WO2019042770A1

WO2019042770A1 - Media-isolated low-energy valve

Info

Publication number: WO2019042770A1
Application number: PCT/EP2018/072090
Authority: WO
Inventors: Rainer Zwickel
Original assignee: Eto Magnetic Gmbh
Priority date: 2017-08-30
Filing date: 2018-08-15
Publication date: 2019-03-07
Also published as: DE102017119941A1

Abstract

The invention relates to an electromagnetically actuated valve device comprising armature means (14, 56-60) that can be moved as a reaction to the powering of stationary coil means (30) in order to open a preferably media-isolated fluid channel (12), said armature means being movable in a valve housing, against a restoring force from energy storage means (22) preferably comprising a spring, in an axial movement direction, towards stationary core means (40-44; 54) that conduct a coil magnetic flux and define an opening position of the armature means, the stationary core means comprising permanent magnet means (42; 70) that are associated and/or coupled in a magnetic-flux-conducting manner such that in the opening position, the permanent magnet means exert a permanent-magnetic force rectified by a coil magnetic force of the powered coil means on the armature means, and the energy storage means are designed and/or dimensioned such that the restoring force, particularly in the opening position of the armature means, is greater than the permanent-magnetic force and smaller than than the sum of the permanent-magnetic force and the coil magnetic force.

Description

Media-separated low-energy valve

The present invention relates to an electromagnetically actuated valve device according to the preamble of the main claim. Furthermore, the present invention relates to a use of such an electromagnetically actuated valve device.

Generic solenoid operated valve devices are well known in the art and, for example, in one embodiment as so-called media separated valve devices (in which a valve fluid to be switched by the valve has no physical contact with the valve mechanism or valve components, except the fluid channel, also used for medical applications. For example, FIG. 3 shows, for example, an electromagnetically actuated valve for a dialysis apparatus, in which a dialysis fluid to be switched is passed through a valve housing 10 with a nozzle 12 to be opened or closed by the valve. This (typically made of a media-compatible plastic) nozzle 12 as a valve seat is controlled open or closed by an end of an anchor unit 14 formed valve rubber 16 (including Faltenbalgstruktur), which, in the sectional view of FIG. 3 clearly visible, a nozzle-side , a widening head forming tappet portion 18 of the anchor unit 14 encloses. In the example shown, the plunger section 18 integrally continues a cylindrical anchor body 20, which in turn, supported by a compression spring 22, relative to a (equally cylindrical) stationary core unit 24 axially, ie along a defined longitudinal axis 26 and longitudinal movement, is movably guided. In the manner of an otherwise (equally known) magnetic actuator device is the core unit 24 and the anchor unit 14 um- closed by a winding 30 formed on a (non-magnetic) bobbin 28, which can be supplied with current via suitable electrical connections, not shown in the figure, by suitable ballast electronics (not shown). In response to such energization, a coil magnetic flux is generated which forms a flux circuit from the core unit 24 via a surrounding outer housing 32, a flux guide 34 (radially extending to the longitudinal direction 26) pressed thereinto, to the armature unit 14 and core unit 24. This results, recognizable by the conical shape of the core unit 24 in the direction of the anchor unit 14, a working air gap between the core and anchor; Similarly, the magnetic flux is introduced into the anchor unit 14 via a between the anchor unit 14 and the surrounding flux guide 34 by means of a trained air gap. The compression spring 22, which at one end is supported by an armature-side flat side of the stationary core unit and on the other hand by a bottom of a core-side axial bore in the anchor body 20, biases the armature unit 14 together with end-side valve in the manner shown in FIG. 3 in the de-energized state of the winding 30 or closure rubber 16 in the direction of the nozzle 12, so that in this de-energized state, the flow of fluid through the valve device is closed. It is therefore a so-called normally closed configuration (NC = normally closed). Only by energizing the winding 30 and thus a tightening in the direction of the core 24 force on the anchor unit 14 (against a restoring force of the return spring 22), the air gap between the core and armature is closed and the valve rubber 16 exposes the nozzle portion 12 (valve seat) so that the fluid flow is possible. A termination of the energization then leads, by action of the return spring 22, back to a closing of the valve seat, so that the apparatus shown in Fig. 3 as the generic prior art realizes a monostable actuator functionality. In the exemplary (nevertheless preferred) intended use of a valve circuit or valve control of a dialysis fluid for a dialysis machine, this means that for the opening of the valve (and hence the enabling of a fluid flow through the valve), the winding 30 must be energized continuously. At the same time, the generic, generic technology described in connection with FIG. 3 realizes a so-called fail-safe mode, thus ensuring that the return spring 22 always returns the armature unit 14 in the event of malfunction of the control, failure of an electrical power supply or other unplanned operating states in the closed position (position of FIG. 3) spends when no energization of the coil 30 more. In this way, a defined fluid flow state is ensured in particular also for the intended medical use, in particular, in case of disturbance of the voltage supply no unintentional (further) fluid supply of a dialysis patient can take place.

However, in particular also in the present medical context, the valve technology which is fail-safe in the manner described is in need of improvement. in fact, continuous (and proper) fluid supply, for example, of the dialysis machine to be regarded as an example, always requires continuous energization of the coil 30, and it is just about the example of a dialysis use that involves activations lasting several hours. This then not only ensures a corresponding continuous electrical energy requirement (which, for example, with regard to portable or mobile applications as potentially detrimental effect), also caused by (unavoidable) electrical coil resistances of the winding 30, a heat development, which is potentially detrimental to the (thermal sensitive) valve fluid and may require additional heat insulation measures. As a possible solution, which can be assumed to be known in principle from the prior art, the electromagnetic Aktorik the superpicture valve device instead of monostable - the return spring as a force storage means provides in the de-energized state of the winding for a defined reset function in a closed position Valve device - electroless bistable to design, ie the actuator switches between the initial position and an open position (armature unit 14 to the left in Fig. 3 deflected) and then each remains stably stable in these positions. Such bistability could be ensured, for example, by a mechanical latching function, alternatively by permanent magnet functionality, in which, for example, an armature-side permanent magnet, which adheres to the core unit in the extended state, ensures that the armature unit is in its extended (open) position remains in the de-energized state of the winding 30. However, this then requires a reset about by means of a suitable (reversed polarity) current pulse on the winding 30, which is to be avoided, especially in a sensitive medical context, because it should come about as a power failure of a power supply or the winding 30 acting on Vorschaltelektronik would In fact, this additional impulse for releasing the armature unit from the opening position (as it would then also be necessary in the case of a mechanical lock) no longer reliably ensures operation.

The object of the present invention is therefore to improve an electromagnetically actuated valve device according to the preamble of the main claim in terms of their operating characteristics, in particular to avoid or to avoid a potentially disadvantageous heat development and / or continuous energy consumption by continued energization of the coil means (winding) Nevertheless, it should be ensured in a reliable manner and for the realization of a fail-safe functionality that at the end of a power supply (be it intentionally, be it by malfunction) the valve closes reliably, without the need for additional control, a buffer voltage or other Bestromungsmaßnahmen. The object is achieved by the monostable solenoid-operated valve device having the features of the main claim; advantageous developments of the invention are described in the subclaims. Furthermore, protection in the context of the present invention is claimed for an advantageous use of this electromagnetically actuated valve device according to the invention for realizing a solenoid valve for medical applications, in which again the dialysis application discussed in the context of the invention is considered to be particularly preferred. In an advantageous manner according to the invention, the stationary core means (core unit) are first assigned with permanent magnet means such that they exert a permanently magnetically attracting force on the armature means (armature unit), at least in the extended operating condition applied to the core means or while it is energized.

This permanent magnetic force (which, like the electromagnetic or coil magnetic force generated by the energization of the coil means, the restoring force of the force storage means is opposite) then ensures that for holding the anchor means in the extended opening position of the valve device with respect to moving the anchor means, In particular, a release of the anchor means from the closed starting position, reduced coil current is necessary. This then advantageously has the effect that, in the opening and energizing state (potentially several hours on the example of the dialysis machine), the electrical energy consumption for the energization drops and advantageously the disadvantageous heating can be significantly reduced, since at the stop position of the armature unit (anchor means) on the core, the permanent magnet means make a contribution to the holding force, which must not be (more) applied by the energization.

At the same time, in the context of the present invention, the actuator components are dimensioned such that the permanent-magnetic holding force does not exceed the restoring force applied by the force-storing means to the armature unit; Rather, the (greater) spring force of the energy storage means ensures that despite attractive permanent magnetic adhesive force on the armature core at the core this is returned at the end of energization in the (the valve seat occluding) starting position, so that the above-discussed fail-safe mode is reliably implemented (And without it in particular further electronic control or Bestromungsmaßnahmen required for the coil means).

It is favorable, on the one hand and within the scope of preferred developments of the invention, to attach or embed the permanent magnet means, such as a further preferably axially magnetized permanent magnet body or permanent magnet disc, on or into the magnetically conductive core material. In this way, it is possible in particular to produce a module-like integrated module which has the additional advantage of retrofitting common (non-permanent-magnetic) core modules with otherwise unchanged or comparable dimensions, with the potential that even a modular system that is favorable in terms of production technology would be created can.

In this advantageous development of the invention as an integrated core module, it is additionally advantageous to enclose the permanent magnet body (such as a disk-like shape) axially at both ends of a core material (realized, for example, from soft iron) and coat the core material. side by means of a (then magnetically non-conductive) sleeve to provide shock relief. This then has the advantage that, based on the usually brittle and impact-prone permanent magnet material, an effective decoupling from mechanical damage to the core assembly can be realized, for example against an impact of the armature unit on the core.

An equally preferred alternative embodiment of the invention provides for the core-side permanent magnet means to be provided on the core assembly (core means) in such a way that they are provided radially outward or edgewise and preferably outside a (coil) magnetic flux flowing through the core means. As a result of this advantageous measure, a potentially undesirable influence on the electromagnetic coil magnetic flux by the permanent magnet unit can be prevented or reduced, wherein it is then additionally further-developing that an opposing motion partner, namely the armature means, form an equally radially projecting (and to provide something like a collar).

The present invention advantageously makes it possible, as stated above, to reduce a coil current which maintains the permanent opening state, since the permanent magnet means provided according to the invention make an additional holding power contribution. In order to simplify and optimize the control of the coil means so far, it is provided according to the invention further, the coil means electrical driving means for generating and applying the energization upstream so that an introduced into a winding of the coil means electrical power in the energization state between a higher power (about corresponding to a higher coil current) for a movement of the anchor means before reaching the opening position at the core means and a lower Ren performance (ie, a contrast lowered coil current) with or after reaching the opening position can be switched or controlled. While it is possible on the one hand to carry out this change or control position-dependent by evaluating a signal of a position sensor (suitably detecting an armature position) by the actuation means, it is nevertheless advantageous and preferred (and also feasible with little technical outlay) timer means to associate with the driving means or to integrate in this, that, after completion of a predetermined time interval after the start of the energization, the coil current is lowered in a predetermined manner (this time interval is then set or set and predetermined that it covers the period, which the anchor means need to reach from the de-energized home position the opposite open or stop position on the core means).

In the manner described, a monostable electromagnetically actuated valve can thus be realized in a surprisingly simple and elegant manner, which has superior safety properties (namely implementation of a fail-safe mode without necessary switching modifications or operating voltage buffers) combined with favorable electrical energy consumption properties and associated advantages heat. Thus, the present invention is eminently suitable for (thermally sensitive) valve tasks in a medical context, such as switching or control of a dialysis fluid, but the present invention is not limited to this application. Rather, the present invention is suitable for those monostable valve tasks, which combine defined failure operating conditions with optimized electrical energy consumption. Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and with reference to the figures; These show in Figure 1 is a schematic longitudinal sectional view of an electromagnetic actuator component for the realization of a solenoid valve as an electromagnetically actuated valve device according to a first embodiment of the invention. a detailed view of core means (core assembly) according to an embodiment of the invention compared to the embodiment of Figure 1; 1 shows a longitudinal sectional view through a generic electromagnetically actuated valve device for medical uses, FIG. 3 likewise illustrating the context of use of the present invention, by the actuator assembly according to FIG. 1 corresponding to the known actuator of FIG. 3 replaced; and FIG. 15 is a longitudinal sectional view of an actuator assembly of an electromagnetically operated valve device according to a third embodiment, in which core-side permanent magnet means are provided outside a coil-magnetic flux circuit.

In the exemplary embodiments to be described below and the context of use, identical reference numerals indicate correspondingly identical or directly functionally equivalent components, assemblies and functional components. Thus, the longitudinal sectional view of FIG. 1 shows an actuator assembly (in particular for cooperation with the further valve components of FIG. 3, which is to be considered as disclosed in the present invention and included in the present invention context) which replaces the core means 24 of FIG by a multi-part core structure, comprising a first core body 40, a disk-like (and axially magnetized according to the axial direction 26) permanent magnet body 42 and this in turn adjacent (and opposite the core body 40 arranged) second core body 44, so that in the longitudinal sectional view of Fig. 1 recognizable axially three-part structure arises. Enclosed is the permanent magnet plate 42 additionally provided by a radially shell side provided sleeve 46 of a non-magnetic material (eg brass or plastic material), which has the task, on the one hand coat the brittle permanent magnet material of the permanent disc 42 surround, but beyond also shock-absorbing or (related on the permanent magnets) to act as a shock absorber by buffering impact forces acting against the (brittle) permanent magnet material, for example by an impact of the armature unit 14 on the core total unit 42 to 46.

Advantageously, the permanent magnet 42 ensures that upon approach of the armature unit 14 due to energization of the winding 30, the electromagnetic forces rectilinearly superimposed permanent magnet forces of the permanent magnet disc 42 act on the armature unit and keep it there, at the latest upon reaching the stop position on the core , This common holding force of the energized winding 30 and the permanent magnet disc 42 counteracts a restoring spring force of the force storage means (spiral compression spring) 22, which is dimensioned so that when energized, the anchor means 14 are reliably held on the core. At the same time, the return spring 22 (Relative in particular to the permanent magnet 42) dimensioned so that when energized winding 30, the restoring spring force 22 exceeds a permanent magnetic attraction or adhesion to the armature unit 14, with the effect that only the Permanentmagnetschei- be 42, the anchor unit can not hold the core , This therefore by the expansion effect of the spring 22 back into the currentless closing or closing position (insofar as shown in FIG. 3) is spent. Accordingly, in this way, despite the contribution of the permanent magnet 42 at the stop state, which is effective both energetically and with respect to the coil heating, the fail-safe functionality is ensured, ie in the event of an energization end or a power failure, the action of the spring 22 always takes place defined and reliable return of the anchor unit 14 in the de-energized rest and closure state.

Fig. 2 shows a constructive variation of the module as in Fig. 1 (and thus in principle against common solid body of a core unit 24) interchangeable module: It can be seen how, to produce a best possible magnetic transition, the both sides of the permanent magnet disc 42 'bordering first (40 ') and second (44') core body form an axially continuous, cylindrical unit, wherein in the shell region radially outward of the permanent magnet disc 42 'and into the axially adjacent both sides core body, a circumferential protective and impact sleeve 46' is formed of non-magnetic material. The variant of FIG. 2 also illustrates, in the form of a core-side axial bore 48, an alternative possibility for receiving a compression spring 42 or the like energy store; an opening region 50 of the core body 40 'which opens to the right in the plane of the figure of FIG. 2 then serves to receive a (possibly also suitably conically shaped) armature unit. Fig. 4 shows another embodiment for realizing the present invention.

It can be seen how a yoke core unit 54 (one-piece, provided with a saturation recess 52) surrounds an anchor body 56 movable along the axial direction 26, together with plunger sections 58, 60 anchoring on both sides (wherein 58 is made of magnetically non-conductive material), wherein plain bearings 62, 64 ensure the relative axial mobility and a compression spring 22 is supported at one end by an inner annular shoulder of the yoke core 54, at the other end by an end wall of the anchor body 56 and thus the armature unit, in the plane of the figure of FIG. 4 in the direction to the right in a closed position (biased by not shown in detail, approximately analogous to Fig. 3 coupled valve components in the form of a valve rubber relative to a stationary valve seat).

While a winding 30 surrounds the yoke core unit 54 on the shell side and is accommodated in a coil housing 66 together with flux guide disk 67, and the groove 52 circulating around the circumference of the cylindrical yoke core 54 effects a magnetic separation along the axial direction in an otherwise known manner by saturation, in the exemplary embodiment 4 (the here realized as a rotating disc 70 and frontally attached to the housing 66, 67) permanent magnet unit radially outside of a certain coil of the assembly 54 see see provided (which is then in the course of a here on the anchor body 56 provided Flußleitscheibe 72, the anchor body 56 and over the cone air gap back to the yoke core 54 extends). Between the assemblies 70 and 72 arises in this way another, variably variable (as dependent on the anchor position) air gap through which the permanent magnetic attraction of the permanent magnet 70 on the associated magnetic flux. disc partner 72 acts. The reference numeral 74 shows a elastomeric buffer body, which, however, could also be understood by way of example as, for example, a tube (through which the device of FIG. 4 is connected in a medium-separating manner) passing through the device.

A schematically shown fixing member 76 secures the housing 66, 67 together ansitzendem permanent magnet ring 70 in the axial direction and against a possible impact or impact in the coil activation (which, against the restoring pressure force of the spring 22, then the armature unit 56, 58, 60 in would move the figure plane to the left).

Again, analogously to the above-described embodiment, the dimensioning of this restoring spring force 22 relative to the permanent magnetically attracting effect of the permanent magnet means 70 on the partner 72 so that when energized coil 30, the restoring spring force of the spring 22 exceeds an adhesive force of the permanent magnet means 72, ie the Anchor unit in a (as shown in FIG. 4) closed and normally stable rest and closure position is spent.

Claims

Electromagnetically actuated valve device with anchor means (14, 56-60) movable in response to an energization of stationary coil means (30) for opening a preferably media-separated fluid channel (12),

the force-storing means (22) having an axial movement in the direction of stationary core means (40-44; 54) conducting a coil magnetic flux and defining an opening position of the armature means are movably guided in a valve housing against a return force of preferably a spring,

characterized in that

the stationary core means have permanent magnet means (42; 70) associated with and / or magnetically flux-conductively coupled such that in the opening position the permanent magnet means exert a permanent magnetic force rectified by a coil magnet force of the energized coil means on the armature means and the force storage means are so arranged and / or dimensioned in that the restoring force, in particular at the opening position of the anchor means, is greater than the permanent magnetic force and less than the sum of the permanent magnetic force and the coil magnetic force.

Device according to Claim 1, characterized in that the core means are realized as a multi-part and preferably module-like assembly (42-46; 42'-46 ') in which a permanent magnet body (42, 42') which realizes the permanent magnet means is inserted with magnetic flux conduction, recorded and / or embedded. 3. Device according to claim 2, characterized in that the axially magnetized permanent magnet body along the direction the axial movement direction between immediately adjacent core bodies (40, 44, 40 ', 44') of the assembly is provided.

Apparatus according to claim 2 or 3, characterized in that the module-like and preferably radially symmetrical and / or cylindrical design of the module shell side of a sleeve (46, 46 ') is enclosed.

Device according to one of claims 1 to 4, characterized in that the permanent magnet means provided as a permanent magnet body at a radially projecting and / or abkragenden portion (66) of the core means

and for magnetically co-operating with a radially projecting and / or projecting anchor portion (72) of the anchor means (56-60) are formed to form an air gap with an air gap width dependent on an anchor position.

Apparatus according to claim 5, characterized in that the permanent magnet body (70) radially and / or axially outside of an at least partially cylindrical outer wall of the core means (54) formed electromagnetic flow circuit section is provided.

Device according to one of claims 1 to 6, characterized in that the coil means are preceded by electrical drive means for generating and applying the energization, which are formed so that an introduced into a winding of the coil means electrical power in the energization state between a higher power for movement the anchor means before reaching the opening position at the core means and a lower power with or after reaching the opening position is tax and / or changeable.

Apparatus according to claim 7, characterized in that the control means timer and / or position detecting means for detecting a position of the core means are assigned and / or upstream.

Use of the electromagnetically operated valve device according to one of claims 1 to 8 for the realization of a normally closed, in particular by means of a membrane or a bellows mediengetrennten monostable solenoid valve for medical applications, in particular for switching a Dialyseflu- ids, wherein in the non-energized state, the solenoid valve is closed and / or a fluid flow is interrupted.

Use according to claim 9, characterized in that the normally closed solenoid valve have no means for electronic anchor provision in the closed position, in particular no means for a reversal of the current supply.