EP2212542A1

EP2212542A1 - Electromagnetically actuated valve

Info

Publication number: EP2212542A1
Application number: EP08804555A
Authority: EP
Inventors: Ferdinand Reiter
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2007-10-24
Filing date: 2008-09-22
Publication date: 2010-08-04
Anticipated expiration: 2028-09-22
Also published as: CN101910609B; JP2013007387A; US20110100332A1; JP5627654B2; BRPI0817774A2; EP2212542B1; WO2009053191A1; JP2011501035A; CN101910609A; DE102007050817A1; US9038604B2; JP5517942B2

Abstract

The invention relates to an electromagnetically actuated valve, particularly a fuel injection valve for fuel injection systems of internal combustion engines. The valve comprises an electromagnetic actuating element having a magnetic coil (1), a stationary core (2), a valve casing (5), and a movable armature (17) for activating a valve-closing body (19), which interacts with a valve seat surface (16) provided on a valve seat body (15). A sleeve-shaped guide body (62) is inserted into an inner longitudinal bore (23) of the armature (17) and into an inner flow bore (28) of the interior pole (2), wherein the guide body (62) is stationary in the armature (17) or in the interior pole (2) and is loosely guided in the other component. The valve is suitable as a fuel injection valve, particularly for use in fuel injection systems of mixture-compressing, spark-ignited internal combustion engines.

Description

description

title

Electromagnetically actuated valve

State of the art

The invention is based on an electromagnetically actuated valve according to the preamble of the main claim.

In the figures 1 and 2, a known electromagnetically operable valve in the form of a fuel injection valve of the prior art is shown, which has a conventional structural design of a circumferential guide collar on the outer periphery of a movable armature. During its axial movement of the armature slides with its guide collar in the inner opening of a valve sleeve along its inner wall, which is insofar guided within the valve sleeve, whereby tilting or tilting of the armature is avoided.

Further variants of the guidance of a movable armature of an electromagnetically operated fuel injection valve are likewise known. Thus, DE 41 37 994 Al it can be seen that an at least partially encircling guide nose can be embossed in a nozzle carrier, whereby this guide nose for guiding the armature on the outer circumference provides. It is also known to emboss several distributed over the circumference guide lugs in the region of a magnetic throttle point of an elongated valve body, which guide the armature during its axial movement (DE 195 03 820 Al). From DE 100 51 016 Al a fuel injection valve is already known, in which on the outer circumference of the armature guide collar segments are formed, which are located in the region of the strongest radial magnetic flux. Advantages of the invention

The electromagnetically actuated valve according to the invention with the characterizing features of claim 1 has the advantage of a compact design. The valve is particularly inexpensive to produce, since the anchor guide is particularly simple and inexpensive realized. According to the invention, a guide body is introduced into an inner longitudinal bore of the armature and into an inner flow bore of the inner pole, wherein the guide body is fixed in the armature or inner pole and is loosely guided in the respective other component. The contact surface serving the guide is advantageously reduced compared to the solutions of the prior art. The guide is on a smaller diameter level. An improvement in function is given insofar as disadvantageous radial forces are avoided because of the guide-free outer circumference of the armature.

The measures listed in the dependent claims advantageous refinements and improvements of the claim 1 electromagnetically actuated valve are possible.

To make the guide body sleeve-shaped and thin-walled and made of a material with austenitic structure is particularly advantageous. In particular, the guide body as a deep-drawn part is cost-effective. The austenitic material has the advantage that there is no magnetic short circuit between the inner pole and the armature.

It is advantageous to provide a Verdrehfixierung, in which in a corresponding manner at the armature or inner pole and the guide body torsional forming functional elements are mounted. The rotational fixation is advantageous for the constancy of functional values of the valve, such as flow and angle and the wear behavior. drawing

Embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description. Show it

1 shows an electromagnetically actuated valve in the form of a fuel injection valve according to the prior art, FIG. 2 shows a partial view II of FIG. 1 of the known fuel injection valve according to the prior art, which identifies the region relevant to the invention,

Figure 3 is a partial view of a valve according to the invention

Figure 4 is a section along the line IV-IV in Figure 3 with a first

Variant of the anchor and

Figure 5 shows a section along the line V-V in Figure 3 with a second embodiment of the armature.

Description of the embodiments

In the figure 1 is exemplified an electromagnetically operable valve in the form of a fuel injection valve for fuel injection systems of mixture-compression, spark-ignited internal combustion engines according to the prior art for a better understanding of the invention.

The valve has a surrounded by a magnetic coil 1, serving as an inner pole and partially as a fuel flow largely tubular core 2. The magnetic coil 1 is of an outer, sleeve-shaped and stepped running, z. B. ferromagnetic valve jacket 5, which is an outer pole serving as outer magnetic circuit component, completely surrounded in the circumferential direction. The magnetic coil 1, the core 2 and the valve shell 5 together form an electrically excitable actuator.

While embedded in a bobbin 3 magnetic coil 1 with a winding 4 surrounds a valve sleeve 6 from the outside, the core 2 in an inner, concentric with a valve longitudinal axis 10 extending opening 11 of the valve sleeve. 6 brought in. The valve sleeve 6 is elongated and thin-walled. The opening 11 serves, inter alia, as a guide opening for a valve needle 14 which is axially movable along the valve longitudinal axis 10. The valve sleeve 6 extends in the axial direction, for example over approximately half the total axial extent of the fuel injection valve.

In addition to the core 2 and the valve needle 14, a valve seat body 15, which is attached to the valve sleeve 6, e.g. is fastened by means of a weld 8. The valve seat body 15 has a fixed valve seat surface 16 as a valve seat. The valve needle 14 is formed for example by a tubular armature 17, a likewise tubular needle portion 18 and a spherical valve-closing body 19, wherein the valve-closing body 19, for. is firmly connected to the needle portion 18 by means of a weld. At the downstream end side of the valve seat body 15 is a e.g. cup-shaped spray orifice plate 21 is arranged, the bent and circumferentially encircling retaining edge 20 is directed against the flow direction upwards. The solid connection of the valve seat body 15 and spray disk 21 is z. B. realized by a circumferential tight weld. In the needle portion 18 of the valve needle 14, one or more transverse openings 22 are provided, so that the armature 17 in an inner longitudinal bore 23 by flowing fuel escape to the outside and on

Valve closure body 19 e.g. can flow along flats 24 to the valve seat surface 16 along.

The actuation of the injection valve takes place in a known manner electromagnetically. For axial movement of the valve needle 14 and thus to open against the

Spring force of an acting on the valve needle 14 return spring 25 and

Closing the injector serves the electromagnetic circuit with the

Solenoid 1, the inner core 2, the outer valve shell 5 and the armature 17th

The armature 17 is aligned with the valve closing body 19 facing away from the end of the core 2. Instead of the core 2, e.g. also serving as a pole

Cover part, which closes the magnetic circuit, be provided.

The spherical valve closing body 19 acts with the valve seat surface 16 of the valve seat body 15, which tapers frustoconically in the flow direction together, which is formed in the axial direction downstream of a guide opening in the valve seat body 15. The spray perforated disc 21 has at least one, for example, four ejection openings 27 formed by erosion, laser drilling or punching.

Among other things, the insertion depth of the core 2 in the injection valve is crucial for the stroke of the valve needle 14. The one end position of the valve needle 14 is fixed at non-energized magnetic coil 1 by the system 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 energized solenoid 1 by the system of

Ankers 17 at the downstream core end results. The stroke is adjusted by an axial displacement of the core 2, which is subsequently connected according to the desired position fixed to the valve sleeve 6.

In a concentric with the valve longitudinal axis 10 extending flow bore 28 of the core 2, which serves to supply the fuel in the direction of the valve seat surface 16, except for the return spring 25, an adjustment in the form of an adjusting sleeve 29 is inserted. The adjusting sleeve 29 is used to adjust the spring preload applied to the adjusting sleeve 29 return spring 25, which in turn is supported with its opposite side to the valve needle 14 in the region of the armature 17, wherein an adjustment of the dynamic Abspritzmenge with the adjusting sleeve 29. A fuel filter 32 is disposed above the adjusting sleeve 29 in the valve sleeve 6.

The inlet end of the valve is made of a metal

Fuel inlet 41 formed, which is surrounded by this stabilizing, protective and surrounding Kunststoffumspritzung 42. A concentric to the valve longitudinal axis 10 extending flow bore 43 of a pipe 44 of the fuel inlet nozzle 41 serves as a fuel inlet. The plastic extrusion coating 42 is sprayed, for example, in such a way that the plastic directly surrounds parts of the valve sleeve 6 and of the valve jacket 5. A secure seal is achieved, for example via a labyrinth seal 46 on the circumference of the valve shell 5. To Kunststoffumspritzung 42 includes a mitangespritzter electrical connector 56th Figure 2 shows a partial view II of Figure 1 of the known fuel injection valve according to the prior art, which identifies the invention relevant area. In particular, the guide area of the armature 17 becomes clear. On the outer circumference of the movable armature 17 has in a known manner a circumferential guide collar 60 or more distributed over the circumference nubby or nose-like guide collars 60, to guide him in the valve sleeve 6 safely and without jamming. Conversely, the guide collar 60 or the guide collars 60 may also be integrally formed on the valve sleeve 6, in which case the outer circumference of the anchor 17 is designed with a constant diameter cylindrical. The return spring 25 accordingly has a clear clearance to the wall of the flow bore 28 in the core 2 or to the wall of the longitudinal bore 23 in the armature 17.

Figure 3 shows a partial view of a valve according to the invention, in which the guide of the armature 17 is moved from its outer periphery inwardly into the longitudinal bore 23. According to the invention, the armature 17 is guided during its axial longitudinal movement through a sleeve-shaped guide body 62. The sleeve-shaped guide body 62 is designed thin-walled, wherein it is in the guide body 62 because of its cost-effective manufacturability, in particular a deep-drawn part. Advantageously, the guide body 62 is made of a material with an austenitic structure, so that no magnetic short circuit between the core 2 and armature 17 is formed. An austenitic material also meets the requirement for a substance with high electrical resistivity to avoid eddy currents.

Two variants of the attachment of the guide body 62 are conceivable. In a first variant, the guide body 62, as shown in Figure 3, fixedly installed in the flow bore 28 of the core 2, while the axially movable armature 17 can move along the guide body 62, which dips into the inner longitudinal bore 23 of the armature 17. When energized solenoid 1 is the

Anchor 17 is attracted toward the core 2 to its stop surface. About the size of this to be traversed by working gap 63, the stroke of the valve needle 14 is defined. When the valve is closed, so the system of the valve closing body 19 on the valve seat surface 16, the size of the working gap 63 is maximum. To this extent the guide body 62 must be able to dip at least into the longitudinal bore 23 of the armature 17, ie the available relative movement length of the guide body 62 in the longitudinal bore 23 is equal to or greater than the maximum working gap 63. The bearing is in the core 2 in this embodiment; the guide, so the floating bearing is located in the anchor 17th

In a second variant, the guide body 62 is fixedly installed in the longitudinal bore 23 of the armature 17, wherein then the axially movable armature 17 moves together with the guide body 62, which dips into the inner flow bore 28 of the core 2. When the solenoid coil 1 is energized, the armature 17 is tightened in the direction of the core 2 up to its stop surface. When the valve is closed, so the system of the valve closing body 19 on the valve seat surface 16, the size of the working gap 63 is maximum. To this extent, the guide body 62 must be able to dive at least into the flow bore 28 of the core 2, i. the available free travel length of the guide body 62 in the flow bore 28 is equal to or greater than the maximum working gap 63. The fixed bearing is in this embodiment in the armature 17; the guide, so the movable bearing is located in the core 2. In both variants described, the guide body 62 on the fixed bearing side, for. attached by pressing.

Figure 4 shows a section along the line IV-IV in Figure 3 with a first embodiment of the armature 17. In this case, the sleeve-shaped guide body 62 is circular, which dips into a likewise circular longitudinal bore 23 of the armature 17 or is fixed in it.

However, it is also conceivable to provide in the armature 17 or in the core 2 a Verdrehfixierung that guarantees a rotationally secure position of the armature 17 during its axial movement. Figure 5 shows a section along the line VV in Figure 3 with a second embodiment of the armature 17, which includes an exemplary Verdrehfixierung. The guide portion of the guide body 62 is designed for example as a hexagon, which dips into a correspondingly shaped longitudinal bore 23 of the armature 17. Forms the anchor 17, the fixed bearing side, the Verdrehfixierung may be provided in the core 2 in a comparable manner. The Verdrehfixierung can alternatively also on other flattenings, multiple edge, Recesses or bulges, which are mounted in a corresponding manner on the armature 17 or core 2 and on the guide body 62, be realized. Verdrehfixierung is generally advantageous for the constancy of functional values of the valve, such as flow and angle and the wear behavior.

Claims

claims

1. Electromagnetically actuated valve, in particular fuel injection valve for fuel injection systems of internal combustion engines, with a valve longitudinal axis (10), with an excitable actuator in the form of an electromagnetic circuit with a magnetic coil (1), an inner pole (2), an outer magnetic circuit component (5) and a movable armature (17) for actuating a valve closing body (19) cooperating with a valve seat surface (16) provided on a valve seat body (15), characterized in that a guide body (62) is inserted into an inner longitudinal bore (23) of the armature (17) and in an inner flow bore (28) of the inner pole (2) is introduced, wherein the guide body (62) in the armature (17) or inner pole (2) is fixed and is loosely guided in the other component.

2. Electromagnetically actuated valve according to claim 1, characterized in that the guide body (62) is sleeve-shaped and thin-walled.

3. Electromagnetically actuated valve according to claim 1 or 2, characterized in that the guide body (62) is made of a material having an austenitic structure.

4. Electromagnetically actuated valve according to one of the preceding claims, characterized in that the available relative movement length of the inner pole (2) fixed

Guide body (62) in the longitudinal bore (23) of the armature (17) is equal to or greater than the maximum working gap (63) between the inner pole (2) and armature (17).

5. Electromagnetically actuated valve according to one of claims 1 to 3, characterized in that the available free movement length of the armature (17) fixed guide body (62) in the flow bore (28) of the inner pole (2) equal to or greater than the maximum working gap (63) between the inner pole (2) and armature (17 ).

6. Electromagnetically actuated valve according to one of the preceding claims, characterized in that the guide body (62) is fixed on the fixed bearing side by means of press-fitting.

7. Electromagnetically actuated valve according to one of the preceding claims, characterized in that the guide body (62) is circular.

8. Electromagnetically actuated valve according to one of the preceding claims, characterized in that a Verdrehfixierung is provided in the form of flats, polygons, depressions or bulges, in a corresponding manner on the inner longitudinal bore (23) of the armature (17) or the inner flow bore (28) of the inner pole (2) and on the guide body (62) are mounted.

9. Electromagnetically actuated valve according to one of the preceding claims, characterized in that the outer circumference of the armature (17) is unbundled.