JP2009535585A - Solenoid valve with material-connected anchor connection - Google Patents

Abstract

The invention relates to a method for production of an armature assembly (24) and an armature assembly (24). The armature assembly (24) is of application in a solenoid VALVE (14) for operation of a fuel injector (10). The solenoid valve (14) comprises an energisable solenoid coil (22). An outer moulding (44; 54, 58, 60) is provided on The circumference (52) of an armature pin (28) or a hydraulic switch element (28). An armature plate (26) is produced in the region of The outer moulding (44; 54, 58, 60) by means of The MIM method (Metal Injected Molding).

Description

Prior art DE 19650865A1 relates to a solenoid valve. Here, the magnet anchor of this electromagnetic valve is composed of a number of members, and has an anchor disk and an anchor bolt. The anchor bolt is guided in the slide part. In order to prevent the anchor disk from swinging after the solenoid valve is closed, the magnet anchor is provided with a damping device. With this device exactly the required short solenoid valve switching time is observed. Solenoid valves are used in particular in injection devices with a high-pressure storage injection system (common rail). As a modern solution described in DE 19650865A1, anchor plates are guided on anchor bolts. On the one hand, the anchor plate is forced by a return spring and on the other hand is guarded by an adjusting disc. This adjusting disk is inserted into the notch on the peripheral surface of the anchor bolt.

  In the solution described in DE 1993 2781 A1, an anchor assembly is proposed. Here, the anchor plate is fixed to the anchor bolt via a guide bolt. The guide bolt is guided in a slot formed in the anchor bolt at the guide portion of the anchor plate. The anchor plate is thus accommodated with play with respect to the circumferential surface of the anchor bolt.

  Solenoid valves are used as actuators in high pressure storage injection systems (common rails) for cost reasons and for structural space reasons. The magnetic circuit of the solenoid valve includes a magnet coil and an anchor accommodated in a magnet core. Here, this anchor is connected to the switching member to be moved. There are several ways to connect between the anchor and the switching member. In DE 19650865A1, the anchor bolt of the anchor plate is mounted on the guard disk described above. The dynamic characteristics of the solenoid valve are adversely affected by the unavoidable play between the guard disc, the notch in the end face of the anchor plate, and the notch provided on the peripheral surface of the anchor bolt for accommodating the guard disc. Is given.

  In a one-piece anchor assembly in which the anchor plate and anchor bolt are manufactured from the same material, the material selected is a compromise between the wear requirements to be observed and the magnetic circuit design of the magnetic circuit. It has the disadvantage of being. Anchor assembly solution, consisting of two parts connected by material, presses the anchor plate onto the anchor bolt or forms a peel rivet connection (Schaelniet-Verbindung) between the anchor plate and the circumferential surface of the anchor bolt It is to be. Here, the anchor group has an anchor plate that moves relative to the anchor bolt. The disadvantage of this solution is the high demand for the fine geometry of the components, ie anchor plates and anchor bolts, prior to material connection. The connection of the two-part anchor assembly between the anchor plate and the anchor bolt is also possible by a material connection type seaming method such as welding or gluing. The disadvantage of such a connection method is that, on the one hand, it takes a lot of work to install, and on the other hand, only a slight strength is obtained, and the precision with which such a connection is formed is limited. is there.

  In the case of an anchor assembly consisting of two parts, ie in the case of an anchor assembly consisting of two separate structural groups (anchor plates and anchor bolts), the following advantages generally occur. That is, there is an advantage that the material for the magnetic circuit, that is, the material of the anchor plate and the material of the sealing function carried by the anchor bolt can be optimally selected according to each requirement. Therefore, in consideration of the above-mentioned peripheral conditions, efforts are made to use an anchor assembly composed of two members. These are optimally selected for the substance according to the function.

SUMMARY OF THE INVENTION The present invention provides MIM (metal injection molding) for anchor plates belonging to the magnetic circuit of solenoid valves between switching members that directly open or close anchor bolts or pneumatic-hydraulic connections (Pneuhydraulische Verbindung). Propose to consist of technology. For this purpose, at least one notch, for example in the form of a groove or notch, is added to the peripheral surface of the anchor bolt, for example, or to the peripheral surface of the hydraulic switching member, in the region of the connection location with the anchor plate. This notch is formed in a complementary manner to the geometrical shape of the outer circumference of the anchor bolt or hydraulic switching member in the region of the opening of the anchor plate through which the anchor bolt or hydraulic switching member passes. be able to.

  The geometry of the outer circumferential surface of the anchor bolt or hydraulic switching member is easily manufactured. Here, the demand for tolerances is low. In the case of a solenoid valve, the gap required for function is adjusted by the MIM tool and occurs during metal injection molding, ie during the injection of melts of metal material. In addition, when the anchor bolt or the hydraulic switching member is spliced through the MIM method, the necessary post-treatment, for example, re-polishing for adjusting the gap at the end face of the anchor plate is not necessary. Ideally, the anchor plate is formed as a component of the porcelain circuit, retreating with respect to the normally flat end face of the anchor bolt or hydraulic switching member. Accordingly, a step is generated between the anchor bolt penetrating the anchor plate or the end face of the hydraulic switching member. This step defines a gap between the end face of the anchor plate facing the magnet core and the end of the magnet core facing the anchor plate.

  The material of the anchor bolt or hydraulic switching member is optimally selected according to the wear point of view. A magnetic material is preferably selected for the anchor plate. This provides a high magnetic force and avoids eddy current losses. In the anchor plate, the opening or notch is integrally formed with an arbitrarily selectable geometric shape for mass reduction and flow optimization. This is constructed without post-processing the anchor plate. When the solenoid valve proposed by the present invention is used in a fuel injector, the controlled amount controlled from the control space capable of pressure relief in the fuel injector through such an opening or notch is reduced to the low pressure side recirculation. It flows into the part without great flow resistance. Here, the hollow space in which the electromagnetic valve is accommodated is used as a low-pressure side recirculation part for controlling the amount of fuel discharged from the control space.

  The connection produced by the MIM method between the anchor bolt or hydraulic switching member and the integrally formed anchor plate is such that when the hydraulic switching member or anchor bolt collides with the enclosing closure member, the valve Absorbs the acceleration force generated when it collides with the seat. Depending on the manufacturing process and the value of the resulting acceleration force, a plurality of notches, notches on the inner shell of the opening or perforation through the anchor plate, complementary to and complementary to the anchor bolt or hydraulic switching member Alternatively, a geometry with one or more flanges or undercuts is formed, which ensures that acceleration forces are absorbed. Advantageously, by using the MIM method, a metal component made of a metallic material can be formed into a component made of a different material. In this way, the individual components to be spliced together can be selected taking into account the optimum material properties tailored to the field of use.

FIG. 1 shows a first embodiment of a connection proposed by the present invention in an anchor assembly in a pressure compensated 2/2 valve,
Figures 2.1, 2.2, 2.3 and 2.4 show different embodiments of the MIM connection of the anchor assembly,
FIG. 3 shows an anchor assembly proposed by the present invention for use with an externally open valve (A-valve),
FIG. 4 shows the MIM connection proposed by the present invention in an anchor assembly for use with a sleeve valve.

Embodiment FIG. 1 shows a pressure-compensated 2/2 valve. The fuel injector is operated by this valve. The anchor assembly includes an anchor plate and an anchor bolt or a hydraulic switching member. The anchor plate is integrally formed with the anchor bolt by MIM connection.

  In FIG. 1, it is shown that a fuel injector 10 shown only partially here has an injector body 12. The fuel injector 10 includes a solenoid valve 14. The electromagnetic valve 14 includes a magnet pot 16. A magnet coil 22 is accommodated in the magnet pot. A through-opening 18 passes through the magnet pot 16. This through opening is for accommodating the retaining spring 20.

  Below the magnet pot 16, an anchor assembly 24 having an anchor plate 26 is provided. The anchor plate 26 is integrally formed with the anchor bolt or is integrally formed with the hydraulic switching member 28. The fixing between the anchor plate 26 and the anchor bolt 28 or the hydraulic switching member 28 takes place in the form of a MIM (metal injection molding) connection 30.

  The anchor bolt 28 or the hydraulic switching member 28 of the anchor assembly 24 is accommodated in the perforated portion 32 of the injector body 12. For example, when the anchor plate 26 of the anchor assembly 24 is connected to the hydraulic switching member 28, the lower end surface of the hydraulic switching member 26 is configured in the injector body 12 according to the embodiment. Works with seat 36. A hydraulic space 40 is provided in the injector body 12. In this hydraulic pressure space, for example, a pressure relief line 38 for pressure relief of a control space for operating the injection valve of the fuel injector 10 is provided.

  When the fuel injector 10 shown in FIG. 1 is energized, the anchor plate 26 or the anchor plate 26 integrally formed on the peripheral surface of the hydraulic switching member 28 is attracted by the magnet coil 22, and the valve seat 36 is fixed to the anchor bolt 28 or 28. It opens at the lower end face of the hydraulic switching member 28. As a result, a pressure relief of the hydraulic pressure space 40 occurs, and a control amount flows into the low pressure side reflux section 34 of the injector 12 through the pressure relief line 38, the hydraulic pressure space 40 and the opened valve seat 36.

  On the other hand, when the energization of the magnet coil 22 is released, the anchor assembly 24 is pressed into the valve seat 36 by the retaining spring 20 surrounded by the magnet pot 16. Therefore, the connection of the flow between the pressure relief line 38 for pressure relief of the control space and the low pressure side return portion 34 is blocked by the closed valve seat 36 in the injector body 12.

  Figures 2.1, 2.2, 2.3 and 2.4 show embodiments of MIM connections in the anchor assembly.

  FIG. 2.1 shows that the anchor bolt 28 or the hydraulic switching member 28 has a peripheral surface 52. An outer contour 44 is provided in a region where the anchor disk 36 of the anchor drilling portion 24 is integrally formed on the peripheral surface 52 of the anchor bolt 28 or the hydraulic switching member 28. Depending on the selected structure of the outer contour 44 at the peripheral surface 52 of the anchor bolt 28 or hydraulic switching member 28, a shape-connected connection 46 between the anchor plate 26 and the anchor bolt 28 or hydraulic switching member results. When the anchor plate 26 is integrally formed by the MIM method, the shape connection type connection 46 is formed by integrally forming the anchor plate 26 with the anchor bolt 28 or the hydraulic switching member 28. The anchor plate 26 of the anchor assembly 24 is preferably integrally formed on the anchor bolt 28 or the peripheral surface 52 of the hydraulic switching member 28 as follows. In other words, the protrusions 48 are integrally formed between the end face 50 of the anchor disk 26 and the end face of the anchor bolt 28 or the hydraulic switching member 28. This protrusion defines a gap between the end face 50 of the anchor disk 26 and the magnet coil 22 surrounded by the magnet core 16.

  If a magnetic material is advantageously selected for the anchor plate 26 in order to achieve a high magnetic force and a slight eddy current loss, the material forming the anchor bolt 28 or the hydraulic switching member 28 has an optimum wear. The optimum substance is selected. The anchor plate 26 is formed integrally with the anchor bolt 28 by forming the MIM connecting portion 30 by the MIM method. In this case, post-processing costs are minimized.

  FIG. 2.2 shows an alternative embodiment of the MIM connection of the anchor assembly 24.

  It can be seen from FIG. 2.2 that a peripheral notch 54 extends on the peripheral surface 52 of the anchor bolt 28 or the hydraulic switching member 28. A protrusion 56 is formed when the anchor plate 26 is formed integrally with the depth of the peripheral notch 54 on the peripheral surface of the anchor bolt 28 or the hydraulic switching member 28. After forming the anchor plate 26, the MIM connecting portion 30 is formed between the protrusion 56 and the peripheral notch 54 on the peripheral surface 52 of the anchor bolt 28 or the hydraulic switching member 28. The components are spliced together with a shape connection.

  Also in the embodiment of the anchor assembly 24 shown in FIG. 2.2, a protrusion 48 occurs between the end face 50 of the anchor plate 26 and the end face of the anchor bolt 28 or the hydraulic switching member 28. This protrusion defines a gap between the end face of the anchor plate 26 and the end face of the magnet coil 22 surrounded by the magnet pot 16 with the anchor assembly 24 attached.

  FIG. 2.3 shows another embodiment of an anchor assembly having a MIM connection.

  In this embodiment, a flange 58 is formed on the peripheral surface 52 of the anchor bolt 28 or the hydraulic switching member 28. The flange 58 protruding beyond the peripheral surface 52 of the anchor bolt 28 or the hydraulic switching member 28 forms a correspondingly structured notch on the inner surface of the anchor plate 26 when the anchor plate 26 is integrally formed. To do. Also in the embodiment of the anchor assembly 24 shown in FIG. 2.3, the protrusion 48 is adjusted by the MIM tool between the end face of the anchor bolt 28 or the hydraulic switching member 28 and the end face of the anchor plate 26. . Therefore, when the anchor plate 26 is integrally formed with the anchor bolt 28 or the hydraulic switching member 28, a gap is generated between the anchor plate 26 and the magnet coil 22 due to the corresponding shaft arrangement of the flange 58.

  FIG. 2.4 shows an embodiment of an anchor assembly proposed by the present invention. Here, at least one undercut portion 60 is formed on the peripheral surface 52 of the anchor bolt 28 or the hydraulic switching member 27. The undercut portion 60 on the peripheral surface 52 of the anchor bolt 28 or the hydraulic switching member 28 is surrounded by a material for manufacturing the anchor plate 26 by the MIM method when the anchor plate 26 is integrally formed. A shape connection 46 is formed between the anchor plate 26 and the anchor bolt 28 or the hydraulic switching member 28. This withstands high acceleration forces.

  The embodiment shown in FIGS. 2.1-2.4 of the anchor assembly 24 generally features a MIM connection 30 between the anchor plate 26 and the anchor bolt 28 or hydraulic switching member 28. The contour 44 of the anchor bolt 28 or the peripheral surface 52 of the hydraulic switching member 28 is easily manufactured in the starting part with few requirements for tolerances. The formation of the gap is adjusted with the MIM tool by a corresponding dimensional design of the protrusion 48 between the end face of the anchor plate 26 and the end face of the anchor bolt 28 or the hydraulic switching member 28, and during the MIM process, ie the liquid phase metal. When the material is injected or attached, the anchor plate 26 is integrally formed within the manufacturing frame of the MIM connecting portion 30. The material of the anchor bolt 28 or hydraulic switching member 28 is optimally selected with respect to wear characteristics, and the anchor plate 26 integrally formed with the anchor bolt 28 or hydraulic switching member 28 is optimally selected with respect to the magnetic properties of the material. . Although not shown in FIGS. 2.1 to 2.4, through openings, through perforations or notches can be provided to reduce the mass of the anchor plate 26. This reduces on the one hand the mass of the anchor plate 26 and on the other hand optimizes the discharge of the controlled amount from the control space.

  FIG. 3 shows the anchor assembly proposed by the present invention with a valve that opens to the outside (A-valve).

  From FIG. 3, it can be seen that the fuel injector 10 includes an injector head 12. The electromagnetic valve 14 is accommodated here. As shown in FIG. 3, the anchor assembly 24 includes an anchor plate 26, which is connected in form connection with an anchor bolt 28 or a hydraulic switching member 28 via an MIM connection 30. A valve seat surface that cooperates with the valve seat 36 of the injector body 12 is formed on the peripheral surface of the anchor bolt 28 or the hydraulic switching member 28. In FIG. 3, the anchor assembly 24 opens outward when the magnet coil 22 surrounded by the magnet pot 16 is energized. For this purpose, a circumferential taper 66 is formed on the circumferential surface of the anchor bolt 28 or the hydraulic switching member 28. This area is joined by a pressure relief line 38 not shown in FIG. 3 but for pressure relief of the control space constructed in the injector body 12. When the valve seat 36 is opened during energization of the magnet coil 22 and during the upward movement of the anchor assembly 24, the control volume is controlled by the circumferential taper 66 on the circumferential surface of the pressure relief line 38, the anchor bolt 28 or the hydraulic switching member 28. It is discharged to the low-pressure side reflux section 34 through the formed hollow space and the opened valve seat 36. Another reflux that is discharged through the guide leak is located at the lower end of the perforated portion 32 in the injector body 12. Here, the anchor bolt 28 or the hydraulic pressure switching member 28 is realized in a narrow allowable range. The following can be seen from the embodiment shown in FIG. That is, it can be seen that the upper end face of the anchor bolt 28 or the hydraulic switching member 28 cooperates with the stopper 62. Here, this stopper limits the opening stroke of the anchor assembly 24. In FIG. 3, the stroke stopper 62 is configured on the lower end surface of the magnet pot 16.

  FIG. 4 shows another embodiment of the anchor assembly proposed by the present invention with a sleeve valve.

  FIG. 4 shows a fuel injector 10 having a sleeve valve in the injector body 12 for pressure relief of the pressure relief line 38 in the control space. The anchor assembly 24 includes a valve sleeve 68 in this embodiment. This is guided through the MIM connection 30 together with the anchor plate 26. A cylindrical valve body 70 to which a force is applied via the retaining spring 20 is accommodated in the valve sleeve 38. A force is applied to the valve body 70 formed in a cylindrical shape via the retaining spring 20.

  When the magnet coil 22 of the magnet pot 16 is energized, the end face 50 of the anchor plate 26 is attracted. Accordingly, the valve sleeve 68 is detached from the valve seat 36 on the upper surface of the injector head 12. As a result, the junction 74 of the pressure relief line 38 in the control space formed in the injector body 12 is decompressed. This is because the meshing edge 76 formed on the lower end surface of the valve sleeve 68 is separated from the flat surface of the injector body 12. For example, in the embodiment shown in FIG. 4, the merge point 74 of the pressure relief channel 38 can merge into the dome-shaped ridge 72 on the flat surface of the injector body 12 of the fuel injector 10. When the meshing edge 76 of the valve sleeve 68 is retracted from the dome-shaped ridge 72, the control amount flowing out from the pressure relief channel 38 is lateral and from the injector body 12 of the fuel injector 10 in the direction of the low pressure recirculation part 34. Discharged.

First embodiment of the connection proposed by the present invention in an anchor assembly in a pressure compensated 2/2 valve Different embodiments of anchor assembly MIM connections An anchor assembly proposed by the present invention used in a valve (A-valve) that opens to the outside MIM connection proposed by the present invention in an anchor assembly for use with a sleeve valve

Claims (10)

A method of manufacturing an anchor assembly (24) for a solenoid valve (14) comprising:
The solenoid valve (14) has a magnet coil (22) that can be energized,
The method comprises the following steps:
a) forming an outer contour (44; 54, 58, 60) on the peripheral surface (52) of the anchor bolt (28) or hydraulic switching member (28);
b) forming an anchor plate (26) in the region of the outer contour (44, 54, 58, 60) by the MIM (metal injection molding) method;
A method of manufacturing an anchor assembly for a solenoid valve.   The method according to claim 1, wherein in step a) at least one notch (54) or groove is formed in the peripheral surface (52) of the anchor bolt (28) or hydraulic switching member (28).   The method according to claim 1, wherein in step a) at least one flange (58) or undercut (60) is formed on the peripheral surface (52) of the anchor bolt (28) or hydraulic switching member (28). .   In step b), the material of the anchor disk (26) and the outer contour (44; 54, 58, 60) of the peripheral surface (52) of the anchor bolt (28) or the hydraulic switching member (28); The method according to claim 1, wherein a connection by material connection is formed between the two.   In the step b), a protrusion (48) defining a gap is formed between the end face of the anchor bolt (28) or the hydraulic switching member (28) and the end face (50) of the anchor plate (26). The method of claim 1.   The method according to claim 1, wherein a through opening or notch is formed in the anchor disk (26) in step b). An anchor assembly (24) for a solenoid valve (14) comprising:
The anchor assembly has an anchor plate (26) and an anchor bolt (28) or a hydraulic switching member (28).
The anchor plate (26) is integrally formed with the anchor bolt (28) or the peripheral surface (52) of the hydraulic switching member (28) by the MIM method in the region of the outer contour (44; 54, 58, 60). ,
An anchor assembly for a solenoid valve, characterized in that   Anchor according to claim 7, wherein the anchor bolt (28) or the peripheral surface (52) of the hydraulic switching member (28) has at least one groove or at least one notch-shaped recess (54). Assembly.   On the peripheral surface (52) of the anchor bolt (28) or the hydraulic switching member (28), at least one raised portion (58, 60) protruding on the peripheral surface (52) is formed. The anchor assembly according to claim 7.   The anchor assembly according to claim 7, wherein the anchor plate (26) is manufactured from a magnetic material and the anchor bolt (28) or the hydraulic switching member (28) is manufactured from a material that is optimal with respect to wear.

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