DE102007052363A1 - Control valve for fuel injector for internal combustion engine, has closing element at guidance, which is pivoted in longitudinal direction and closing element has seat edge - Google Patents

Abstract

The control valve (12) has a closing element (20) at a guidance, which is pivoted in a longitudinal direction. The closing element has a seat edge, with which it interacts with a valve seat (26). The valve seat is formed at a valve piece (38) or at a plane surface. The guidance limits a gap or a gap filter (30) above the valve seat. A gap width (32) of the gap filter amounts to smaller or same of a valve lift (34). An independent claim is included for a fuel injector for an internal combustion engine with a control valve.

Description

DE 10 2007 028 485 refers to a control valve for a fuel injection valve. The control valve for a fuel injector comprises a control sleeve which defines a pressure chamber and which is movably mounted in its longitudinal direction. The control sleeve has a sealing surface on one end face. With this, the control sleeve cooperates with a valve seat, which is formed by a valve body. In the valve body, a recess in the pressure chamber facing side of the valve body is formed. The control sleeve and the recess in the valve body are designed so that the deformation of the control sleeve and valve body by the pressure in the pressure chamber leads to no or only a very small movement between the valve seat and the sealing surface of the control sleeve.

Control or switching valves like that DE 10 2007 028 485 known control valve are exposed due to the prevailing in high-pressure injection system pressures, the operating temperatures, the accelerations of the components and the like more, very high mechanical loads.

The Component geometries of the subject switching or control valves are partly in terms of occurring and to be observed Tolerances in the range of less microns, so in addition to the above listed mechanical stresses contained in the fuel Particles can cause abrasive wear. In particular, the valve seat is in such control or switching valves particularly endangered, since this in the fuel flow a Bottleneck with high flow rates represents. Although the fuel is filtered by multiple filtration systems, Nevertheless, isolated particles can be a size reach the valve lift of the valve member of the switching or Exceed control valve. Achieve such a particle the valve seat, he can not pass this. The valve seat has in this case in terms of the particle of this size the function of a split filter. The particle will stay with you for so long each injection against the valve seat with it formed Seat edge beaten until a fragmentation occurs and he looks up from his original size a size is reduced, which allows the Valve seat in the direction of the low-pressure side return to happen. Depending on how hard the one to smash Particles are smaller or larger abrasive Wear on the seat edge.

remedy is currently being created by the fact that in many valve applications, be it switching or control valves in fuel injection systems, so in particular on high-pressure accumulator injection systems of self-igniting Internal combustion engines, protective layers on both the preferred needle-shaped trained injection valve member as well as the components of the seat be applied to such a fuel injector. One more way to reduce the abrasive wear using expensive tool steels as a material for the valve components. Tool steels are usually more expensive and more expensive to work with. The measures taken serve essentially to the valve seat of a control or switching valve stronger and more resistant than the particles, which may possibly occur on such a valve seat.

Disclosure of the invention

According to the invention This object is achieved in that a gap filter immediately is created in front of the valve seat, which upstream of the valve seat is and therefore the striking may be larger Particles contained in the fuel to the highly accurately manufactured Components at the area of the valve seat, in particular the seat edge, prevented. This allows one over the life the switching or control valve seen much more robust valve seat realize.

One Such valve seat with upstream gap filter can, for. B. in switching or control valves with a sleeve-shaped trained closing element and pressure balanced Switching or control valves with preferably needle-shaped closing element Find use. The advantage of the present solution Above all, it can be seen that the split filter is close to the seat Orientation and possibly close sitting destruction in the fuel contained larger particles takes place. In the proposed solution according to the invention is via the fixed components of the switching or control valve just before the valve seat creates a fixed gap, the is less than or equal to the valve lift of the switching or control valve. All the particles that can overcome this gap, can with a complete stroke of the Valve member of the switching or control valve and the valve seat happen. Possible damage are doing primarily at the valve seat upstream Slit filter occur and not on the highly accurately machined components in the region of the valve seat of the fuel injector.

The According to the invention proposed solution can be used both with switching or control valves with a sleeve-shaped configured closing element can be used as well with pressure-balanced I-valves, on which a flat seat is executed is as well as to switching or control valves, as sleeve valves are formed and z. B. have a conical seat.

Brief description of the drawings

Based In the drawings, the invention will be described in more detail below.

It demonstrate:

1 a fuel injector with seated close acting as a gap filter gap,

2 the embodiment according to 1 with a larger first particle shown in front of the gap filter and a small smaller particle smashed in the gap downstream of the open seat,

3 an embodiment of the gap filter on an inwardly opening valve (I-valve) and

4 the gap filter according to the invention proposed on a sleeve seat having a sleeve valve.

embodiments

1 shows a first embodiment of the inventively proposed fuel injector, on the seat close a gap filter is formed.

As 1 shows, includes the fuel injector 10 a control valve 12 , which in the embodiment according to 1 a sleeve-shaped closing element 20 to grasp what an anchor bolt 24 in a guided tour 66 is guided. The control valve 12 further comprises a fixed valve seat 26 that as a seal seat 27 acts.

The control valve 12 of the fuel injector 10 according to the embodiment in 1 is via a magnetic coil 16 operated in a magnetic core 14 is included. The magnetic coil 16 opposite is a with the sleeve-shaped closing element 20 integrally formed anchor plate 18 , The anchor plate 18 or the sleeve-shaped closing element 20 is by a closing spring 22 in the closing direction of the fixed valve seat 26 applied. At the bottom of the in 1 shown symmetrical to the injector axis 60 trained anchor bolt 24 there is an end face 28 , who proposed the inventively proposed close-gap filter, here as a seat-close gap 30 is formed, limited. A gap width extending between the front 28 of the anchor bolt 24 and a plane surface 70 of the fixed valve seat 26 extends is by reference numerals 32 identified. The gap width 32 the inventively proposed close-sitting gap filter 30 is preferably less than or equal to a valve lift 34 selected. All particles (see illustration according to 2 ) the seat near gap filter 30 can overcome, during full stroke, ie a complete valve lift 34 of the control valve 12 the fixed valve seat 26 happen. Possibly occurring damage is thereby proposed on the invention, as close as possible arranged gap filter 30 arise, but not on the valve seat 26 whose components are machined with high precision.

How out 1 Furthermore, it is the fixed valve seat 26 that as a seal seat 27 acts on a valve piece 38 educated. The valve piece 38 is by means of a valve clamping screw 40 in the injector body 58 of the fuel injector 10 attached. The valve piece 38 limits a control room 44 that by an inlet throttle 42 is pressurized with fuel under system pressure. System pressure is understood below to mean the pressure below which the fuel stands, that of a high-pressure space 62 over the high pressure inlet 36 flows in. This system pressure is z. B. in a high-pressure accumulator body (common rail) generates a high-pressure accumulator injection system.

About the inlet throttle 42 the system pressure acts on a control room 44 of the valve piece 38 is limited. The system pressure in the control room 44 prevails, impinges on an end face 48 a particular needle-shaped injection valve member 46 , The injection valve member 46 indicates at least one in the illustration according to 1 not shown injection port in the combustion chamber of the internal combustion engine free or closes this. This is done depending on the pressure in the control room 44 prevails.

The preferably needle-shaped injection valve member 46 is by means of a guide 64 in the valve piece 38 guided.

A pressure change in the control room 44 , ie a pressure relief via a valve piece 38 passing through the drainage channel 52 in which an outlet throttle 54 is included. The drainage channel 52 opens in the valve piece 38 below the fixed valve seat 26 that as a seal seat 27 acts. Outflow from the fixed valve seat 26 extends a Absteuerraum 50 in which a control amount after opening the fixed valve seat 26 according to the arrow 56 to the low pressure area of the fuel injector 10 is diverted. In the pressure relief of the pressurized with system pressure control chamber 44 there is a vertical lifting movement of the particular needle-shaped injection valve member 46 in the opening direction, so that the at least one - in 1 not shown - injection opening at the combustion chamber end of the fuel injector 10 is released and fuel can be injected into the combustion chamber of the internal combustion engine.

The pressure relief of the control room 44 ie the opening of the fixed valve seat 26 that as a seal seat 27 acts takes place during energization of the magnetic core 14 enclosed magnetic coil 16 , When the solenoid is energized 16 Do this in one piece with the anchor plate 18 trained, sleeve-shaped closure element 20 the valve lift 34 in the opening direction, ie in a vertically upward direction and opens the sealing seat 27 ,

The representation according to 2 is the in the embodiment according to 1 to be seen in the open state shown in the closed state.

How out 2 is apparent in the presentation according to 2 a tax amount from the tax room 44 deactivated. The control of the control amount from the control room 44 , in which system pressure prevails, takes place via the drainage channel 52 in which is the outlet throttle 54 , performed as a cross-sectional constriction of the drainage channel 52 , is located. The tax quantity contains a first particle 68 in a size corresponding to the cross section of the split filter formed close to the seat 30 exceeds. The size of the first particle 68 is in the illustration according to 2 exaggerated.

In the illustration according to 2 is the seal seat 27 open. This is the solenoid 16 energized and the anchor plate 18 with at this sleeve-shaped closing element 20 is in vertical direction according to the valve lift 34 move upwards. Due to the seat-trained gap filter 30 will the in 2 illustrated first Parti cle 68 , the one the gap width 32 has excess size, at the front 28 of the anchor bolt 24 smashed. As a result, the high-precision machined fixed valve seat 26 protected, the solution proposed by the invention following, now no longer gets the task, first particles 68 to smash. Due to the inventively proposed seat-trained gap filter 30 occur possible damage to the components of the seat close formed gap filter 30 on, but not on the fixed valve seat 26 , From the illustration according to 2 indicates that the compressed to system pressure fuel through the open sealing seat 27 escapes. A first particle 68 which is larger than the gap width 32 the seat-trained gap filter 30 is in the seat close trained split filter 30 get stuck and open the sealing seat 27 do not reach. As shown in the illustration 2 also shows, a smaller particle, cf. second particle 70 in the illustration according to 2 , however, the seated trained gap filter 30 or its gap width 32 pass through, but subsequently through the open sealing seat 27 directly into the Absteuerraum 50 rinsed and from there in the direction of the low-pressure side return, as by reference numerals 56 indicated, transported. Due to the high flow speed in the area of the open sealing seat 27 and in the seat close trained gap filter 30 , be the big first particles 68 at the entrance of the seat-trained gap filter 30 smashed until she saw the split filter close to the seat 30 can happen. During subsequent, complete driving through the valve lift 34 becomes the smashed first particle 68 or its individual parts 70 in the diversion room 50 transported.

In the illustration according to 2 is the embodiment of the fuel injector 10 who in 1 with closed sealing seat 27 is shown in the open state. The magnetic coil 16 from the magnetic core 14 is enclosed, is energized and therefore the anchor plate 18 with formed thereon sleeve-shaped closing element 20 according to the valve stroke 34 against the action of the closing spring 22 move in vertical direction upwards. Due to the opening of the sealing seat 27 the control quantity flows out of the control room pressurized with system pressure 44 through the drainage channel 52 in the diversion room 50 one. Due to the lowered pressure in the control room 44 drives the front side 48 the preferably needle-shaped injection valve 46 in the control room 44 one. As a result, at least one, at the combustion chamber end of the fuel injector 10 in 2 also not shown injection port open, so standing under system pressure fuel in the high-pressure chamber 62 is present, can be injected into the combustion chamber of the internal combustion engine.

From the Absteuerraum 50 from the flows out of the control room 44 escaped fuel according to the arrow 56 a low-pressure return to. Low-pressure side return runs of the fuel injectors 10 , via which the individual combustion chambers of a single-cylinder or multi-cylinder internal combustion engine are supplied with fuel, are supplied to a return, via which the diverted fuel is returned to the tank.

3 shows an embodiment of the present invention proposed control valve on a pressure balanced I-valve.

As 3 shows includes the fuel injector shown there 10 the control valve 12 in which, in this embodiment, the anchor plate 18 with the anchor bolt 24 is designed as a component. The anchor plate 18 and the anchor bolt 24 are symmetrical to the injector axis 60 executed. The anchor bolt 24 is characterized by in the closing direction of the control valve 12 acting closing spring 22 applied. The anchor bolt 24 with anchor plate 18 is relative movable to a stationarily arranged stationary sleeve 31 , in which the anchor bolt serving as a closing element 24 in a guided tour 66 is guided. At the anchor bolt 24 is a seat edge 80 formed with a plane surface 78 interacts. This disc-shaped configured component, through which the high-pressure inlet 36 runs, forms the fixed valve seat 26 , which in the representation according to 3 at the I-valve shown there 72 as a closed sealing seat 27 is executed. The high pressure inlet 36 flows into a pressure room 74 , In the pressure room 74 is located in the 3 in the closed position shown sealing seat 27 upstream of the seat-mounted gap filter 30 , The gap filter 30 on the one hand, through the plane surface 78 of the fixed valve seat 26 and on the other hand by an annular surface on the stationary sleeve 31 limited. About the high pressure inlet 36 in the pressure room 74 entering particles of the first particle size 68 - as in 2 shown - be in the seat-mounted split filter 30 due to the prevailing gap width 32 smashed. The gap width 32 the seat-close split filter 30 as shown in 3 is chosen so that it is less than or equal to the valve lift 34 , indicated in the 1 and 2 , is. When opening the seat valve 12 as shown in 3 only get second particles 70 through the seat-mounted gap filter 30 to the return 76 passing through the fixed valve seat 26 extends, the diameter of which is less than or equal to the fully passed valve lift 34 is.

Consequently, the fragmentation of one takes place through the high-pressure inlet 36 in the pressure room 74 registered first particle 68 with a the gap width 32 the seat-close split filter 30 exceeding diameter in seat-mounted split filter 30 not by the highly accurately machined components of the 3 Flat seat shown in the closed state, which here the sealing seat 27 forms. From the illustration according to 3 shows that the fixed sleeve 31 with the component which the fixed valve seat 26 forms, along a fugue 82 connected is.

4 shows a sleeve valve with a conical seat.

As 4 shows comprises a sleeve valve 84 the anchor plate 18 , with the sleeve-shaped closing element 20 connected is. This is along a lead 66 at the anchor bolt 24 guided, whose front page with reference numerals 28 is designated. Between the front side 28 of the anchor bolt 24 , which is symmetrical to the injector axis 60 is formed and the plane surface 78 of the valve piece 38 , there is a gap close to the seat 30 , which forms the seat-close gap filter. In the seat-mounted split filter 30 an outflow channel opens 52 in which the outlet throttle 54 is trained. Over this is tax amount from the control room 44 of the valve piece 38 deactivated. Also in the in 4 illustrated embodiment of the sleeve valve 84 may be out of the control room 44 discharged first particles 68 within the gap filter close to the seat 30 smashed and get - as in 2 with another embodiment of the control valve 12 shown - in the Absteuerraum 50 without damaging the highly accurately machined surfaces, in this case a conical surface 88 a bowling seat 86 or a seat edge 80 on the underside of the sleeve-shaped closing element 20 he follows.

From the illustration according to 4 it follows that the seat-near split filter 30 in the gap width 32 is formed, which in the 1 and 2 illustrated valve lift 34 equivalent. The fragmentation of possibly over the Absteuerkanal 52 at pressure relief of the control room 44 fuel purged in the first particle 68 takes place on the front side 28 of the anchor bolt 24 , on which the sleeve-shaped closing element 20 in the lead 66 is guided vertically displaceable. Thus, the seat edge 80 of the bowling seat 86 as well as the conical surface 88 that are on the valve piece 38 to the plane surface 78 below the front side 38 of the anchor bolt 24 adjoins, not affected by the fragmentation of the particles, as their fragmentation in the upstream of these components sitting gap filter 30 he follows.

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 102007028485 [0001, 0002]

Claims (10)

Control valve ( 12 ) for a fuel injector ( 10 ) with a closing element ( 20 ) at a guided tour ( 24 ), which are mounted to each other in the longitudinal direction movable and the closing element ( 20 ) a seat edge ( 80 ), with which it is fitted with a valve seat ( 26 . 27 ; 86 ) cooperating on a valve piece ( 38 ) or on a plane surface ( 78 ), characterized in that the guide ( 24 . 31 ) above the valve seat ( 26 . 27 ; 86 ) a gap or a gap filter ( 30 ) whose gap width ( 32 ) less than or equal to a valve lift ( 34 ) is. Control valve ( 12 ) according to claim 1, characterized in that the closing element ( 20 ) is sleeve-shaped and on an anchor bolt ( 24 ) or the anchor bolt ( 24 ) relative to a surrounding this sleeve ( 31 ). Control valve ( 12 ) according to claim 1, characterized in that the seat-near gap or the seat-near gap filter ( 30 ) in the outflow direction ( 56 . 76 ) of the fuel, the valve seat ( 26 . 27 ; 86 ) is connected upstream. Control valve ( 12 ) according to claim 1, characterized in that the closing element ( 20 ) or the leadership ( 24 ) a seat edge ( 80 ) having a plane surface ( 78 ) on the valve seat ( 26 . 27 ) or a conical surface ( 88 ) on a conical seat ( 86 ) cooperates. Control valve ( 12 ) according to claim 1, characterized in that the gap width ( 32 ) from one end face ( 28 ) of the anchor bolt ( 24 ) or an end face of the anchor bolt ( 24 ) enclosing sleeve ( 31 ) and a plane surface ( 78 ) of the fixed seat ( 26 . 27 ; 86 ) is limited. Control valve ( 12 ) according to claim 1, characterized in that this as a pressure-balanced, inwardly opening I-valve ( 72 ) or as a sleeve valve ( 84 ) with conical seat ( 86 ) is executed. Control valve ( 12 ) according to claim 6, characterized in that the inwardly opening I-valve ( 72 ) one from a plane surface ( 78 ) and sleeve ( 31 ) limited pressure space ( 74 ), which by a high-pressure line ( 36 ) is acted upon. Control valve ( 12 ) according to claim 1, characterized in that downstream of the valve seat ( 26 . 27 ; 86 ) a diversion room ( 50 ) is provided. Control valve ( 12 ) according to claim 1, characterized in that the gap width ( 32 ) with respect to the valve seat ( 26 . 27 ; 86 ) is fixed. Fuel injector ( 10 ) for internal combustion engines with a control valve ( 12 ) according to one of claims 1 to 9, which regulates the pressure in a control room ( 44 . 74 ), with a needle-shaped injection valve member ( 46 ) which opens or closes at least one injection opening and the control room ( 44 . 74 ) via a high-pressure inlet ( 36 ) is acted upon by standing under a system pressure fuel.