WO2007012393A1

WO2007012393A1 - Electromagnetic actuating unit

Info

Publication number: WO2007012393A1
Application number: PCT/EP2006/006704
Authority: WO
Inventors: Christoph Ross; Josef Groeschel
Original assignee: Schaeffler Kg
Priority date: 2005-07-27
Filing date: 2006-07-08
Publication date: 2007-02-01
Also published as: DE102005034986A1

Abstract

The invention relates to an electromagnetic actuating unit (2) of a directional control valve (1), having an armature (16), which is mounted such that it can be axially displaced in an armature guide sleeve (12). In this case, provision is made for the individual components of the actuating unit (2) to be designed, arranged and assembled such that the mounting complexity and the costs during manufacture are reduced to a minimum, the intention being to reduce the hysteresis of the characteristic of the electromagnetic actuating unit (2) to a minimum. Furthermore, a method for the production of a composite component, at least comprising a coil former (5) and a profiled armature guide sleeve (12), is specified.

Description

Name of the invention

Electromagnetic actuator

description

Field of the invention

The invention relates to a magnetic actuator of a hydraulic We- geventils with a bobbin, an armature and an armature guide sleeve and a method for producing a composite component of a magnetic actuator, wherein the composite component comprises at least one bobbin made of plastic and a cup-shaped anchor guide sleeve.

Such directional control valves are used in internal combustion engines, for example for controlling hydraulic camshaft adjusters or switchable cam followers. The directional control valves consist of an electromagnetic actuator and a valve section. The valve section represents the hydraulic section of the directional control valve, wherein at least one inlet connection, at least one working connection and a tank connection are formed on the latter. By means of the electromagnetic actuator unit specific connections of the valve portion can be hydraulically connected to each other and thus the pressure medium flows are directed.

For the use of a directional control valve for controlling a camshaft adjuster, this is normally designed as a 4/3 proportional directional control valve. Such a proportional valve is disclosed for example in DE 199 56 160. The electromagnetic actuator is composed in this case of a first magnetic yoke, a coil, a second magnetic yoke, a housing, an armature and a connecting element, which receives an electrical connector, which serves to power the coil together.

The valve section consists of a valve housing and one axially therein displaceably arranged control piston. The valve housing is arranged within a receiving opening of the second magnetic yoke and fixedly connected thereto. On the outer circumferential surface of the valve housing four annular grooves are formed, which serve as pressure medium connections. Openings are formed in the groove surfaces of the annular grooves, as a result of which pressure medium can reach the interior of the valve housing. In the interior of the valve housing, a control piston is arranged axially displaceable, wherein the outer diameter of the control piston is adapted to the inner diameter of the valve housing. Furthermore, ring grooves are also formed on the control piston, via which adjacent pressure medium connections can be connected to one another.

The coil, the first and the second magnetic yoke are arranged coaxially within the housing of the electromagnetic actuator. The first and the second yoke are offset from each other in the axial direction. In the region between the first and the second magnetic yoke is located radially within the magnetic yokes of the armature, which is surrounded in the radial direction of the coil. The armature, the housing, the first and the second magnetic yoke form a flux path for the magnetic flux lines, which are caused by energizing the coil.

By energizing the coil, the armature is urged in the direction of the second magnetic yoke, wherein this movement is transmitted by means of an anchor rod attached to the control piston. This is now moved against a spring supported on the valve housing in the axial direction.

Directional valves for controlling switchable cam followers are usually designed as switching valves. Such a switching valve is, in one embodiment known as a 3/2-way valve, for example from DE 102 52 431 A1. The electromagnetic actuator in turn consists of a housing, an armature, a connection element, a first and a second magnetic yoke. The function and design of the electromagnetic actuator are largely analogous to that of the proportional valve. In this case, an inlet connection, a working connection and a tank connection are formed on the valve section. The working connection communicates via a respective valve seat designed as opening with both the inlet and the tank connection. Within the valve housing, a control piston is further arranged, on which two closing elements are formed. Each closing element can, depending on the position of the control piston within the valve housing, block or release the pressure medium flow through one of the valve seats. Depending on the axial position of the control piston, the working connection can thus be selectively connected to the inlet connection or to the tank connection. The axial position of the control piston is in turn set via the axial position of the armature relative to the second magnetic yoke.

DE 100 51 614 A1 discloses an electromagnetic actuating unit of a proportional valve. In this case, an armature guide sleeve is arranged within a magnetic yoke, in which an armature is received axially displaceable. The armature guide sleeve is cup-shaped with a bottom and a cylindrical portion formed with a cylindrical inner circumferential surface. The cylindrical inner circumferential surface serves to guide the armature, wherein the bottom limits the axial travel of the armature in an axial direction. The friction between the armature and the armature guide sleeve has a significant influence on the characteristics of the valve, especially on the occurring hysteresis. For this reason, the lowest possible friction is desirable. For this reason, friction-reducing measures, such as formations of the armature or bearing elements between these components are provided in the prior art. For example, it may be provided to provide the anchor with a sliding coating, such as Teflon. Between the bottom of the armature guide sleeve and the armature flush with the inner surface of the armature, a closed cavity is formed. This cavity can on the one hand, act by a negative pressure occurring in this, inhibiting movement of the armature away from the ground. Furthermore, in this cavity entering leakage oil a inhibiting axial movement of the anchor to the ground. In DE 100 51 614 A1 is proposed to solve this problem to provide the anchor with axial holes or axially extending grooves on the outer circumferential surface to allow pressure equalization between the cavities before and behind the anchor.

A disadvantage of the proposed embodiment, the high production costs, which are caused by the machining post-processing of the existing of a magnetizable material anchor. Furthermore, the coating of the armature necessitates an additional processing step, which has a disadvantageous effect on the production outlay and the costs.

Summary of the invention

The invention is therefore based on the object to avoid these disadvantages and thus to provide an electromagnetic actuator of a directional control valve, wherein the assembly effort is minimized and thus its production costs are reduced. Particular attention should be paid to a friction-optimized armature guide within an armature guide sleeve and the reduction of the hysteresis of the characteristic of the directional control valve. Specifically, the buildup of underpressure or overpressure within the armature guide sleeve should be counteracted due to the armature movement.

According to the invention the object is achieved in that the electromagnetic actuator of a hydraulic directional valve is designed with a bobbin, an armature and an armature guide sleeve, wherein the armature guide sleeve consists of a metallic, non-magnetizable material and is disposed within a cylindrical, blind hole-like recess of the bobbin, said the armature guide sleeve has a substantially cylindrical section, on the inner lateral surface of which at least three radially inwardly extending elevations extending in the axial direction are formed, the armature being axially displaceable is disposed within the armature guide sleeve and wherein the elevations serve as anchor treads.

Due to the formation of the elevations on an inner lateral surface of the armature guide sleeve, which are designed such that a cylindrical outer lateral surface of the armature bears against these, axially extending lubricant channels are formed in the circumferential direction between the elevations. The elevations serve the anchor as treads. On the one hand, due to the reduction of the contact surface of the armature on the armature guide sleeve, the occurring mixed friction between these components decreases. Furthermore, lubricant entering the armature guide sleeve can reach the treads via the lubricant channels. These measures reduce the friction occurring significantly, so that additional storage elements or costly post-processing of the anchor can be omitted. Another advantage of this embodiment is that at the same time the pressure equalization between the axially located to the armature cavities and the lubricant discharge can be done via the lubricant channels.

In a further development of the invention it is provided that the bobbin consists of plastic and rests against the outer lateral surface of the cylindrical portion. Due to the design of the bobbin and the armature guide sleeve as a composite component of the assembly effort of the electromagnetic actuator can be reduced. In addition, the Ankerführungs- sleeve is supported by the bobbin and thus protected against deformation by the anchor.

The armature guide sleeve can be made by means of a chipless forming process from a sheet metal part. It can be provided that the cylindrical see section has a wave-shaped profile in cross section. In this

Embodiment, the material of the bobbin on the outer man- telfläche the Ankeführungshülse engage in the wave-shaped profile of the surveys.

The formation of the armature guide sleeve from a sheet metal part by means of a chipless forming process, represents a cost-effective production method. It can be provided to manufacture the armature guide sleeve by means of a deep-drawing process from a sheet metal blank. Due to the formation of the elevations by means of a wavy in the circumferential direction of the armature guide sleeve profile, this can be made completely by means of chipless forming process. In this case, the rigidity of the armature guide sleeve, especially the elevations, be increased by the fact that arranged on the outer circumferential surface of the armature guide sleeve bobbin is adapted to the wave-like profile. In this case, the armature guide sleeve can be formed, for example, by means of an injection molding process on the outer circumferential surface of the armature guide sleeve.

In a specification of the invention, the radial extent is each

Elevation less than 0.06 mm.

Advantageously, the anchor guide sleeve is made of a stainless steel. The armature guide sleeve defines in the electromagnetic actuator an air gap between a magnetic yoke and the armature. To fulfill this function, it must be made of a non-magnetizable material. The use of a stainless steel is advantageous, which allows the use of non-cutting forming process.

The object is further achieved by the use of a method according to the invention for producing a composite component of a magnetic actuator of a directional control valve, wherein the composite component comprises at least one bobbin made of plastic and a cup-shaped anchor guide sleeve, wherein at the armature guide sleeve of the pot shape deviating functional element are formed, the extend into the interior of the pot shape, wherein the composite component is made starting from a cup-shaped sheet metal blank and wherein the bobbin by means of a plastic Forming process is formed within a plastic forming tool on the outer circumference of the armature guide sleeve, with the following method steps:

Arranging the sheet blank located on a lead punch within the forming tool, the otherwise the inner punch

Surface of the sheet metal blank adapted outer surface of the Vorhaltestempels is provided with corresponding to the functional elements recesses,

Filling of the plastic in the forming tool, filling of the tool by the plasticized, pressurized plastic, which pushes the corresponding areas of the sheet metal blank into the recesses of the Vorhaltestempels,

- curing the plastic and

- Removal of the finished composite component.

The molding method may be, for example, an injection molding method, a transfer molding method or a molding method.

In this case, it may be provided to carry out the indentations as beads formed on the axial end face of the lead-in punch, wherein the material of the sheet metal blank displaced into these beads forms stops for an armature sleeve arranged within the armature guide sleeve.

Additionally or alternatively, the indentations may be formed as arranged on the lateral surface of the Vorhaltestempels, axially extending grooves, wherein the displaced in these grooves material of the sheet metal blank forms running surfaces for an arranged within the armature guide sleeve anchor.

The manufacture of the existing of a plastic bobbin of the electromagnetic actuator takes place in the majority of cases by means of an injection molding process. Alternatively, other plastic molding methods, such as transfer molding or compression molding, may be used. The proposed procedure ensures that the bobbin is firmly connected to the anchor guide sleeve. Another advantage of this method is that of the pot-like shape deviating functional element of the armature guide sleeve during the formation of the bobbin, NEN without additional operations, NEN can be formed.

For this purpose, it is provided, starting from a pot-shaped sheet metal blank, during the injection molding, transfer molding or compression molding process, in which the bobbin is formed on the outer surface of the sheet metal blank to form the functional elements of the armature guide sleeve. Such functional elements may be, for example, arranged on the inner circumferential surface of the armature guide sleeve, radially inwardly projecting and axially extending elevations, which serve as running surfaces for the anchor. It is also conceivable to form stops for the armature which protrude into the armature guide sleeve at the bottom of the cup-shaped armature guide sleeve in the axial direction and restrict the axial displacement path of the armature in this direction.

For this purpose, a Vorhaltestempel is introduced into the interior of the sheet metal blank, whose outer contour corresponds to a negative of the desired outer contour of the armature guide sleeve. Sheet metal blank and Vorhaltestempel are arranged within a forming tool, in the interior of a cavity is formed, the outer contours of which correspond to the outer contours of the bobbin. Subsequently, the desired plastic in plasticized form, introduced under pressure, which fills the cavity. By the during the molding process in which the bobbin is formed, applied to the plasticized plastic pressure, the wall of the sheet blank is displaced into the recesses of the Vorhaltestempel. After curing of the plastic by cooling the mass or special hardening process, the finished composite component can be removed from the mold. As a result, the functional elements can be formed without additional costs and work steps during the production of the bobbin and the armature guide sleeve can be firmly connected to the bobbin. Brief description of the drawings

Further features of the invention will become apparent from the following description and from the drawings, in which embodiments of the invention are shown in simplified form. Show it

1 shows a first embodiment of an electromagnetic actuator according to the invention using the example of a 4/3-way proportional valve,

1a shows a second embodiment of an electromagnetic actuator according to the invention,

FIG. 2 shows a cross section along the line H-II in FIG. 1 a,

3 shows a third embodiment of an electromagnetic actuator according to the invention using the example of a 3/2-way switching valve,

FIG. 4 shows schematically a working step of a production method.

Detailed description of the drawing

FIG. 1 shows a first embodiment of an electromagnetic actuating unit 2 according to the invention using the example of a directional control valve 1 designed as a 4/3-way proportional valve. The directional control valve 1 has an electromagnetic actuating unit 2 and a valve section 3.

The electromagnetic actuating unit 2 has a bobbin 5 and a connection element 6 formed integrally therewith. The bobbin 5 carries a coil 7 consisting of several turns of a suitable wire. The radially outer surface of the coil 7 is surrounded by a sleeve-shaped material layer 8, which is made of a non-magnetizable material Material exists. The material layer 8 may for example consist of a suitable plastic and be sprayed onto the wound coil 7. Within the connecting element 6, an electrical connector 9 is received, via which the coil 7 can be connected to a current or Spannungsquel- Ie.

The bobbin 5 is formed with a substantially cylindrical, blind hole-like recess 10, which is arranged concentrically to the coil 7. Furthermore, the bobbin 5 and the connecting element 6 at the bottom end of the recess 10 receives a sleeve-shaped first magnetic yoke 11. Within the recess 10, a pot-shaped armature guide sleeve 12 is arranged, wherein the outer contour of the inner contour of the recess 10 is adjusted. The armature guide sleeve 12 is thin-walled, with a wall thickness of about 0.1 mm, executed and comprises a cylindrical portion 12 b, which is bounded by a sleeve bottom 12 c. The sleeve bottom 12c is provided with axially inwardly extending stops 13b. The armature guide sleeve 12 extends in the axial direction along the entire recess 10, which surrounds the bobbin 5 at its opening in the radial direction at least partially.

The bobbin 5 is disposed within a cup-shaped housing 14. The open end of the housing 14 projects beyond the connecting element 6 in the axial direction, wherein this, and thus the bobbin 5, are fixed within the housing 14 by means of a flared connection 15.

Within the armature guide sleeve 12, an armature 16 is slidably disposed in the axial direction. The displacement of the armature 16 is limited in one direction by the stops 13 b and in the other direction by a second magnetic yoke 17. The second magnetic yoke 17 has a tubular portion 18 and an annular portion 19 adjoining it in the axial direction. The tubular section 18 extends through an opening 21 formed in the bottom 20 of the housing 14 into the opening 10 in the recess 10 of the coil housing. Body 5 arranged armature guide sleeve 12. In this case, the outer diameter of the tubular portion 18 is the diameter of the opening 21, except for a possibly existing game adapted. The inner diameter of the axial end of the tubular section 18 facing the armature 16 is made larger than the outer diameter of the armature 16. Thus, it can dip into this section. In addition, the outer circumferential surface of the tubular portion 18 tapers towards the armature 16.

The housing 14 is supported on the annular portion 19 via a mounting flange 22. The mounting flange 22 serves for fastening the directional valve 1 to a surrounding construction, not shown. The second magnetic yoke 17 may be formed as shown in Figure 1 as a one-piece component. An alternative embodiment is shown in FIG. 1a. In this embodiment, the second magnetic yoke 17 consists of two components, the pole core 23 and a sleeve-shaped extension 24 formed integrally with the mounting flange 22.

Between the tubular portion 18 of the second magnetic yoke 17, the bottom 20 of the housing 14 and the armature guide sleeve 12, a sealing ring 25 a is arranged. This prevents, in cooperation with the armature guide sleeve 12, that in the electromagnetic actuator 2 penetrating pressure fluid, usually engine oil, passes to the bobbin 5, whereby it is protected from damage by the pressure medium.

Figure 2 shows a cross section through the electromagnetic actuator 2 along the line H-II in Figure 1. In this case, only a part of the bobbin 5, the armature guide sleeve 12 and the armature 16 is shown.

The armature guide sleeve 12 is formed on the cylindrical portion 12b with radially inwardly projecting elevations 13a, which extend in the axial direction. The elevations 13a are shown disproportionately large here for illustrative purposes. Although the radial extension of the elevations 13a can be realized in any desired size, completely smaller than 0.06 mm. The outer diameter of the cylindrical outer circumferential surface of the armature 16 is designed such that it is guided by the elevations 13 a, which serve as running surfaces. As a result, in the circumferential direction of the armature 16 between the elevations 13a lubricant channels 26 are formed, which extend in the radial direction.

By reducing the contact surface of the armature 16 on the armature guide sleeve 12, the surface-dependent mixing friction between these components is reduced.

Pressure fluid, in this case engine oil, which also acts as a lubricant, can enter via the opening 21 in the electromagnetic actuator 2 and get into the lubricant channels 26, whereby the contact surfaces between the armature 16 and the elevations 13a are sufficiently supplied with lubricant. These measures make it possible to dispense with special, friction-reducing designs of the armature 16 or additional bearing elements, such as sliding layers.

Between the sleeve bottom 12c and the sleeve bottom end of the armature 16, a first cavity 39 is formed. An axial displacement of the armature 16 establishes a pressure in this first cavity 39, which pressure deviates from a second cavity 40 delimited by the other axial end face of the armature 16. Due to the formation of the lubricant channels 26, the pressure compensation between the cavities 39, 40 can take place via this. The formation of the lubricant channels 26 on the one hand reduces the friction between the armature 16 and the armature guide sleeve 12, on the other hand can take place between the cavities 39,40 pressure equalization. This significantly reduces the hysteresis of the valve characteristic.

In addition, it may be provided to form the push rod 33 as a profiled body and to arrange them in a bore extending through the armature 16, whereby in the first cavity 39 occurred pressure medium can be returned to the second cavity 40. As shown in Figure 2, the bobbin 5 can rest on the outer circumferential surface of the armature guide sleeve 12, which engages in the elevations 13a, whereby their stability is ensured.

The bobbin 5 and the armature guide sleeve 12 are advantageously designed as a composite component. As a result, on the one hand, the number of individual parts of the electromagnetic actuator 2 is reduced, whereby the production can be carried out more cost-effectively. Furthermore, this allows the formation of the functional elements 13 cost-neutral, compared to a purely cylindrical armature guide sleeve 12 done. This can be realized for example by means of the manufacturing method described below. The bobbin 5 is formed by means of a plastic molding process on an outer surface of the armature guide sleeve 12. Suitable shaping methods are, for example, injection molding, transfer molding, compression molding or similar processes. For this purpose, a thin-walled, pot-shaped or sleeve-shaped sheet metal blank 12a, which according to the method represents the armature guide sleeve 12, is positioned within a mold of a shaping tool. In this case, within the sheet metal blank 12a a Vorhal- test stamp 37 is arranged, whose outer surface corresponds to the inner surface of the finished molded anchor guide sleeve 12. The outer surface of the Vorhaltestempels 37 thus represents a negative of the inner surface of the armature guide sleeve 12.

This is shown schematically in FIG. The sheet metal blank 12a is designed cup-shaped, while the outer circumferential surface of the Vorhaltestempels 37 abuts against the inner circumferential surface of the sheet metal blank 12a. On the outer circumferential surface of the Vorhaltestempels 37 Einformυngen 38 are provided, which are formed in the illustration as circumferentially spaced, axially extending grooves.

Subsequently, plasticized plastic is introduced into the mold under pressure. The boundary surfaces of the mold are adapted to the outer surface of the desired bobbin 5. The pressurized plastic fills the Shape, attaches to the outer surface of the sheet metal blank 12a and displaces the wall of the sheet metal blank 12a in the grooves. As a result, the bobbin 5 and the elevations 13a of the armature guide sleeve 12 are formed, and the connection between the coil body 5 and the armature guide sleeve 12 is produced.

As an alternative to injecting plasticized plastic, solid plastic can be introduced into the mold, whereby it is plasticized under pressure and the composite component is produced.

After curing of the plastic, the composite component can be removed from the mold.

As well as the elevations 13a, for example, the stops 13b can be formed. For this purpose, formed on the axial end face of the Vorhaltestempels 37 as beads formed recesses 38, in which the plastic displaces the sheet metal blank 12a.

During the manufacture of the bobbin 5, at the same time the first magnetic yoke 11 can be integrated into this. For this purpose, the first magnetic yoke 11 is positioned in the forming tool on the outer circumferential surface of the armature guide sleeve 12, and then the bobbin 5 is formed.

As can be seen in FIG. 1, the valve section 3 of the directional control valve 1 designed as a 4/3-way proportional valve consists of a valve housing 27 and a control piston 28. The valve housing 27 can either be integral with the second magnetic yoke 17 (right side of the drawing). or be designed as a separate component (left side of the drawing). In the case of a separate embodiment of the valve housing 27, this is connected, for example, by means of a screw, welding, flare or gleichwirkender connection methods with the second magnetic yoke 17. On the outer lateral surface of the valve housing 27, a plurality of annular grooves 29 are formed, which communicate via recesses 30 formed in the groove bottoms of the annular grooves 29 with the interior of the substantially hollow cylindrical valve housing 27. The annular grooves 29 and the opening facing away from the electromagnetic actuator 2 opening in the valve housing 27 serve as pressure Central connections A, B, P, T. The middle annular groove 29, which serves as inlet port P, communicates via a pressure medium line, not shown, with a pressure medium pump, also not shown. The two outer annular grooves 29, which serve as working ports A, B communicate via pressure fluid lines, also not shown, each having one or a group of oppositely acting pressure chambers of a camshaft adjuster, also not shown. The axial connection (tank connection) T communicates with a pressure medium reservoir, also not shown.

Within the valve housing 27, the control piston 28 is arranged axially displaceable. On the outer circumferential surface of the control piston 28 designed as annular webs control sections 31 are formed. The outer diameter of the control sections 31 is adapted to the inner diameter of the valve housing 27. By means of a suitable axial positioning of the control piston 28 relative to the valve housing 27, adjacent pressure medium connections A, B, P can be connected to one another. The work connection A, B, which is not connected to the inlet connection P, is connected to the tank connection T at the same time. In this way, the individual pressure chambers of the camshaft adjuster pressure medium can be selectively supplied or derived from these.

The control piston 28 is acted upon at one end with the force of a spring element 32 in the direction of the electromagnetic actuator 2. At the other axial end of the control piston 28 is a push rod 33, which extends through a bore of the second magnetic yoke 17 and is fixedly connected to the armature 16.

In the de-energized state of the coil 7, the control piston 28 is urged in the direction of the electromagnetic actuator 2 due to the force of the spring element 32.

The housing 14, the first magnetic yoke 11, the armature 16 and the second magnetic yoke 17 are made of a magnetizable material, while the connecting element 6, the push rod 33, the bobbin 5 and the kerführungshülse 12 made of a non-magnetizable material. Thus, by energizing the coil 7 within the electromagnetic actuator 2 via the armature 16, the first magnetic yoke 1 1, the housing 14, the second magnetic yoke 17 and an air gap 34 located between the armature 16 and the second magnetic yoke 17 established a magnetic flux, which urges the armature 16 in the direction of the valve section 3. As a result, the control piston 28 is displaced by means of the push rod 33 against the force of the spring element 32 in the axial direction. By a suitable control of the current flowing in the coil 7, the control piston 28 can be adjusted relative to the valve housing 27 in any position between two end stops and thus the pressure medium flows are regulated to or from the pressure chambers of the camshaft adjuster.

The assembly of the electromagnetic actuator 2 will be explained below. First, the housing 14 is positioned on the first magnetic yoke 17. Characterized in that the outer diameter of the tubular portion 18 is adapted to the diameter of the opening 21, these components are centered to each other. The axial position is determined by the bottom 20 and the annular portion 19. Subsequently or in the same step, a caulking 25 between the bottom 20 and the second magnetic yoke 17 is formed. Subsequently, the sealing ring 25 a is inserted, the armature 16 is placed on the second magnetic yoke 17 and the bobbin 5 is positioned with the connection element 6 and the armature guide sleeve 12 between the housing 14 and the tubular portion 18. The armature 16 is centered by the push rod 33 firmly connected to it and its outer circumferential surface, which cooperates with the elevations 13a of the inner lateral surface of the armature guide sleeve 12. The centering of the bobbin 5 is effected by means of the housing 14 and the tubular portion 18. For this purpose, the outer diameter of the bobbin 5 and the material layer 8 are adapted to the inner diameter of the housing 14. Furthermore, the inner diameter of the armature guide sleeve 12 is adapted to the outer diameter of the tubular portion 18. Subsequently, the flare connection 15 between the housing 14 and made the connection element 6 and, in a separate embodiment of the valve housing 27, the valve section 3 is mounted.

FIG. 3 shows a further embodiment of an electronic actuating unit 2 according to the invention using the example of a directional control valve 1 designed as a 3/2-way switching valve. Such valves are used, for example, to control a locking mechanism of switchable cam followers. This directional control valve 1 in turn consists of an electromagnetic actuator 2 and a valve section 3. The electromagnetic actuator 2 is largely identical to the actuator unit 2 illustrated in FIGS. 1 and 1a. In contrast to these embodiments, at the axial end of the actuator second magnetic yoke 17, which faces the armature 16, no conical section is formed. This serves in the first two embodiments to represent an electromagnetic actuator 2 with a linear characteristic. In the embodiment shown in Figure 3, such a linear relationship is not necessary, since this directional control valve 1 uses only two control states, namely a de-energized state and a maximum energized state. The valve section 3 in turn consists of a valve housing 27 and an axially displaceable therein control piston 28. In contrast to the embodiment shown in Figure 1, only three pressure medium connections A, B, T are formed on the valve housing 27 in this embodiment. Within the valve housing 27, two valve seats 35 are arranged, wherein each valve seat 35 can cooperate with a closure member 36 formed on the control piston 28.

In Figure 3, the directional control valve 1 is shown in the energized state. Due to the magnetic flux generated by the coil 7, the armature 16 and thus the control piston 28 are displaced axially downwards in the illustration. As a consequence, the upper closing body 36 closes the upper valve seat 35, whereby the connection between the working port A and the tank port T is blocked, while pressure medium from the inlet port P on the open lower valve seat 35 to the working port A. can. In the de-energized state of the coil 7 eliminates the magnetic force on the armature 16, whereby the control piston 28 is displaced by the flow forces of the pressure medium at the inlet port P in the axial direction upwards. As a result, the lower closing body 36 comes into contact with the lower valve seat 35, whereby the connection between the inlet connection P and the working connection A is interrupted and at the same time the connection between the working connection A and the outlet connection T, via the upper valve seat 35, is established.

In this embodiment, the armature guide sleeve 12 and the armature 16 are formed in accordance with the embodiments of FIGS. 1 and 1a.

The embodiment of an electromagnetic actuator 2 according to the invention can of course also be used in directional control valves 1, in which the valve section 3 is not fixedly connected to the actuator 2 but is arranged in the axial direction relative to one another without a fixed connection. Such directional control valves 1 are used, for example, as a central valve for camshaft adjuster insert, in which the valve portion 3 is disposed within a camshaft and rotates with this, while the actuator 2 in the axial direction thereto, fixed to a cylinder head or a cylinder head cover.

reference numeral

1 way valve

2 actuator

3 valve section

5 bobbins

6 connection element

7 coil

8 material layer

9 plug connection

10 recess

11 first yoke

12 anchor guide sleeve

12a sheet metal blank

12b cylindrical section

12c sleeve bottom

13 functional element

13a survey

13b stop

14 housing

15 crimp connection

16 anchors

17 second magnetic yoke

18 tubular section

19 Annular section

20 floor

21 opening

22 mounting flange

23 polkernels

24 extension

25 caulking

25a sealing ring

26 lubricant channel

27 valve housing 28 control piston

29 ring groove

30 recesses

31 control section 32 spring element

33 push rod

34 air gap

35 valve seat

36 closing body 37 Advance stamp

38 indentations

39 first cavity

40 second cavity

P inlet connection

T tank connection

A first work connection

B second work connection

Claims

claims

1. Electromagnetic actuator (2) of a hydraulic directional control valve (1) with - a bobbin (5), an armature (16) and an armature guide sleeve

(12), wherein the armature guide sleeve (12) consists of a metallic, non-magnetizable material and within a cylindrical, blind hole-like recess (10) of the bobbin (5) is arranged, - wherein the armature guide sleeve (12) is a substantially at least three radially inwardly extending, extending in the axial direction elevations (13 a) are formed, wherein the armature (16) is arranged axially displaceable within the armature guide sleeve (12) and wherein the elevations ( 13a) serve as running surfaces for the armature (16).

2. Electromagnetic actuator (2) according to claim 1, characterized in that the bobbin (5) consists of plastic and on the outer outer surface of the cylindrical portion (12b) rests.

3. Electromagnetic actuator (2) according to claim 1, characterized in that the cylindrical portion (12 b) has a corrugated profile in cross section.

4. Electromagnetic actuator (2) according to claim 3, characterized in that the material of the bobbin (5) on the outer circumferential surface of the Ankeführungshülse (12) engages in the wave-shaped profile of the elevations (13 a).

5. Electromagnetic actuator (2) according to claim 1, characterized in that the armature guide sleeve (12) is made by means of a chipless forming process from a sheet metal part

6. A method for producing a composite component of an electromagnetic actuator (2) of a directional control valve (1),

- wherein the composite component comprises at least one bobbin (5) made of plastic and a cup-shaped armature guide sleeve (12), wherein on the armature guide sleeve (12) of the pot shape deviating functional tion elements (13) are formed, which extend into the interior of the pot shape,

- The composite component is made starting from a cup-shaped sheet metal blank (12 a) and

- Wherein the bobbin (5) by means of a plastic molding process within a plastic forming tool on the outer circumference of the armature guide sleeve (12) is formed, comprising the following method steps:

Arranging the sheet-metal blank (12a) arranged on a lead-out punch within the shaping tool, the outer surface of the lead-in punch otherwise matching the inner surface of the sheet-metal blank (12a) being provided with indentations corresponding to the functional elements (13); the shaping tool,

- Filling the tool by the plasticized, pressurized plastic, this being the corresponding areas of the sheet metal blank

(12a) urges in the recesses of the Vorhaltestempels, curing of the plastic and removal of the finished composite component.

7. The method according to claim 7, characterized in that the recesses are designed as formed on the axial end face of the Vorhaltestempels Si- ck, wherein the displaced in these beads material of Sheet metal blanks (12a) stops (13b) for a within the armature guide sleeve (12) arranged anchor (16).

8. The method according to claim 7, characterized in that the impressions are formed as arranged on the lateral surface of the Vorhaltestempels, axially extending grooves, said displaced in these grooves material of the sheet metal blank (12a) running surfaces for a within the armature guide sleeve (12). arranged armature (16) forms.

9. The method according to claim 7, characterized in that the shaping process is an injection molding process.

10. The method according to claim 7, characterized in that the shaping process is a transfer molding process.

11. The method according to claim 7, characterized in that the shaping process is a compression molding process.