EP0906507B1 - Fuel injection valve and use of the same - Google Patents

Description

State of the art

The invention is based on a fuel injector according to the preamble of claim 1, and using a Fuel injection valve according to the preamble of the claim 13th

From US Pat. No. 5,156,124 is already a Fuel injector known to be electromagnetic can be actuated. For this purpose, the fuel injector usual components of an electromagnetic circuit, such as a magnetic coil, an inner pole and an outer pole. at this known injection valve is a so-called side feed injector, in which the Fuel supply largely below the magnetic circuit he follows. Contact pins protrude from the solenoid out of the fuel injector, which has a certain length encapsulated with plastic and in this are embedded. The plastic extrusion is on one End of the fuel injector applied and provides not an independent component of the injection valve. The same applies to what is known from DE-OS 34 39 672 Fuel injector. Also protrude from here Magnetic coil outgoing contact pins to an electrical Connector that is made of plastic and the Partially surrounds contact pins behind the solenoid. The the injection molding forming the connector is there sprayed onto the metal valve housing.

From EP-OS 0 690 224 there is already one Fuel injector known that has a nozzle opening owns, which is already in the installed state of the valve Is located inside an intake duct, so that avoidance a wall wetting a spraying largely directly on Inlet valve of an internal combustion engine is possible. Corresponding beam directions can be achieved by the Nozzle opening of the injection valve along an axis that runs parallel to the axis of the Injector has. A comparable one Fuel injection valve is also from DE-OS 40 32 425 known.

According to US-A-5 044 563 two Assemblies of the fuel injector, a functional part and a connecting part, pre-assembled separately from one another or set. The functional part includes essentially an electromagnetic circuit and an off Valve seat body and valve closing body formed Sealing valve. In the connection part, however, are the electrical and the hydraulic connection of the injection valve intended.

Advantages of the invention

The fuel injector according to the invention with the characterizing features of claim 1 has the advantage that it can be manufactured inexpensively in a simple manner and is mountable. Also, variations can be made very easily the designs of the fuel injector become. All described embodiments of the Fuel injectors have the advantage of one inexpensive to manufacture with a great many Design variants. Largely in large numbers identical (differences e.g. in the size of the Valve needle strokes or the number of turns of the solenoid) manufactured functional parts can with many various connecting parts, for example in the Size and shape, in the design of the electrical Connector, in the formation of the lower end face of the connector or also in terms of their color, their Marking, their label or another Differentiate labeling, be connected. The logistics in the manufacture of fuel injectors basically simplified.

The separation into two modules results in Advantage that all negative influences when manufacturing the largely made of plastic connector (large Overmolding pressures, heat development) of which the important ones Components of the functional part that perform valve functions be kept away. The relatively dirty one Overmolding process can advantageously outside the assembly line of the functional part.

According to the invention this can do all the important valve functions exercising functional part can be performed very briefly. In This advantageously results in simplified access to the parts of the injector to be set. In front all things there are clearly shortened ways for that Introduction of measuring arrangements, e.g. from probes to Measurement of the stroke of the valve needle or tools for Setting the dynamic spray rate on the Adjusting. Compared to known injection valves the entry paths of such measuring or setting tools from round 60 mm on e.g. Can be shortened by 10 to 20 mm. In the As a consequence, the assembly line clearly emerges reduced cycle times, which means more at the same time Injectors can be adjusted than before.

By the measures listed in the subclaims advantageous developments and improvements in Claim 1 specified fuel injector possible.

A very large variation of the electrical connecting elements on the functional part and Be made connector. It is always like that possible to connect the electrical connectors on both Functional part as well as on the connecting part either plug-like or socket-like or as a combination to train both possibilities.

It is also advantageous to have a lower, downstream one End face of the connector part inclined to one by the Connection part along the longitudinal axis of the valve form, so that then fully assembled Fuel injector the valve longitudinal axes of the Functional part and the connecting part not with each other aligned. In this way, kinked or angled fuel injectors are generated. On such fuel injector is such. B. on Intake pipe of an internal combustion engine arranged that the Injection area of the injection valve clearly into that Intake pipe extends, and even largely that Functional part can lie in the intake manifold. A wall wetting the intake manifold can be sprayed on or more intake valves of the internal combustion engine due the angled design of the injection valve on simple Ways to be avoided, thereby reducing the exhaust emissions Internal combustion engine and fuel consumption reduced become.

drawing

Embodiments of the invention are in the drawing shown in simplified form and in the following Description explained in more detail. 1 shows a first 2 according to the invention second embodiment of a Fuel injector, Figure 3, a third Embodiment of a fuel injector and Figure 4 is a schematic installation option of a Fuel injector according to Figure 3 on one Internal combustion engine.

Description of the embodiments

This is exemplarily and partially simplified in FIG. 1 shown electromagnetically actuated according to the invention Valve in the form of an injector for Fuel injection systems from mixture-compressing, spark-ignited internal combustion engines has one of one Magnetic coil 1 surrounded, as an inner pole and partially as Fuel flow serving largely tubular Core 2. Core 2 is upstream of solenoid 1 in radial direction stepped, so that the core 2 with its upper cover section 3, the magnetic coil 1 partially envelops and a particularly compact structure of the Injector in the area of the solenoid 1 allows. The magnetic coil 1 is from an outer, for. B. surrounded ferromagnetic valve jacket 5 as the outer pole, the completely surrounds the magnetic coil 1 in the circumferential direction and at its upper end firmly with the core 2 z. B. by a Weld 6 is connected. To close the magnetic Circle is the valve jacket 5 at its lower end stepped, so that a guide section 8 is formed, which is similar to the lid section 3 of the core 2 Solenoid 1 axially limited and the limitation of Magnetic coil area 1 down or in downstream direction. The guide section 8 has an inner, concentric to a longitudinal valve axis 10 extending opening 11, which serves as a guide opening for a along the valve longitudinal axis 10 axially movable valve needle 12 serves.

Closes at the lower guide section 8 of the valve jacket 5 a valve seat body 14, which is a fixed Has valve seat surface 15 as a valve seat. The Valve seat body 14 is, for example, with a of a laser generated second weld 16 firmly with the Valve jacket 5 connected. The solenoid 1, the Guide section 8 of the valve jacket 5 and the Valve seat body 14 up to valve seat surface 15 form one Through opening, in which the valve needle 12, by a tubular anchor 17 and a spherical one Valve closing body 18 is formed, moved. At the is downstream end of the valve seat body 14 z. B. in a recess 19 a flat spray perforated disc 20 arranged, the fixed connection of Valve seat body 14 and spray plate 20 z. B. by an all-round tight weld seam 21 is realized. The tubular anchor 17 is at its downstream, the Spray plate 20 facing end with the z. B. spherical valve closing body 18, for example, by Welding firmly connected, in the connection area 22nd Grooves, holes or channels are provided so that the Armature 17 flowing through in an inner longitudinal bore 23 Step out of the fuel and on the valve closing body 18 can flow along to the valve seat surface 15.

The injection valve is actuated in a known manner Way electromagnetic. For the axial movement of the Valve needle 12 and thus to open against the spring force a return spring 25 or closing the injection valve serves the electromagnetic circuit with the magnetic coil 1, the inner core 2, the outer valve jacket 5 and the armature 17. The armature 17 is connected to the valve closing body 18 end facing away from the core 2.

The spherical valve closing body 18 interacts with the tapered in the direction of flow Valve seat surface 15 of the valve seat body 14 together, the in the axial direction downstream of a guide opening in Valve seat body 14 is formed. The spray hole disc 20 has at least one, for example four through Eroding or stamping shaped injection openings 27.

The insertion depth of the core 2 in the injection valve is below other decisive for the stroke of the valve needle 12. Thereby the one end position of the valve needle 12 is not at excited solenoid 1 by the system of Valve closing body 18 on the valve seat surface 15 of the Valve seat body 14 set while the other End position of the valve needle 12 when the solenoid coil 1 is excited by the installation of the armature 17 at the downstream core end results. The stroke is adjusted by an axial Moving the core 2 according to the desired Position subsequently firmly connected to the valve jacket 5 is, wherein a laser welding to achieve the Weld 6 is useful.

In a concentric to the valve longitudinal axis 10 Flow bore 28 of the core 2, which is the supply of the Serves fuel in the direction of the valve seat surface 15 is in addition to the return spring 25, an adjusting sleeve 29 inserted. The adjusting sleeve 29 is used to adjust the Spring preload of the adjoining the adjusting sleeve 29 Return spring 25, which in turn with their opposite side on the armature 17 supports, also a setting of the dynamic spray quantity with the Adjustment sleeve 29 takes place.

The injection valve described so far stands out through its particularly compact structure, so that a very small, handy injection valve is created Valve jacket 5, for example, has an outer diameter of only approx. 11 mm. Individual components are simplified shown; however, the injector includes one fully functioning magnetic circuit, as of basic structure already from electromagnetic actuable injection valves is known (DE-OS 34 39 672 or DE-OS 195 12 339).

These components described above form a pre-assembled independent assembly, the following functional part 30 is called. The functional part 30 thus includes essentially the electromagnetic circuit 1, 2, 5 and a Sealing valve (valve closing body 18, valve seat body 14) with a subsequent beam processing element (Spray plate 20). The finished set and assembled functional part 30 has z. B. a flat top End face 32 on, for example, two Stick out contact pins 33. About the electrical Contact pins 33 that act as electrical connectors serve, the electrical contacting takes place Magnetic coil 1 and thus its excitation.

A second is completely independent of the functional part 30 Manufactured assembly, the following as a connector 40th referred to as. The independent and pre-assembled Connection part 40 is only indicated symbolically in FIG. 1; Figure 3 is an embodiment of a connector 40 can be seen in detailed labeling, also on the only indicated connection parts 40 of Figures 1 and 2 is transferable. The connector 40 stands out above all Things out in that it is the electrical and the hydraulic connection of the fuel injector includes. The largely designed as a plastic part Connector 40 therefore has a Tubular base body serving fuel inlet connection 42. In a concentric to a connector longitudinal axis 10 ' extending flow bore 43 of the fuel inlet connector 42 by the upstream end of the Fuel injector in the axial direction from A fuel filter 44 flows through the fuel inserted or pressed in (Figure 3). The fuel filter 44 protrudes into the flow bore 43 of the Fuel inlet connector 42 at its inlet end and ensures that such are filtered out Fuel components that due to their size in the Injector blockages or damage could cause. The flow hole 43 can over their axial length z. B. be formed several times.

A hydraulic connection of connector 40 and Functional part 30 is in the fully assembled Fuel injector achieved in that the Flow bores 43 and 28 of the two assemblies to one another brought that an unimpeded flow through the Fuel is guaranteed. Then z. B. the End faces 48 and 32 of the connecting part 40 and the Functional part 30 directly against each other and are fixed connected with each other. Can in the connection area for example, for secure sealing sealing elements be provided.

In addition, two electrical are in the connector 40 Contact elements 45 provided during the Plastic injection molding process of the base body 42 encapsulated and are then embedded in the plastic. To serve largely as a fuel inlet port Base body 42 made of plastic also belongs co-molded electrical connector 46 (Figure 3). The electrical contact elements 45 end at one End as exposed contact pins 47 of the electrical Connector 46, which with a corresponding not shown electrical connection element, such as. B. one Contact strip, for complete electrical contacting of the injection valve can be connected. At their the Connector 46 opposite end run the Contact elements 45 to a lower end face 48 of the Connection part 40 and form an electrical there Connecting element 49, the z. B. executed socket-like can be. When fully assembled The fuel injector act on the electrical Fasteners 33 and 49 together so that a safe electrical connection is established, the contact pins 33 z. B. in the socket-like connecting elements 49 on Intervene connector 40. About the electrical Connector 46 and the electrical The connection area 33, 49 is thus electrical Contacting the solenoid 1 and thus its excitation.

Figure 2 shows a second embodiment of a fuel injector shown partially. The compared to the embodiment shown in Figure 1 constant or equivalent components are included identified by the same reference numerals. The Fuel injector of Figure 2 corresponds to essentially the fuel injector of FIG. 1, which is why in the following only the different areas of the magnetic circuit are explained in more detail. To manage the Valve needle 12 and specifically the armature 17 is in the Functional part 30 an elongated ferritic sleeve 52 provided that at least in the area of the armature 17 inner opening 53 that is dimensionally accurate with respect to the inner diameter has. The sleeve 52 ends in the downstream direction seen for example in the area of the guide section 8 of the Valve jacket 5, with which they are, for example, with a Weld 54 is firmly connected. In the inner opening 53 the sleeve 52 is next to the axially movable valve needle 12 also the core 2 introduced, which in turn after the successful Stroke setting is firmly connected to the valve housing in concrete case with the sleeve 52 with an upper weld 55. In addition to the leadership of the armature 17 or the inclusion of the Core 2, the sleeve 52 also fulfills a sealing function, see above that in the embodiment shown in Figure 2 dry solenoid 1 is present. It will also do that achieved that instead of the lid portion 3 of the core 2nd now a disk-shaped cover element 56 the magnet coil 1 covered on its side facing the connecting part 40. The covering element 56 resting on the valve jacket 5 is through the weld 6 firmly with the valve jacket 5 connected. An inner bore 58 in cover member 56 allows the sleeve 52 and thus also the core 2 extended training so that both the bore 58th protruding over the upper end face 32 towards Stand out connector part 40, the upper End face 32 is fixed by the cover element 56. When mounting the connection part 40 on the functional part 30 can the protruding part of the core 2 and the sleeve 52nd to increase connection stability in the Project flow bore 43 of the connecting part 40. in the Connection area of both modules 30 and 40 is such. B. a Sealing ring 59 is provided on the end face 32 of the Covering element 56 surrounding the sleeve 52.

Figure 3 shows the two independent and already preassembled modules functional part 30 and connecting part 40 before the final assembly of the Fuel injector. The connector 40 is through a fuel inlet port 42 representing Plastic body formed on which the electrical connector 46 is molded. The electrical connector 46 is in Plastic injection molding process for the production of the connecting part 40 injected onto the fuel inlet port 42. Along the connector longitudinal axis 10 'runs in Fuel inlet port 42 the continuous, z. B. tiered Flow bore 43, in the at its inlet end Fuel filter 44 is introduced. The flow bore 43 ends at the lower, downstream end face 48 of the Connection part 40, this end face 48 in Embodiment according to Figure 3 not perpendicular, d. H. so inclined to the longitudinal axis of the connector 10 '. The Functional part 30 corresponds to that already shown in FIG. 1 Functional part 30 shown. The functional part 30 also extends along a longitudinal valve axis 10, in particular the core 2, the valve jacket 5 and the armature 17 are formed concentrically to the longitudinal axis 10 of the valve. Facing the connecting part 40, the functional part 30 closes with an upper, upstream end face 32. in the assembled state of the fuel injector two end faces 32 and 48 of the functional part 30 and Connection part 40 to each other so that the electrical Connecting elements 33 and 49 and the hydraulic Interconnecting elements 28 and 43 cooperate.

Since the end face 48 of the connector 40 is inclined to Longitudinal connector axis 10 ', the end face 32 of the Functional part 30, however, perpendicular to the valve longitudinal axis 10 runs, there is a kinked or angled Fuel injection valve in which the two longitudinal axes 10 and 10 'at an angle a to each other and thus not cursing with each other. An advantageous one Application example of such an angled Figure 4 shows the fuel injector Fuel injector is one of them Fuel injection arrangement in a valve receptacle 69 an intake manifold 60 leading to a combustion chamber 61 Internal combustion engine leads, arranged. The valve seat 69 extends along a receiving longitudinal axis 70. In The receiving longitudinal axis 70 advantageously has one different sense of direction than the valve longitudinal axis 10 of the Functional part 30.

The fuel injector is immediately in front at least one inlet valve 62 of the combustion chamber 61 for example having a circular cross section and extending along a longitudinal axis 71 of the intake manifold Intake pipe 60 becomes the intake air for the internal combustion engine provided, the control of the amount of air via a Throttle body, not shown, upstream of the Fuel injection valve takes place in the intake manifold 60. The Fuel injector is so on intake manifold 60 attached and aligned that the to be hosed Fuel substantially directly onto intake valve 62 with a fuel jet 65, and not on the Walls of the intake manifold 60 or the cylinder head of the Internal combustion engine in which the inlet valve 62 is arranged is.

The precise spraying of the fuel on the Inlet valve 62 without wetting the walls becomes special through the two-part training of Fuel injector achieved, over the slope the end face 48 on the connector 40 very targeted Spray angle can be adjusted. By bending it of the functional part 30 relative to the connecting part 40 the beam geometry compared to the known Make fuel injectors much more flexible. The Fuel injector can be on the intake manifold 60 so-called extended tip injector can be provided what means that the injection point of the injection valve in the Intake pipe 60 is placed in front. This can even go so far happen that the functional part 30 largely within the Suction tube 60 is located, so that even the electromagnetic Circle 1, 2, 5 is largely placed in the intake manifold 60. The Fuel injector can be in the valve seat 69 be installed such that the elongated valve longitudinal axis 10 of the functional part 30 either the intake pipe longitudinal axis 71 cuts or not cuts, so that in the latter Case the two aforementioned longitudinal axes 10 and 71 lie skew to each other (e.g. interesting at idiosyncratic asymmetrical cylinder head design). For an effective seal between the Fuel injector and the one receiving it Valve seat 69 on the intake manifold 60 provide sealing rings 63 and 64, e.g. B. O-rings.

The two modules functional part 30 and connecting part 40 after the corresponding pre-assembly in a last Process step firmly connected. To do this the functional part 30 and the connecting part 40 so together brought that the end faces 32 and 48 lie against each other and an electrical and hydraulic connection of both Assemblies 30, 40 is made. As a joining process of the two assemblies 30 and 40 are particularly suitable Gluing, ultrasonic welding or flanging. When gluing is Pay particular attention to the fact that the adhesive connection is sufficiently stressable. To connect should be able to carry out by means of ultrasonic welding the functional part 30 in the area of the upper end face 32 a plastic area can be provided, the z. B. at the Overmolding of the magnetic coil 1 can be shaped.

In addition to the various joining methods that can be used different ways of making the electrical and hydraulic connection conceivable. Two Possibilities of hydraulic connection of the Functional part 30 and the connecting part 40 are already the Figures 1 and 2 removable. On the one hand, they can Flow bores 28 and 43 connected to one another in a butt joint be (Figure 1); on the other hand, the flow holes 28 and 43 interlock partially overlapping (Figure 2). The electrical contact can, for. B. take place in such a way that two contact pins 33 of the functional part 30 in two Contact bushes 49 of the connecting part 40 engage. Of course, it is also possible that electrical connectors 49 on the connector 40 in Provide pin shape while the electrical Connecting elements 33 of the functional part 30 socket-like would be executed. Another option is close to the respective end faces 32 and 48, respectively plug-like and socket-like connecting element 33, 49 to train, which then mutually interact. Electrical contacting can, however also with the CIN:: APSE® technology, for example can be achieved with the gold-coated molybdenum wires are formed like a button contact. This solderless connection technology allows the production of very reliable electrical connections that are mechanical are completely free of resonance.

All described embodiments of the Fuel injectors have the advantage of one inexpensive to manufacture with a great many Design variants. Largely in large numbers identically manufactured functional parts 30 can with very many different connecting parts 40 that are for example in size, in the design of the electrical connector 46 or in training distinguish the end face 48, are connected. The Logistics in the manufacture of fuel injectors is basically simplified.

Claims (14)

1. Fuel injection valve for fuel injection systems of internal combustion engines, having an electromagnetic circuit which comprises at least one solenoid (1), one internal pole (2) and one external pole (5), having a valve closing element (18) which is part of a valve needle (12) which can move in the electromagnetic circuit, said valve closing element (18) interacting with a valve seat (15) provided on the valve seat element (14); said fuel injection valve having an electrical terminal (45, 46, 47), a hydraulic port (42, 43), a premounted functional part (30) and a premounted connecting part (40), and the functional part (30) comprising essentially the electromagnetic circuit (1, 2, 5), a sealing valve composed of valve seat element (14) and valve closing element (18), electrical connecting elements (33) and hydraulic connecting elements (28), and the connecting part (40) having the electrical terminal (45, 46, 47), the hydraulic port (42, 43), electrical connecting elements (49) and hydraulic connecting elements (43); the functional part (30) and the connecting part (40) forming independent assemblies which can be permanently connected to one another, and a reliable electrical and hydraulic connection of the two assemblies (30, 40) being ensured by the interaction between the electrical connecting elements (33, 49) and the hydraulic connecting elements (28, 43), characterized in that the electromagnetic circuit (1, 2, 5) of the functional part (30) has a core (2) which has an internal, continuous flow bore (28) which forms a fuel passage in the direction of the sealing valve (14, 18).
2. Fuel injection valve according to Claim 1, characterized in that the connecting part (40) is largely a plastic element which forms a fuel inlet connector (42) with a continuous flow bore (43), an electrical connecting plug (46) being formed on the fuel inlet connector (42).
3. Fuel injection valve according to Claim 2, characterized in that, starting from the electrical connecting plug (46), at least two contact elements (45) run through the connecting part (40) as far as the electrical connecting elements (49).
4. Fuel injection valve according to Claim 2 or 3, characterized in that the electrical connecting elements (49) are formed near to a downstream end face (48) of the connecting part (40) on which the downstream end of the flow bore (43) is also located.
5. Fuel injection valve according to Claim 1 or 4, characterized in that the electrical connecting elements (49) of the connecting part (40) are embodied so as to be similar to plugs and/or sockets.
6. Fuel injection valve according to Claim 1, characterized in that contact pins extend from the solenoid (1) of the functional part (30) and end as electrical connecting elements (33) near to an upstream end face (32) of the functional part (30).
7. Fuel injection valve according to Claim 1 or 6, characterized in that the electrical connecting elements (33) of the functional part (30) are embodied so as to be similar to plugs and/or sockets.
8. Fuel injection valve according to Claims 5 and 7, characterized in that the electrical connecting elements of the functional part (30) are two contact pins (33) and the electrical connecting elements of the connecting part (40) are two contact sockets (49).
9. Fuel injection valve according to Claims 4 and 6, characterized in that the two end faces (32, 48) of the functional part (30) and of the connecting part (40) bear against one another in the mounted state of the fuel injection valve in such a way that the electrical connecting elements (33, 49) and the hydraulic connecting elements (28, 43) interact.
10. Fuel injection valve according to Claim 1, characterized in that the core (2) of the functional part (30) is embodied in such a way that it projects into the flow bore (43) of the connecting part (40) in the mounted state of the fuel injection valve.
11. Fuel injection valve according to Claim 1, characterized in that the connecting part (40) extends along a connecting part longitudinal axis (10'), and the functional part (30) extends along a valve longitudinal axis (10), which axes (10', 10) are not aligned with one another in the mounted state of the fuel injection valve.
12. Fuel injection valve according to Claim 11, characterized in that the connecting part (40) has a downstream end face (48) which runs at an incline with respect to the connecting part longitudinal axis (10').
13. Use of a fuel injection valve according to one of Claims 1 to 12, which has a functional part (30) and a connecting part (40), in an internal combustion engine having at least one intake manifold (60) and a valve receptacle (69), extending along a receptacle longitudinal axis (70), on the intake manifold (60), characterized in that the valve longitudinal axis (10) of the functional part (30) has a different direction from the receptacle longitudinal axis (70) of the valve receptacle (69).
14. Use according to Claim 13, characterized in that the intake manifold (60) has an intake manifold longitudinal axis (71) which is not cut by the prolonged valve longitudinal axis (10).

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