WO2008049667A1 - Injector for injecting fuel into combustion chambers of internal combustion engines - Google Patents

Abstract

The invention relates to an injector (1) for injecting fuel into combustion chambers of internal combustion engines, particularly a common rail injector. According to the invention, a pin (25) which penetrates a sleeve (23) of a control valve (18) is disposed in a resting manner on an injector component, particularly an injector body (2), or is designed in a monolithic fashion therewith, away from a control chamber (12).

Description

description

title

Injector for injecting fuel into combustion chambers in internal combustion engines

State of the art

The invention relates to an injector according to the preamble of claim 1.

EP 1 612 403 A1 describes a common-rail injector with a pressure-balanced control valve in the axial direction for blocking and opening a fuel discharge path from a control chamber. By means of the control valve, the fuel pressure can be influenced within the control chamber, wherein the control chamber is supplied via a pressure channel with fuel from a high-pressure fuel storage. Due to the variation of the fuel pressure within the control chamber, a nozzle needle whose upper end face protrudes into the control chamber, moved between an open position and a closed position, wherein the nozzle needle in its open position releases the fuel flow into the combustion chamber of an internal combustion engine. The control valve has an adjustable in the axial direction by means of an electromagnetic actuator valve sleeve, which cooperates sealingly with a conically shaped valve seat surface. The valve seat surface of the control valve is formed on a component which is defined within the injector body, through which the fuel discharge path for fuel is led out of the control chamber and on which a bolt penetrating the sleeve and receiving axial pressure forces is formed. A disadvantage of the known injector is that the axially displaceable valve sleeve is guided in the axial direction exclusively by its inner circumference on the outer circumference of the bolt. As a result, high leakage losses occur on the valve seat surface and / or in the radial guide gap between the valve sleeve and the bolt. The leakage quantity can be reduced by using smaller guide diameters. Due to the internal pressure in the fuel passage and the associated strength problems a minimum diameter is not to fall below.

DISCLOSURE OF THE INVENTION Technical Problem

The invention is therefore based on the object to propose an injector in which the leakage losses in the region of the control valve are minimized.

Technical solution

This object is achieved with the features of claim 1. Advantageous developments of the invention are specified in subclaims. In addition, all combinations of at least two of the features disclosed in the description, the drawings and / or the claims fall within the scope of the invention.

The invention is based on the idea to support the bolt passing through the valve sleeve on the opposite side of the valve seat on an injector, to attach to this or form integrally with this. In this case, a solution in which the bolt is supported only on the injector body is preferred, or is attached to the injector body, since in this case the bolt can be manufactured as a separate component and thus easier to manufacture. By the support and / or attachment of the bolt on the opposite side of the valve body on the injector higher accuracies with respect to the position of the valve sleeve operatively connected to the armature plate can be realized with respect to an electromagnet, whereby small lateral forces act on the valve sleeve and the bolt, which in turn minimizes component wear and leakage losses.

Advantageously, the fuel discharge from the control chamber is not integrated in the bolt, whereby smaller diameter and thus smaller leakage quantities can be realized.

In an embodiment of the invention is provided with advantage that axially between the valve sleeve and the nozzle needle, which can be made in one or more parts, a throttle body is disposed within which the pressure channel with inlet throttle for supplying the control chamber with fuel, for example, from a control chamber surrounding Pressure chamber or directly from a connected to a high-pressure fuel storage supply line and / or a drain passage with outlet throttle for hydraulic connection of the control chamber are introduced to the control valve. The drainage channel forms the fuel drainage path for fuel from the control chamber to a low pressure chamber or is at least part of the same. Preferably, both the pressure channel with inlet throttle and the outlet channel with outlet throttle are introduced within the throttle body. According to a preferred embodiment of the invention it is provided that the valve sleeve is formed integrally with the anchor plate. As a result, a separate component can be saved, which reduces the overall manufacturing tolerance of the injector. It is further provided that the integrally formed with the anchor plate valve sleeve is received within a receiving bore, wherein not the sleeve is guided radially outwardly on the peripheral wall of the receiving bore, but only the anchor plate. Thus, a first guide portion of the valve sleeve and anchor plate combination is located relatively far from the valve seat surface, thereby eliminating the need for a long cylindrical guide on the outer surface of the valve sleeve. Thus, only the outer peripheral surfaces of the anchor plate and the corresponding short cylindrical portion of the receiving bore need to be ground. An exact grinding of the armature surface of the valve sleeve and the other receiving bore wall can be omitted with advantage. If the component, into which the receiving bore for accommodating the valve sleeve formed integrally with the anchor plate is inserted, is the throttle body, it is possible to dispense with a separate valve body, as a result of which the overall tolerances are reduced. In addition, the number of surfaces to be sealed is minimized. Also advantageous is the achievable with the design exact concentricity between the electromagnet of the solenoid drive and the armature plate. Deviations from this concentricity usually lead to radial disturbance forces in the magnetic circuit.

Preferably, the valve seat surface is formed partially spherical, so at least in the contact region of the valve sleeve describes a spherical shape. This will provide an optimal center ration of the valve sleeve on the valve seat surface, which in combination with the guidance of the armature plate within the receiving bore effectively prevents radial displacement and tilting of the valve sleeve about the center of the valve seat.

Advantageously, the receiving bore within the armature plate and the valve sleeve receiving member is designed as a stepped bore, wherein the electromagnet is supported on an annular shoulder of the stepped bore within the component. As a result, the parallelism between the armature plate and electromagnet is improved. Alternatively, it is conceivable that the electromagnet on the, preferably flat, surface of the component, in particular the throttle plate, is supported.

According to an alternative, advantageous embodiment of the invention, it is provided that the armature plate and the valve sleeve are formed as separate components, wherein the bolt enclosed by the valve sleeve additionally passes through the armature plate. Also in this embodiment variant can be dispensed with an immediate axial guidance of the valve sleeve over its entire outer circumference. In addition to the guide function for the valve sleeve, the bolt has the task of roughly centering the armature plate in the radial direction. The valve spring for closing the control valve acts in the axial direction on the armature plate, whereby the armature plate is spring-loaded on the valve sleeve and this in turn in the direction of the valve seat surface. The valve spring counteracts a weaker spring, which exerts a spring force in the opening direction on the valve sleeve. Due to the separate design of anchor plate and valve sleeve, the two components can be made of different lent materials are formed. In particular, the anchor plate is formed of highly magnetically conductive material, whereas the valve sleeve is wear-optimized.

In order to compensate for angular errors between the armature plate and the valve sleeve and to ensure a large-scale power transmission between armature plate and valve sleeve is provided in an embodiment of the invention advantageously that either directly between the armature plate and valve sleeve or between a setting on which the armature plate is supported and the valve sleeve a Convex-concave pairing is realized. For example, the adjusting ring is supported with a concave recess on a convex elevation on the end face of the valve sleeve, so that a kind of ball joint is realized, whereby angular errors can be compensated.

In order to minimize parallelism errors between armature plate and electromagnet, it is provided in an embodiment of the invention that a radial gap is provided between a component enclosing the armature plate and the armature plate, ie the armature plate with its peripheral surface does not bear directly on the component surrounding it and thereby freely alignable on the electromagnet. The recess in which the anchor plate is received, is dimensioned such that assuming exactly parallel alignment between anchor plate and a parallel surface of the recess, in particular a (bottom) shoulder of the recess, and at the same time on the valve seat Verstellter valve sleeve axial gap between the anchor plate and the parallel surface remains. In other words, in the case of exactly parallel alignment between armature plate and parallel surface is an all-inclusive Axial gap between lower stop (parallel surface) and anchor plate provided. Through this axial gap ensures that the spring force of the valve sleeve is not introduced into the parallel surface, but preferably only in the valve sleeve. The anchor plate can be supported exclusively on one side and not fully on the parallel surface in the presence of an angular error. The parallel surface limits the maximum alignment angle of the armature disk to the longitudinal axis of the bolt. Preferably, the parallel surface is designed as a shoulder in a retaining sleeve, which in turn is supported on a throttle plate. Double plank grinding of the anchor plate and the shoulder (parallel surface) of the holding sleeve makes it possible to produce very small parallelism errors which can only be achieved in the case of conventional injectors by means of severely limited axial runs. On the side opposite the parallel surface side of the armature plate, a lifting gap is provided between the armature plate and the electromagnet, which plate is overcome when the electromagnet is energized by the armature plate (together with the valve sleeve). The residual air gap, ie the remaining gap between the armature plate and the magnet in the open control valve state, can be represented by a coating of the electromagnet or a step in the armature plate. The anchor plate strikes in the case of providing a coating directly to this.

With small seat angles of approximately 90 ° total angle, the valve sleeve can move only slightly in the radial direction from its centric position with open control valve. This larger seat angle, so comparatively flat valve seat surfaces can be realized, is in an embodiment of the invention, an additional guide sleeve provided radially adjacent to the valve seat surface, which prevents radial pivoting of the valve sleeve when the control valve is open. Even with this solution, the valve sleeve is not guided cylindrically over its entire length, but only in a short, lower section. In this case, the valve sleeve and / or the valve sleeve surrounding the guide sleeve must be formed such, for example, by providing flats that a fuel flow from the valve sleeve interior is ensured in the low pressure chamber. For example, this Abströmmöglichkeit the fuel can be realized by extending in the axial direction of the grooves on the outer diameter of the valve sleeve or on the inner diameter of the guide sleeve.

According to a further alternative, advantageous embodiment of the invention, it is provided that the valve sleeve passes through a guide ring and is guided over this on a peripheral wall of a bore. The valve sleeve is thus supported only indirectly on the peripheral wall. Also in this alternative embodiment of the invention, a cylindrical guide of the valve sleeve over its entire outer circumferential surface is avoided, whereby the guide surfaces to be ground are minimized. In addition, the valve sleeve is guided on the bolt enclosed by it, which is preferably designed in two parts, wherein the two axially adjacent portions of the bolt via a kind of ball joint (convex-concave pairing) support each other, inter alia, to compensate for angular errors. So that the guide ring can not be displaced relative to the valve sleeve, it is provided in a further development of the invention that the guide ring is spring-loaded via the valve spring in the axial direction. In this case, the guide ring is supported indirectly or directly on the valve sleeve. Preferably, a retaining ring is provided for indirect support, which is held in a circumferential groove of the valve sleeve.

Preferably, in the previously described variant of the invention, the armature plate is received with radial clearance in a receiving bore, in particular a valve body, so that the alignment of the valve sleeve takes place only over the guide ring and the seat.

Furthermore, it is advantageously provided that the valve seat surface is flat, i. just, is formed, whereby the valve seat surface is aligned parallel to the valve seat surface or the component comprising this, in particular the throttle plate due to the valve spring acting on the valve sleeve shortly thereabove. This makes it possible to manufacture the guide surfaces on the valve sleeve and the guide ring on the one hand and on the guide ring and the peripheral wall on the other hand with relatively large tolerances, which reduces the manufacturing cost.

Brief description of the drawings

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawing; this shows in:

FIG. 1a: a sectional partial view of a first exemplary embodiment of an injector, in which the

Anchor plate and the valve sleeve are integrally formed, FIG. 1b is a further sectioned partial view of the embodiment according to FIG. 1a, FIG.

FIG. 2 shows a second exemplary embodiment of an injector, in which also the anchor plate and the

Valve sleeve are integrally formed and in which an electromagnet of an electromagnet ^¬ drive is supported on a flat top of a Dros ^¬ selplatte,

3a shows a sectional partial view of a third embodiment of an injector, in which the anchor plate and the valve sleeve are formed separately, and in which the anchor plate via an adjusting ring hinged to the

Valve sleeve supported in the axial direction,

3b shows a sectional view of a detail from FIG. 3a, which shows the arrangement of the anchor plate within the injector body,

4a shows a sectional partial view of a fourth embodiment of an injector with ge ^¬ separated trained anchor plate and valve sleeve, wherein radially adjacent to the valve seat ^¬ surface an additional guide ring is provided for the valve sleeve,

4b: a plan view of the valve sleeve and the guide ring,

4c: a side view of the valve sleeve, 4d shows a plan view of a possible embodiment of the guide ring,

5a shows a sectional partial view of a fifth embodiment, in which the anchor plate is formed integrally with the valve sleeve, wherein the valve sleeve is guided via a radial guide ring on a peripheral wall,

Fig. 5b: a perspective view of the unit

Anchor plate and valve sleeve according to FIG. 5a with valve spring, guide ring and a retaining ring.

Embodiments of the invention

In the figures, the same components and components with the same function with the same reference numerals.

All shown embodiments have in common that they manage without or with only a comparatively short guide on the outer circumference of the valve sleeve.

In Fig. 1, an injector 1 is shown in fragmentary form. The injector 1 has an injector body 2, a nozzle body 3 and a cylindrical throttle body 4 accommodated between the injector body 2 and the nozzle body 3. A nozzle retaining nut 5 is screwed to the injector body 2 and thus clamps the nozzle body 3 and the throttle body 4 against the injector body 2. The lower portion of the injector 1 is not completely shown, but can be described, for example, as in DE 100 24 703 A1 be executed. It is not shown that the nozzle retaining nut 5 is penetrated by the nozzle body 3 in the axial direction. Within the nozzle body 3, a bore 6 is introduced, in which an elongated nozzle needle 7 is guided axially movable. At a needle tip, not shown, of the nozzle needle 7, a closing surface is provided, with which the nozzle needle can be brought into tight contact with a needle seat formed within the nozzle body 3. When the nozzle needle 8 rests against the needle seat (not shown) (see DE 100 24 703 A1), ie is in a closed position, the fuel outlet from a nozzle hole arrangement is blocked. If, on the other hand, it has been lifted from the needle seat, fuel can flow from the annular space 8 formed between the nozzle needle 7 and the inner circumference of the bore 6 past the needle seat to the nozzle hole arrangement, where it is sprayed into a combustion chamber substantially under high pressure (rail pressure) become.

The nozzle needle 7 is biased by a biasing spring 9 in the direction of its closed position.

The biasing spring is supported on the one hand on the nozzle needle

7 (not shown) and on the other hand on a sleeve-shaped component 10, which is thereby pressed against the underside of the throttle body 4. The sleeve-shaped component is in this case formed by the annular space formed as a pressure chamber

8 surrounded. Radially within the sleeve-shaped component 10 and in the axial direction of the throttle body 4 and an upper end face 11 of the nozzle needle 7 is limited a control chamber 12 which is connected via a pressure channel 13 with inlet throttle 14 within the throttle body 4 with a supply line 15, via the fuel can flow from a high-pressure fuel storage, not shown. Fuel can flow out of the control chamber 12 through a control valve 18 into a low-pressure chamber 19 and from there via a return channel, not shown, via an outlet channel 16 with outlet throttle 17 within the throttle body 4. Depending on the operating state, the fuel pressure within the low-pressure space is approximately between 0 and 10 bar, whereas fuel flows through the supply channel 15 at a pressure between approximately 1800 and 2000 bar.

By means of an electromagnetic actuator 20, which comprises an electromagnet 21 and an axially relative thereto adjustable armature plate 22, the control valve 18 can be adjusted from the illustrated closed position to an open position.

By the biasing spring 9 and the action of the pressure prevailing in the control chamber 12 fuel pressure on the end face 11 of the nozzle needle 7, an axially directed to the combustion chamber closing force is exerted on the nozzle needle 7. This closing force counteracts axially an opening force, which is exerted due to the action of the fuel under high pressure to a on the nozzle needle 7, not shown step surface. If the control valve 18 is in a closed position and the fuel drain is blocked by the drainage path 22, the closing force is greater than the opening force in the stationary state, for which reason the nozzle needle 7 then assumes its closed position. If the control valve 18 is then opened, fuel flows from the control chamber 12 via the drain passage 16 (part of the fuel drain path) in the low-pressure chamber 19 from. The flow cross sections of the inlet throttle 14 and the outlet throttle 17 are matched to one another such that the inflow through the pressure channel 13 is weaker than the outflow through the outlet channel 16 and thus results in a net outflow of fuel when the control valve 18 is open. The resulting pressure drop in the control chamber 12 causes the amount of closing force falls below the amount of the opening force and the nozzle needle 7 lifts from the needle seat.

This general functional description of the injector 1 relates to all illustrated embodiments, possibly with minor modifications.

In the embodiment according to FIGS. 1 a and 1 b, the anchor plate 22 is formed integrally with a valve sleeve 23 of the control valve 18, the valve sleeve 23 sealingly cooperating with a valve seat surface 24 that is partially spherical in this embodiment. The valve sleeve 23 encloses an elongated (guide) pin 25, which is axially spaced from the valve seat surface 24 supported on the injector body 2. The bolt 25 is pressed against the valve body 2 by the fuel pressure inside the valve sleeve 25 and thus forwards all axial forces to the injector body 2, so that only a fuel pressure in the radial direction acts on the valve sleeve 23, whereby the control valve 18 in the axial direction pressure balanced.

The valve sleeve 23 is centered over the part-spherical valve seat surface 24 and leads over its inner circumference on the outer circumference of the bolt 25. An additional guide is in Area of the peripheral wall 26 of the anchor plate 22 is provided. The peripheral wall 26 is guided on an inner wall 27 of a receiving bore 28 within the throttle body 4. There are always two guides in the embodiments according to FIGS. Ia, Ib and 2. In the closed, depressurized state (motor off) of the control valve, these are the valve seat and the outer diameter of the anchor plate. The bolt is aligned by the anchor. When pressurized, the bolt is pushed up and its upper end assumes a fixed position due to the static friction. Thus, in the open state, the upper end of the bolt defines a fixed point. The orientation of the armature thus takes place via the bolt with its upper fixed end and also over the outer diameter of the anchor plate. In the open state, the valve sleeve 23 has no contact with the valve seat, whereby the valve seat can no longer center the anchor.

The electromagnet 21 of the actuator 20 is received in a bore 29 of the injector body 2 and is spring-loaded in the direction of the armature plate 22 via a spring element 30 which is supported on the one hand on the injector body 2 and on the other hand on an end face of the electromagnet 21. The receiving bore 28 within the throttle body 4 is designed as a stepped bore, so that an annular shoulder 31 arises within the receiving bore 28, on which the electromagnet 21 is supported. The receiving bore 28 has in the region in the plane above the paragraph 31 the same diameter as the bore 29 within the injector body. 2

Within the electromagnet 21, a passage opening 32 is provided, which is penetrated by the bolt 25. In the Through opening 32, a valve spring 33 is arranged, which is supported on the one hand on a setting ring 34 for adjusting the valve spring force and on the other hand on the plane in the drawing upper, the electromagnet 21 facing side of the armature plate 22, whereby the armature plate 22 is spring-loaded on the valve seat surface 24.

When the electromagnet 21 is energized, an axial tensile force acts on the armature plate 22, which is thereby lifted until it reaches the electromagnet 21, whereby high-pressure fuel from the control chamber 12 radially between valve seat surface 24 and lower end surface of the valve sleeve 23 in the low-pressure chamber 19 can flow, which is formed radially within the receiving bore 28 in the throttle body 4 and the valve sleeve 23 receives.

From Fig. Ib, which is an offset sectional view of the injector shown in Fig. Ia, a portion of the supply line 15 is shown within the throttle body 4, which supplies the pressure chamber formed as an annular space 8 with high-pressure fuel. From the annular space 8, this fuel can flow out of the nozzle hole arrangement (not shown) in the region of the needle point when the needle needle 7 is lifted from the needle seat.

It is advantageous in the embodiment shown that the throttle body simultaneously forms a valve body and thus a separate component can be saved. At the same sealing surfaces are saved and due to the support of the electromagnet 21 within the receiving bore 28, a high accuracy of the concentricity between the electromagnet and armature plate 22 is achieved. The embodiment according to FIG. 2 essentially corresponds to the exemplary embodiment according to FIGS. 1a and 1b, so that only the differences will be discussed below. Concerning the similarities reference is made to the previous description. In contrast to the embodiment of FIG. Ia, the receiving bore 28 is not formed as a stepped bore, so that the electromagnet 21 is not supported in the axial direction within the receiving bore 28. As a support surface for the electromagnet 21 is rather the electromagnet 21 facing planar surface 36 of the throttle body. 4

FIGS. 3a and 3b show a further exemplary embodiment of an injector 1. The anchor plate 22 and the valve sleeve 23 are designed as separate components. The anchor plate 22 is formed by a simple symmetrical disc. In this case, the armature plate 22 of the valve spring 33 which is received in the central passage opening 32 of the electromagnet 21, spring-loaded axially in the direction of an adjusting ring 36, which in turn is supported in the axial direction of the valve sleeve 23, thereby the flat conical valve seat 24th is pressed. Anchor plate 22, adjusting ring 36, via whose thickness selection the anchor plate stroke is adjustable, and valve sleeve 23 are penetrated by the pin 25, which is supported on the injector body 22, more precisely on the bottom 37 of the bore 29 in the injector body 2. In the adjusting ring 36, a concave recess 38 is provided, via which the adjusting ring 36 and thus the armature plate 22 on the convex, for the recess 38 formkongruenten end face 39 of the valve sleeve 23 is supported. Via a coil spring 40, which is supported on the one hand at the bottom 41 of a bore 42 in the throttle body 4 and on the other hand on an annular shoulder 43 of the valve sleeve 23, the valve sleeve 23 is spring-loaded in the opening direction. Thus, the electromagnetic actuator 20 only has to overcome the difference of the spring forces, the valve spring 33 and the weaker spring 40.

The armature plate 22 is accommodated within a retaining sleeve 44, which is supported on the throttle body 4 in the axial direction. By the spring element 30, the electromagnet 21 is spring-loaded on the retaining sleeve 44 and pressed together with the retaining sleeve 44 on the throttle body 4. From an annular shoulder 45 within the holding sleeve 44, a parallel surface is formed to the bottom surface 46 of the anchor plate 2 in the plane of the drawing.

The position of the armature plate 22 within the retaining sleeve 44 and below the electromagnet 21 is shown in detail in Fig. 3b. It can be seen that between the peripheral wall 26 of the anchor plate 22 and the inner wall 47 of the holding sleeve 44, a radial gap 48 is provided. At the same time, when the surface 45 of the anchor plate 22 is exactly parallel to the parallel surface (paragraph 45) of the holding sleeve 44, a full axial gap 49 is present. At the same time, when the electromagnet 21 is not energized, an axial stroke gap 50 is provided between the electromagnet 21 and the armature plate 22. The lower axial gap 49 (orientation gap) is realized in that the adjusting ring 36 slightly projects beyond the shoulder 45 in the axial direction. This ensures that the spring force of the valve spring 33 is introduced into the valve sleeve 23 and not in the paragraph 45. The Hubspalt 50 ensures a free Alignment between solenoid 21 and armature plate 22, whereas the ball-joint connection between the valve sleeve 32 and adjusting 36 allows large-scale power transmission between the armature plate 22 and valve sleeve 23 and a compensation of angular errors.

The exemplary embodiment according to FIG. 4 a substantially corresponds to the exemplary embodiment according to FIG. 3 a, so that reference is made to the previous description with regard to the similarities. In contrast to the embodiment of FIG. 3a, the valve seat surface 24 is less inclined, whereby the valve sleeve 23 can slip more easily in the radial direction. To prevent this, a guide sleeve 51 is provided, which is arranged radially adjacent to the valve seat surface 24 and the valve sleeve 23 leads over a small axial portion. The guide sleeve 51 is centered with the valve closed by the valve sleeve, which in turn is centered by the valve seat. In the open state, the guide sleeve maintains its position, since it is spring-loaded by the coil spring 40 in the direction throttle body 4 and thus held in position.

In order to allow a fuel drain from the drain passage 16 via the interior 52 of the valve sleeve 23 in the low-pressure chamber 19, the valve sleeve is in a lower portion, as shown in Fig. 4b, with three staggered by 120 °, extending in the axial direction flats 53 provided by the axial direction between the guide sleeve 51 and valve sleeve 23 channels 54 are formed, can flow through the fuel in the low-pressure chamber 19. In Fig. 4c, a flattening 53 of the valve sleeve 23 is shown in a side view.

Additionally or alternatively, grooves 55 extending in the axial direction can be provided on the inner circumference of the guide ring 21, through which the fuel can flow into the low-pressure space 19.

FIG. 5 a shows a further exemplary embodiment of an injector 1.

In contrast to the embodiments described above, the valve spring 33 is not received within the passage opening 32 in the electromagnet 21, whereby the passage opening 32 may have a smaller cross section, which in turn higher magnetic forces can be realized with the same width of the electromagnet 21.

As in the exemplary embodiment, the anchor plate 22 is designed in one piece with the valve sleeve 23, as shown in FIG. In contrast to the exemplary embodiment according to FIG. 1 a, a radial play is provided between the peripheral wall 26 of the anchor plate 22 and the circumferential wall 56 of a bore 57 within a valve body 58. The valve body 28 is arranged in the axial direction between the valve body 2 and the throttle body 4. Through the valve body 58 passes through the supply line 15, which opens into a pocket 59, from where under high pressure fuel on the one hand in the pressure chamber formed as an annular space 8 and the inlet channel 14 with inlet throttle 15 in the control chamber 12 and from there via the Outflow channel 16 with outlet throttle 17 can flow into the low-pressure chamber 19. From there leads a return line, not shown continue to a storage tank. The assembly of anchor plate 22 and valve sleeve 23 receives a two-piece formed bolt 25, wherein the bolt 25, which also passes through the electromagnet 21, on the injector 2 supports. An upper bolt part 60 in this case has a smaller cross-section than an axially adjacent lower bolt part 61. The lower bolt part 61 is supported via a convex-concave pairing 62 (a kind of ball joint) on the upper bolt part 60, whereby angular errors can be compensated.

The valve spring 33, which acts on the valve sleeve 23 in the closing direction by spring force, is supported, on the one hand, on a shoulder 63 within the valve body 58 and, on the other hand, on a guide ring 64. The guide ring 64 in turn is supported on a securing ring 65 in the axial direction, wherein the securing ring 65 is held in a circumferential groove 66 in the region of the lower end of the valve sleeve 23 in the plane of the drawing. The valve sleeve 23 cooperates with a flat seat seat formed valve seat 24. The valve sleeve 23 is automatically aligned parallel to the surface of the throttle body 4 by the valve spring force acting on the valve sleeve 23 just above the valve seat surface 24. This ensures the parallelism in the axial gap 50 between the armature plate 22 and the electromagnet 21. The valve sleeve 23 is guided on the inner circumferential wall 67 of a valve body bore 68 via the guide ring 64, which serves as a setting disk for adjusting the spring force of the valve spring 33. A guide of the entire outer surface of the valve sleeve 23 is not necessary. As a result, only a small portion of the inner peripheral wall 67 of the valve body bore needs to be ground. The positioning of the valve sleeve 23 over the guide tion ring 64 in the radial direction must be so accurate that the radial gap between the peripheral wall of the anchor plate 22 and valve body is fully present, ie over 360 ° to avoid disturbing forces and tilting moments on the armature plate 22 and thus on the valve sleeve 23. As a result, the guide surfaces on the valve sleeve 23 and the guide ring 58 and the inner circumference 67 can be manufactured with relatively large tolerances.

In Fig. 5b, the unit of anchor plate 22 and valve sleeve 23 is shown in a perspective view, wherein the valve sleeve 23 is wrapped over an axial portion of the valve spring designed as a helical spring 33 which extends radially in the drawing plane down to the guide ring 64 and this in turn supported on the retaining ring 65. It can be seen that the retaining ring 65 is supported in the circumferential groove 66 in the region of the lower end of the valve sleeve 23.

Claims

claims 1. injector for injecting fuel into combustion chambers of internal combustion engines, in particular common rail injector, with at least one armature plate (22) and at least one electromagnet (21) comprising an electromagnetic actuator (20) having a bolt (25) enclosing valve sleeve (23) of a control valve (18) is axially actuated relative to a valve seat surface (24), wherein by means of the control valve (18) a fuel drain path from a control chamber (12), which with a fuel supply serving pressure channel ( 13) is in hydraulic communication, lockable and can be released, which in turn influenced the fuel pressure in the control chamber (12) and thereby one with the control chamber (12) operatively connected nozzle needle (7) between a Fuel flow releasing opening position and a Closed position is adjustable, characterized in that the bolt (25) in the axial direction of the control chamber (12) away on an injector component, in particular an injector body (2), arranged supportingly attached to this, or is integrally formed therewith. 2. An injector according to claim 1, characterized in that in a throttle body (4) of the pressure channel (13) with an inlet throttle (14) for supplying the control chamber (12) with fuel and / or a flow channel (16) with outlet throttle (17). for the hydraulic connection of the control chamber (12) with the control valve (18) are introduced. 3. Injector according to one of claims 1 or 2, characterized in that the valve sleeve (23) is formed integrally with the anchor plate (22), and that both the anchor plate (22) and the valve sleeve (23) within a receiving bore (23). 28), in particular in the throttle body (4), are received, wherein the valve sleeve (23) is arranged at a radial distance from the receiving bore wall and the armature plate (22) is guided with its lateral peripheral wall (26) on the receiving bore wall. 4. Injector according to one of the preceding claims, characterized in that the valve seat surface (24) is formed partially spherical. 5. Injector according to one of claims 3 or 4, characterized in that the electromagnet (21) axially directly on a flat surface of the throttle body (4) or on a shoulder (31) of the trained as Stufenboh- tion receiving bore (28) within the throttle body (4) is arranged supporting. 6. Injector according to one of claims 1 or 2, characterized in that the anchor plate (22) and the valve sleeve (23) are formed as separate components, and that the bolt (25), the anchor plate (22) is arranged passing through, and that the armature plate (22) is spring-loaded by means of a valve spring (33) in the direction of the valve sleeve (23) and thereby towards the valve seat surface (24), and that a weaker spring (40) counteracting the valve spring (33) is provided is that the spring force is applied to the valve sleeve (23) in the direction of the anchor plate (22). 7. An injector according to claim 6, characterized in that the armature plate (22) directly or via an adjusting ring (36) on the valve sleeve (23) is supported, whereby between the armature plate (22) and valve sleeve (23) or between the adjusting ring (36) and valve sleeve (23) a convex-concave pairing (62) is realized. 8. Injector according to one of claims 6 or 7, character- ized in that the anchor plate (22) between the Electromagnet (21) and an axially spaced parallel surface (45) is arranged, and that between the armature plate (22) and a peripheral this encompassing component a radial clearance is provided, and that in exactly parallel alignment between armature plate (22) and parallel surface (45 ) and at the same time on the valve seat surface (24) displaced valve sleeve (23) an axial gap (49) between the armature plate (22) and parallel surface (45) remains. 9. Injector according to one of claims 1 or 2, characterized in that the valve sleeve (23) passes through a guide ring (64) and is guided over this at a peripheral wall surrounding this. 10. An injector according to claim 9, characterized in that a valve spring (33) the feederkraftbeaufschlagt the guide ring (64) in the direction of an integrally formed with the valve sleeve (23) or connected to this support surface (65).