DE4143610C2 - Solenoid stator assembly for IC engine fuel injectors - Google Patents

Abstract

The stator assembly (10) comprises an E-shaped stator core (12) including three parallel pole pieces extending orthogonally therefrom. Each of the outer pole pieces (20,22) has an attachment slot formed (42,44) in its outermost side. A coil is disposed around an insulating spool disposed on the central pole piece, and leads from the coil are connected to terminals. A flange on one end of the spool exerts outward forces on the outer pole pieces, prestressing them to resist further flexing caused by outwardly directed forces applied by fuel under pressure. An insulating cover (60) is moulded around the solenoid stator assembly. The cover is bonded to the stator core by the attachment slots to enhance adherence of the cover material to the stator core and provide a barrier to any fuel attempting to traverse the interface between the insulating cover and the outer pole pieces.

Description

The invention relates to a stator arrangement for electronically controlled fuel injection systems, which consist of:

• - A C- or E-shaped stator core with a yoke and two of the yoke ends perpendicular and par to each other allel-running outer pole legs and with an E- shaped stator core with a center and parallel to the two outer pole legs arranged means pole leg,
• - A stator winding around one of the pole legs, which is provided with connections,
• - electrical insulation between the stator winding and the stator core,
• - and an insulating coating that covers the entire sta Gate arrangement with the exception of the connections and at enveloping the pole leg end faces.

Mechanically controlled fuel injection systems have been around since related to many years. Ever increasing demands improved vehicle performance and economy in However, fuel consumption has a great need escalate more sophisticated fuel injection systems to let. Microprocessor technology is not just one has become an inexpensive means to meet the demands of Present, but seems to have the potential  possess to meet the demands of the future.

In connection with the application of microprocessor tech The development of the electronically controlled Fuel injection layers. This development coincides with the constant increase in the reliability of the entire drive chain together, this reliability from industry is provided to the maintenance costs and the regular Reduce maintenance intervals. Electronically controlled Fuel injection systems have the advantage with the electronically controlled motors, which are used in the Trans port industry can be used to be compatible by leading engine manufacturers.

A typical mechanically controlled fuel injection system has a piston that reciprocally within one Hole or a sleeve through z. B. a camshaft and a rocker arm is driven to increase the injection pressure produce. The time of injection and the amount of fuel are created by screws and openings in the piston and the associated rifle are arranged, checked.

With a typical electrically controlled fuel spray system, as shown in US 45 68 021 the injection pressure is mechanical actuated piston generated; however, it becomes a solenoid used to control the valve which determines the injection time point and the amount of fuel checked.

It is a result of the transfer of control over the Injection time and the amount of fuel from mechanical on electronic means that improvements in effectiveness example of fuel injection systems under microprocessor control became feasible. Among other additional Advantages of electronically controlled fuel injection systems have fewer moving parts, fewer Weight, need as a result of the fact that less  Service settings are required to mechanical ab balance usage, less maintenance and cost less.

A construction area, which, however, is particularly attentive required to ensure the integrity of the Stator arrangement from any harmful influences this which is exposed to the fuel which is under extremely high pressures, on the order of 70 bar. Every contact surface of the stator core with the phenolic casing and the phenolic-wrapped winding on the Center pole leg is exposed to fuel under high pressure, which is the divergence of the arrangement at the touch causes hairline cracks in the phenolic housing leads and requires its renewal. The initial practical commercial design modifications by the applicant envisioned using the outer side of each outer pole leg to provide a T-shaped groove, so that phenolic casing if it is about the stand and the Winding subassembly was cast mechanically in the Stand intervention. This improved the overall stability of the Order, but after a while it started under high pressure standing fuel, mainly in the area of the remaining Intermediate pole faces with phenolic insulation material to negatively influence this resistance.

Partially the problem, which is related to the accessibility of these interfaces for the under high Pressurized fuel resulted from the process with which the phenolic insulating material over the stand and the winding assembly was cast, worsened.

This procedure involved placing the stator and the Coil arrangement within the form using vertical outstanding positioning pins, which are in positioning holes were recorded, with the positioning holes in a Phenol washer was molded between the pole parts was arranged at their distal ends. The Positioning holes formed a flow channel through which  the high pressure fuel access to the inner interfaces of the pole legs won, so that after a time, a separation occurred at these interfaces.

In the known stator arrangements, this can be so insulating coating material whose effectiveness only from the Strength of the bond between it and the stator core depends, detach from the stator core and through between stator core and coating material propelled fuel hairline cracks because parts of the stator core on which the coating material is applied, bent and there the fluid dynamics between alternating reinforcement and the stator core has an eroding effect through cavitation.

Partly the problem, which is related with the accessibility of these interfaces for the under high pressure fuel and the ver tied spread of hairline cracks through the material properties of the housing and the coil winding used phenol exacerbated from which out posed so that it tends to swell, especially if it is exposed to methanol fuel and to a lesser extent Dimensions when exposed to diesel fuel.

The invention is based on the object, a Stator arrangement for electronically controlled fuels to create spraying systems that are mechanically significant simple construction reliable against fuel influences is protected.

The object is achieved according to the invention in that a pretensioning device between the two pole legs is provided with which the two pole legs near their both free ends facing away from the yoke with one permanent spreading force can be applied and spread apart are cash.

As a result, the two are facing away from the yoke  Both ends of the two pole legs each have a force applied in the generally consistent but in opposite Directions act around the two outer pole legs from each other to lean away. This preload enables the two Outer pole legs of any additional parallel force which applied to them, resist and thereby This prevents the pole legs from being displaced.

In one embodiment of the invention it is provided that the Biasing device in an E-shaped stator core from one first and a second web. Here is the first Bridge between the one outer pole leg and the center pole thighs near their two free ones facing away from the yoke Ends insertable. The second bridge is between the Outer pole leg and the middle pole leg near their two Ends facing away from the yoke can be used. These two bridges are wider than the respective distances between the two Outer pole legs and the middle pole leg in not spread apart condition. By inserting the two The two outer pole legs of are in the stator core the center pole leg spread apart.

In one embodiment of the invention it is provided that the Pretensioner a force in the order of 1.1 applies up to 3.35 kilonewtons on the two outer legs.

In a further embodiment of the invention, that the insulating coating is made of phenolic material in situ is poured. The insulation coating thus completely seals the Interstices of the stator arrangement of penetrating fuel from. This prevents the pressurized Fuel is allowed in the gaps between the stator to penetrate order. Thus, something is brought about by it Preventing the insulation cover from tearing.

A further embodiment of the invention is thereby characterized in that for receiving and positioning the Connections an insulating cover on the stator core in the  Is arranged near the yoke. This insulating cover takes a first and a second clamp and holds them while the insulating coating is poured around the stator assembly, in Position.

In one embodiment it is provided that the insulating cover consists of phenolic material.

In a further embodiment according to the invention, an E-shaped stator core as electrical insulation between the stator winding and the center pole leg Coil frame provided. This coil frame creates in addition a suitable shape on which the winding, preferably wound in three layers and relieved positioning the winding on the center pole leg. By using a coil frame, additional Achieved quality control benefits. A leader from the top layer of the winding can be done by performing secured between the winding and the coil in such a way that the wires of the winding hold the conductor against the coil. With such a secured conductor there is no band or wedge required to prevent winding from winding or to prevent the conductor from another element to Example an outer pole leg, touched, and the inside of the Winding can completely with during the casting process Be filled with phenol.

This embodiment of the invention can be developed further be that the stator winding has an upper and a lower end having. The first line end of the stator winding is located itself on the top end of the stator winding and the second The end of the stator winding is from the lower end of the stator winding between the stator winding and the coil frame the upper end of the stator winding. It will second line end through the stator winding against the Coil frame held in place without additional Backup are required.  

It is appropriate that the coil frame made of phenolic Material exists.

In a further embodiment of the invention it is provided that with an E-shaped stator core as a biasing device Coil frame is provided around the center pole leg is arranged around and the center pole leg of the Stator winding electrically isolated. This coil frame has between the two outer pole legs near theirs from the yoke facing free ends on an end flange. At this It is possible to design wedges, preferably made of plastic between the end flange and the two outer pole legs drive, the wedges this from the center pole leg force it away and pretension it.

Another possibility is that the end flange is dimensioned wider than the respective distances between the two outer pole legs and the center pole leg in not spread apart condition. By inserting the Coil frames in the stator core are therefore the two The outer pole leg can be spread apart from the center pole leg.

The invention is described below with reference to an embodiment be explained in more detail. In the accompanying drawings shows:

Fig. 1 is a side view, partly in section, of an electromechanically controlled fuel injection system including the basic components of a stator arrangement according to the invention

Fig. 2 is a perspective view of the stator assembly, completely along the same plane, as shown in the partial sectional view of FIG. 1, th geschnit,

Fig. 3 is an enlarged side view of the stator assembly, partially in section, of Fig. 1,

Fig. 4 is a perspective view of the stator of FIG. 1 without insulating coating,

Fig. 5 is a partially sectioned view of the Statoranord voltage of FIG. 4 as it is positioned in a mold before it receives the insulating coating,

Fig. 6 is a view of the biasing ridges,

Fig. 7, partially broken away perspective view of a coil which is a component of the stator assembly of FIG. 4,

Fig. 8 is a bottom view of a stator of Fig. 4,

FIG. 9 is a split, sectional side view of the stator core of FIG. 4, illustrating the biasing of the stator core, and

Fig. 10 is a schematic representation of the different steps of the manufacturing process for the stator assembly of FIG. 3.

In Fig. 1 of the drawings, a stator assembly, generally designated by the reference numeral 10, generally referred to as the effective element of a representative electro-mechanically controlled fuel injection system with the reference numeral 11, which is mounted on a motor 13 is shown. As shown in FIGS . 2 and 3 of the drawings, the stator arrangement 10 has an E-shaped stator core 12 which has a yoke, generally provided with the reference symbol 14 , with a first end 16 and a second end 18 . A first outer pole leg 20 extends substantially at right angles from the first end 16 of the yoke 14 , a second outer pole leg 22 extends from the second end 18 of the yoke 14 in a direction substantially parallel to that of the first outer pole leg 20 and one Center pole leg 24 extends from an area of the yoke that is located midway between the first and second outer pole legs 20 and 22, respectively, with the direction of the center pole leg being substantially parallel to that of the first and second outer pole legs 20 and 22 . In a preferred embodiment of the invention, the stator core is layered and contains approximately 50 layers, each layer being shaped as shown in Fig. 1 and oriented from side to side.

The first and second outer pole legs 20 and 22 each have an outermost side 26 and 28 , and the first and second outer pole legs 20 and 22 and the center pole leg 24 each have a distal end, generally designated by the reference numerals 30 , 32 and 34 , which respectively Have end faces 36 , 38 and 40 . The first outer pole leg 20 has on its outermost side 26 in the vicinity of its distal end 30 a fastening groove 42 which runs essentially parallel to the yoke 14 of the stator core 12 . The second outer pole leg 22 has a fastening groove 44 shaped in the same way on its outermost side 28 in the vicinity of its distal end 32 . The mounting grooves 42 and 44 can have a number of shapes, each of which can be made as part of the original stamping step with which the layers are formed on a stamping machine. For example, the mounting grooves 42 and 44 may each be rectangular in cross-section (not shown), and their sides may be rectangular relative to the outermost sides 26 and 28 of the first and second outer pole legs 20 and 22 . The fastening grooves 42 and 44 can also each have a dovetail cross section (not shown). Alternatively, the sides of the mounting grooves 42 and 44 may each form an acute angle with respect to the outermost sides 26 and 28 and may be bent toward the yoke 14 of the stator core 12 . The fastening grooves 42 and 44 , which have a dovetail-shaped or angled cross-section, have, among other advantages, the advantage that, in addition to the chemical bonding of an insulating coating 60 to the outer pole pieces 20 and 22 , they have any forces which would result in the insulating layer 60 being pulled off the outer pole pieces 20 and 22 cause resistance.

While it can be understood that a variety of configurations can be used, each of the mounting grooves 42 and 44 in the preferred embodiment, as best shown in FIG. 4, is generally T-shaped in cross-section. The shape of the mounting grooves 42 and 44 improves their ability to anchor the bypass insulating coating while providing an excellent barrier to fuel that would otherwise be pressed under pressure between the insulating coating 60 and the outer pole legs 20 and 22 .

As the drawings shown in FIG. 4, to the Mittelpolschenkel 24 is a winding, generally indicated by the reference numeral 46, disposed of electric wire 48, the wire having at least a first and a second end 48, extending from the winding 46 extend to form a first conductor 50 and a second conductor 52 , respectively. The first and second conductors 50 and 52 are each connected to at least a first terminal 54 and a second terminal 56 . An electrical insulating member or device separates the winding 46 from the stator core 12 to prevent electrical contact with the center pole leg 24 . In one embodiment of the stator arrangement 10 , the insulating part can have the form of a coil 62 (shown in FIG. 7 and described hereafter) which basically surrounds the center pole leg 24 and is arranged around the winding 46 .

The molded insulating coating 60 (FIGS . 1, 2 and 3) is connected to at least the stator core 12 and essentially envelops the stator assembly 10 with the exception of the upper parts of the first and second terminals 54 and 56 ( FIG. 4 of the drawings) and the corresponding end faces 36 , 38 and 40 of the first and second outer pole legs 20 and 22 and the center pole leg 24 . The insulating coating is poured into the respective mounting grooves 42 and 44 in the first and second outer pole legs 20 and 22 to improve the adhesion between the covering material and the first and second outer pole legs 20 and 22 and to create a tortuous channel which allows the flow prevented from stray fuel.

FIG. 5 of the drawings shows the stator arrangement 10 in a representative form, generally designated by the reference symbol 86 , before it has received an insulating coating 60 ( FIG. 1). The mold 86 has an upper part 88 and a lower part 90 , which defines a mold cavity, generally designated by the reference symbol 92 , between the yoke and the lower part. An inlet or gate 94 , through which molten material, from which the insulating coating 60 is formed, is poured is arranged in the upper part 88 of the mold 86 . An associated air hole 96 is also arranged in the upper part 88 . While it should be understood that the insulating coating 60 can be formed from any of a number of fusible electrical insulating materials, the coating used in the preferred embodiment is a phenolic coating with low swelling properties when used with different types of fuels, particularly methanol fuel and to a lesser extent Diesel fuel is exposed. "Rogers Rx 630 Phenolic", which is manufactured by the Fiberite company, is particularly useful.

The outer pole legs 20 and 22 are biased by the application of a force near the distal end 30 of the first outer pole leg 20 and the application of a force near the distal end 32 of the second outer pole leg 22 , the forces being basically the same but in opposite directions Act direction to tilt the first and second outer pole legs 20 and 22 away from each other. The preload provides the first and second outer pole legs 20 and 22 with preload forces such that they can counteract all additional, parallel forces which are applied to the first and second outer pole legs 20 and 22 and can prevent the additional displacements caused by the parallel forces. The first and second outer pole legs 20 and 22 can be biased ( FIG. 6) by placing a first land 74 between the first outer pole leg 20 near their respective distal ends 30 and 34 and a second land 76 between the second outer pole leg 22 and the Center pole leg 24 is arranged near their respective distal ends 32 and 34 . The first and second land 74 and 76 have dimensions which exceed the respective distances between the first and second outer pole legs 20 and 22 and the central pole leg 24 by a certain amount when the first and second outer pole legs 20 and 22 are not inclined. While it should be understood that the degree of preload should vary as a function of the solenoid application and that some relaxation or shrinkage of the lands occurs during the casting of the insulating coating, the outer pole legs 20 and 22 of the preferred embodiment have been disclosed herein is a final biasing force in the range of 1.1 to 3.35 kilonewtons, and preferably a biasing force of 2.225 kilonewtons.

In the preferred embodiment of the stator assembly 10 ( FIG. 4), an insulation coil 62 (shown in detail in FIG. 7 of the drawings) is used to provide electrical insulation between the winding 46 and the center pole leg 24 of the stator core 12 . The coil 62 also has a suitable shape on which the winding 46 can be wound and facilitates the positioning of the winding on the center pole leg 24 .

The spool 62 has an elongated drum part 63 , from one end of which a first end flange 64 extends and from the other end of which a second end flange 66 extends at right angles. The first end flange 64 has a pair of diametrically opposed notches along its outer edge, generally designated by the reference numeral 68 , in order to create corresponding paths for the first and second conductors 50 and 52 . The second end flange 66 has at least one notch along its outer edge, generally designated by the reference numeral 70 , in order to create a path for the second conductor 52 . The drum part 63 has at least one channel 65 on its outer surface, which extends from a notch 68 in the first end flange 64 to the notch 70 of the second end flange 66 . In the preferred embodiment of the coil 62 , the notches 68 and 70 are provided in the first and second end flanges 64 and 66 and the connecting channel 65 on both sides of the coil 62 and arranged symmetrically on the outer edges of the coil 62 to facilitate assembly . While it should be understood that the coil 62 may be formed from any of a variety of electrical insulation materials, the coil 62 used in the preferred embodiment is phenol with low swelling properties when used with different types of fuel, particularly methanol fuel and less Extent of diesel fuel that is exposed. "Fiberite FM 4004 Phenolic" as manufactured by the Fiberite company is particularly useful.

The spool 46 is preferably wound in three layers, the first layer starting at the end of the drum portion 63 of the spool 62 which is near the first end flange 64 and the third layer at the end of the drum portion 63 which is in the vicinity of the second end flange 66 of the coil 62 is ended. The first conductor 50 is led to the first terminal 54 through a notch 68 in the first end flange 64 . The second conductor is led under the winding 46 on the notch 70 in the second end flange 66 along a channel 65 in the drum part 63 of the coil 62 and through the other notch 68 in the first end flange 64 to the second terminal 56 .

The fact that the coil 62 provides the possibility of guiding the second conductor 52 between the winding 46 and the coil 62 results in significant advantages in front of their devices, which require more conventional guiding of the conductors. By securing the second conductor 52 under the winding in the manner disclosed, no tape or other fastening device is necessary to prevent the spool 46 from winding up or to prevent the second conductor 52 from being attached to another Component as the first or second outer pole leg 20 or 22 come into contact.

An insulating cover 72 is arranged on the stator core 12 in the vicinity of its yoke 14 . The cover 72 has recesses that receive the first and second clamps 54 and 56 and hold the clamps in place while the insulation coating 60 is being molded around the stator assembly 10 . Parts of the insulating cover 72 overlap associated parts of the coil 62 to create an insulating barrier between the first and second conductors 50 and 52 and the stator core 12, respectively. While it should be understood that the insulation cover 72 may be formed from any of a variety of electrical insulation materials, the insulation cover used in the preferred embodiment disclosed herein is phenol with low swelling properties, preferably the same phenol. as used for the coil 62 to ensure full compatibility during the casting of the housing 60 .

The second end flange 66 of the coil 62 extends from the first outer pole leg 20 near its distal end 30 to the second outer pole leg 22 near its distal end 32 . The part of the second end flange 66 which is arranged between the first outer pole leg 20 and the second outer pole leg 22 has dimensions which by a certain amount exceed the associated distance between the first and second outer pole legs 20 and 22 , if these are not inclined. This is shown in detail in Figs. 8 and 9. When used, the second end flange 66 applies a force near the distal end 30 of the first outer pole leg 20 and a force near the distal end 32 of the second outer pole leg 22 , the forces acting in principle but in opposite directions to the first and second Außenpolschenkel 20 and 22 wegzuneigen of the Mittelpolschenkel 24 and the first and second Außenpolschenkel 20 and 22 so as to bias that the biasing forces all additional, parallel forces that might be applied to the first and second Außenpolschenkel 20 and 22, counteract and prevent any additional displacement caused by the parallel forces.

Side a of FIG. 9 shows the stator core 12 before the coil 62 has been completely placed on the center pole leg 24 of the stator core 12 . As shown, the end flange 66 of the coil 62 extends a certain distance d below the inner surface of the first outer pole leg 20 . Side b of FIG. 9 shows the stator core 12 after the coil 62 has been fully inserted. As shown, the second end flange 66 has the second outer pole leg 22 offset from the central pole leg 24 by an angle α. As a result of the displacement process through the second end flange 66 , the first and second outer pole legs 20 and 22 are biased. To facilitate the positioning of the second end flange 66 between the first and second outer pole legs 20 and 22 , the respective distal ends 30 and 32 can be formed using the T-shaped grooves 42 and 44 , which are used to anchor force-applying parts (not shown) ) are arranged to be spread apart.

Each of the end faces 36 and 38 of the first and second outer pole legs 20 and 22 has a positioning bar 80 and 82 which extends along a boundary near the center pole leg 24 to facilitate positioning of the stator core 12 during assembly. Each positioning bar 80 and 82 has an edge 84 near the center pole leg 24 , the edge 84 being chamfered to facilitate the insertion of the second end flange 66 of the coil 62 between the first and second outer pole legs 20 and 22 . The positioning bars 80 and 82 are during the process of completing the stator assembly 10 , e.g. B. removed by grinding.

It should be understood that practical features, such as. B. sleeves that are passed through the insulating coating 60 are included here to provide holes 98 through which screws 100 ( FIG. 1) can be passed to secure the stator assembly 10 to an electromechanically controlled fuel injection system 11 .

The method for producing a preferred embodiment of the stator arrangement can best be understood with the aid of the steps, which are highlighted in FIG. 10 of the drawings, in connection with the previously described FIGS. 4 to 9. The winding 46 is preferably wound in three layers. The first layer is started at the end of the barrel portion 63 of the spool 62 near the first end flanges 64 , and the third layer is terminated at the end of the barrel portion 63 located near the second end flange 66 of the spool 62 . Beginning with the first end flange 64 , the coil 62 is slipped onto the center pole leg 24 of the stator core 12 until the second end flange 66 touches the positioning strips 80 and 82 on the first and outer hollow parts 20 and 22 , respectively.

The distal ends 30 and 32 of the first and second outer pole legs 20 and 22 can be spread to facilitate passage of the second end flange 66 between the first and second outer pole legs 20 and 22 , with the T-shaped grooves 42 and 44 , which in the Outer pole pieces 20 and 22 are arranged, used to anchor force-applying parts (not shown). The bevelled edges 84 of the positioning strips 80 and 82 additionally facilitate the insertion of the second end flange 66 into its position.

After the coil 62 is placed on the center pole leg 24 , the insulating cover 72 is placed on the stator core 12 near its yoke. The first and second conductors 50 and 52 are connected to the first and second terminals 54 and 56 , respectively, and the first and second terminals 54 and 56 are arranged in the recesses formed in the insulating cover 72 . The first conductor 50 is routed to the first terminal 54 through a notch 68 in the first end flange 64 . The second conductor 52 is led under the winding 46 through the notch 70 in the second end flange 66 along the channel 65 in the drum part 63 of the coil 62 and through another notch 68 in the first end flange 64 to the second terminal 56 .

After the stator core 12 , the coil 62 , the winding 46 , the insulating cover 72 and the clamps 54 and 56 have been assembled as described, they are inserted into the mold 86 as shown in FIG. 5. The stator arrangement 10 is arranged on the lower part 90 of the mold 86 in such a way that the positioning strips 80 and 82 are arranged in the associated recesses in the lower part 90 of the mold 86 . The upper part 88 of the mold 86 is then placed on the yoke 90 of the mold 86 and forms a mold cavity 92 around the stator arrangement 10 . Molten insulation material, which is phenolic in the preferred embodiment of the invention, is inserted into the mold 86 through the inlet or gate 94 to form an insulating coating 60 ( Figs. 1-3), the gases which are formed during casting escape from the mold cavity 92 through the associated air hole 96 in the upper part 88 of the mold 86 .

The insulating material is bonded at least to the stator core 12 and essentially envelops the stator arrangement 10 with the exception of the parts of the first and second terminals 54 and 56 , the end faces 36 and 38 of the first and second outer pole legs 20 and 22, and the end face 40 of the center pole leg 24 . When the insulating coating 60 has settled sufficiently, the upper part 88 of the mold 86 is separated from the lower part 90 of the mold and the stator assembly 10 is removed from the mold 86 . The positioning strips 80 and 82 are removed from the respective first and second outer pole legs 20 and 22 by a mechanical method, as described, for. B. grinding is removed.

The invention has been described above a stator arrangement with an E- shaped stator core be exemplary wrote, with a corresponding stator arrangement of course also with a C-shaped stator is executable.  

Reference list

10th

Stator arrangement

11

Fuel injection system

12th

Stator core

13

engine

14

yoke

16

first yoke

18th

second yoke

20th

first outer pole leg

22

second outer pole leg

24th

Center pole leg

26

first outermost page

28

second outermost page

30th

first turned end

32

second turned end

34

third turned end

36

first face

38

second face

40

third face

42

first fastening groove

44

second fastening groove

46

Stator winding

48

Lead wire

50

first line end

52

second line end

54

first clamp

56

second clamp

60

Insulation cover

62

Coil frame

63

Drum means

64

first end flange

66

second end flange

68

first notch

70

second notch

72

Insulating cover

74

first footbridge

76

second bridge

80

first positioning bar

82

second positioning bar

84

Edge

86

representative form

88

Top

90

Lower part

92

Mold cavity

94

goal

96

Air hole

Claims (11)

1. Stator arrangement for electronically controlled fuel injection systems consisting of:

• a C-shaped or E-shaped stator core with a yoke and two outer pole legs extending perpendicularly and parallel to one another from the yoke ends and, in the case of an E-shaped stator core, with a central pole leg arranged in the middle and parallel to the two outer pole legs,
• a stator winding around one of the pole legs, which is provided with connections,
• - electrical insulation between the stator winding and the stator core,
• - as well as an insulating coating that envelops the entire stator arrangement, with the exception of the connections and the end faces of the pole legs,

characterized in that a pretensioning device is provided between the two pole legs with which the two pole legs can be acted upon and spread apart with a permanent spreading force near their two free ends facing away from the yoke. 2. Stator arrangement according to claim 1, characterized in that the biasing device in an E-shaped stator core from a first web ( 74 ), which between the one outer pole leg ( 20 ) and the center pole leg ( 24 ) near their two by the yoke ( 14 ) Free ends facing away ( 30 , 34 ) can be used, and a second web ( 76 ) which between the outer pole leg ( 22 ) and the central pole leg ( 24 ) near their two free ends ( 32 , 34 ) facing away from the yoke ( 14 ) can be used, exists and
that these two webs ( 74 , 76 ) are wider than the respective distances between the two outer pole legs ( 20 , 22 ) and the center pole leg ( 24 ) in the non-spread state, so that by inserting the two webs ( 74 , 76 ) in the stator core ( 12 ) the two outer pole legs ( 20 , 22 ) and the center pole leg ( 24 ) can be spread apart. 3. Stator arrangement according to claim 1 or 2, characterized in that a force in the order of 1.1-3.35 kilonewtons on the two outer pole legs ( 20 , 22 ) can be applied by the biasing device. 4. Stator arrangement according to one of claims 1-3, characterized in that the Iso lierüberzug ( 60 ) is cast in situ from phenolic material. 5. Stator arrangement according to one of claims 1-4, characterized in that an insulating cover ( 72 ) on the stator core ( 12 ) is arranged in the vicinity of the yoke ( 14 ) for receiving and positioning the connections ( 54 , 56 ). 6. Stator arrangement according to claim 5, characterized in that the insulating cover ( 72 ) consists of phenolic material. 7. Stator arrangement according to one of claims 1-6, characterized in that a coil frame ( 62 ) is provided in an E-shaped stator core as electrical insulation between the stator winding ( 46 ) and the center pole leg ( 24 ). 8. Stator arrangement according to claim 7, characterized in that the stator winding ( 46 ) has an upper and a lower end, the first line end ( 50 ) of the stator winding ( 46 ) is on the upper end of the stator winding ( 46 ) and the second The line end ( 52 ) of the stator winding ( 46 ) is led from the lower end of the stator winding ( 46 ) between the stator winding ( 46 ) and the coil frame ( 62 ) to the upper end of the stator winding ( 46 ), the second line end ( 52 ) being passed through the stator winding ( 46 ) is held in position against the coil frame ( 62 ) without the need for additional fuses. 9. Stator arrangement according to one of claims 7 or 8, characterized in that the coil frame ( 62 ) consists of phenolic material. 10. Stator arrangement according to claim 1, characterized in that in an E-shaped stator core as a biasing device, a coil frame ( 62 ) is provided, which is arranged around the center pole leg ( 24 ) and the center pole leg ( 24 ) and from the stator winding ( 46 ) electrically isolated,
that this coil frame ( 62 ) has an end flange ( 66 ) between the two outer pole legs ( 20 , 22 ) near their free ends ( 30 , 32 ) facing away from the yoke ( 14 ),
that this end flange ( 66 ) is dimensioned wider than the respective distances between the two outer pole legs ( 20 , 22 ) and the center pole leg ( 24 ) in the non-spread state, so that by inserting the coil frame ( 62 ) in the stator core ( 12 ) the two outer pole legs ( 20 , 22 ) can be spread apart from the center pole leg ( 24 ). 11. Stator arrangement according to claim 10, characterized in that the end faces ( 36 , 38 ) of the two outer pole legs ( 20 , 22 ) each have a positioning bar ( 80 , 82 ) which extend on the sides facing the center pole leg ( 24 ) in order to facilitate the positioning of the stator core ( 12 ) in a mold ( 86 ),
that these positioning strips ( 80 , 82 ) have bevelled edges ( 84 ) to facilitate the insertion of the end flange ( 66 ) of the coil frame ( 62 ) between the pole legs, and
that these positioning strips ( 80 , 82 ) in the course of the manufacture of the stator arrangement ( 10 ) can be removed.