DE102006061947A1 - Fuel injector - Google Patents

Abstract

A fuel injection valve (1) serves as an injector for fuel injection systems of air-compressing, self-igniting internal combustion engines. The fuel injection valve (1) has a valve housing (2) and a solenoid valve (20) arranged in the valve housing (2). In this case, the solenoid valve (20) via a servo control circuit (40) controls a quantity of fuel which can be sprayed through nozzle openings (15, 58). The solenoid valve (20) blocks in a first position a connection of a first outlet (34) and a second outlet (35) of the servo control circuit (40) with a return (32). In a second position, the solenoid valve (20) releases the first outlet (34) and the second outlet (35). Furthermore, the solenoid valve (20) releases the first outlet (34) in a third position and blocks the second outlet (35). As a result, a plurality of switching positions can be realized with a single solenoid valve (20) in order to influence the quantity of fuel sprayed off per unit of time or the jet geometry.

Description

State of the art

The The invention relates to a fuel injection valve for fuel injection systems of internal combustion engines. Specifically, the invention relates to an injector for fuel injection systems of air-compressing, self-igniting Internal combustion engines.

From the DE 101 64 123 A1 For example, a fuel injector for direct injection of diesel fuel into an internal combustion engine is known. The known fuel injection valve has a valve housing consisting of several housing parts. In this case, a fuel inlet nozzle is provided, wherein within the valve housing, a channel for the passage of fuel is formed, which opens into a pressure chamber, which is provided in Abspritzrichtung below a servo control circuit of the fuel injection valve. From this channel branches off at the height of the Hubübersetzungseinrichtung from an inlet throttle, is passed over the fuel from the channel into a control chamber of the hydraulic coupler. Furthermore, an outlet throttle is provided, which connects the control chamber with a 2/2-way valve. If an injection takes place, the switching valve is briefly opened, so that the pressure in the control chamber drops, resulting in the spraying of fuel from the pressure chamber into a chamber of the internal combustion engine.

That from the DE 101 64 123 A1 known fuel injection valve has the disadvantage that the shape of the injection curve is fixed by the structural design of the fuel injector substantially fixed, the length of the injection profile can be influenced by the switching times for the switching valve, so that for more than injection curve shaping changes in design of the fuel injector are required.

Disclosure of the invention

The inventive fuel injection valve with the features of claim 1 has the advantage over that the solenoid valve has at least three different positions, so that further shaping of the course of injection possible are, with a relatively inexpensive design achievable is.

By the measures carried out in the subclaims are advantageous developments of specified in claim 1 Fuel injection valve possible.

Advantageous is it that the servo control circuit has a control room, that an inlet is provided with an inlet throttle, which in the Control room empties that the first flow and the second flow connected to the control room are that the first drain a throttle and that the second drain has a throttle. Consequently are depending on the chosen one Switch position of the solenoid valve Variations in the overall effect about the two processes from the control room resulting throttling effects possible. Thus, the ratio the overall effect of the drainage throttles with respect to the effect of Inlet restrictor can be varied. Thus, especially the opening and closing movement of a valve needle of the fuel injection valve are influenced by the course of the ejected fuel quantity to vary.

Advantageous is it that the servo control circuit to drive a first Valve needle part a first control chamber, which is connected to the first outlet is, and for driving a second valve needle part a second Control space, which is connected to the second sequence, and that a first inlet with an inlet throttle, in the first Control chamber opens, and a second inlet with an inlet throttle, which opens into the second control room, are provided. Thus, a differentiated control of the valve needle parts via the prints in the control rooms possible.

Further it is advantageous that the first valve needle part with a valve seat surface cooperates with a sealing seat to prevent the fuel from spilling over to control at least one nozzle opening, and that the second valve needle part with the valve seat to a sealing seat cooperates to spray a fuel over to control at least one more nozzle opening. As a result, a variable control of the nozzle opening and the other nozzle opening possible, so that different amounts of fuel that are hosed off and different beam geometries relative to each Location of the nozzle opening and the other nozzle opening can be realized.

In Advantageously, the solenoid valve has a first bestrombare Magnetic coil, a second magnetizable coil and an intermediate the magnet coils provided permanently magnetized anchor. Depending on the current supply of the respective solenoid coil can different switching positions of the solenoid valve will be realized. Especially it is advantageous that the two Solenoids are energized so that each has a magnetic repulsion of the anchor is achieved. This makes the anchor reliable held in the middle position, the magnetic forces possible flow forces over a valve needle of the solenoid valve transferred to the armature will compensate.

It is advantageous that the permanent likes netisierten anchor has an annular permanent magnet with two concentrically arranged, spaced apart in the radial direction poles. In this case, a Curie temperature (depolarization temperature) of the permanent magnets is above 100 ° C. The Curie temperature indicates from which temperature the magnet loses its magnetization. When the Curie temperature is above 100 ° C, it is ensured that no demagnetization of the permanent magnets occurs during normal operation of the fuel injection valve.

In Advantageously, there is a remanence of the permanent magnets each over 0.3 T. This is a relatively small configuration of the magnet volume possible. An embodiment of the permanent magnets made of neodymium and / or iron and / or boron has the advantage that due to a relatively high energy density allows a very small volume of construction is and / or large magnetic forces respectively short switching times are possible.

Advantageous it is that a seat diameter of a sealing seat of the solenoid valve, to block the connection between the first flow and the second sequence with the return in the first position is smaller than a needle diameter of a valve needle of the solenoid valve is. This keeps the valve needle of the solenoid valve automatically in the seat.

Further it is advantageous that the needle diameter of the valve needle of the Solenoid valve smaller than a seat diameter of another sealing seat that is to lock the second drain in the third position serves. This keeps the valve needle of the solenoid valve even in the other end position by itself in the seat.

Spezill the solenoid valve can be designed so that the valve needle of the solenoid valve in both end positions automatically in respective seat. Only to hold the valve needle of the Solenoid valve in a middle position is then a permanent current required of the solenoid valve.

Brief description of the drawings

preferred Embodiments of the invention are in the following Description with reference to the accompanying drawings, in which corresponding elements match with one another Reference numerals are provided, explained in more detail. It shows:

1 a first embodiment of a fuel injection valve of the invention in an excerpt, axial sectional view and

2 A second embodiment of a fuel injection valve of the invention in an excerpt, axial sectional view.

embodiments the invention

1 shows a first embodiment of a fuel injection valve 1 the invention in a schematic, axial sectional view. The fuel injector 1 can be used in particular as an injector for fuel injection systems of air-compressing, self-igniting internal combustion engines. Specifically, the fuel injector is suitable 1 for commercial vehicles or passenger cars. A preferred use of the fuel injection valve 1 consists of a fuel injection system with a common rail, the diesel fuel under high pressure to several fuel injection valves 1 leads. The fuel injection valve according to the invention 1 However, it is also suitable for other applications.

The fuel injector 1 has a multi-part valve housing 2 in a suitable manner with a nozzle body 3 connected is. On the nozzle body 3 is a valve seat surface 4 formed with a valve closing body 5 cooperates to a sealing seat. The valve closing body 5 is integral with a valve needle 6 trained in a fuel room 7 of the nozzle body 3 is provided. The fuel injector 1 is via a high pressure line 8th with a high pressure pump 9 connected, wherein the connection can be made indirectly via a common rail. The high pressure line 8th has a branch, so that the high pressure line 8th on the one hand directly into the fuel room 7 empties. On the other hand, there is an inlet throttle 10 provided over which the high pressure line 8th in a control room 11 empties. The control room 11 is through the nozzle body 3 or one with the nozzle body 3 connected throttle plate, a control chamber sleeve 12 and a piston portion 13 the valve needle 6 limited. This is the control chamber sleeve 12 via a spring element 14 against the nozzle body 3 or pressed the throttle plate. Depending on the in the control room 11 prevailing pressure causes a resultant force on the valve needle 6 , which is an opening or closing of the valve closing body 5 causes, so that between the valve seat surface 4 and the valve closing body 5 formed sealing seat is open or closed, wherein in the open state, fuel via nozzle openings 15 from the fuel room 7 can be sprayed into a combustion chamber of the internal combustion engine.

The fuel injector 1 also has a solenoid valve 20 on, inside the valve body 2 is provided. The solenoid valve 20 has a valve needle 21 on. Furthermore, the solenoid valve 20 a valve closing body 22 and an anchor 23 on. Here is the valve closing body 22 at one end of the valve needle 21 arranged and the anchor 23 is in the area of another end of the valve needle 21 arranged. The anchor 23 is permanently magnetized and accordingly has at least one permanently magnetic material, for example a ferrite material or neodymium and / or iron and / or boron. The magnetic polarization of the armature 23 is in the 1 represented by "N" for North Pole and "S" for South Pole. The anchor 23 is in an anchor room 24 of the nozzle body 3 arranged so that a certain adjustment movement of the anchor 23 and thus an adjustment of the valve needle 21 of the solenoid valve 20 is possible.

The with the valve needle 21 connected anchors 23 is between a first solenoid 25 and a second solenoid 26 of the solenoid valve 20 arranged. The magnetic coils 25 . 26 have ferromagnetic metal rings 27 . 28 each with a 13-profile on. Inside the metal rings 27 . 28 are wire coils 29 . 30 provided, which are energized independently of each other. The first solenoid 25 is so energizable that a magnetic repulsion of the anchor 23 from the first solenoid 25 is reachable. Further, the second solenoid is 26 so energizable that a magnetic repulsion of the anchor 23 from the second solenoid 26 is reachable. The first solenoid 25 and / or the second solenoid 26 can also each be energized in an opposite direction to an attraction of the anchor 23 to the first solenoid 25 or the second solenoid 26 to reach. The solenoid valve 20 but is at least designed so that in each case a repulsion of the anchor 23 from the first solenoid 25 and the second solenoid coil 26 by appropriate energization of the magnetic coils 25 . 26 is reachable. With the energization of the first solenoid coil 25 and / or the second maget coil 26 in the opposite direction, the switching behavior of the solenoid valve 20 , in particular the switching speed, are additionally influenced.

The solenoid valve 20 has a control valve room 31 on, over a return 32 can be connected to a tank or the like. In the in the 1 shown first position of the solenoid valve 20 is a means of Ventilschließkorpers 22 formed sealing seat 33 closed, leaving the connection between the control valve room 31 and the return 32 Is blocked. The control room 11 is by means of a first procedure 34 and a second process 35 with the control valve room 31 connected. In this case, the first sequence 34 a throttle 36 on and the expiration 35 has a throttle 37 on. The throttles 36 . 37 thus, in relation to the control room 11 Drainage dar. The processes 34 . 35 flow into the control valve room 31 , where in the in the 1 shown first position a connection of the processes 34 . 35 with the return 32 Is blocked. However, in the illustrated embodiment, a connection of the two processes 34 . 35 over the control valve room 31 , During operation of the fuel injection valve 1 can the solenoid valve 20 placed in the first position and held in this by the second solenoid coil 26 is energized while the first solenoid coil 25 is current-free. This will cause a repulsion of the anchor 23 from the second solenoid 26 reached.

The solenoid valve 20 can be placed in a second position by both the first solenoid coil 25 as well as the second solenoid coil 26 be energized, causing a repulsion of the anchor 23 both with respect to the first solenoid 25 as well as with respect to the second solenoid coil 26 is reached. In this second position is the anchor 23 thus at least substantially in the middle between the two magnetic coils 25 . 26 because there's the anchor 23 acting, repulsive magnetic forces of the magnetic coils 25 . 26 cancel in about. By adjusting the anchor 23 From this middle position is a resulting restoring force on the anchor 23 generated, for example, increases exponentially with the adjustment from the middle position. In the second position is the sealing seat 33 open, allowing a connection between the control valve room 31 and the return 32 consists. Thus, in the second position, both the first sequence 34 as well as the second process 35 over the control valve room 31 with the return 32 connected. Possibly occurring flow forces on the valve closing body 22 act, by the at an adjustment of the valve closing body 22 Restoring force generated from the second position, from the magnetic fields of the two magnetic coils 25 . 26 results, compensated. Thus, the anchor becomes 23 and thus the valve needle 21 as well as the valve closing body 22 held at least substantially in the second position.

In the second position, the resulting throttle effect is less than each throttle effect of the throttles 36 . 37 as fuel from the control room 11 about the two processes 34 . 35 in the control valve room 31 to the return 32 flows. This results in a relatively small ratio of the effective effect of the two flow restrictors 36 . 37 in terms of the effect of the inlet throttle 10 , This allows a relatively fast opening of the valve needle 6 achieve, so that a rapid increase in the amount of fuel delivered per unit time via the nozzle openings 15 achieved.

The solenoid valve 20 also has a third position, in which the valve closing body 22 by closing a sealing seat 38 the second process 35 closes. In this third position, there is thus no connection between the second sequence 35 and the control valve room 31 while the first Ab run 34 with the control valve room 31 is connected and at the same time an open connection between the control valve chamber 31 and the return 32 consists. Thus, the overall throttle effect is in terms of the processes 34 . 35 only through the throttle 36 given. Therefore, a relatively large ratio of the total throttle effect of the processes 34 . 35 that equal the effect of the outlet throttle 36 is, in relation to the inlet throttle 10 reached. By switching the solenoid valve 20 from the first position to the third position can thus a slower opening of the valve needle 21 can be achieved so that the amount of fuel sprayed off per unit time increases more slowly when switching from the first position to the second position. The third switching position is achieved by the first solenoid coil 25 is energized and the second solenoid 26 is switched off.

A seat diameter of the sealing seat 33 of the solenoid valve 20 that locks the connection between the first expiration 34 and the second process 35 with the return 32 in the first position, is smaller than a needle diameter of the valve needle 21 of the solenoid valve 20 , The control valve room 31 has high pressure, while the return 32 Low pressure has. Thus, the valve needle holds 21 Even without further energization of the solenoid valve automatically in the sealing seat 33 ,

Furthermore, the needle diameter of the valve needle 21 of the solenoid valve 20 smaller than a seat diameter of the other sealing seat, which locks the second drain 35 serves in the third position. After switching the solenoid valve to the third position, the control valve chamber 31 Low pressure, while the anchor space 24 High pressure has. Thus, the valve needle 21 also in this position automatically in the sealing seat 38 held.

Thus, in both end positions an automatic holding of the valve needle 21 be achieved in the respective sealing seat, so that in each case a hydraulic fixation is achieved.

The switching of the solenoid valve 20 in the first position, which in the 1 can also be done by the first solenoid is energized so that an attraction of the armature 23 is reached. Accordingly, a switching of the solenoid valve 20 in the third position also be achieved in that the second solenoid 26 so energized that tightening the anchor 23 is reached. Further, the switching speed can be increased by, for example, the first solenoid coil 25 so energized that a repulsion of the anchor 23 is reached while the second solenoid coil 26 energized in the opposite direction, leaving an attraction of the anchor 23 from the second solenoid 26 is achieved, a fast switching of the in the 1 to reach the first position shown in the third position.

To protect the permanently magnetized armature 23 against tensile forces may be a coating or packaging of the anchor 23 or at least part of the anchor 23 done, for example, by pouring the anchor 23 in a glass fiber reinforced plastic, by gluing the anchor 23 in aluminum plates, by stapling or pressing in the anchor 23 between austenitic iron plates or the like.

In the valve housing 2 may also be configured as a high-pressure line fuel line 39 be provided with the high pressure line 8th connected is. In this case, the fuel injector is in operation 1 also in the anchor room 24 , high pressure fuel.

The inlet throttle 10 , the control room 11 , and the drainage throttles 36 . 37 are part of a servo control cycle 40 of the fuel injection valve 1 , The in the 1 illustrated embodiment of the servo control circuit 40 represents a possibility in which the three switching states of the solenoid valve 20 is used advantageously for varying the A / Z ratio. The solenoid valve 20 but also with differently designed servo control circuits 40 be combined. The solenoid valve 20 controls by means of the servo control circuit 40 a quantity of fuel passing through the nozzle orifices 50 can be sprayed, wherein the control essentially by the choice of the respective position of the solenoid valve 20 is affected. Further possibilities of influencing arise in particular by influencing the switching speed of the solenoid valve 20 ,

2 shows a second embodiment of a fuel injection valve 1 in a simplified, schematic sectional view. In this embodiment, the valve needle 6 a first valve needle part 41 and a second valve needle part 42 on. The control of the first valve needle part 41 takes place via a first control room 43 passing through the control room sleeve 12 , another control chamber sleeve 44 , the valve needle parts 41 . 42 and a throttle plate 45 is limited. The activation of the second valve needle part 42 takes place via a second control room 46 passing through the further control chamber sleeve 44 , the second valve needle part 42 and the throttle plate 45 is limited. In the throttle plate 45 are several throttles 36 . 37 . 47 . 48 designed, namely the inlet throttles 47 . 48 and the drainage throttles 36 . 37 , The inlet throttle 47 a first feed 51 flows into the first control room 43 , The inlet throttle 48 a second inlet 52 flows into the second control room 46 , The outlet throttle 36 is part of the first process 34 , the first control room 43 With the control valve room 31 combines. The outlet throttle 37 is part of the second process 35 , the second control room 46 with the control valve room 31 combines. Furthermore, spring elements 14 . 49 provided that the control chamber sleeves 12 . 44 against the throttle plate 45 apply and the valve needle parts 41 . 42 in the unpressurized state in the in the 2 Adjust illustrated starting position in which the fuel injection valve 1 closed is.

The inlet throttle 47 is part of the first feed 51 from the inlet 8th in the first control room 43 leads. Furthermore, the inlet throttle 48 Part of the second inlet 52 from the inlet 8th in the second control room 46 leads. Thus, the first inlet opens 51 in the first control room 43 and the second feed 52 flows into the second control room 46 ,

The nozzle body 3 has the nozzle openings 15 as well as further nozzle openings 50 on. In this case, the first valve needle part forms 41 with the valve seat surface 4 a sealing seat, the nozzle openings 15 seals. Furthermore, the second valve needle part forms 42 with the valve seat surface 4 a sealing seat, the other nozzle openings 50 seals. Depending on the pressures in the first control room 43 and in the second control room 46 can different positions of the first valve needle part 41 and the second valve needle part 42 be reached to the nozzle openings 15 and the other nozzle openings 50 each open or close, leaving fuel through the nozzle openings 15 and / or the other nozzle openings 50 and / or that no fuel over the nozzle openings 15 . 50 is hosed. As a result, on the one hand the quantity of fuel sprayed off per unit of time and, on the other hand, the jet geometry of the sprayed-off fuel can be influenced.

The control of the prints in the control rooms 43 . 46 via the solenoid valve 20 , The solenoid valve allows this 20 due to the at least three different switching positions, a control of both the first valve needle part 41 as well as the second valve needle part 42 , wherein in the third switching position, an actuation of only the first valve needle part 41 can be done. Thus, to control the two valve needle parts 41 . 42 only one control valve, namely the solenoid valve 20 , required. This results in a compact design of the fuel injection valve 1 and the possibility of the fuel injector 1 produce economically.

The servo control circuit 40 includes in this embodiment, the throttles 36 . 37 . 47 . 48 , the first control room 43 and the second control room 46 ,

The Invention is not limited to the described embodiments limited. In particular, the invention is suitable for Servo-controlled injectors, as for example in the diesel direct injection be used.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10164123 A1 [0002, 0003]

Claims (16)

Fuel Injector ( 1 ), in particular injector for fuel injection systems of air-compressing, self-igniting internal combustion engines, with a in a valve housing ( 2 ) arranged solenoid valve ( 20 ) and a servo control circuit ( 40 ), whereby the solenoid valve ( 20 ) by means of the servo control cycle ( 40 ) controls an amount of fuel passing through at least one orifice ( 15 . 50 ) is sprayable, wherein the solenoid valve ( 20 ) in a first position, a connection of a first sequence ( 34 ) and a second process ( 35 ) of the servo control circuit ( 40 ) with a return ( 32 ) locks, in a second position, the first sequence ( 34 ) and the second process ( 35 ) and in a third position the first sequence ( 34 ) and the second process ( 35 ) locks. Fuel injection valve according to claim 1, characterized in that the servo control circuit ( 40 ) a control room ( 11 ) that an inlet ( 8th ) with an inlet throttle ( 10 ) provided in the control room ( 11 ) concludes that the first process ( 34 ) and the second process ( 35 ) with the control room ( 11 ), that the first sequence ( 34 ) a throttle ( 36 ) and that the second sequence ( 35 ) a throttle ( 37 ) having. Fuel injection valve according to claim 1, characterized in that the servo control circuit ( 40 ) for driving a first valve needle part ( 41 ) a first control room ( 43 ), with the first procedure ( 34 ) and for driving a second valve needle part ( 42 ) a second control room ( 46 ) associated with the second flow ( 35 ) and that a first feed ( 51 ) with an inlet throttle ( 47 ) entering the first control room ( 43 ), and a second feed ( 52 ) with an inlet throttle ( 48 ), which enters the second control room ( 46 ), are provided. Fuel injection valve according to claim 3, characterized in that the first valve needle part ( 41 ) with a valve seat surface ( 4 ) cooperates with a sealing seat in order to spray off fuel via at least one nozzle opening (FIG. 15 ), and that the second valve needle part ( 42 ) with the valve seat surface ( 4 ) cooperates with a sealing seat to spray off fuel via at least one further nozzle opening ( 50 ) to control. Fuel injection valve according to one of claims 1 to 4, characterized in that the solenoid valve ( 20 ) a first energizable solenoid coil ( 25 ), a second energizable solenoid coil ( 26 ) and a permanently magnetized armature ( 23 ) having. Fuel injection valve according to claim 5, characterized in that the permanently magnetized armature ( 23 ) has an annular permanent magnet with two concentrically arranged, spaced apart in the radial direction poles. Fuel injection valve according to claim 6, characterized characterized in that a Curie temperature of the permanent magnets each about 100 ° C is located. Fuel injection valve according to claim 6 or 7, characterized in that a remanence of the permanent magnets each over 0.3 T is. Fuel injection valve according to one of the claims 6 to 8, characterized in that the permanent magnets of a Material are made, the neodymium and / or iron and / or boron having. Fuel injection valve according to one of claims 5 to 9, characterized in that for switching the solenoid valve ( 20 ) at least one magnetic coil ( 25 . 26 ) is energized so that a magnetic repulsion of the armature ( 23 ) of this magnetic coil ( 25 . 26 ) is reachable. Fuel injection valve according to one of claims 5 to 10, characterized in that for switching the solenoid valve ( 20 ) in the second position, the first magnetic coil ( 25 ) and the second magnetic coil ( 26 ) are energized so that a repulsion of the armature ( 23 ) from both the first solenoid coil ( 25 ) as well as from the second magnetic coil ( 26 ) is reachable. Fuel injection valve according to one of claims 5 to 11, characterized in that for switching the solenoid valve ( 20 ) in the first position, the first magnetic coil ( 25 ) and the second magnetic coil ( 26 ) are energized so that an attraction of the armature ( 23 ) from the first solenoid coil ( 25 ) and / or a repulsion of the anchor ( 23 ) from the second solenoid coil ( 26 ) is reachable. Fuel injection valve according to one of claims 5 to 12, characterized in that for switching the solenoid valve ( 20 ) in the third. Position the first solenoid ( 25 ) and the second magnetic coil ( 26 ) are energized so that a repulsion of the armature ( 23 ) from the first solenoid coil ( 25 ) and / or attraction of the anchor ( 23 ) from the second solenoid coil ( 26 ) is reachable. Fuel injection valve according to one of claims 1 to 13, characterized in that the solenoid valve ( 20 ) in the first position the first sequence ( 34 ) with the second sequence ( 35 ) connects. Fuel injection valve according to one of claims 1 to 14, characterized in that a Seat diameter of a sealing seat ( 33 ) of the solenoid valve ( 20 ), which blocks the connection between the first flow ( 34 ) and the second process ( 35 ) with the return ( 32 ) in the first position, smaller than a needle diameter of a valve needle ( 21 ) of the solenoid valve ( 20 ). Fuel injection valve according to one of claims 1 to 15, characterized in that a needle diameter of a valve needle ( 21 ) of the solenoid valve ( 20 ) smaller than a seat diameter of another sealing seat ( 38 ), which is to block the second process ( 35 ) in the third position.