DE102017222501A1 - Valve for metering a fluid - Google Patents

Abstract

A valve (1) for metering a fluid, which serves in particular as a fuel injection valve for internal combustion engines, comprises an electromagnetic actuator (10) and a valve needle (5) which can be actuated by the actuator (10), wherein an armature (6) is attached to the valve needle (5) ) of the actuator (10) is guided. On the valve needle (5) a stop element (7, 8) is arranged, which limits a movement of the armature (6) relative to the valve needle (5). Between the armature (6) and the stop element (7, 8) at least one of the valve needle (5) guided damping disc is arranged.

Description

State of the art

The invention relates to a valve for metering a fluid, in particular a fuel injection valve for internal combustion engines. Specifically, the invention relates to the field of injectors for fuel injection systems of motor vehicles, in which there is preferably a direct injection of fuel into combustion chambers of an internal combustion engine.

From the DE 10 2013 222 613 A1 For example, a valve for metering fluid is known. The known valve has an electromagnet for actuating a valve needle controlling an orifice. The electromagnet is used to actuate a displaceable on a valve needle armature. Here, the armature has a valve needle adjacent to the bore, which forms a spring receptacle for a Vorhubfeder.

Disclosure of the invention

The valve according to the invention with the features of claim 1 has the advantage that an improved design and operation are possible. In particular, a bounce between the armature and a valve needle arranged on the stop can be reduced, without an operating behavior is impaired.

The measures listed in the dependent claims advantageous refinements of the specified in claim 1 valve are possible.

In the valve for metering the fluid serving as armature armature is not fixedly connected to the valve needle, but cantilevered between stop elements, resulting in a Ankerfreiweg. At least one stop element can be realized as a stop sleeve and / or stop ring. However, a stop element may also be formed integrally with the valve needle. About a spring, the armature is adjusted in the idle state with respect to the valve needle fixed stop surface of a stop, so that the armature rests there. When the valve is actuated, the complete armature free travel is then available as an acceleration section, whereby the spring is shortened during acceleration. During operation, a larger opening pulse can then be transmitted from the armature to the valve needle.

Between one of the stop elements and the armature at least one damping disc is arranged. If appropriate, at least one damping disk can also be provided between the other stop element and the armature. Preferably, the at least one damping disk is arranged on the stop element, at which the armature comes to rest in the closed state of the valve. On the at least one damping disk can then be achieved a rapid calming of the armature. As a result, on the one hand the closing behavior can be improved, since undesired secondary injections are avoided. On the other hand, a quick reassurance of the anchor allows a re-actuation already after a short time, which shortens a required pause time between individual actuation processes, since the anchor freewheel is reliably available as an acceleration path only in the settled state of the armature.

The bounce behavior can in principle be influenced by the dimensioning of the contact surfaces involved. A larger contact surface tends to cause greater damping and thus a reduction in the bounce, but at the same time an increase in hydraulic or pneumatic bonding, which results in reduced dynamics when actuated. A strong hydraulic adhesive effect results especially in ethanol-containing fuels and / or low temperatures. In particular, this can negatively affect an opening process of the valve. In the following, a distinction is no longer made between a hydraulic and a pneuatischen adhesive effect, the term of hydraulic bonding is synonymous rather synonymous for those of the pneumatic bonding to understand. The development according to claim 2 has the advantage that a hydraulic adhesive effect on actuation of the at least one damping disk supported on the stop surface anchor can be reduced in relation to a situation in which the armature bears directly against the stop surface of the stop element. In this case, when lifting the armature still opens a gap, whereby the hydraulic adhesive effect is reduced. In this case, preferably, a gap opens which inclines from all possible damping gaps (gaps) at least for hydraulic bonding. After lifting, in particular after opening the valve needle and the beginning of the injection, then open preferably also regularly the other gap or the other column. When closing then act at least two column, the squish representing and between the damping disc and the armature and between the damping disc and the stop element and optionally between adjacent damping discs, simultaneously and thereby reinforce the damping effect. Due to the hydraulic damping forces, closing automatically results in a symmetrization of the gaps acting as a nip, whereas preferably only one gap opens when opening. Advantageously, this can be a clear shortened Nachprelldauer the anchor can be achieved without the hydraulic bonding of the armature is reinforced especially at the beginning of an operation. As a result, the actuation behavior can be improved both at the beginning of an actuation and during a reassurance of the armature. Thus, it is particularly advantageous if an advantageous development according to claim 3 and optionally claim 4 is realized.

The development with the features of claim 5 has the advantage that a fluid flow of the liquid fluid flowing through the flow channels, a release of the damping disk can be supported by the armature or the damping disks from each other. This is particularly advantageous in combination with an advantageous development according to claim 6. However, an effect dissolving the damping disks can also result from the movement through an armature space filled with the liquid fluid. Advantageous embodiments in which a projection of each of the damping disks does not completely overlap with the projective union of the remaining damping disks are specified in claims 7 to 9. The specified in the claims 7 to 9 features can be realized individually, but also in a suitable combination.

Advantageous ways to design a damping disk are specified in claim 10. If a plurality of damping discs are provided, then they can each have the same thickness and / or be formed from the same material, in particular a metal foil. Depending on the application, it is also conceivable, in principle, that differently designed damping disks, which differ in their thickness and / or their material, are provided.

list of figures

• 1 ein Ventil in einer auszugsweisen, schematischen Schnittdarstellung entsprechend einem ersten Ausführungsbeispiel in einer Ausgangstellung;
• 2 ein Ventil in einer auszugsweisen, schematischen Schnittdarstellung entsprechend einem ersten Ausführungsbeispiel bei einer Betätigung;
• 3 ein Ventil in einer auszugsweisen, schematischen Schnittdarstellung entsprechend einem ersten Ausführungsbeispiel bei einer Betätigung;
• 4 ein Ventil in einer auszugsweisen, schematischen Schnittdarstellung entsprechend einem ersten Ausführungsbeispiel bei einem Schließvorgang;
• 5 ein Ventil in einer auszugsweisen, schematischen Schnittdarstellung entsprechend einem zweiten Ausführungsbeispiel bei einem Schließvorgang;
• 6 bis 12 mögliche Ausgestaltungen einer Dämpfungsscheibe eines Ventils und
• 13 eine Anordnung mehrerer Dämpfungsscheiben in einer Blickrichtung entlang einer Längsachse einer Ventilnadel eines Ventils zur Erläuterung einer möglichen Ausgestaltung eines Ventils.

Preferred embodiments of the invention are explained in more detail in the following description with reference to the accompanying drawings, in which corresponding elements are provided with identical reference numerals. Show it:

• 1 a valve in an excerpt, schematic sectional view according to a first embodiment in an initial position;
• 2 a valve in an excerpt, schematic sectional view according to a first embodiment in an actuation;
• 3 a valve in an excerpt, schematic sectional view according to a first embodiment in an actuation;
• 4 a valve in an excerpt, schematic sectional view according to a first embodiment in a closing operation;
• 5 a valve in an excerpt, schematic sectional view according to a second embodiment in a closing operation;
• 6 to 12 possible embodiments of a damping disk of a valve and
• 13 an arrangement of a plurality of damping discs in a viewing direction along a longitudinal axis of a valve needle of a valve to explain a possible embodiment of a valve.

Embodiments of the invention

1 shows a valve 1 for metering a fluid in an excerptional, schematic sectional representation according to a first exemplary embodiment in an initial position. The valve 1 especially as a fuel injector 1 be educated. A preferred application is a fuel injection system, wherein such fuel injection valves 1 as high-pressure injection valves 1 are formed and are used for direct injections of fuel into the associated combustion chambers of the internal combustion engine. In this case, liquid or gaseous fuels can be used as the fuel. Accordingly, the valve is suitable 1 for metering fluids.

The valve 1 has a housing (valve housing) 2 on, in the stationary a pole 3 is arranged. Through the housing 2 is a longitudinal axis 4 determined, with the valve needle 5 in a suitable manner along the longitudinal axis 4 is guided.

At the valve needle 5 is an anchor (magnet armature) 6 arranged. At the valve needle 5 are also a stopper 7 and another stop element 8th arranged. At the stop elements 7 . 8th are stop surfaces 7 ' . 8th' educated. The anchor 6 can in this case during actuation between the stop elements 7 . 8th be moved, with an anchor path 9 is predetermined. The anchor 6 , the indoor pole 3 as well as a magnetic coil, not shown, and also not shown outer pole are components of an electromagnetic actuator 10 ,

At the valve needle 5 is a valve closing body 11 formed with a valve seat surface 12 interacts with a sealing seat. Upon actuation of the anchor 6 this one is going towards the pole 3 accelerated, as it is in the 2 is shown. If the anchor 6 at the stop 7 ' the stop element 7 strikes and thereby the valve needle 5 pressed, then fuel can 13 ' over the opened sealing seat and at least one nozzle opening 13 be injected into a room, especially a combustion chamber, as in the 3 is shown. The valve 1 has a return spring 14 on that the valve needle 5 then with a disappearing magnetic field over the stop element 7 in her in the 1 illustrated initial position adjusted in which the sealing seat is closed.

The anchor 6 based on a cylindrical basic shape 20 with a through hole 21 , where the anchor 6 at the through hole 21 at the valve needle 5 is guided. Here, the anchor points 6 one of the stop surface 7 ' the stop element 7 as well as the inner pole 3 facing end face 22 and one of the stop surface 8th' the stop element 8th facing end face 23 on. The front ends 22 . 23 of the anchor 6 are turned away from each other.

The anchor 6 has a spring receptacle 25 on. The spring recording 25 is here on the front page 22 of the anchor 6 open. One in the starting position of the anchor 6 partly in the spring seat 25 arranged spring 26 becomes upon actuation of the anchor 6 shortened relative to its initial length, being completely in the spring retainer 25 can dive. The spring 26 ensures that the anchor 6 in its initial position as close as possible to the stop element 8th and thus the Ankerfreiweg 9 is available for a subsequent operation as an acceleration section. During a closing process becomes the anchor 6 after closing the sealing seat of the spring 26 towards the stop 8th adjusted as it is in 4 is shown.

In this embodiment is between the anchor 6 and the stopper element 8th a damping disk 27 arranged. In the in the 1 shown starting position is the damping disk 27 on the one hand on the front side 23 of the anchor 6 and on the other hand on the stop surface 8th' the stop element 8th on. Upon actuation of the anchor 6 preferably a hydraulic adhesive effect between the damping disk predominates 27 and the front side 23 of the anchor 6 so the damper disk 27 at the beginning of the operation with the anchor 6 in an opening direction 31 is adjusted, as it is in the 2 is illustrated. This flows into the anchor space 32 provided fluid, in particular a liquid fuel, in a resulting gap 33 between the damping disc 27 and the stop surface 8th' as it is in the 2 through arrows 33A . 33B is illustrated. This can be done on the stop element 8th one of the damping disc 27 facing recess 34 be formed, the size of the stop surface 8th' reduced. Thus, just at the beginning of the operation, a hydraulic adhesive effect, the acceleration of the armature 6 in the opening direction 31 reduced, avoided.

With increasing duration of the control, in particular after the opening of the sealing seat, the damping disc dissolves 27 from the front side 23 of the anchor 6 , In this embodiment, the anchor 6 several flow channels 35 . 36 on, with a projection of the damping disk 27 in the front side 23 with opening cross sections 35 ' . 36 ' the flow channels 35 . 36 at the front 23 overlaps. About the flow of fluid passing through the flow channels 35 . 36 of the anchor 6 the damping disk 27 flows, thus releasing the damping disc 27 from the front side 23 of the anchor 6 At least it supports, as it is in the 3 through arrows 37A . 37B is illustrated.

When the magnetic field of the actuator 10 disappears and the anchor 6 at least after the closing of the sealing seat by its existing at the time of closing of the sealing seat impulse and the spring 26 continue in the closing direction 38 is adjusted, then preferably results on the one hand, a gap 39 between the damping disc 27 and the front side 23 of the anchor 6 and on the other hand, the gap 33 between the damping disc 27 and the stop surface 8th' the stop element 8th , The gap 33 . 39 act as a squish column 33 . 39 , wherein the fluid present in these by the movement of the armature 6 compressed and displaced. Due to the pressure conditions, the damping disk sets 27 preferably not unilaterally to the anchor 6 or to the stop element 8th on. Preferably, the damping disc remains 27 in an intermediate position between the stop element 8th and the anchor 6 until the damper disc 27 at the end of the closing direction 38 successful return movement of the armature 6 is trapped as it is in the 4 is illustrated. This will affect the return of the anchor 6 on the stop element 8th two damping gaps 33 . 39 parallel, whereby the hydraulic damping is amplified and in particular already at larger distances of the armature 6 from the stop element 8th starts. This can be a quick reassurance of the anchor 6 be achieved.

5 shows a valve 1 in an excerpt, schematic sectional view according to a second embodiment, wherein a state during a closing operation is shown. In this embodiment, a plurality of damping discs 28 . 29 . 30 intended. Each of the damping discs 28 to 30 can in this case according to the damping disc 27 of the valve 1 of the first embodiment. The damping discs 28 to 30 may correspond here in terms of their respective thickness and with respect to the selected material. Geometrically, the damping discs 28 to 30 be configured in the same or different ways. In an opening operation in the opening direction 31 open the gap 39 between the anchor 6 and the damping disk 28 , Column 40 . 41 between the damping discs 28 to 30 and the gap 33 between the damping disc 30 and the stopper element 8th ,

Preferably, the gaps open 33 . 39 . 40 . 41 not symmetrical at the beginning of an actuation. Preferably opens when lifting the armature 6 first the gap 33 between the closest to the stop element 8th located damping disk 30 and the stopper element 8th , This will cause the damper discs 28 to 30 first with the anchor 6 adjusted. Subsequently, a detachment process occurs, in which the damping discs 28 to 30 from the anchor 6 and solve each other. This creates the column 33 . 39 to 41 , which in the return movement in the closing direction as a crimp 33 . 39 to 41 serve. When returning the anchor 6 that will be in the columns 33 . 39 to 41 fluid compresses and displaces, making it a corresponding to the number of gaps 33 . 39 to 41 reinforced damping effect comes. In this case, the occurring hydraulic forces act on the damping discs 28 to 30 such that symmetrical conditions, in particular comparable distances, between the damping discs 28 to 30 to adjust. This results in particular at the end of the return movement, at the anchor 6 by means of the damping discs 28 to 30 on the stop element 8th strikes, optimal damping.

6 to 12 show possible embodiments for the damping disk 27 and the damping discs 28 to 30 , In principle, each damping disk can 27 to 30 according to one of the 6 to 12 be formed embodiments shown. A preferred embodiment of the damping disk 27 or the damping discs 28 to 30 is described in more detail below.

The damping disk 27 is preferably designed annular, as it is in the 6 is shown. Here, the damping disk 27 an axial through-hole 45 on, by the valve needle in the mounted state 5 extends. The damping disk 27 can then in an advantageous manner to the valve needle 5 be guided.

The damping discs 28 to 30 can in a possible embodiment according to the 7 to 9 be educated. Here are the damping discs 28 to 29 each flow openings 46 to 48 on, wherein for simplicity of illustration only one of the flow openings 46 to 48 is marked. The flow openings 46 to 48 are in this embodiment as flow holes 46 to 48 designed. The number of flow openings 46 to 48 differs for each of the damper discs 28 to 30 , The flow openings 46 to 48 are here so on the damping discs 28 to 30 formed between two adjacent flow openings 46 to 48 a damping disk 28 to 30 in each case the same angular distance 49 to 51 is predetermined. Preferably, the damping disk 28 closest to the anchor 6 located, the largest number of flow openings 48 and thus the smallest angular distance 51 , The result is correspondingly with the damping disk 30 closest to the stop element 8th is the smallest number of flow openings 46 and thus the largest angular distance 49 , Thus, the number of flow openings decreases 46 to 48 from the anchor 6 to the stop element 8th preferably off, while the angular distance 49 to 51 preferably increases.

Due to these different geometries, the release of the damping discs 28 to 30 improved from each other. This results from the flow openings 46 to 48 a support by the fluid. Preferably, this is not a damping disk 29 . 30 from the closer to the anchor 6 lying damping discs 28 . 29 completely covered. In addition, it is advantageous if the damping discs 28 to 30 at least in some areas of the flow 37A . 37B from the flow channels 35 . 36 of the anchor 6 are exposed.

10 to 12 show possible embodiments of the damping discs 28 to 30 with which in particular a separation of the damping discs 28 to 30 can be supported by each other. Here are the damping discs 28 to 30 radially outwardly extending projections 55 to 57 on, wherein for simplicity of illustration only one of the projections 55 to 57 is marked. The projections 55 to 57 are in this embodiment as noses 55 to 57 educated. The damping discs 28 to 30 each have a different number of protrusions 55 to 57 preferably uniformly over a circumference of the respective damping disk 28 to 30 are arranged distributed. This results in angular distances 58 to 60 between each adjacent projections 55 to 57 the individual damping discs 28 to 30 coming from the damping disk 28 closest to the anchor 6 located, to the damper disc 30 closest to the stop element 8th is, lose weight. Accordingly, the number of projections decreases 55 to 57 from the damping disk 28 towards the damping disc 30 to.

The basis of the 7 to 9 described flow openings 46 to 48 and the basis of the 10 to 12 described protrusions 55 to 57 can also work together on damping plates in a suitable way 28 to 30 be realized. Furthermore, it is conceivable that individual damping discs 28 to 30 with flow openings 46 to 48 while others are provided with protrusions 55 to 57 are provided. Furthermore, the individual cross sections of the flow openings 46 to 48 possibly also vary. Furthermore, the angular distances must 49 to 51 or the angular distances 58 to 60 not necessarily uniform between flow openings 46 to 48 or projections 55 to 57 a single damping disc 28 to 30 his. Furthermore, the projections must 55 to 57 not necessarily be configured symmetrically with respect to a radial axis. Furthermore, the projections can also be 55 to 57 a single damping disc 28 to 30 differ from each other. Accordingly, the flow openings 46 to 48 have different and not necessarily uniform geometries.

13 illustrates a possible arrangement of the in the 10 to 12 illustrated damping discs 28 to 30 in a viewing direction along the longitudinal axis 4 the valve needle 5 of the valve 1 , The angular distances 58 to 60 are specified so that in the closing direction 38 along the longitudinal axis 4 considered at each damper disk 28 to 30 at least part of its surface is freely accessible and thus exposed to the flow.

The invention is not limited to the described embodiments.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102013222613 A1 [0002]

Claims (10)

Valve (1) for metering a fluid, in particular a fuel injector for internal combustion engines, with an electromagnetic actuator (10) and a valve needle (5) which can be actuated by the actuator (10), wherein an armature (6) of the actuator (6) on the valve needle (5) 10), wherein on the valve needle (5) at least one stop element (7, 8) is arranged, which limits a movement of the armature (6) relative to the valve needle (5), characterized in that between the armature (6) and at least one damping disk (27-30) guided on the valve needle (5) is arranged on the stop element (7, 8). Valve after Claim 1 , characterized in that the at least one damping disc (27-30) between an end face (22, 23) of the armature (6) and a stop surface (7 ', 8') of the stop element (7, 8) is arranged. Valve after Claim 1 or 2 , characterized in that the armature (6), the at least one damping disc (27-30) and the stop surface (7 ', 8') are formed so that the damping disc (27) or closest to the stop surface (7 ', 8') located damping disk (30) in operation temporarily from the stop surface (7 ', 8') triggers and temporarily against the stop surface (7 ', 8'). Valve after Claim 3 characterized in that upon movement of the armature (6) away from the abutment member (7, 8), a hydraulic adhesive effect between the damping disc (27) and the abutment surface closest to that of the abutment surface (7 ', 8') ) and the abutment surface (7 ', 8') of the stop element (7, 8) is smaller than a hydraulic adhesive effect between the damping disc (27) and an end face (22, 23) of the damping disc (27) Anchor (6) or as a respective hydraulic adhesive effect between each two adjacent damping discs (28-30) and between a closest to an end face (22, 23) of the armature (6) located damping disc (28) and the end face (22, 23) of the armature (6). Valve after Claim 3 or 4 , characterized in that the armature (6) has at least one flow channel (35, 36) through which, at least during a movement of the armature (6) in an armature space (32), a fluid located in the armature space (32) flows, and in that at least one damping disk (27-30) viewed in a projection along a longitudinal axis (4) of the valve needle (5) has at least one opening cross section (35 ', 36') of the at least one flow channel (35, 36) on one of the damping disk (27 -30) facing the front side (22, 23) of the armature (6) overlaps. Valve after one of the Claims 1 to 5 , characterized in that between the armature (6) and the stop element (7, 8) a plurality of the valve needle (5) guided damping discs (28-30) are arranged and that in a projection along a longitudinal axis (4) of the valve needle ( 5), each of the damper discs (28-30) does not fully overlap with the projective union of the remaining damper discs (27-30). Valve after one of the Claims 1 to 6 , characterized in that between the armature (6) and the stop element (7, 8) a plurality of the valve needle (5) guided damping discs (28-30) are arranged and that the damping discs (28-30) in a projection along a Longitudinal axis (4) of the valve needle (5) seen in pairs differ. Valve after Claim 6 or 7 , characterized in that in each damping disc (28-30) radially outside the valve needle (5) at least one flow opening (46-48), in particular flow bore (46-48), is configured and that the damping discs (28-30) with a between the damping discs (28-30) in pairs differ in number of flow openings (46-48) are configured. Valve after Claim 6 or 7 , characterized in that on each damping disc (28-30) with respect to a longitudinal axis (4) of the valve needle (5) radially outwardly extending projections (55-57), in particular lugs (55-57) are formed and that the damping discs (28-30) with a pair between the damping discs (28-30) differ in number of projections (55-57) are configured. Valve after one of the Claims 1 to 9 characterized in that the damping disc (27-30) has a thickness, as viewed along a longitudinal axis (4) of the valve needle (5), selected from a range of about 30 μm to about 250 μm, and / or that the damping disc ( 27-30) is formed from a metal foil, which is preferably based on a steel, in particular an austenitic steel.

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