DE19853102A1 - Fuel injector - Google Patents

Abstract

The invention relates to a fuel injector for fuel injection systems of internal combustion engines, comprising two pre-assembled independent modules, namely a functional part (30) which essentially comprises an electromagnetic circuit (1, 2, 5) and a sealing valve (15, 19), and a connecting part (40) which consists primarily of a hydraulic connector (42, 43) and an electrical connector (55, 56, 57). In the fully assembled injector electrical connecting elements (34, 59) and hydraulic connecting elements (28, 43) of the two modules (30, 40) cooperate such as to ensure a reliable electrical and hydraulic connection. An over-moulding (60) in the area of the connection ensures the mechanical connection of the two modules (30, 40), a high injector stability and sufficient tightness. This fuel injector is especially well suited for use in fuel injection systems of mixture-compressing, spark-ignited internal combustion engines.

Description

State of the art

The invention is based on a fuel injector according to the genus of the main claim.

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 the 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.

DE-P 197 12 591.3 has already proposed a Fuel injector from two pre-assembled modules, a functional part and a connecting part, put together, manufactured and adjusted separately and subsequently firmly connected to each other. With the Connecting both assemblies will also be electrical and created a hydraulic connection. Adding the both assemblies are made using ultrasonic welding, Glue or flare.

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 can be installed safely and reliably. In advantageous Way, a great mechanical stability of the Fuel injector reached. In addition is ensures that electrical connectors within of the valve is safe and protected.

In addition, variations in the construction of the Fuel injector are made. this will thereby achieved that two assemblies of Fuel injector, a functional part and a Connection part, pre-assembled separately from each other or can be 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. 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, your label or another Differentiate labeling, be connected. The logistics in the manufacture of fuel injectors basically simplified.

The separation into two modules results in the Advantage that all negative influences when manufacturing the largely made of plastic connector (large Overmolding pressures, heat development) of which the important 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.

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

It is particularly advantageous for the extrusion coating Establishing a firm connection between the two assemblies to choose a plastic that is at a higher temperature has its melting point than that for the connector used plastic. This ensures that a  polymeric connection between the two plastics is received. It is advantageous to use the outer circumference of the To carry out a labyrinth seal. At the Injecting around a heat distribution is achieved that a allows good melting. It is also achieved that high mechanical stability in this area and thus of the entire fuel injector and a good one Tightness are guaranteed.

It is an advantage that all important valve functions performing the functional part very briefly. In This advantageously results in simplified access to the parts of the injection valve to be set. In front all things there are clearly shortened ways for that Introducing measuring arrangements, such as. B. from probes Measurement of the stroke of the valve needle or tools for Setting the dynamic spray quantity on the Adjustment element.

Advantageously, the connector on the downstream end several axially protruding segments be provided after the molding process in the Protrude extrusion. Through this into the encapsulation protruding segments, the heat dissipation during the Overmolding process improved. At the same time, the hot volume kept quite small in the molding process. This allows significantly reduce the molding cycle time. Furthermore is advantageously the mass accumulation within the Overmolding reduced. The formation of voids can be done in this way be reduced effectively. Through the segments arise in addition, turbulence in the flowing plastic. this leads to increased strength of the entire extrusion coating.

It is advantageous to have a fuel filter in the functional part to arrange. It lends itself as a screen mesh  Use metal filter cloth. Until the final assembly of the Valve is thus guaranteed that no dirt particles in get inside the functional part.

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

drawing

Embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description. In the drawings Fig. 1 shows a first inventive fuel injection valve with two independently pre-assembled modules in the assembled state, Fig. 2, a first assembly representing connection part of the valve according to Fig. 1, Fig. 3, a second module representing functional part of the valve according to Fig. 1, Fig. 4 shows a second embodiment of a functional part, Fig. 5 shows an electrical connection area in a schematic representation, Fig. 6A to 6C three embodiments for contact pins corresponding to a section along the line VI-VI in Fig. 5, Fig. 7A to 7D four embodiments for female contacts corresponding to a section along the line VII-VII in Fig. 5, Fig. 8 shows a second embodiment of a connecting part, Fig. 9 is a bottom view of the connector of FIG. 8 and FIG. 10 is a bottom view of a further connector.

Description of the embodiments

The electromagnetically actuated valve in the form of an injection valve for fuel injection systems of mixture-compressing, spark-ignited internal combustion engines, shown by way of example and partially in simplified form in FIG. 1, has a largely tubular core 2 surrounded by a magnetic coil 1 , serving as the inner pole and partially as fuel flow. The magnetic coil 1 is of an outer, sleeve-shaped and stepped, z. B. surrounded ferromagnetic valve jacket 5 as an outer pole, which completely surrounds the magnet coil 1 in the circumferential direction. The magnet coil 1 , the inner pole 2 and the outer pole 5 together form an electrically excitable actuating element. As a further embodiment variant, not shown, the actuating element can also be designed as a piezo actuator.

While the magnet coil 1 embedded in a coil former 3 surrounds a valve sleeve 6 from the outside, the core 2 is introduced into an inner opening 11 of the valve sleeve 6 , which is concentric with a longitudinal axis 10 of the valve. The z. B. ferritic valve sleeve 6 is elongated and thin-walled and has a jacket section 12 and a bottom section 13 , the jacket section 12 in the circumferential direction and the bottom section 13 in the axial direction delimiting the opening 11 at its downstream end. The opening 11 also serves as a guide opening for a valve needle 14 that is axially movable along the longitudinal axis 10 of the valve.

In addition to the core 2 and the valve needle 14 , a valve seat body 15 is arranged in the opening 11 , the z. B. sits on the bottom portion 13 of the valve sleeve 6 and has a fixed valve seat surface 16 as a valve seat. The valve needle 14 is formed for example of a tubular anchor portion 17, a likewise tubular needle portion 18 and a spherical valve closing body 19, wherein the valve closing body for the nineteenth B. is firmly connected to the needle portion 18 by means of a weld. On the downstream end of the valve seat body 15 is, for. B. in a frustoconical recess 20 a flat spray washer 21 is arranged, the fixed connection of valve seat body 15 and spray orifice plate 21 z. B. is realized by a circumferential dense weld. In the needle section 18 of the valve needle 14 , one or more transverse openings 22 are provided, so that fuel flowing through the armature section 17 in an inner longitudinal bore 23 comes out and flows on the valve closing body 19, for. B. can flow along flats 24 to the valve seat surface 16 .

The injection valve is actuated in a known manner, for example electromagnetically here. Actuation by means of a piezo actuator is also conceivable. The electromagnetic circuit with the magnet coil 1 , the inner core 2 , the outer valve jacket 5 and the armature section 17 serves to axially move the valve needle 14 and thus to open against the spring force of a return spring 25 engaging the valve needle 14 or to close the injection valve. The armature section 17 is aligned with the core 2 with the end facing away from the valve closing body 19 .

The spherical valve closing body 19 interacts with the valve seat surface 16 of the valve seat body 15 which tapers in the shape of a truncated cone and is formed in the axial direction downstream of a guide opening in the valve seat body 15 . The spray hole disk 21 has at least one, for example four, spray openings 27 formed by eroding, laser drilling or punching.

The insertion depth of the core 2 in the injection valve is, among other things, decisive for the stroke of the valve needle 14 . The one end position of the valve needle 14 when the magnet coil 1 is not energized is determined by the contact of the valve closing body 19 on the valve seat surface 16 of the valve seat body 15 , while the other end position of the valve needle 14 when the magnet coil 1 is excited results from the contact of the armature section 17 at the downstream core end . The stroke is adjusted by axially displacing the core 2 , which is subsequently firmly connected to the valve sleeve 6 in accordance with the desired position.

In addition to the return spring 25, an adjusting element in the form of an adjusting spring 29 is inserted into a flow bore 28 of the core 2 , which runs concentrically with the valve longitudinal axis 10 and serves to supply the fuel in the direction of the valve seat surface 16 . The adjusting spring 29 is used to adjust the spring preload of the return spring 25 abutting the adjusting spring 29 , which in turn is supported with its opposite side on the valve needle 14 , the dynamic spray quantity also being adjusted using the adjusting spring 29 . The adjusting element can also be designed as an adjusting bolt, adjusting sleeve etc. instead of an adjusting spring.

The injection valve described so far is characterized by its particularly compact structure, so that a very small, handy injection valve is produced. These components form a pre-assembled, independent assembly, which is referred to below as functional part 30 and is shown separately in FIG. 3 as such an assembly. The functional part 30 thus essentially comprises the electromagnetic circuit 1 , 2 , 5 and a sealing valve (valve closing body 19 , valve seat body 15 ) with a subsequent jet processing element (spray disk 21 ).

The coil space formed between the valve jacket 5 and the valve sleeve 6 and almost completely filled by the magnetic coil 1 is limited in the direction facing the valve seat body 15 by a stepped radial region 32 of the valve jacket 5 , while the closure on the side facing away from the valve seat body 15 is limited by a disk-shaped cover element 33 is guaranteed. The coil body 3 extends through it in a recess in the cover element 33 . In this area, for example, two contact pins or sockets 34 protrude from the plastic of the coil former 3 and thus from the functional part 30 . The electrical contacting of the magnetic coil 1 and thus its excitation takes place via the electrical contact pins or sockets 34, which serve as electrical connecting elements.

Completely independently of the functional part 30 , a second assembly is produced, which is referred to below as the connecting part 40 . The independent and preassembled connection part 40 is assembled in FIG. 1 with the functional part 30 as part of the entire injection valve and is shown separately in FIG. 2. The connecting part 40 is characterized above all by the fact that it comprises the electrical and the hydraulic connection of the fuel injector. The connection part 40 , which is largely designed as a plastic part, therefore has a tubular base body 42 serving as a fuel inlet connection. For example, a fuel filter 44 is inserted or pressed into a flow bore 43 of the base body 42 , which runs concentrically to the longitudinal axis 10 of the valve and through which the fuel flows in the axial direction from the inflow end of the fuel injector. The fuel filter 44 protrudes into the flow bore 43 of the base body 42 at its inlet end and filters out those fuel components which, due to their size, could cause blockages or damage in the injection valve.

A hydraulic connection of connection part 40 and functional part 30 is achieved in the fully assembled fuel injector in that the flow bores 43 and 28 of both assemblies are brought together so that an unimpeded flow of fuel is ensured. An inner opening 46 in the cover element 33 allows the valve sleeve 6 and thus also the core 2 to be designed such that both protrude through the opening 46 and at least the valve sleeve 6 projects significantly beyond the cover element 33 in the direction of the connecting part 40 . When the connecting part 40 is mounted on the functional part 30 , a lower end region 47 of the base body 42 can protrude into the projecting part of the valve sleeve 6 in order to increase the connection stability in the opening 11 of the valve sleeve 6 .

The end region 47 of the connecting part 40 is designed, for example, in a stepped manner, the base body 42 tapering sharply from the outer diameter on a lower end face 58 . Together with a lower ring collar 49 , the end face 58 defines an annular groove 50 in which a sealing element, for. B. an O-shaped sealing ring 51 is arranged. Adequate sealing is thus ensured in the connection area of the two assemblies 30 and 40 .

In addition, two electrical contact elements 55 are provided in the connecting part 40 , which are overmolded during the plastic injection molding process of the base body 42 and are subsequently embedded in the plastic. The base body 42 made of plastic, which serves largely as a fuel inlet connector, also includes an injection-molded electrical connector plug 56 . The electrical contact elements 55 end at one end as exposed contact pins 57 of the electrical connector 56 , which with a corresponding electrical connection element, not shown, such as. B. a contact strip, can be connected for complete electrical contacting of the injection valve. At its end opposite the connector 56 , the contact elements 55 extend to the lower end face 58 of the connecting part 40 and form an electrical connecting element 59 there , which, for. B. is also designed as an exposed contact pins. When the fuel injector is fully assembled, the electrical connecting elements 34 and 59 work together in such a way that a secure electrical connection is created, the contact pins 59, for. B. engage in the socket-like, eyelet-like, clip-like, pin-shaped or cable lug-shaped connecting elements 34 on the functional part 30 . Examples of this are shown in FIGS. 5 to 7. The electrical contacting of the magnetic coil 1 and thus the excitation thereof thus take place via the electrical connector 56 and the electrical connection area 34 , 59 .

Figs. 2 and 3 show the two separate and already pre-assembled functional part 30 and connector part 40 before the final assembly of the fuel injector. It should be expressly stated that both the functional part 30 and the connecting part 40 can each be modular in themselves, which means that certain subassemblies can be used for the simplified manufacture and assembly of the assemblies 30 and 40 . An example of such a further modular subdivision is given below for the assemblies 30 and 40 , which are not shown in the figures, however.

In FIG. 2, a possible module separating line 64 is indicated with a dash-dot line, which is intended to show that the connector plug 56 can also be designed in a variable manner, in order then to be used on different base bodies 42 . In such a configuration, the hydraulic connection (base body 42 with flow bore 43 ) and the electrical connection (connector plug 56 with contact pins 57 ) are initially separate from one another. Only in the assembled state do the two subassemblies produce the connection part 40 described . For the secure electrical connection of the two sub-assemblies, corresponding electrical connection elements are provided in the connection area, which can be designed like the electrical connection elements 34 and 59 . The subassemblies are firmly connected by welding, soldering, gluing or overmolding.

The functional part 30 can also be composed of modular subassemblies in that z. B. the jet processing element in the form of the spray plate 21 is installed in a separate injection assembly for the time being, which is only subsequently integrated on the functional part 30 . It offers itself, for. B. multi-layer, by means of so-called multilayer electroplating perforated disks in the injection assembly, which can be a disk-shaped perforated disk carrier. The perforated disks can have opening contours with which very different spray patterns or a swirl application of the spray can be generated. The spray assembly, which can be configured in many ways, can be attached, for example by means of (laser) welding, downstream of the valve seat 16 to the valve seat body 15 or to a housing part of the functional part 30 . Similar to what was proposed in DE-P 197 12 591.3, an inclined position of the entire functional part 30 , the spray assembly with the spray nozzle 21 can e.g. B. be inclined at an angle to the longitudinal axis as a subassembly on the functional part 30 .

The two assemblies, functional part 30 and connecting part 40 , are firmly connected to one another after the corresponding preassembly in a last method step. For this purpose, the connecting part 40 is inserted into the opening 11 of the valve sleeve 6 in the functional part 30 until the end face 58 comes to a stop, for example, on the valve sleeve 6 , whereby the hydraulic connection of the two assemblies 30 , 40 with the corresponding seal by the sealing ring 51 already occurs is realized on the valve sleeve 6 . The electrical connection between the two assemblies 30 , 40 is also established, since the electrical connection elements 34 and 59 engage on both sides ( FIG. 1).

According to the invention the assemblies 30, 40 in the connecting area for the mechanical connection of the two assemblies 30, 40 encapsulated. In this case, the volume between the lower end face 58 of the connecting part 40 and the cover element 33 of the functional part 30 up to the outer circumference of the base body 42 or the valve jacket 5 is filled with plastic in a ring on the outer circumference of the valve sleeve 6 , so that a flush closure towards the outside is formed ( Fig. 1). This extrusion coating 60 reliably protects the electrical connecting elements 34 , 59 from the influences of the engine compartment (dirt, fuel).

A plastic is selected for the encapsulation 60 designed as a "belly bandage", which has its melting point at a higher temperature than the plastic used for the connecting part 40 , so that a polymeric connection between the two plastics is established. Above the end face 58 , the outer circumference of the base body 42 is designed as a labyrinth seal 61 , in which a plurality of grooves or furrows 62 extend in a ring on the circumference of the base body 42 . The material between the individual furrows 62 should run fairly pointed radially outward in order to create a heat distribution in this connection area during the encapsulation, which enables good melting. In addition, the larger surface area achieved by the furrows 62 ensures that a very secure connection of the two plastics is achieved, which ensures high mechanical stability in this area and thus the entire fuel injection valve and good tightness.

On the other hand, the quality of the connection between the encapsulation 60 made of plastic and the metal functional part 30 is improved in that at the upper, the connection part 40 facing end 63 of the valve jacket 5 z. B. several grooves are screwed or rolled.

Fig. 4 shows a second embodiment of a function part 30. The components that remain the same or have the same effect as the embodiment shown in FIGS. 1 and 3 are identified by the same reference numerals.

The fundamental difference compared to the previously described exemplary embodiment is that a fuel filter 44 'is arranged on the functional part 30 , either in addition to the fuel filter 44 already attached to the connecting part 40 or advantageously instead of the fuel filter 44 on the connecting part 40 . The fuel filter 44 'is supported, for example, on a step 66 of the valve sleeve 6 above the core 2 . The relatively large diameter of the opening 11 of the valve sleeve 6 in the area of the step 66 allows the use of a flat filter instead of a basket filter (shown in FIG. 1). The screen mesh can also be curved, as can be seen from FIG. 4. It is advisable to use a metal filter mesh as the mesh, which has a sufficient free filter area with a mesh size of 30 µm. During the handling of the preassembled functional part 30 up to the final assembly with the connecting part 40, it is thus guaranteed that no dirt particles get into the interior of the functional part 30 .

Various possibilities for establishing the electrical connection between the two components 30 , 40 are shown in FIGS. 5 to 7. Here, FIG. 5 shows the electrical connection portion with the electrical connecting elements 34, 59 in a schematic view, while FIGS. 6A to 6C, three embodiments for contact pins 59 of the connection part 40 corresponding to a section along the line VI-VI in Fig. 5 and Fig. 7A to 7D show four embodiments for contact sockets 34 of the functional part 30 corresponding to a section along the line VII-VII in FIG. 5.

The electrical connecting elements 59 of the connecting part 40 are thus designed in the form of pins according to FIGS. 5 and 6 as contact pins 59 . At their ends, the contact pins 59 have, for example, insertion bevels 68 with which the establishment of the electrical connection with the corresponding connecting elements 34 of the functional part 30 is facilitated. As Figs. 6A to 6C is removable, the cross-sections of the contact pins 59 can be, for. B. rectangular ( Fig. 6A), largely square ( Fig. 6B) or circular ( Fig. 6C).

Since, in the case shown in FIG. 5, the connecting element 59 is designed in the form of a pin, it is expedient to design the corresponding connecting element 34 in the form of a socket in order to implement a safe and reliable electrical connection. In Fig. 7 are examples of socket-like, eye-like, staple-like, cable-shoe-shaped, but also pin-shaped connecting elements 34 are shown. The ends of the connecting elements 34 facing away from the magnetic coil 1 likewise have insertion bevels 68 ′. FIG. 7A shows a conventional cable lug 70 , which can grip around a contact pin 59 like a clamp. To accommodate contact pins 59 of different sizes, the cable lug 70 can be made elastic. FIG. 7B shows a double-lug 71, which can be used for two different styles or 59 contact pin. Fig. 7C and 7D show two variants of a profile connection member 34, wherein the connecting member 34. Fig. According 7D are designed as a flat profile pin 73 34 Fig. According to 7C as an L-profile pin 72 and the connecting element. The two last-mentioned variants do not enclose the contact pins 59 to be contacted, but rather there is contact by tight contact. After the electrical connection has been established, the fixation can also be supported by an additional welding point before the encapsulation 60 is applied.

Of course, however, it is also possible to provide the electrical connecting elements 34 on the functional part 30 in the form of a pin, while the electrical connecting elements 59 of the connecting part 40 would then be designed more like a socket, eyelet or cable lug. Another possibility is to form a plug-like and socket-like connecting element 34 , 59 on the functional part 30 and on the connecting part 40 , which then interact with one another. Electrical contacting can also be achieved, for example, with the CIN :: APSE® technology, in which gold-coated molybdenum wires are formed like a button contact. This solderless connection technology allows very reliable electrical connections to be made that are mechanically completely resonance-free.

Fig. 8 shows a second embodiment of a connecting part 40. The components that remain the same or have the same effect as the embodiment shown in FIGS. 1 and 2 are identified by the same reference numerals.

In comparison to the exemplary embodiment according to FIG. 2, the connecting part 40 according to FIG. 8 has a modified design, particularly in the region of the end region 47 . For example, a step 76 is provided on the end face 58 , which serves as a guide collar for the valve sleeve 6 of the functional part 30 indicated by a broken line. With an upper sleeve section surrounds the valve sleeve 6 z. B. adjacent stage 76 in the assembled state of the valve. In addition, at least one segment 77 protrudes from the connecting part 40 starting from the end face 58 in the direction of the functional part 30 . The at least one segment 77 has an arcuate shape and, viewed in the radial direction, is formed at a distance from the step 76 , but not directly on the outer circumference of the connecting part 40 , at which the encapsulation 60 indicated by a two-dot line ends.

FIG. 9 shows a bottom view of the connecting part 40 according to FIG. 8 in the direction of arrow IX. It can be seen here that three segments 77 are provided on the connecting part 40 , all of which are designed in the shape of a circular arc, but for example have different extension lengths in the circumferential direction. This may be necessary due to the contact pins 59 . The segments 77 are only a short distance apart. Seen in the axial direction, the segments 77 z. B. still slightly beyond the central end region 47 .

From the connection part 40, so a plurality of segments 77 extend axially into the area of the required for the firm connection of connector part 40 and functional part 30 overmolding 60th The volume 77 of the encapsulation area is reduced by approximately 30% and the maximum wall thickness of the encapsulation 60 by approximately 50% compared to the encapsulation 60 shown in FIG. 1 by the segments 77 . In Fig. 8 it is indicated that the segments 77 result in an inner extrusion area 60 a and an outer extrusion area 60 b, which are filled with plastic during the encapsulation, the two extrusion sections then formed by plastic between the segments 77 and below the Segments 77 are interconnected. In this way, the segments 77 are embedded in the encapsulation 60 after the encapsulation. The segments 77 are arranged in such a way that there is no mass accumulation within the extrusion coating 60 and the wall thicknesses are uniform. Furthermore, it is advantageous to arrange the segments 77 in such a way that there is a strong swirling of the flowing plastic during the encapsulation process.

Fig. 10 shows a further embodiment in a view from below of a connecting part 40. Here too, three segments 77 projecting into the later extrusion coating 60 are provided, a small segment 77 being arranged between the two contact pins 59 and the other two segments 77 each extending in a circular arc over approximately 120 °.

All of the described exemplary embodiments of the fuel injection valves have the advantage of being inexpensive to manufacture with a large number of design variants. Function parts 30 , which are largely identical in construction in large numbers, can be connected to a large number of different connection parts 40 , which differ, for example, in size, in the design of the electrical connector 56 , etc. The logistics in the manufacture of fuel injectors are thus fundamentally simplified.

Claims (16)

1. Fuel injection valve for fuel injection systems of internal combustion engines, with an excitable actuating element ( 1 , 2 , 5 ), with a movable valve closing body ( 19 ) which interacts with a valve seat ( 16 ) assigned to a valve seat body ( 15 ), with an electrical connection ( 55 , 56 , 57 ) and with a hydraulic connection ( 42 , 43 ), with a preassembled functional part ( 30 ) and a preassembled connecting part ( 40 ), the functional part ( 30 ) essentially the actuating element ( 1 , 2 , 5 ), a sealing valve comprising valve seat body ( 15 ) and valve closing body ( 19 ), first electrical connecting elements ( 34 ) and first hydraulic connecting elements ( 28 ), and the connecting part ( 40 ) the electrical connection ( 55 , 56 , 57 ), the hydraulic connection ( 42 , 43 ), second electrical connecting elements ( 59 ) and second hydraulic connecting elements ( 43 ), the functional part ( 30 ) and the connecting part ( 40 ) form independent assemblies which are fixedly connected to one another by means of an overmolding ( 60 ) provided in the connection area of the two assemblies ( 30 , 40 ), and by the interaction of the first and second electrical connecting elements ( 34 , 59 ) and the first and second hydraulic connecting elements ( 28 , 43 ) a reliable electrical and hydraulic connection of both assemblies ( 30 , 40 ) is guaranteed. 2. Fuel injection valve according to claim 1, characterized in that the connecting part ( 40 ) is largely a plastic body which forms a fuel inlet connection as a base body ( 42 ) with a continuous flow bore ( 43 ), an electrical connector ( 56 ) on the base body ( 42 ) is formed. 3. Fuel injection valve according to claim 2, characterized in that the plastic selected for the extrusion coating ( 60 ) has its melting point at a higher temperature than the plastic used for the connecting part ( 40 ). 4. Fuel injection valve according to claim 2 or 3, characterized in that on the outer circumference of the base body ( 42 ) a labyrinth seal ( 61 ) with a plurality of grooves or furrows ( 62 ) is executed, which is covered by the extrusion coating ( 60 ). 5. Fuel injection valve according to one of the preceding claims, characterized in that on the connecting part ( 40 ) at least one axially in the direction of the functional part ( 30 ) projecting segment ( 77 ) is provided, which is embedded after the molding process in the overmolding ( 60 ). 6. Fuel injection valve according to claim 5, characterized in that the at least one segment ( 77 ) is designed in the shape of a circular arc. 7. Fuel injection valve according to one of the preceding claims, characterized in that the functional part ( 30 ) has a thin-walled valve sleeve ( 6 ), in the inner opening ( 11 ) of the valve seat body ( 15 ), the valve needle ( 14 ) and a core ( 2 ) are introduced as the inner pole and which is surrounded by a magnet coil ( 1 ), the magnet coil ( 1 ) being at least partially enclosed by a valve jacket ( 5 ) as the outer pole. 8. Fuel injection valve according to claim 7, characterized in that the valve jacket ( 5 ) on its the connecting part ( 40 ) facing end ( 63 ) has a plurality of grooves. 9. Fuel injection valve according to claim 7 or 8, characterized in that the valve sleeve ( 6 ) of the functional part ( 30 ) is designed so that in the assembled state of the fuel injection valve in the opening ( 11 ) projecting end portion ( 47 ) of the connecting part ( 40 ) envelops. 10. Fuel injection valve according to claim 9, characterized in that a sealing ring ( 51 ) is arranged at the end region ( 47 ) of the connecting part ( 40 ). 11. Fuel injection valve according to one of the preceding claims, characterized in that a fuel filter ( 44 ') is integrated in the functional part ( 30 ). 12. Fuel injection valve according to claim 11, characterized in that the fuel filter ( 44 ') has a metal filter fabric as a mesh screen. 13. Fuel injection valve according to one of the preceding claims, characterized in that the second electrical connecting elements ( 59 ) of the connecting part ( 40 ) are plug-like and / or socket-like and the first electrical connecting elements ( 34 ) of the functional part ( 30 ) are plug-like and / or socket-like . 14. Fuel injection valve according to claim 13, characterized in that the first electrical connecting elements ( 34 ) of the functional part ( 30 ) are bush-like, eyelet-like, clip-like, cable lug-shaped or profiled. 15. Fuel injection valve according to one of the preceding claims, characterized in that the connecting part ( 40 ) and / or the functional part ( 30 ) has separately pre-assembled subassemblies. 16. The fuel injector according to claim 2, characterized in that the electrical connector ( 56 ) can be connected in a connection region to the base body ( 42 ), electrical connection elements corresponding to one another for establishing a reliable electrical connection.