DE10361762A1 - Fuel injector - Google Patents

Abstract

A fuel injection valve (1) has an actuator, which is in operative connection with a valve needle (3). The valve needle (3) has a valve closing body (4) on the discharge side, which cooperates with a valve seat surface (6) to form a sealing seat. An ejection opening (7) opens at an exit point (46). The exit point (46) of the ejection opening (7) protrudes relative to all sides of the immediately surrounding surface from which it opens.

Description

State of technology

The The invention is based on a fuel injection valve after Genus of the main claim.

For example, is from the DE 199 50 760 A1 a fuel injection valve is known in which the injection opening opens at a surrounding the ejection opening flat surface.

In other also known from the prior art fuel injection valves ends the injection opening on a conically tapering outer surface of a circular cone, wherein the above and below the injection opening extending outer surfaces of a Angle of 180 ° to each other exhibit.

adversely in the fuel injection valves known from the prior art is in particular that by the flat, not protruding arrangement of the injection opening in a flat surface or between two mutually in cross-section to each other in a Line running surfaces, one for the prevention of precipitation of fuel sufficient gas flow is not can be achieved. The formation of combustion residues in and around the injection opening is thereby increased. The combustion process can not optimally over the Life of the fuel injection valve to be controlled. Of the Consumption and pollutant development are increased.

Advantages of invention

The Fuel injection valve according to the invention with the characterizing features of the main claim has the Advantage that through the exposed position of the exit point of the ejection opening the Strength the gas movements sufficient to the environment of the exit point free from deposits that keep the injection process unfavorable would affect.

By in the subclaims listed activities are advantageous developments of the specified in the main claim Fuel injection valve possible.

In a first development opens the injection opening in the area of transition a first surface in a second area out, with the two surfaces to each other with an outside angle arranged by more than 180 ° are. The conical sections produced thereby can Fuel injection valve by simple and inexpensive process steps getting produced.

advantageously, expands the spray opening conical to the outside. One at the entrance of the injection opening from the wall of the injection opening detached fuel flow is characterized in the injection opening safely maintained. For example, in the form of a vortex zone or Kavitationsblase formed detached from the walls fuel flow prevented wetting the walls of the injection orifice with fuel and causes by hydrodynamic shear forces a self-cleaning of the injection opening during the injection process. As these detached Flow over the full length the injection opening is maintained no in the injection opening Form deposits. Furthermore can the injection opening longer without disadvantages be formed, whereby the stability of the discharge side end of the fuel injection valve is increased. This is also going through a stepped, outward achieved widening design of the ejection openings, wherein moreover advantageously still a direct flame entry into the flow-determining internal lying Smaller diameter section is prevented when the first one Section at least partially through the second section opposite the Combustion chamber or in the combustion chamber arising and propagating Flame front is hidden.

From It is also an advantage Form the second section by a circumferential groove. hierduch the second section can be easily and inexpensively generated, in particular in fuel injection valves with multiple spray openings.

drawing

embodiments The invention are shown in simplified form in the drawing and explained in more detail in the following description. Show it:

1 a schematic section through an example of a generic designed fuel injector,

2 FIG. 2 a schematic section through a first exemplary embodiment of a fuel injection valve according to the invention in the region of the injection opening, FIG.

3 FIG. 2 a schematic section through a second exemplary embodiment of a fuel injection valve according to the invention in the region of the injection opening, FIG.

4 FIG. 2 a schematic section through a third exemplary embodiment of a fuel injection valve according to the invention in the region of the injection opening, FIG.

5 a schematic representation of a fourth embodiment of a fuel injection valve according to the invention in the region of the injection opening and

6 a schematic section through a fifth embodiment of a fuel injection valve according to the invention in the region of the injection opening.

description the embodiments

following Be exemplary embodiments of Invention described by way of example. Matching components are with matching reference numerals Mistake.

Before using the 2 to 6 preferred embodiments of the invention will be described in more detail, is intended to better understanding of the invention initially based on 1 a generic fuel injection valve will be briefly explained with respect to its essential components.

An in 1 illustrated first embodiment of a generic fuel injection valve 1 is in the form of a fuel injector 1 designed for fuel injection systems of mixture-compression, spark-ignited internal combustion engines. The fuel injector 1 is particularly suitable for the direct injection of fuel into a combustion chamber, not shown, of an internal combustion engine with jet-guided combustion process.

The fuel injector 1 consists of a nozzle body 2 in which a valve needle 3 is arranged. The valve needle 3 has spraying on a valve closing body 4 up with a on a valve seat body 5 arranged valve seat surface 6 cooperates to a sealing seat. In the fuel injection valve 1 In the exemplary embodiment, this is an inwardly opening fuel injection valve 1 , which has an injection opening 7 features. The nozzle body 2 is through a seal 8th against an outer pole 9 a magnetic coil 10 sealed. The magnetic coil 10 is in a coil housing 11 encapsulated and placed on a coil carrier 12 wound, which at an inner pole 13 the solenoid 10 is applied. The inner pole 13 and the outer pole 9 are by a distance 26 separated from each other and each other by a non-ferromagnetic connecting member 29 connected. The magnetic coil 10 is via an electrical line 19 from one via an electrical plug contact 17 energized electric current. The plug contact 17 is from a plastic casing 18 surrounded by the inner pole 13 can be injected.

The valve needle 3 is in a valve needle guide 14 guided, which is designed disk-shaped. For stroke adjustment is a paired shim 15 , On the other side of the dial 15 is the anchor 20 , This is about a first flange 21 with the valve needle 3 in connection, which by a weld 22 with the first flange 21 connected is. On the first flange 21 supports a spiral return spring 23 from, which in the present design of the fuel injection valve 1 through a sleeve 24 is brought to bias.

In the valve needle guide 14 , in anchor 20 and on a guide element 36 run fuel channels 30 . 31 and 32 , The fuel is supplied via a central fuel supply 16 fed and through a filter element 25 filtered. The fuel injector 1 is through a rubber ring 28 against a fuel distributor line, not shown, and through a seal 37 sealed against a cylinder head, not shown.

At the discharge side of the anchor 20 is an annular damping element 33 , which consists of an elastomer material, arranged. It lies on a second flange 34 on which over a weld 35 cohesively with the valve needle 3 connected is.

At rest of the fuel injection valve 1 becomes the anchor 20 from the return spring 23 against its stroke direction so acted upon, that the valve closing body 4 on the valve seat surface 6 is held in sealing contact. Upon energization of the solenoid 10 builds up this a magnetic field, which is the anchor 20 against the spring force of the return spring 23 moved in the stroke direction, wherein the stroke by a in the rest position between the inner pole 12 and the anchor 20 working gap 27 is predetermined. The anchor 20 takes the first flange 21 , which with the valve needle 3 is welded, also in the stroke direction with. The with the valve needle 3 related valve closing bodies 4 lifts from the valve seat surface 6 and the pressurized fuel is supplied through the injection port 7 hosed into the combustion chamber, not shown.

If the coil current is switched off, the armature drops 20 after sufficient degradation of the magnetic field by the pressure of the return spring 23 from the inner pole 13 which causes the valve needle 3 related first flange 21 moved against the stroke direction. The valve needle 3 is thereby moved in the same direction, whereby the valve closing body 4 on the valve seat surface 6 touches down and the fuel injector 1 is closed.

The fuel injector 1 has one central axis 47 on, in which in this embodiment in particular the valve needle 3 , the valve closing body 4 and the nozzle body 2 are arranged coaxially.

2 shows a first embodiment of a fuel injection valve according to the invention 1 , The nozzle body 2 of the in this embodiment, inwardly opening fuel injector 1 is integral with the valve seat body 5 educated. The injection-molded opening produced, for example, by drilling or laser drilling 7 runs straight at an angle of for example 30 ° to the central axis 47 in the valve seat body 5 , wherein it has a constant diameter in the course.

The valve seat body 5 is formed on the outside of a circular cone and has at least one circumferential first surface 39 and a circumferential second surface 40 up to the middle axis 47 take different angles. The injection opening 7 flows at the transition of the first area 39 to the second area 40 at an exit point 46 from the valve seat body 5 out. The first area 39 points to the second surface 40 one outside the valve seat body 5 extending outside angle 41 of more than 180 °, for example 210 °. This is the exit point 46 and the immediate area around the exit point 46 relative to all surrounding outer surfaces of the valve seat body 5 out.

3 shows a schematic section through a second embodiment of the fuel injection valve according to the invention 1 in the area of the injection opening 7 , similar to the first embodiment 2 , In contrast to the first embodiment, the diameter of the spray opening widens 7 conical in the direction of injection.

4 shows a schematic section through a third embodiment of the fuel injection valve according to the invention 1 in the area of the injection opening 7 , similar to the first embodiment 2 , In contrast to the first embodiment, the diameter of the spray opening widens 7 through a stage 42 in Abspritzrichtung. Through the stage 42 In this embodiment, the course of the injection opening 7 into an upstream first section 44 and a second portion thereof in the discharge direction 45 divided. The second section 45 For example, is cylindrical and made by drilling, in this embodiment, the two sections 44 . 45 are arranged coaxially with each other. The second section 45 can also by a circumferential groove 43 , what a 5 is shown in more detail, be realized, in which case the cross sections of the two sections 44 . 45 , as in 4 shown are also arranged coaxially with each other. By one at the lower end at the exit point 46 or at the discharge end of the second section 45 trained edge 38 , is the first section 44 opposite the combustion chamber or in the combustion chamber to the injection opening 7 obscured by the moving flame front.

5 shows a schematic representation of a fourth embodiment of the fuel injection valve according to the invention 1 in the area of the injection opening 7 , similar to the third embodiment 4 , In contrast to the third embodiment, the valve seat body 5 several spray openings 7 on. In addition, the second section 45 or the stage 42 through the valve seat body 5 at the height of the injection openings 7 radial circumferential groove 43 educated. The two illustrated spray openings 7 each have a first section 44 with different diameters. The diameter can be at most as large as the height of the groove 43 or smaller.

6 shows a fifth embodiment of a fuel injection valve according to the invention 1 , The nozzle body 2 of the fuel injection valve opening outward in this embodiment 1 is integral with the valve seat body 5 educated. The second area 40 is outside the valve closing body 4 arranged. The valve closing body 4 limited with the valve seat body 5 the injection opening 7 , wherein the injection opening 7 is conically widened downstream of the sealing seat and the injection orifice 7 in the open state takes the form of a circumferential annular gap.

The Invention is not limited to the illustrated embodiments. The Features of the embodiments can be combined in any way.

Claims (8)

Fuel Injector ( 1 ), in particular for the direct injection of fuel into a combustion chamber, with an actuator, an actuatable by the actuator valve closing body ( 4 ), which is provided with a valve seat surface ( 6 ) cooperates to a sealing seat, and at least one injection opening ( 7 ) located at an exit point ( 46 ), characterized in that the exit point ( 46 ) of the injection opening ( 7 ) protrudes relative to all sides of the immediately surrounding surface from which it discharges. Fuel injection valve according to claim 1, characterized in that the injection opening ( 7 ) in the area of the transition of a first area ( 39 ) into a second area ( 40 ), whereby the two surfaces ( 39 . 40 ) with an outside angle ( 41 ) are arranged to each other, which is greater than 180 °. Fuel injection valve according to claim 1 or 2, characterized in that the injection opening ( 7 ) extended conically outwards. Fuel injection valve according to one of the preceding claims, characterized in that the injection opening ( 7 ) stepped through at least one stage ( 42 ) to the outside and thereby at least one inside first section ( 44 ) and an outer second section ( 45 ) having. Fuel injection valve according to claim 4, characterized in that the first section ( 44 ) at least partially through the second section ( 45 ) is concealed from the combustion chamber or the flame front propagating in the combustion chamber. Fuel injection valve according to Claim 4 or 5, characterized in that the two sections ( 44 . 45 ) are arranged coaxially with each other. Fuel injection valve according to Claim 4 or 5, characterized in that the stage ( 42 ) by one between the two surfaces ( 39 . 40 ) circumferential groove ( 43 ) is formed. Fuel injection valve according to Claim 2, characterized in that one of the surfaces ( 39 . 40 ) on the valve closing body ( 4 ) is arranged.