that the at least one slot (40) is formed in the body (8) at the end of the body (8) facing away from the valve member (4). Injection valve according to one of the Claims 5 or 6th , characterized in that the slot (40) in the body (8) extends along the axial direction (a) of the injection valve (1). Injection valve according to one of the preceding claims, characterized in that the body (8) is at least partially formed from a closed-cell material. Injection valve according to one of the preceding claims, characterized in that an inner diameter (d) of the flow channel (9) formed in the body (8) is less than 3.0 millimeters, preferably less than 2.5 millimeters, in particular preferably less than 2.1 Millimeters. Water injection system for an internal combustion engine (100) with at least one injection valve (1) according to one of the preceding claims, wherein the water injection system (50) further comprises a water tank (15) for storing water and a conveying element (16) for conveying water from the water tank ( 15) to the injection valve (1).

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