Electromagnetic drive mechanism and proportional solenoid valve equipped with the same

Abstract

The present invention provides an electromagnetic drive mechanism (2) and a proportional electromagnetic valve (1) equipped with the same. The drive mechanism (2) has a coil assembly (25) capable of passing current and having two electromagnetic coils (26, 27). The electromagnetic coils are surrounded on the outside by pole rings (36, 37) that guide flux and limit an armature (13), which can be driven to perform a stroke movement (14). The armature (13) has an armature body (55) that guides flux, which continuously and partially covers the two pole rings (36, 37) axially and has at least one annular armature body end section (72, 73), which has a peripheral surface that tapers conically toward the inside in the axial direction. When current is passed through the coil assembly (25), the coil magnetic field generated thereby interacts with the permanent magnet field (34) of the permanent magnet (32) and causes a synthetic driving force responsible for generating the stroke movement.

Description

Technical Field

[0001] The invention relates to an electromagnetic drive mechanism, comprising a stator, the stator comprising a coil assembly capable of conducting current and having two electromagnetic coils arranged coaxially to a main axis and spaced apart from each other, the stator comprising a flux-conducting yoke mechanism comprising two flux-conducting pole rings which respectively surround one of the two electromagnetic coils on the outside axially facing away from the other electromagnetic coil in a coaxial orientation and laterally, and an armature coaxially surrounded by the coil assembly, the armature comprising a flux-conducting armature body which is continuously penetrated by a permanent magnet field of a permanent magnet of a drive mechanism like the yoke mechanism of the stator, the armature body comprising two armature body end sections with cylindrical outer peripheral surfaces which are axially opposite to each other and are arranged adjacent to each of the two pole rings, wherein the armature can be axially moved back and forth relative to the stator during a stroke movement due to the interaction between the permanent magnet field and the coil magnetic field which can be caused by a controlled current passing through the coil assembly and can be positioned in different stroke positions.

[0002] The invention further relates to a proportional solenoid valve designed for controlling a flow of a fluid, comprising a valve housing, a valve member movable relative to the valve housing when a control movement is carried out, and an electromagnetic drive for effecting the control movement of the valve member. Background Art

[0003] This type of proportional solenoid valve equipped with an electromagnetic drive mechanism of the type mentioned at the beginning is derived from DE 10 2012 018566 A1. The known drive mechanism has two electromagnetic coils arranged at an axial distance relative to each other, and the electromagnetic coils are surrounded by pole rings that guide the flux on the outsides facing away from each other, and an annular flux guide is also arranged between the electromagnetic coils. The aforementioned components belong to a stator fixed in position with respect to the valve housing, and the stator surrounds an axially movable armature, which has an armature body that guides the flux. The armature body includes two components that guide the flux, and a permanent magnet is arranged between the components. The armature is provided with a valve member at the end side, and the valve member is preloaded to a closed position against the valve seat by means of a spring mechanism. The two electromagnetic coils are wound in opposite directions and are electrically connected in series, so that when current is passed through them, they generate two coil magnetic fields, and their field lines run in opposite directions relative to each other. The axial length of the armature corresponds to the clear distance between the two pole rings of the stator. The controlled flow of current through the electromagnetic coil can cause an interaction between the resulting coil magnetic field and the permanent magnet field of the permanent magnet, from which an axial drive force acting on the armature is obtained, so that the armature can be driven to perform a stroke movement and can be positioned steplessly in different stroke positions. In this way, the electromagnetic valve can be operated with a proportional control behavior, which is advantageous for pressure-controlled or flow-controlled applications.

[0004] DE 10 2011 115 115 A1 discloses a valve mechanism whose stator has a coil which is axially surrounded on both sides by annular magnets. The coil surrounds an armature which acts as a valve body and has a ferromagnetic armature body, the length of which corresponds to the clear distance between the two annular magnets.

[0005] The drive device known from DE 199 00 788 A1 has an axially movable drive element with a magnetizable section, which extends coaxially through an electromagnetic coil, which is axially surrounded on both sides by annular magnets. In order to cause a stroke movement of the drive element, the electromagnetic coil can be energized, so that an interaction with the permanent magnet field occurs, which drives the magnetizable section.

[0006] DE 10 2009 021 639 A1 describes a solenoid valve having a solenoid coil arranged in a fixed position on a valve housing, which is axially surrounded on both sides by annular permanent magnets. The solenoid coil surrounds an armature, which carries a valve member opposite a valve seat and can be driven to perform a stroke movement by controlled current flow through the solenoid coil.

[0007] 10 2004 056 236 A1 describes an electromagnetic drive which is formed by a bistable back-stroke magnet. The back-stroke magnet has a stator with two coils which are axially surrounded on the outside by a cover on the side and between which a radially polarized annular magnet is arranged. The stator surrounds an armature assembly having an axially movable cylindrical armature body into which the two covers are sunk at the end.

[0008] JP S60-84 805 A describes a three-dimensionally stabilized electromagnetic device with a movable armature which can be stopped precisely in a neutral position.

[0009] Known electromagnetic drives based on the reluctance drive principle can only be used inadequately for proportional applications due to the strong nonlinearity in their force-distance characteristic curve. Summary of the invention

[0010] The invention is based on the object of taking measures in order to achieve a good proportional control behavior with an electromagnetic drive and a proportional solenoid valve assigned thereto over a large stroke range while at the same time having high dynamics.

[0011] In order to achieve the stated object, in an electromagnetic drive of the type mentioned at the outset, it is provided according to the invention that the armature body, in each stroke position of the armature, with its two armature body end sections, sinks into the respectively adjacent pole ring with only partial axial overlap, so that a radial annular gap exists between each armature body end section and the pole ring adjacent thereto, wherein the axial overlap length and thus the axial annular gap length depend on the stroke position of the armature, wherein at least one of the two armature body end sections is annular in shape and has an inner circumferential surface which tapers conically from its free end axially inwardly, so that the radial thickness of the annular cross section of the armature body end section at right angles to the main axis continuously decreases towards its free end.

[0012] This object is also achieved according to the invention in the case of a proportional solenoid valve of the type mentioned at the outset in that its electromagnetic drive is designed in the above-mentioned manner, wherein the valve member is drive-coupled to the armature for generating its control movement.

[0013] Electromagnetic drives are particularly suitable for use in proportional solenoid valves, but can also be used for other drive tasks.

[0014] Within the electromagnetic drive, an axially movably supported armature with its armature body having the property of guiding flux is in magnetic interaction with a yoke assembly arranged on the stator, preferably annularly and symmetrically constructed and guiding flux, wherein a permanent magnet preload is generated by the additionally present permanent magnets. The armature body has such a length that the armature body is immersed in the corresponding adjacent pole rings with the two armature body end sections independently of the stroke position currently occupied by the armature, so that there is an axial overlap between each armature body end section and a partial length of the adjacent pole ring. A radial annular gap is constructed between each pole ring and the armature body end section immersed therein, through which both the permanent magnet field of the permanent magnet and the coil magnetic field of the adjacent electromagnetic coil pass when a corresponding current is passed. In conjunction with the annular outer shape of at least one of the armature body end sections, which has an inner cone at least in the length section connected to the free end, the armature body is loaded with a resultant axial driving force despite the radial magnet gap, which can be explained by the occurrence of magnetic leakage fields, which are generated due to the relatively small annular cross section of the armature body end section that is available for the magnetic flux and continuously decreases towards the free end of the armature body end section. As a result, according to the invention, a mixture of radial and axial components of the magnetic resistance force is used to produce a stroke-force characteristic curve that is as proportional as possible by means of a special, conically tapering shaping of at least one axial end section of the armature body. By the design according to the invention, a relatively linear, proportional behavior is obtained in the edge region itself. In addition, in conjunction with the permanent magnet preload, particularly high dynamics can be achieved with low inductance. The high dynamics are particularly prominent when the permanent magnets belong to the stator according to the preferred design and thus do not contribute to the moving mass. The armature body end section which is designed conically on the inside is preferably designed such that the conically tapering inner circumferential surface has a radial spacing at every point relative to a central longitudinal axis of the armature body which coincides with the main axis.

[0015] An inner cone formed in at least one annular armature end section extends axially from the free end of the end face of the armature end section with an increasing tapering into the armature end section, wherein the inner cone preferably extends over the entire axial length of the annular armature end section, but can also be shorter and can transition into a hollow cylindrical length section.

[0016] Advantageous developments of the invention emerge from the dependent claims.

[0017] Preferably, the two armature body end sections are annularly designed and have an inner peripheral surface that tapers conically from the free end to the axial interior. The two armature body end sections are preferably constructed identically. By arranging the armature body end sections on both sides in an internal cone, a driving force can be generated in the two axial directions with a bistable functionality. If only a monostable functionality is desired, which works, for example, by means of a spring return, in principle only a single-sided inner cone is sufficient. In this case, the opposite side can be implemented, for example, in a cylindrical manner, but also with a continuous partially axial covering portion that exists independently of the stroke position of the armature by means of the adjacent pole ring.

[0018] The axial length of the armature body having flux-conducting properties is preferably selected such that in the middle stroke position of the armature, in which the two armature body end sections are immersed with the same axial covering length into the respectively adjacent pole ring, the axial covering length on both sides corresponds to 0.3 to 1.5 times the maximum stroke that can be performed by the armature during its stroke movement. In the case of this arrangement, the axial covering length on one side corresponds, for example, to the armature stroke.

[0019] The cone angle of the conical inner circumferential surface of the armature body end section, which can also be referred to as opening angle, is preferably in the range of 20° to 120° inclusive, wherein the cone angle is in particular in the range of 40° to 80° inclusive.

[0020] The annular armature body end section is preferably flattened or rounded at its free end. Alternatively, the armature body end section can also end with an axially oriented edge.

[0021] The permanent magnet is expediently designed in the form of an annular ring, so that it can be referred to as an annular magnet. In particular, the permanent magnet is arranged coaxially with respect to the main axis.

[0022] It is considered particularly advantageous if the annular permanent magnet is magnetized radially. Here, one of the two magnetic poles is in the region of the outer circumference and the other of the two magnetic poles is in the region of the inner circumference of the annular permanent magnet.

[0023] It is considered particularly expedient to implement the permanent magnets as a component of the stator. Preferably, the armature has no permanent magnetic components at all. Since the permanent magnets belonging to the stator do not have to perform the stroke movement of the armature, the armature can be operated with high switching dynamics and with a fast reaction time to electrical actuation signals. In addition, the armature can be manufactured in one piece very cost-effectively.

[0024] Advantageously, a preferably annular permanent magnet belonging to the stator is arranged axially between the two electromagnetic coils in a coaxial orientation. Thus, each of the two electromagnetic coils is located between a permanent magnet and one of the two pole rings. The permanent magnet field of the permanent magnet consists of two partial magnetic fields, which each pass through the armature body with flux-conducting properties and also each pass through one of the two pole rings with flux-conducting properties.

[0025] Preferably, the yoke mechanism also includes a flux-conducting yoke sleeve that radially surrounds the two electromagnetic coils, the two pole rings and the permanent magnets on the outside, and the yoke sleeve is in flux-conducting connection with the two pole rings and preferably also with the permanent magnets. The two aforementioned sub-magnetic fields are guided by the yoke sleeve between the permanent magnets and the corresponding pole rings in the area radially outside the electromagnetic coils.

[0026] Preferably, the armature is movable relative to the stator between two axially opposite end-of-travel positions. Advantageously, the armature is permanently preloaded into one of the two end-of-travel positions by a spring mechanism acting between the stator and the armature. With the aid of such a spring preload, a monostable operating behavior of the armature can be achieved very simply. In the case of a proportional solenoid valve, a "normally closed" or "normally open" valve type can be achieved in particular with the aid of an armature preloaded into the end-of-travel position by a spring mechanism.

[0027] If the drive mechanism is provided with a bistable functionality of the armature, a spring mechanism is preferably also present.

[0028] Preferably, the spring means is associated with one of the two axial end regions of the armature and is inserted there axially between the armature and a component of the stator. The spring means is expediently a compression spring means.

[0029] Suitably, the armature is radially supported with respect to the stator and can be guided axially linearly displaced. Preferably, there is no contact between the armature body and the stator. Suitably, the annular air gap extends radially between the armature body and the stator over the entire axial length of the armature body. Suitably, two guide bolts of the armature that are respectively attached to the armature body are responsible for the linear guidance with respect to the stator, the guide bolts are respectively assigned to one of the two axial end regions of the armature and the guide bolts are respectively supported in a radial manner and can be axially displaced and sunk into the guide recess constructed at the stator. The guide bolts are especially made of a material that does not play a role in guiding flux, so that the guide bolts neither affect the permanent magnet field nor the coil magnetic field in any way. The guide bolts are suitably structural components separated from each other, but can also be formed by the two end sections of the one-piece guide body passing through the armature body.

[0030] The armature body preferably has a completely cylindrical shaping on the outside, which advantageously does not have any gradations.

[0031] The guide bolt is preferably also designed to be cylindrical at its radial outer circumference.

[0032] At least one of the two stator-side guide recesses is expediently formed by a central annular opening of the cylindrically designed contour of the two pole rings. In principle, each of the two pole rings can delimit one of the two guide recesses. However, it is preferred as a possible embodiment that one of the two pole rings does not have any guiding tasks and that instead a guide peg assigned to the pole ring sinks into a guide recess of the stator, which is delimited by other components of the stator, for example by an axial closing element, which preferably has no flux-conducting properties.

[0033] Each annular armature body end section is preferably designed in the form of a collar, at least if it has a conically tapering inner circumferential surface.

[0034] Preferably, each annular armature body end section surrounds an axially open end-side recess of the armature body, which has a planar, preferably circular, bottom surface which extends in a plane at right angles to the main axis.

[0035] Preferably, the two guide bolts extend at least partly within a recess of the armature body on the end side surrounded by the associated annular armature body end section. Here, a radial annular gap can exist between each guide bolt and the associated annular armature body end section, which tapers accordingly in the case of an inner peripheral surface of the armature body end section that tapers conically toward the axial interior.

[0036] Each guide bolt expediently protrudes axially from the armature body. Advantageously, at least the length section of the guide bolt protruding from the end-side recess cooperates with the guide recess of the stator for the purpose of linearly guiding the armature.

[0037] The description of properties that guide the flux is understood to be properties that guide the magnetic flux. If the components of the electromagnetic drive are flux-guiding, their flux-guiding properties are preferably based on a design made of ferromagnetic material, in particular a design made of soft magnetic material. Components that do not guide the flux are made, for example, of plastic material, aluminum material or of austenitic material.

[0038] Expediently, in the region of the free end of the armature body end section or at the axial height of the free end of the armature body end section, the circular surface surrounded by the conical inner circumferential surface is at least 75% and expediently in the range of 90% of the circular surface surrounding the outer circumference of the annular armature body end section.

[0039] The proportional solenoid valve including the electromagnetic drive mechanism is configured as a valve seat in a preferred design, wherein its valve member is arranged at the front end side of the armature and is opposite to the valve seat within a valve chamber limited by the valve housing, the valve seat surrounds the inner channel opening of the first fluid channel leading into the valve chamber, and the valve member abuts against the valve seat in the closed position. There is also an additional, second fluid channel leading into the valve chamber, and when the valve member is moved to the open position lifted from the valve seat by corresponding actuation of the armature, the additional, second fluid channel is connected to the first fluid channel through the valve chamber.

[0040] The armature is expediently axially penetrated by a pressure equalization channel, which, at least in the closed position of the valve member, establishes a fluid connection between the first fluid channel and a pressure equalization chamber bounded by the rear end face of the armature, wherein the cross section of the pressure equalization chamber is as large as the cross section of the inner channel opening of the first fluid channel. As a result, the armature is pressure-balanced, so that the drive force that can be exerted on it is independent of the fluid force of the fluid to be controlled.

[0041] The electromagnetic drive can be equipped with a sensor system that allows the position of the armature to be detected. Such a sensor system includes, for example, a Hall sensor system that cooperates with a permanent magnetic element, wherein the permanent magnetic element is preferably designed as a magnetic ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The invention is explained in more detail below with the aid of the attached drawings, in which:

[0043] Figure 1 A preferred first embodiment of a proportional solenoid valve according to the invention is shown in a partially disassembled state, wherein the solenoid valve is equipped with a preferred embodiment of an electromagnetic drive according to the invention,

[0044] Figure 2 Shown from Figure 1 Another disassembled illustration of the components of Figure 1 Differently, in the drive mechanism, not only the stator is shown, but also the armature is shown in longitudinal section.

[0045] Figure 3 Shown from Figure 1 and 2A longitudinal section of a component of the valve member in the closed position of the valve member, in which the armature assumes one of two possible end positions of the stroke,

[0046] Figure 4 Shown with Figure 3 , but in the open position of the valve member, in which the armature occupies a central stroke position, and

[0047] Figure 5 It also shows that the corresponding Figure 3 and 4 A longitudinal section through which the valve member is shown in the maximum open position and the armature occupies a position about Figure 3 The operating states shown in FIG. 8 are relative to the final travel position. DETAILED DESCRIPTION

[0048] The drawing shows a proportional solenoid valve 1 which is equipped with an electromagnetic drive 2 by which a valve member 3 of the solenoid valve 1 can be driven to perform a linear control movement 4 indicated by a double arrow.

[0049] The drive 2 has an imaginary main axis 5 which, by way of example, is a central longitudinal axis of the drive 1 . The control movement 4 of the valve member 3 takes place in the axial direction of the main axis 5 .

[0050] The solenoid valve 1 has a valve housing 6. The valve housing 6 is exemplarily constructed in multiple parts and comprises a first housing part 7 and a second housing part 8 attached to the first housing part 7. Preferably, the second housing part 8 is detachably fixed to the first housing part 7 by a fixing means 11, in particular a fixing screw.

[0051] The second housing part 8 is preferably formed by the stator 12 of the drive 2. The drive 2 further comprises an armature 13 which can be moved linearly back and forth relative to the stator 12 in the axial direction of the main axis 5, wherein this movement is referred to below as stroke movement 14 and is indicated by a double arrow.

[0052] The drive 2 has a connection element 15 which is designed as a component of the stator 12 and is accessible from the outside and to which a control voltage can be applied, by which the drive 2 can be actuated to generate the stroke movement 14 .

[0053] A deepening is formed in the first housing part 7, which is closed by the attached second housing part 8, so that it forms a valve chamber 16, into which the armature 13 projects with a front end section 17. The valve member 3 mentioned above is arranged on the front end section 17 at the end side, which valve member comprises, by way of example, a rubber-elastic sealing element which is designed, for example, in the form of a disk or plate.

[0054] The first housing part 7 is penetrated by a first fluid channel 22, which opens with a first external connection opening 22a toward the outer surface of the first housing part 7 and further opens with a first internal channel opening 22b into the valve chamber 16. The first internal channel opening 22b is opposite the valve member 3 in the axial direction of the main axis 5 and is surrounded by an annular valve seat 24 facing the valve member 3.

[0055] A second fluid channel 23 which likewise passes through the first housing part 7 opens out with a second external connection opening 23a to the outer surface of the first housing part 7 and further opens with a second internal channel opening 23b into the valve chamber 16 in such a way that, independently of the current position of the valve member 3, an open connection exists between the valve chamber 16 and the second external connection opening 23a.

[0056] In a typical operating mode of the proportional solenoid valve 1, a fluid under overpressure, such as compressed air, is fed into the first fluid channel 22 at the first external connection opening 22a. Figure 3 2, the valve member 3 is abutted against the valve seat 24 in the closed position shown in FIG. 2, the first fluid channel 22 is separated from the valve chamber 16 and thus also from the second fluid channel 23, so that no fluid flow occurs. By corresponding actuation of the drive mechanism 2, the valve member 3 can be driven to perform the control movement 4 as follows, i.e. it assumes the open position lifted from the valve seat 24, wherein Figure 4 and 5 Two possible open positions are described. In each open position, the fluid introduced into the first fluid channel 22 can flow through the opened first inner channel opening 22b into the valve chamber 16 and from there through the second fluid channel 23 and the second outer connection opening 23a out of the valve housing 6 to the connected consumer.

[0057] It is understood that the solenoid valve 1 can also be operated with a reverse flow direction, wherein the fluid to be controlled is supplied at the second outer connection opening 23 a .

[0058] The valve member positions that can be assumed by the valve member 3 within the scope of the control movement 4 are also referred to below as control positions. Figure 3The other control position is the open position lifted from the valve seat 24 , wherein the valve member 3 can be positioned continuously in different open positions which differ from one another in terms of the distances from the valve seat 24 . Figure 5 The maximum open position is shown with the maximum possible distance between the valve member 3 and the valve seat 24. Figure 4 An intermediate open position is shown in , which is intermediate between the closed position and the maximum open position.

[0059] The stepless adjustability of the different opening positions enables the opening of flow cross sections of different sizes, so that the solenoid valve 1 can be used for pressure regulation and / or flow regulation.

[0060] Since the valve member 3 is drive-coupled to the armature 13, the control movement 4 of the valve member 3 is derived from the stroke movement 14 of the armature 13. If the valve member 3 is fixedly mounted on the armature 13, the control movement 4 directly corresponds to the stroke movement 14. This is the case in the exemplary embodiment.

[0061] According to an exemplary embodiment (not shown), the valve member 3 is designed to be separate from the armature 13 , but is nevertheless drive-coupled to the armature 13 via suitable coupling means.

[0062] The armature 13 can move within the range of the stroke movement 14 from Figure 3 The final position of the first stroke seen in Figure 5 The first stroke end position of the armature 13 corresponds to the closed position of the valve member 13, and the second stroke end position corresponds to the maximum open position of the valve member 3. The armature 13 can be positioned steplessly relative to the stator 12 between the two axially opposite stroke end positions.

[0063] A preferred structure of the electromagnetic drive mechanism 2 is described below.

[0064] The stator 12 of the drive mechanism 2 has a coil assembly 25, which is electrically connected to the connection element 15 and can be energized by applying a control voltage to the connection element 15. The coil assembly 25 is arranged coaxially to the main axis 5 and has two electromagnetic coils 26, 27 coaxial with each other, which are also referred to as the first electromagnetic coil 26 and the second electromagnetic coil 27 below.

[0065] The two electromagnetic coils 26 , 27 are preferably designed to be identical with respect to their size and their effective power.

[0066] The two electromagnetic coils 26, 27 each contain a coil winding made of an insulatingly encased coil wire, wherein the two electromagnetic coils 26, 27 are wound in the same direction. Both electromagnetic coils are connected to the connection element 15, so that the application of the actuation voltage simultaneously causes a magnetic field in the two electromagnetic coils 26, 27, which is referred to as a coil magnetic field for better differentiation.

[0067] Preferably, the two electromagnetic coils 26, 27 are connected in series so that the same actuation current flows through them. However, the two electromagnetic coils can also be designed to be separate from each other and actuated separately from each other. It is important that the coil magnetic field has a field direction 28, which is indicated by an arrow in the figure and is oriented relative to each other in the region axially between the two electromagnetic coils 26, 27.

[0068] Each electromagnetic coil 26 , 27 preferably has a winding portion 26 a , 27 a made of coil wire and an annular coil carrier 26 b , 27 b which carries the winding portion 26 a , 27 a and is made, in particular, of a plastic material.

[0069] Furthermore, the stator 12 includes an annular permanent magnet 32, which is arranged axially between the two electromagnetic coils 26, 27 in a coaxial orientation with respect to the main axis 5. The permanent magnet 32, in conjunction with a flux-guiding yoke 33 of the stator 12 (to be explained), brings about a permanent-magnetic prestressing of the armature 13. Flux-guiding means are understood to mean that magnetic field lines and thus the magnetic flux can be guided.

[0070] The permanent magnet 32 ​​can in principle also be embodied as a component of the armature 13 , but has proven to be particularly advantageous if it is integrated into the stator 12 , as is the case in this exemplary embodiment.

[0071] The permanent magnet 32 ​​designed as a ring magnet is preferably magnetized radially. The inner field direction of the permanent magnet field 34 in the permanent magnet 32 ​​is indicated at 35 by an arrow.

[0072] Based on the design of the yoke mechanism 33 described later, the permanent magnet field 34 is composed of two sub-magnetic fields 34a, 34b, which respectively extend around the respective one of the two electromagnetic coils 26, 27 in a manner comparable to the two coil magnetic fields. This means that the permanent magnet field 34 always runs in the same direction relative to one coil magnetic field and in the opposite direction relative to the other coil magnetic field. Which of the two coil magnetic fields is oriented in the same direction or in the opposite direction relative to the permanent magnet field 34 depends on the direction of the current flowing through the two electromagnetic coils 26, 27.

[0073] The flux-guiding yoke 33 already mentioned consists of a plurality of components, each of which has flux-guiding properties. The flux-guiding properties are brought about in particular by the components being made of ferromagnetic material, in particular soft magnetic steel being used. Alternatively, the flux-guiding properties can also be brought about, for example, by ferromagnetic particles being embedded in a non-flux-guiding polymeric base material.

[0074] The yoke 33 has two flux-guiding pole rings 36, 37, which are also referred to below for better distinction as first pole ring 36 and second pole ring 37. The two pole rings 36, 37 are components of the stator 12 and are arranged coaxially with respect to the main axis 5 on the outer side of one of the two electromagnetic coils 26, 27, axially opposite to the respective other electromagnetic coil 27, 26. Thus, each electromagnetic coil 26, 27 is surrounded laterally by a permanent magnet 32 ​​on its axial inner side facing the other electromagnetic coil 27, 26 and by one of the two pole rings 36, 37 on the opposite axial outer side.

[0075] Preferably, the permanent magnet 32 ​​and the two pole rings 36 , 37 each lie directly axially against the associated electromagnetic coil 26 , 27 , in particular in an insulated manner against the associated coil carrier 26 b , 27 b .

[0076] The yoke arrangement 33 expediently also has a flux-conducting yoke sleeve 38, which is arranged coaxially to the main axis 5 and has such an axial length that it radially surrounds not only the permanent magnet 32 ​​but also the two electromagnetic coils 26, 27 and the two pole rings 36, 37 on the outside. The yoke sleeve is preferably hollow-cylindrical in design.

[0077] The yoke sleeve 38 is in flux-conducting connection with the two pole rings 36, 37. For this purpose, the two pole rings 36, 37 have, by way of example, an outer diameter that corresponds to the inner diameter of the yoke sleeve 38, so that there is direct contact. Additionally or alternatively, the components can also be pressed into one another or adhesively bonded to one another.

[0078] The permanent magnet 32 ​​is preferably also in a flux-conducting connection with the yoke sleeve 38. For this purpose, the permanent magnet 32 ​​preferably has an outer diameter that corresponds to the inner diameter of the yoke sleeve 38, so that the two components rest radially against one another. Depending on the given conditions in the case of the two pole rings 36, 37, the permanent magnet 32 ​​can be pressed in or glued in, for example.

[0079] In the accompanying drawings, Figure 4At 42 , an axial slot can be seen in the outer circumference of the permanent magnet 32 ​​, through which slot the coil wire connecting the two electromagnetic coils 26 , 27 is passed.

[0080] The length section of the inner circumference of the yoke sleeve 38 which extends axially over the two electromagnetic coils 26, 27 and the permanent magnet 32 ​​expediently has a smaller diameter than the two external end sections 43, 44 of the yoke sleeve 38 which are axially connected thereto, thereby resulting in each axial stop shoulder 45, against which one of the two pole rings 36, 37 with a correspondingly larger outer diameter rests axially.

[0081] The drive 2 is preferably fastened to the valve housing 6 in such a way that it is plugged with the front outer end section 43 of the yoke sleeve 38, which is associated with the front end section 17 of the armature 13, onto an annular fastening projection of the first housing part 7 that surrounds the valve chamber 16. The sealing ring 47 located therebetween ensures a fluid-tight seal.

[0082] At the back side 48 of the drive mechanism 2 opposite the front end section 17 of the armature 13 in the axial direction of the main axis 5, the yoke sleeve 38 is axially plugged onto the stator 12, in particular a cover-shaped closing element 52, with the rear outer end section 44. The closing element 52 is preferably made of a material that does not play a flux-conducting role. Exemplarily, the closing element 52 is axially supported on the yoke sleeve 38 with an annular shoulder 53 and is fastened to the yoke sleeve 38 and the first housing part 7 by means of a fixing element. A sealing ring 49 is also conveniently located between the closing element 52 and the yoke sleeve 38.

[0083] The yoke 33 together with the annular permanent magnet 32 ​​and the two electromagnetic coils 26 , 27 encloses an armature receiving space 54 coaxial to the main axis 5 , in which the armature 13 extends axially. The armature 13 has a central longitudinal axis 19 which coincides with the main axis 5 by way of example.

[0084] The armature 13 has a flux-conducting armature body 55 with a radially outwardly oriented outer peripheral surface 56, which is expediently cylindrical in design. The outer diameter of the armature body 55 is at least smaller than the inner diameter of the yoke 33 and the permanent magnet 32 ​​and the two electromagnetic coils 26, 27, so that the armature body is enclosed by the stator 12 while retaining a small annular air gap.

[0085] In the region of the front end section 17, the armature 13 has a guide pin 62 which protrudes axially beyond the front of the flux-conducting armature body 55. A further, rear guide pin 63 is located at the rear end section 57 of the armature 13, axially opposite the front end section 17, and protrudes at the rear side beyond the armature body 55. By means of the two guide pins 62, 63, the armature 13 can be guided in a linearly displaceable manner to carry out the stroke movement 14 while the stator 12 is supported radially.

[0086] Each guide bolt 62, 63 is sunk with a guide section 62a, 63a, which has a radially outwardly directed cylindrical guide surface 62b, 63b on its outer circumference, into a front or rear guide recess 58, 59 formed by the stator 12. The two guide recesses 58, 59 have an inner diameter that matches the outer diameter of the associated guide section 62a, 63a, so that the guide surface 62b, 63b rests against it in an axially displaceable manner and each guide bolt 62, 63 can slide in the associated front or rear guide recess 58, 59 during the stroke movement 14.

[0087] Preferably, the rear guide recess 59 is designed as an axial deepening in the closing element 52. The front guide recess 58 can in principle also be formed by a component of the stator 12 that does not belong to the yoke mechanism 33, but preferably by the central annular opening 36a of the cylindrically designed contour of the first pole ring 36. As a result, the stator 12 can be realized with a very short structural length.

[0088] The two guide bolts 62, 63 are expediently made of a material that does not have a flux-conducting effect for the magnetic flux. The two guide bolts are made of a plastic material or a stainless steel material, for example.

[0089] During the stroke movement 14 , the guide bolts 62 , 63 slide in the axial direction in the respectively associated guide recesses 58 , 59 with radial support.

[0090] Preferably, the two guide pins 62, 63 are designed separately from each other and are fixed independently of each other on the armature body 55. This is the case in the described embodiment. Here, each guide pin 62, 63 has a pin-shaped fixing projection 64 on the back side, by means of which the guide pin is inserted into a through hole 65 that passes through the armature body 55 in the center. Each fixing projection 64 expediently has an external thread, by means of which it is screwed into the internal thread of the through hole 65.

[0091] The two guide bolts 62 , 63 are inserted into the through-hole 65 from mutually opposite end sides.

[0092] According to an exemplary embodiment not illustrated, the two guide bolts 62 , 63 extend through an integral component of a one-piece guide body which extends through the through-opening 65 .

[0093] Suitably, each guide bolt 62, 63 has a head section 66 axially connected to the fixing projection 64. The end section of the head section 66 axially opposite to the fixing projection 64 forms the associated guide section 62a, 63a. The head section 66 has a larger diameter than the fixing projection 64 and is supported on the opposite end face 68 of the armature body 55 with an annular rear end face 67 surrounding the fixing projection 64.

[0094] The armature body 55 has two end sections which are opposite to each other in the longitudinal direction 19 of the armature 13 and which are to be referred to as armature body end sections 72, 73. For better differentiation, the armature body end section 72 assigned to the front end section 17 is also referred to as the first armature body end section 72, and the armature body end section 73 assigned to the rear end section 57 of the armature 13 is also referred to as the second armature body end section 73.

[0095] The two armature body end sections 72 , 73 have a cylindrical outer peripheral surface 74 , which is in turn formed by a length section of the outer peripheral surface 56 which extends over the entire armature body 55 at the radial outer periphery.

[0096] The armature body 55 has an axial length which is greater than the clear distance between the two pole rings 36, 37, that is to say the clear distance of the axial inner distance of the two pole rings 36, 37, which is measured between two inner axial end faces 75 of the two pole rings 36, 37 facing each other. On the other hand, the armature body 55 is shorter than the distance measured between two outer axial end faces of the two pole rings 36, 37 facing away from each other. Furthermore, mechanical interaction with the stator 12 ensures that the armature body 55 is sunk with the two armature end sections 72, 73 into the adjacent first or second pole ring 36, 37 in each stroke position which can be adjusted during operation of the drive 2. However, the sunk depth is always smaller than the axial length measured between the inner axial end face 75 and the outer axial end face 76 of the respective pole ring 36, 37. That is to say that in each stroke position there is only a partial axial overlap of the two armature body end sections 72 , 73 with the respectively adjacent first or second pole ring 36 , 37 .

[0097] In every stroke position of the armature 13, that is to say both in the two end stroke positions and in every stroke position therebetween, there is a radial annular gap 77 between each armature body end section 72, 73 and the pole ring 36, 37 surrounding it, the axial length of which corresponds to the axial covering length between the armature body 55 and the respective pole ring 36, 37 and is smaller than the axial length of the respective pole ring 36, 37.

[0098] Preferably, each armature body end section 72 , 73 is radially surrounded on the outside by the associated pole ring 36 , 37 , wherein an associated radial annular gap 77 is located between a cylindrical outer circumferential surface 74 of the armature body end section 72 , 73 and a radial inner circumferential surface 78 of the pole ring 36 , 37 .

[0099] During the stroke movement 14, the axial coverage length of the two armature body end sections 72, 73 changes. The axial coverage length with respect to one pole ring 36 or 37 becomes correspondingly larger, while at the same time the axial coverage length with respect to the other pole ring 37, 36 becomes smaller. Accordingly, the axial annular gap lengths of the two radial annular gaps 77 also change.

[0100] Each radial annular gap 77 delimits, over its axial extent, an annular air gap radially between an outer circumferential surface 74 of the armature body end sections 72 , 73 and a radial inner circumferential surface 78 of the associated pole ring 36 , 37 .

[0101] Preferably, the length dimensions are coordinated with one another in such a way that at the armature 13 Figure 4 In the intermediate stroke position described in the figure, in which the two armature body end sections 72, 73 are immersed in the respectively adjacent pole rings 36, 37 with the same axial covering length, the axial covering length corresponds to 0.3 to 1.5 times the maximum armature stroke, wherein the maximum armature stroke is the armature stroke that the armature 13 can travel between its two end stroke positions.

[0102] In the exemplary embodiment described, a stroke end position of the armature 13 is defined in that the valve member 3 bears against the opposite valve seat 24 in the closed position. Figure 3 Another stroke end position (which in the described embodiment corresponds to the maximum open position of the valve member 3 and which is in Figure 5 ) is provided, for example, in such a way that the armature 13 comes to bear against a component of the stator 12 , for example, against the closing element 52 .

[0103] Another feature of the drive mechanism 2 is that the two armature body end sections 72, 73 of the armature body 55 are designed in annular shape and each have an inner peripheral surface 79 that tapers conically from the axial outside to the axial inside. This is manifested in that the annular armature body end sections 72, 73 taper toward their axially oriented free ends 71. That is, the thickness of the annular cross section of the armature body end section at right angles to the main axis 5 measured in the radial direction with respect to the main axis 5 becomes continuously smaller toward the free ends 71 ​​of the armature body end sections 72, 73.

[0104] In order to obtain such a contour of the armature body end sections 72 , 73 , an axial deepening 82 is expediently introduced into the armature body 55 from each axial end side, said deepening tapering axially inwardly, wherein its radial limiting surface forms the conical inner peripheral surface 79 of the armature body end sections 72 , 73 .

[0105] Preferably and in accordance with the described exemplary embodiment, the conical inner circumferential surface 79 extends, starting from the free end 71 at the end, over the entire length of the axial deepening 82 .

[0106] Alternatively, however, the conical inner peripheral surface 79 can also be shorter and end before the axial inner end of the axial deepening 82, wherein the cylindrical inner peripheral surface of the annular armature body end sections 72, 73 then expediently adjoins the conical inner peripheral surface 79 axially on the inside. The transition between the conical inner peripheral surface 79 and the cylindrical inner peripheral surface is expediently formed by an annular edge.

[0107] The axial deepening 82 is delimited axially on the inside by a bottom surface 68a oriented axially outward. The bottom surface 68a is expediently circular in contour and preferably extends in a plane at right angles to the longitudinal axis 19. The bottom surface 68a is a surface section of the end surface 68 which is axially deeper in the armature body 55 than the free end 71.

[0108] Preferably, at the level of the free ends 71 ​​of the armature body end sections 72, 73, the circular opening surrounded by the conical inner peripheral surface 79 occupies at least 75% of the circular surface surrounding the outer circumference of the annular armature body end sections 72, 73. Preferably, the area ratio is in the range of 90% and preferably is exactly 90%.

[0109] The inner cone of the armature body end sections 72 , 73 advantageously influences the adjustment of the axial stroke position of the armature 13 . The large range of control voltages that can be applied to the coil arrangement 25 with variable magnitude results in a very proportional movement behavior.

[0110] This is particularly due to the fact that the strong magnetic field in the region of the armature body end sections 72, 73 is hindered from being able to pass through without restriction due to the reduced annular cross section of the armature body end sections, so that a leakage field is formed, which exerts an axial magnetic driving force on the armature body 55 despite the radial air gap. When the armature 13 then moves together with the armature element 52, although the flux cross section of the armature body end sections 72, 73 available for the magnetic field, further referred to above as the annular cross section, changes, this has little effect on the driving force, since the magnetic flux changes at the same time, so that the leakage field responsible for the axial driving force is always present. That is, in particular, even in the vicinity of the end position of the stroke, that is, in the edge region of the stroke position to be adjusted, there is a force-stroke characteristic curve that has good linearity, which positively affects the control behavior.

[0111] In each operating state of the drive mechanism 2, the two radial annular gaps 77 are penetrated by the permanent magnet field 34 or by one of the partial magnetic fields 34a, 34b. The current flowing through the coil assembly 25 results in the generation of two coil magnetic fields, which are superimposed on the two partial magnetic fields 34a, 34b of the permanent magnet 32. Depending on the current flow direction of the coil assembly 25, a strengthening of the partial magnetic fields 34a, 34b is obtained in the region of the respective one radial annular gap 77 and a weakening of the partial magnetic fields 34a, 34b is obtained in the region of the respective other radial annular gap 77, so that overall a stronger axial magnetic force effect occurs in the region of the respective one armature body end section 72, 73, while the magnetic force effect is weakened in the region of the other armature body end section 72, 73. The absolute strength can be changed with respect to the magnitude of the applied actuation voltage or the current intensity resulting therefrom.

[0112] It is advantageous for the operating behavior of the drive 2 if a spring mechanism 83 is present, acting between the stator 12 and the armature 13, by means of which the armature 13 is permanently prestressed into one of its two end-of-travel positions relative to the stator 12. The described embodiment is equipped with such a spring mechanism 83, which is designed and arranged in such a way that the armature 13 is elastically prestressed into the end-of-travel position corresponding to the closed position of the valve member 3.

[0113] The spring mechanism 83 is, in particular, a compression spring mechanism.

[0114] The spring mechanism 83 is arranged, for example, axially in the interior of the stator 12 between the rear end section 57 of the armature 13 and the closing element 52. The spring mechanism is accordingly supported axially on the two aforementioned components 57, 52. For example, the spring mechanism comprises a helical spring.

[0115] By way of example, the spring mechanism 83 cooperates with the rear guide bolt 63 on the armature 13. The rear guide bolt 63 has a blind hole-like recess 84 extending in the head section 66, into which the spring mechanism 83 is supported against lateral bending. The spring force FF exerted on the armature 13 by the spring mechanism 83 is indicated by an arrow.

[0116] exist Figures 3 to 5 In FIG. 1 , different possible lift positions of the armature 13 and, correspondingly, different control positions of the valve member 3 connected to the armature 13 are described by way of example.

[0117] Figure 3 The end stroke position of the armature 13 is shown, in which the valve member 3 assumes the closed position. The coil arrangement 25 is energized in such a way that a significantly stronger resultant magnetic field is present in the region of the radial annular gap 77 associated with the first armature body end section 72 than in the region of the rear second armature body end section 73. As a result, the valve member 3 is pressed against the valve seat 24.

[0118] Figure 5 The following operating state is shown in which the resulting magnetic field is significantly greater in the region of the radial annular gap 77 associated with the second armature body end section 73 than in the region of the first armature body end section 72. As a result, the armature 13 is displaced in the direction of the second pole ring 73 so that it assumes a further end position of the stroke, which corresponds to the maximum open position of the valve member 3.

[0119] In being able to Figure 3 In the end position of the stroke, which can be seen in FIG. , the axial coverage length has a maximum value in the region of the first armature body end section 72 and a minimum value in the region of the second armature body end section. Figure 5 In the second stroke final position as seen in , the state is just the opposite.

[0120] Figure 4 The middle stroke position of the armature 13 is shown, in which the covering length is equally large at the two armature body end sections 72, 73. In this case, the actuating voltage applied to the coil assembly 25 is reduced compared to the stroke end position which defines the maximum open position of the valve member 3, so that the adjusted open position is an intermediate open position, the open flow cross section of which is smaller than in the maximum open position.

[0121] In the described embodiment, the two armature body end sections 72, 73 are designed in an annular shape and have an inner peripheral surface 79 that tapers conically toward the axial interior, while in the embodiment not described, only one of the two armature body end sections is designed in the described form. That is to say, the inner cone can be arranged not only on one side but also on both sides. The armature body cones on both sides realize the adjustment force in the two axial directions under the condition of bistable functionality. If only a monostable functionality is desired, which works, for example, by means of spring return, a single-sided armature body cone is sufficient. In this case, the opposing armature body end sections can be constructed, for example, in a cylindrical shape. The explanation about the axial covering portion with the assigned pole ring is also applicable to such a design scheme.

[0122] Preferably, the cone angle 80 (in Figure 5 The cone angles (which can be identified by the double arrow in the figure) are in the range between 20° and 120°. Cone angles in the range between 40° and 80° have proven to be particularly suitable. The range limits are accordingly included in the two range data.

[0123] In the illustrated embodiment, the annular armature body end sections 72, 73 are flattened on the end side at their free ends 71. Nevertheless, the annular end surface has only a small radial dimension. In accordance with the embodiment not illustrated, the free end 71 can also end in a sharp edge with an axially oriented edge or be rounded.

[0124] According to the described embodiment, the two guide bolts 62, 63 can extend at least part of their length within the associated end-side deepening or recess 55 of the armature body 55. By way of example, the end face 68 of the armature body 55, at which the guide bolts 62, 63 rest against the armature body 55, is formed by the axially outwardly oriented bottom face 68a of the end-side recess 82.

[0125] Expediently, an annular radial air gap 85 extends between each guide bolt 62 , 63 and the conical inner circumferential surface 79 of the associated armature body end section 72 , 73 .

[0126] Each guide bolt 62 , 63 projects with its head section 66 axially out of an associated end-side recess 82 , wherein at least a length section outside the end-side recess 82 forms a guide section 62 a , 63 a .

[0127] The proportional solenoid valve 1 is expediently equipped with pressure compensation measures which ensure that no resultant axial fluid pressure acts on the armature 13 at least in the closed position and preferably also in the open position.

[0128] The pressure equalization measures are provided such that the armature 13 is axially passed through the center by a pressure equalization channel 86, which opens with a front channel opening 87 at a closure surface 88 of the end side of the valve member 3 facing away from the armature 13 and further opens with an axially opposite rear channel opening 89 into a pressure equalization chamber 92 located inside the stator 12. The pressure equalization chamber 92 is connected to the rear end section 57 of the armature 13 axially opposite the valve member 3 and is delimited by the rear guide pin 63 and the closing element 52, as an example. A sealing ring 93 fixed radially on the outside in the head section 66 of the rear guide pin 63 ensures that the pressure equalization chamber 92 is separated from the armature receiving space 54 in a fluid-tight manner.

[0129] Preferably, the spring mechanism 83 is arranged in the pressure balance chamber 92 .

[0130] The pressure compensation channel 86 expediently extends axially through the valve member 3 , the armature body 55 and the two guide bolts 62 .

[0131] The cross section of the pressure equalization chamber 92 is the same size as the cross section of the first inner channel opening 22 b which is covered by its end-side closing surface 88 in the closed position of the valve member 3 .

[0132] In the closed position of the valve member 3, the first fluid channel 22 communicates with the pressure balance chamber 92 via the front channel opening 87 and the pressure balance channel 86, so that the same pressure prevails in the latter as in the first fluid channel 22. As a result, the armature 13 is acted upon in both axial directions by the same fluid pressures, which cancel each other out. The same effect occurs when the valve member 3 assumes the open position, because the same pressure prevails in the pressure balance chamber 92 as in the region of the channel opening 87 of the valve chamber 16 located upstream of the front.

[0133] The drive 2 can be equipped with a travel sensor for the armature 13. Furthermore, the proportional solenoid valve 1 can be equipped with a pressure sensor and / or a flow sensor.

Claims

1. An electromagnetic drive, comprising a stator (12), a coil assembly (25) through which current can flow, with two electromagnetic coils (26, 27) arranged coaxially with a main axis (5) and spaced apart from one another, and a flux-conducting yoke (33) with two flux-conducting pole rings (36, 37) which respectively surround one of the two electromagnetic coils (26, 27) on the outside axially facing away from the other electromagnetic coil (26, 27) in a coaxial orientation and laterally surround the two electromagnetic coils (26, 27), The electromagnetic drive mechanism has an armature (13) coaxially surrounded by the coil assembly (25), the armature having an armature body (55) which is used for flux guidance and is continuously penetrated by the permanent magnet field (34) of the permanent magnet (32) of the drive mechanism (1) like the yoke mechanism (33) of the stator (12), the armature body having two axially opposite armature body end sections (72, 73) with cylindrical outer peripheral surfaces (74) and arranged adjacent to one of the two pole rings (36, 37), wherein: The armature (13) can be axially moved back and forth relative to the stator (12) and can be positioned in different stroke positions when performing a stroke movement (14) due to the interaction of the permanent magnet field (34) and the coil magnetic field that can be caused by a controlled current flow through the coil assembly (25), characterized in that the armature body (55) in each stroke position of the armature (13) with its two armature body end sections (72, 73) are immersed in the corresponding adjacent pole ring (36, 37) with only partial axial coverage, so that each armature body end section (72, 73) is covered by the corresponding adjacent pole ring (36, 37). 6, 37) and there is a radial annular gap (77) between the outer peripheral surface (74) of each armature body end section (72, 73) and the radial inner peripheral surface (78) of the adjacent pole ring (36, 37), wherein the two radial annular gaps (77) respectively define an annular air gap radially between the outer peripheral surface (74) of each armature body end section (72, 73) and the radial inner peripheral surface (78) of the adjacent pole ring (36, 37) across the axial annular gap length, wherein the corresponding axial overlap length between the armature body (55) and the corresponding pole ring (36, 37) and the radial inner peripheral surface (78) of the adjacent pole ring (36, 37) are The respective axial annular gap lengths of the two radial annular gaps (77) depend on the stroke position of the armature (13), wherein the respective axial annular gap lengths of the two annular gaps (77) correspond to the respective axial overlapping lengths between the armature body (55) and the respective pole rings (36, 37), wherein the respective axial annular gap lengths of the two annular gaps (77) are smaller than the respective lengths of the respective pole rings (36, 37), wherein at least one of the two armature body end sections (72, 73) is annular in shape and has a radial extension extending axially inwardly from its free end (71). The invention relates to a conically tapering inner peripheral surface (79), so that the radial thickness of the annular cross section of the armature body end section (72, 73) at right angles to the main axis (5) continuously decreases towards its free end (71), wherein the armature (13) has a guide pin (62, 63) at its two axial end regions, which is radially supported and can be axially displaced in a guide recess (58, 59) formed on the stator (12), and wherein the two guide pins (62, 63) are designed separately from each other and are fixed to the armature body (55) independently of each other.

2. The electromagnetic drive mechanism according to claim 1, characterized in that: The two armature body end sections (72, 73) are annular in shape and have an inner circumferential surface (79) which tapers conically axially inwardly starting from their respective free end (71).

3. The electromagnetic drive mechanism according to claim 2, characterized in that: In a central stroke position of the armature (13), the axial covering length corresponds to 0.3 to 1.5 times the maximum stroke that can be performed by the armature (13) during its stroke movement (14), in which central stroke position the two armature body end sections (72, 73) are immersed in the respective adjacent pole rings (36, 37) with the same axial covering length.

4. The electromagnetic drive mechanism according to any one of claims 1 to 3, characterized in that: The cone angle (80) of the conical inner peripheral surface (79) of the armature body end sections (72, 73) is in the range between 20° and 120°, respectively inclusive of the range limits.

5. The electromagnetic drive mechanism according to any one of claims 1 to 3, characterized in that: The armature body end sections (72, 73) are flattened at their free ends (71) at the end faces or are provided with axially oriented edges or are rounded.

6. The electromagnetic drive mechanism according to any one of claims 1 to 3, characterized in that: The permanent magnet (32) is annular in shape and is arranged coaxially with respect to the main axis (5).

7. The electromagnetic drive mechanism according to claim 6, characterized in that: The annular permanent magnet (32) is radially magnetized.

8. The electromagnetic drive mechanism according to any one of claims 1 to 3, characterized in that: The permanent magnet (32) is a component of the stator (12).

9. The electromagnetic drive mechanism according to claim 8, characterized in that: The permanent magnet (32) is arranged axially between the two electromagnetic coils (26, 27) in a coaxial orientation.

10. The electromagnetic drive mechanism according to any one of claims 1 to 3, characterized in that: The yoke arrangement (33) has a flux-conducting yoke sleeve (38) which radially surrounds the two electromagnetic coils (26, 27), the two pole rings (36, 37) and the permanent magnet (32) on the outside and is in flux-conducting connection with the two pole rings (36, 37).

11. The electromagnetic drive mechanism according to any one of claims 1 to 3, characterized in that: The armature (13) is movable relative to the stator (12) between two axially opposite end positions of travel, wherein the armature (13) is permanently prestressed into one of the two end positions of travel by a spring mechanism (83) acting between the stator (12) and the armature (13).

12. The electromagnetic drive mechanism according to any one of claims 1 to 3, characterized in that: The guide pins (62, 63) are made of a material that does not play a role in guiding flux.

13. The electromagnetic drive mechanism according to any one of claims 1 to 3, characterized in that: At least one of the two guide recesses (58, 59) is formed by a central annular opening of the cylindrically designed contour of one of the pole rings (36, 37).

14. The electromagnetic drive mechanism according to claim 12, characterized in that: The two guide bolts (62, 63) extend at least over a portion of their length within an end-side recess (82) of the armature body (55) which is surrounded by an associated annular armature body end section (72, 73).

15. The electromagnetic drive mechanism according to any one of claims 1 to 3, characterized in that: These flux-conducting properties are achieved by designing the relevant components from ferromagnetic materials.

16. The electromagnetic drive mechanism according to any one of claims 1 to 3, characterized in that: The two electromagnetic coils (26, 27) are electrically connected in series and are wound in the same direction.

17. The electromagnetic drive mechanism according to any one of claims 1 to 3, characterized in that: In the region of the free ends (71) of the armature body end sections (72, 73), the circular surface enclosed by the conical inner circumferential surface (79) is at least 75% of the circular surface which surrounds the outer circumference of the annular armature body end sections (72, 73).

18. The electromagnetic drive mechanism according to claim 4, characterized in that: The cone angle (80) lies in the range between 40° and 80°, inclusive of the range limits.

19. The electromagnetic drive mechanism according to claim 10, characterized in that: The yoke sleeve (38) is also in flux-conducting connection with the permanent magnet (32).

20. The electromagnetic drive mechanism according to claim 14, characterized in that: An annular radial air gap (85) exists between each guide bolt (62, 63) and the associated armature body end section (72, 73) and / or each guide bolt (62, 63) protrudes axially from the armature body (55).

21. The electromagnetic drive mechanism according to claim 15, characterized in that: These flux-guiding properties are achieved by designing the relevant components from magnetically soft materials.

22. The electromagnetic drive mechanism according to claim 17, characterized in that: In the region of the free ends (71) of the armature body end sections (72, 73), the circular surface enclosed by the conical inner circumferential surface (79) accounts for at least 90% of the circular surface which surrounds the outer circumference of the annular armature body end sections (72, 73).

23. A proportional solenoid valve, configured to control the flow of a fluid, comprising a valve housing (6), a valve member (3) movable relative to the valve housing (6) when a control movement (4) is performed, and an electromagnetic drive mechanism (2) for causing the control movement (4) of the valve member (3), characterized in that: An electromagnetic drive (2) is provided according to any one of claims 1 to 22, wherein the valve member (3) is drive-coupled to the armature (13) for generating its control movement (4).

24. The proportional solenoid valve according to claim 23, characterized in that: It is constructed as a seat valve, wherein the valve member (3) is arranged at the front end side of the armature (13) and is opposite to a valve seat (24) within a valve chamber (16) limited by the valve housing (6), the valve seat surrounding an internal channel opening (22b) of a first fluid channel (22) leading into the valve chamber (16) and the valve member (3) abuts against the valve seat in a closed position, wherein the armature (13) is axially penetrated by a pressure equalization channel (86), which, at least in the closed position of the valve member (3), establishes a fluid connection between the first fluid channel (22) and a pressure equalization chamber limited by the rear end side of the armature (13), wherein the cross-section of the pressure equalization chamber (92) is as large as the cross-section of the internal channel opening (22b) of the first fluid channel (22).

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