EP3089177A1 - Circuit assembly and method for controlling a bistable magnetic valve for a fluid system - Google Patents

Abstract

The invention relates to a circuit arrangement (35) for controlling a bistable solenoid valve (1) for a fluid system, the circuit arrangement (35) having switching devices (T1, T2, T3, T4, T5, T6) and a control device (40) for actuating the switching devices for a first switching operation and a second switching operation, wherein the control device (40) controls the switching devices (T1, T2, T3, T4, T5, T6) in such a way that in a first switching process, a first electromagnetic device (18) is energized with a switching first current for forming a first electromagnetic field which adjusts the armature from a second armature position to a first armature position), in a second switching operation, a second electromagnetic device (19) is energized with a switching second current to form a second electromagnetic field adjusting the armature from the first armature position to the second armature position. It is provided that the control device (40) controls the switching devices such that the two electromagnet devices (18, 19) are energized respectively in the first switching operation and in the second switching operation, in particular in different directions and different current intensity or delayed in time.

Description

The invention relates to a circuit arrangement and a method for controlling a bistable solenoid valve for a fluid system, in particular a compressed air system in a vehicle. Furthermore, a solenoid valve device with the circuit arrangement and the bistable solenoid valve is provided.

As a bistable solenoid valve, in particular, a 3/2-way valve may be provided which applies a first pressure output in a first armature position to a second pressure output to vent a pressure outlet line or to connect with atmosphere; In this case, a pressure input is blocked. In a second armature position of the pressure input is connected to the first pressure output, z. B. for the pneumatic supply of a compressed air brake. The second pressure output is blocked here.

Thus, two positions can be formed by the solenoid valve. In a bistable solenoid valve both positions are kept safe in the de-energized state by a permanent magnet device, wherein a solenoid device is provided for the switching operations.

The DE 37 30 381 A1 shows such a bistable solenoid valve, which allows a permanent magnet holding force in both positions. In this case, an armature with two axially towards its end formed sealing means axially displaceable and abuts in its two positions to a first end core or second end core, wherein it closes in each of the positions with its respective sealant at the respective end core a fluid passage. A permanent magnet is provided to close a magnetic field via an outer magnetic yoke and the end cores toward the armature. ever after the formation of the air gap, a first permanent magnetic field is stronger or weaker than the respective other permanent magnetic field via the first core or a second permanent magnetic field via the second core. For switching the stable positions, either a first coil or a second coil is energized, which amplifies one of the two permanent magnetic fields to such an extent that, despite the formation of the air gap, it exceeds the magnetic holding force of the other permanent magnetic field and thus enables switching to the other stable end position.

To form the electromagnetic fields, however, a high number of ampere-turns is required, so that large-sized coils are required with considerable production costs and the switching speed is limited.

The US Pat. No. 7,483,254 B1 shows a control circuit for a bistable permanent magnet device, in which a control via pulsed signals, in particular with RC elements takes place.

The EP 0 328 194 A1 describes a bistable valve mechanism with a spring preload, which can be overcome by energization.

The invention has for its object to provide a circuit arrangement and a method for switching or for driving a bistable solenoid valve, which allow safe and fast switching between the positions with little effort.

This object is achieved by a circuit arrangement according to claim 1 and a method for switching the solenoid valve according to claim 13. Furthermore, a solenoid valve device with the circuit arrangement, a control device and the solenoid valve is provided. The dependent claims describe preferred developments.

Thus, both electromagnetic devices are energized during the switching operations.

For a switching operation, the electromagnetic device is thus energized on the switching side, at which the axial air gap between the core and the armature is provided, with a switching current in order to support the lower permanent magnetic field due to the air gap. The other electromagnetic device is preferably used for at least partial compensation of the holding, stronger permanent magnetic field, which holds the armature without an air gap at the other core.

The currents are preferably reversed by the electromagnetic means in the switching operations; Each solenoid device or coil can act in a switching operation switching and in the other switching operation compensating. Thus, preferably in each coil, the compensating current through this coil is set opposite to the (in the other switching operation) switching current from the current direction.

According to the invention it is recognized that the switching operation can be improved by the energization of both coils. Thus, not only the second electromagnet device for amplifying the weaker second permanent magnetic field is energized for the second switching operation from the first position to the second position, but also the first electromagnet device for at least partial compensation of the first permanent magnetic field. As a result of this at least partial compensation, the magnetic holding force of the holding first permanent magnetic field is thus already reduced, and the switching second electromagnetic field can be made smaller in terms of its magnetic field strength or the formation of ampere-turns in order to enable the switching process by amplifying the second permanent magnetic field.

In this case, in particular, it is also recognized that the supplementary energization of the compensating electromagnetic field basically does not require any additional expenditure on hardware, since a switching device, for example, is required anyway. B. switching transistors, are provided for its wiring.

The first electromagnetic field and the first permanent magnetic field thus form a first overall magnetic field, correspondingly forming the second electromagnetic field and the second permanent magnetic field thus form a second total magnetic field.

The two electromagnetic devices, i. in particular a first and second coil, may be connected in parallel or in series and connected together. The current directions for the respective switching operations are reversed accordingly, so that each one electromagnetic field as compensating, i. to compensate for the stronger permanent magnetic field and switching the other magnetic field, i. is used for the active circuit.

According to the invention, it is also recognized in particular that the complementary design of a compensating electromagnetic field can also be problematic, depending on the dynamics and position of the armature, since initially the switching total magnetic field due to the air gap is still small, whereas the "compensating" electromagnetic field used for compensation due to the missing air gap can grow up fast. So z. B. if too fast or too strong energizing the compensating first electromagnetic field may be so great that it not only compensates the first permanent magnetic field, but overcompensated so much that there is a first total magnetic field that is greater in magnitude than that provided for active switching second overall magnetic field, which is weakened by the air gap.

In order to avoid such overcompensation and thus a lack of switching operation, different configurations are provided alternatively or in addition.

According to a preferred embodiment, the currents are changed in magnitude: the compensating electromagnetic field is provided with a weaker compensating current and the switching electromagnetic field is formed with a larger switching current. The different current intensities can be adjusted in particular by pulsed control, in particular by PWM.

In this case, the electromagnet devices can be connected via high-side driver circuits to an upper supply voltage and via a low-side driver circuit (Loside) to a lower supply voltage, e.g. B. mass, are switched. It can be created a circuit arrangement that requires little hardware, z. B. only with a few switches, z. B. six transistors, gets along, which serve to drive the solenoid devices or coils; a more complex timing is generally not required.

The Hiside driver can z. B. directly on and off, and the different currents for the switching and compensating magnetic field by PWM control done. The electromagnetic devices can directly, z. B. parallel, between two serving as a driver driver transistors, in particular MOSFETs are connected, wherein at each terminal of each solenoid device (coil) then two transistors are connected as Loside driver, which are selectively controlled; It is thus possible in each case a "crosswise operation" via a Hiside driver for both coils and selective control of the "opposite" Loside driver.

Thus, preferably, the compensating electromagnetic field is weaker in that the compensating current is set to be weaker in magnitude than the sustaining current. Thus, in each solenoid device, preferably, the compensating current is opposite in direction to the holding current and smaller in magnitude.

Additionally or alternatively, a temporally variable energization or control of the coils can take place, in which the current is not immediately moved to its maximum value, but is raised with a time delay, z. B. with a steady increase and / or with a sudden increase over at least one mean value. So z. B. a time switch-on ramp up and / or a discrete increase over one or more mean values carried out, which allow a mechanical adjustment of the anchor, d. H. z. B. in a period above 10 ms, z. In a period of 100 ms. Thus, the complementary electromagnetic field in the turn-on ramp initially compensates for the air gap loose holding permanent magnetic field, while on the other hand, the switching electromagnetic field amplifies the permanent magnetic field, so that in the duty cycle an electromagnet training is achieved, the anchor in the desired manner in the other switching position pulls before the first permanent magnetic field is overcompensated.

The energization of both electromagnetic devices cooperates in particular synergistically with a radially arranged permanent magnet device, by which a radial permanent magnetic field is formed which extends between the electromagnet devices. Thus, preferably, a radial first and radial second permanent magnetic field are formed, which can each have a holding effect and selectively amplified by the switching electromagnetic field or can be compensated in whole or in part by the holding electromagnetic field. Thus, a permanent magnetic field extends in the radial direction from the inner armature via the permanent magnet and an outer magnetic yoke forming two permanent magnetic fields extending from the yoke either at one axial end over the first core to the armature or at the other end across the second core to the armature, in each of the two positions, respectively an axial air gap is provided from the armature to one of the two cores.

The permanent magnet device may be designed to be annular, d. H. as a ring or disc, which - unlike conventional magnets - is magnetized in the radial direction. Alternatively to a disc can also be several z. B. rod-shaped permanent magnets are used, which are each magnetized radially outwardly and preferably avoid tilting moments of the armature perpendicular to the axial direction by their symmetrical design.

By the permanent magnet means is located radially outside the armature, in particular in the axial direction between the two coils of the two solenoid devices, a larger space is available, so that here also materials can be used, which allow a greater axial extent and thus more cost-effective are as z. B. Rare earth materials.

The solenoid valve device has the circuit arrangement and further the bistable solenoid valve.

Fig. 1

ein bistabiles Magnetventil gemäß einer Ausführungsform in geschnittener Darstellung;

Fig. 2

ein Magnetventil gemäß einer weiteren Ausführungsform mit ergänzendem Polrohr;

Fig. 3

eine Darstellung des Verlaufs der Magnetfeldlinien;

Fig. 4a) und b)

eine erste Ausbildungen der Permanentmagnet-Einrichtung;

Fig. 5

eine zweite Ausbildungen der Permanentmagnet-Einrichtung

Fig. 6

eine Schaltungsanordnung zur Ansteuerung der Spulen gemäß einer ersten Ausführungsform mit a) Reihenschaltung und b) Parallelschaltung beider Spulen;

Fig. 7

eine schaltungstechnische Realisierung einer getrennten Spulenansteuerung gemäß einer Ausführungsform;

Fig. 8

Zeitdiagramme des Spulenstroms gemäß Ausführungsformen mit Rampen-Ansteuerung;

Fig. 9

ein Schnittbild des bistabilen Magnetventils gemäß einer Ausführungsform in der ersten Ankerstellung; und

Fig. 10

ein Schnittbild des bistabilen Magnetventils aus Fig. 9 in der zweiten Ankerstellung.

The invention will be explained in more detail below with reference to the accompanying drawings of some embodiments. Show it:

Fig. 1

a bistable solenoid valve according to an embodiment in a sectional view;

Fig. 2

a solenoid valve according to another embodiment with additional pole tube;

Fig. 3

a representation of the course of the magnetic field lines;

Fig. 4a) and b)

a first embodiments of the permanent magnet device;

Fig. 5

a second embodiments of the permanent magnet device

Fig. 6

a circuit arrangement for driving the coils according to a first embodiment with a) series connection and b) parallel connection of both coils;

Fig. 7

a circuit implementation of a separate coil drive according to an embodiment;

Fig. 8

Timing diagrams of the coil current according to embodiments with ramp drive;

Fig. 9

a sectional view of the bistable solenoid valve according to an embodiment in the first armature position; and

Fig. 10

a sectional view of the bistable solenoid valve Fig. 9 in the second anchor position.

A bistable solenoid valve 1 is in particular for use in a compressed air system, in particular as a 3/2-way solenoid valve with three terminals, preferably a pressure input 2a, a first pressure outlet 2b and a second pressure outlet 2c, the z. B. can serve as a vent formed. Thus, the bistable solenoid valve 1 in a pneumatic system or compressed air system, z. B. the compressed air system of a commercial vehicle, serve, optionally according to the first anchor position I the Fig. 1 to connect to the first pressure outlet 2b the second pressure outlet 2c and thus the vent to vent the compressed air supply line, or to connect the connected to the pressure inlet 2a compressed air supply line, as further below with reference to FIGS. 9 and 10 is explained.

For this purpose, the bistable solenoid valve 1 on an armature guide tube 6 and a longitudinally adjustable in the armature guide tube 6 in the axial direction A guided anchor 7. At the armature 7, a first valve seal 8 is formed, which at a first valve seat 9, z. B. to the closure of the pressure input 2a, comes to rest, as well as continue a second valve seal 10, which abutment against a second valve seat 11, z. B. for closing the second pressure output 2c comes.

The valve seals 8 and 10 are advantageously spring biased by an armature spring 13 for sealing engagement with their respective valve seat 9 and 11, respectively.

The armature 7 is magnetically conductive, d. H. made of ferromagnetic material; in the axial direction A closes to a first side of a first core 12, in which according to this embodiment, the pressure input 2a and the first pressure outlet 2b are formed, and to the other, second side of a second core 14, in which the second pressure outlet 2c for the vent is formed.

Radially outside the armature guide tube 6, a magnetic device 15 is arranged, which has a permanent magnet means 16 and an electromagnet means 17, wherein the electromagnet means 17 in turn with a first coil 18 and a second coil 19 is formed. The entire magnet device 15 in a magnetic yoke 20, 21 is received, which is formed by a Jochtopf 20 with pot bottom 20a and cylindrical pot wall 20b and the Jochtopf 20 to an axial side closing yoke disc 21.

The two cores 12 and 14 are advantageously in the radial direction R directly to the yoke disc 21 and the Jochtopf 20, ie without a radial air gap. Furthermore, the armature 7 lies in its two armature positions or positions directly in the axial direction A or -A on one of the two cores 12, 14 and has an air gap 22 to the respective other core 14, 12. Thus lies in the in Fig. 1 and 2 shown in the first position I of the armature 7 in the axial direction A directly, ie without an air gap, on the first core 12, wherein an axial air gap 22 between the armature 7 and the second core 14 is formed; Accordingly, the armature 7 is in the second position II, not shown here directly to the second core 14, ie also without an air gap, in which case an air gap between the armature 7 and the first core 12 is formed.

The permanent magnet device 16 is advantageously arranged axially between the first coil 18 and the second coil 19 and radially magnetized, ie the magnetization and thus the magnetic flux lines of the permanent magnetic field PM extend in the radial direction R, z. B. radially outward, ie perpendicular to the axis A. Here are according to Fig. 4, 5 different configurations of the permanent magnet device 16 possible.

According to Fig. 4 are z. B. four individual permanent magnets 16a, 16b, 16c and 16d provided, each of which is elongated and extending in each case in a radial direction, ie perpendicular to the axis A, each having the same polarity, for. B. one to the armature guide tube 6 facing north pole N and to the radially outer pot wall 20b of the yoke pot 20 facing south pole S, or vice versa.

According to the embodiment of the Fig. 5 a permanent magnet disc 16e is provided, which is designed as a ring or disc and in this case is magnetized in the radial direction.

In principle, the permanent magnet device 16 z. As well as less, z. B. only two permanent magnets 16a, 16c accordingly Fig. 4 , Or also have a different number of individual permanent magnets, which are advantageously arranged so symmetrical that lateral forces and tilting moments are avoided perpendicular to the axis A.

Since the permanent magnet device 16 is formed outside the armature guide tube 6, it can also be formed with a wider axial extent, so that conventional materials for permanent magnets, for. As an iron alloy or a ceramic material used; the use z. B. rare earth is not required in principle.

The common permanent magnetic field PM thus extends in the radial direction R through the permanent magnet means 16 and subsequently through the yoke 20, 21, being axially in both directions, i. -A and A run, i. along the pot wall 20b as first permanent magnet field PM1 and second permanent magnet field PM2, the permanent magnet fields PM1, PM2 then extending radially downwards along the pot bottom 20b and the yoke disc 21 to the cores 210, 21 at the axial ends, and subsequently axially, i. in the direction of A or -A, to the armature 7 and back to the permanent magnet device 16th

The two permanent magnetic fields PM1, PM2 can thus each z. B. have approximately the shape of a torus; the entire permanent magnetic field PM is thus z. B. a double torus or dumbbell-shaped.

In the first anchor position I or ventilation position of the Fig. 1 the magnetically conductive armature 7 is located on the first core 12, so that in this case the first permanent magnetic field PM1 extends directly from the first core 12 through the armature 7, and in the armature 7 in the axial direction to the permanent magnet device 16. An air gap is formed at best as a radial air gap between the armature 7 and the permanent magnet means 16, but not as an axial gap, so that the first permanent magnetic field PM1 forms a strong magnetic holding force of the armature 7 on the first core 12. The extending through the second core 14 second permanent magnetic field PM2, however, passes through the air gap 22 to the armature 7 and is significantly weakened by the air gap 22. Thus, the magnetic holding force of the first permanent magnetic field PM1 is significantly larger than the attractive force of the second permanent magnetic field PM2; the armature 7 is in the right position, ie the anchor position I of Fig. 1 , kept safe.

Since the bistable magnetic valve 1 is basically symmetrical in the axial direction A with respect to the formation of the two cores 12 and 14 and the coils 18 and 19, the in Fig. 1 not shown second armature position II held securely, since here an air gap is formed correspondingly between the armature 7 and the first core 12, which weakens the first permanent magnetic field PM1, however, there is a strong second permanent magnetic field PM2.

The first coil 18 generates a first electromagnetic field EM1; Accordingly, the second coil 19 generates a second electromagnetic field EM2, which overlap with the permanent magnetic fields PM1, PM2 and each other.

The first electromagnetic field EM1 of the first coil 18 is also toroidal in shape and extends substantially corresponding to the first permanent magnetic field PM1, in particular in rotationally symmetrical design of the permanent magnetic field PM1 after Fig. 5 :

The first electromagnetic field EM1 initially runs within the first coil 18, ie in the axial direction A - depending on the current supply - from the first core 12 in the axial direction inwards or outwards, ie, for example from the outside (in FIG Fig. 1 right) inwardly to the armature 7, and from the armature 7 radially outwardly, ie along the permanent magnet means 16 outwardly, and from there along the pot wall 20b and the cup bottom 20a radially inwardly back to the first core 12. Accordingly when energizing the second coil 19, the second electromagnetic field EM2 similar to the second permanent magnetic field PM2, ie - depending on the polarity - of the second core 14 in the axial direction A to the armature 7 back, or in the opposite direction from the armature 7 to the second core 14 out , and in each case in the radial direction radially outwards along the permanent magnet device 16, the pot wall 20b in the axial direction, and along the yoke plate 21 radially inwardly.

In Fig. 1 Thus, the second electromagnetic field EM2 is again weakened by the air gap 22, the first electromagnetic field EM1, however, not.

The switching operations SV1 and SV2 of the bistable solenoid valve 1 between the first armature position I and the second armature position II effected by energization of both coils 18 and 19. For the second switching operation SV2 of the first armature position I of Fig. 1 Based on a first electromagnetic field EM1 of the first coil 18 is constructed, which is the first permanent magnetic field PM1 opposite and this particular partially compensated, so that the magnetic holding force of the armature 6 on the first core 12 is already at least reduced. Furthermore, the second coil 19 is energized such that the second permanent magnetic field PM2 is amplified by the second electromagnetic field EM2, ie both fields PM2 and EM2 point in the same direction, so that in spite of the air gap 22 acting on the armature 7, in Fig. 1 towards the left magnetic force increases and the armature 7 in Fig. 1 adjusted to the left, causing the air gap 22 is reduced and disappears completely, and an air gap between the armature 7 and the first core 12 is formed.

Thus, one of the electromagnetic fields EM1 and EM2 is compensating and the other switching. For the second switching operation SV2 of the first anchor position I or vent position of the Fig. 1 Thus, a first current I1 guided by the first coil 18 acts compensatingly, ie as a compensating first current I1_k, and a second current I2 conducted through the second coil 19 switches, ie as a switching second current I2_s. For the first switching operation SV1 back into the first armature position I, a compensating second current I2_k is passed through the second coil 19, and a first current I1_s is conducted through the first coil 18.

The two coils 18 and 19 are connected via coil terminals 61a, b and 62a, b to respective circuit arrangements 30, 35.

The two coils 18 and 19 can according to the in Fig. 6 a) and b) shown embodiments of a control device 40 controlled by a circuit arrangement 30, which in particular represents an output stage, are energized together, as a parallel connection or series connection. Thus, a solenoid valve device 5 is formed, which has the bistable solenoid valve 1, the circuit arrangement 30 and the control device 40.

In this case, it is advantageously recognized that an immediate and complete startup of the respective compensating current, in Fig. 1 thus the first current I1_k, can cause the compensating, z. B. first electromagnetic field EM1 is too strong and the difference EM1 - PM1 can be greater in magnitude than the positively overlapping, but weakened by the air gap 22, switching second overall field EM2 + PM2.

Therefore, according to a first embodiment, at least the compensating current I1_k or I2_k is variable in time, z. B. ramped up, advantageously via a ramp and / or with discrete increase. In the case of a series connection of the two currents I1, I2, both currents can thus be ramped up with a time delay. This can be over in Fig. 6 a) or b) shown circuitry 30 done.

The coils 18 and 19 are according to the circuit arrangement 30 of Fig. 6 a) in series or b) connected in parallel, wherein four transistors, preferably circuit MOSFETs Tr1, Tr2, Tr3 and Tr4, are connected as output stage H bridge. This is done via control signals S1, S2, S3, S4 energization either with Tr1 = ON, Tr4 = ON and Tr2 = OFF, Tr3 = OFF to the supply voltage Uv of z. B. 24 V or 12 V via Tr1, the series connection of the coils 19 and 18, and Tr4 to ground GND to lead, or corresponding symmetrically reversed with Tr1 = OFF, Tr4 = OFF, Tr2 = ON and Tr3 = ON to the supply voltage Uv over Tr2 and the series connection of the coils 18 and 19 and Tr3 to ground GND to lead.

The H bridge of the Fig. 5 is here in particular also for the formation of a temporal ramp according to Fig. 8 suitable, in which the common coil current I, ie I1 = I2 = I and thus also I = I_k (compensating current) = I_s (switching current) according to Fig. 8a ) is switched on at time t1 and ramped up to a maximum current value I_max, which it reaches at a time t2. At a subsequent time t3, the common current I can be switched off immediately below. In addition, the Amperewindungen AW are drawn, resulting in the product of the current and the number of turns, the starting-shift duration .DELTA.t1 between t2 and t1 is z. B. Δt2 = 50 to 70 ms, the total switching time .DELTA.t2 between t3 and t1 is z. B. Δt2 = 100 ms. The purely mechanical switching of the valve Depending on the tolerance position of the individual components in the valve between the times t1 and t2.

Fig. 8b shows an alternative control in which at time t1, the current is driven immediately to a mean current value I_mid, and subsequently with a linear ramp up to the time t2 to the maximum value I_max until it is turned off again at time t3. The switching periods Δt1 and Δt2 can have similar values as in Fig. 8a accept.

Thus, between t1 and t2, first in the first position I of Fig. 1 weak first electromagnetic field EM1 is formed, which fully or partially compensates the holding permanent magnetic field, here thus the first permanent magnetic field PM1, but only at time t1 reaches the maximum current value I_max. The starting shift duration .DELTA.t1 is sufficient to achieve a mechanical adjustment of the armature 7 away from the first armature position I; as soon as an air gap forms between the armature 7 and the first core 12, the risk of unintentional holding in the first armature position I has already been significantly reduced.

Fig. 7 shows a circuit arrangement 35, which can be realized without a time ramp, with driving of the transistors, in particular MOSFETs T1, T2, T3, T4, T5, T6, which are provided as itside transistors T1 and T2 and Loside transistors T3 to T6, over Hiside control signals Si1 and Si 2 and Loside- control signals Si3, Si4, Si5, Si6.

For both switching operations SV1, SV2 is in each case the compensating, weaker electromagnetic field, ie in Fig. 1 respectively. Fig. 3 the first electromagnetic field EM1, according to only partially controlled. This can advantageously take place via PWM, wherein the activation by switching states ON, OFF and to form a power current between the minimum and maximum value, the control via PWM, ie temporary control occurs.

Fig. 7a ) shows the circuit, Fig. 7b ) supplementary the following table of activation phases switching operation Si1 Si2 Si3 Si4 Si5 si6 SV1 (II → I) ON OFF OFF 100% OFF 25% SV2 (I → II) OFF ON 25% OFF 100% OFF

Here, the percentages refer to the PWM drive, i. the proportion of "ON" or transistor modulation; the value 25% thus stands in particular for a PWM control in which 25% of the clock period "ON" is present. SV1 is the first switching operation for setting the first armature position I, SV2 corresponding to the second switching operation for setting the second armature position II.

Fig. 7c) and Fig. 7d Graphically illustrates the current paths in the two switching operations SV1 and SV2, with the switching currents I1_s and I2_s and compensating currents I1_k and I2_k, in addition z. B. freewheeling currents FP train.

The diodes D1, D2, D3, D4, D5, D6, D7, D8 are used in the circuit arrangement 35 of Fig. 7 the prevention of reverse currents and the possibility of freewheeling currents of the coils 18 and 19.

Fig. 2 shows an evolution of the Fig. 1 in which a pole tube 28 is additionally provided radially between the permanent magnet device 16 and the armature 7, or the armature guide tube 6, for a better transition allow the field lines and the permanent magnetic field in the armature 7.

FIGS. 9 and 10 show a detailed design of a solenoid valve 1 accordingly Fig. 1 or 2 , The permanent magnet device 16 is here opposite for illustrative purposes Fig. 1 and 2 reversed polarity used. Compressed air 25a is from a compressed air supply 25, z. B. a compressed air reservoir, fed via a compressed air supply line 23 to the pressure input 2a, and passed over the first pressure output 2b and a pressure output line 26 to a consumer 24. To the second pressure outlet 2c, which serves as a vent, a pressure outlet 27 is attached directly or indirectly via a conduit.

In the first anchor position I, ie the venting position of Fig. 9 , the compressed air applied to the pressure inlet 2a and the inner bore 42 of the first core 12 is blocked at the closed first valve, ie between the first valve seat 9 and the first valve seal 8. Compressed air 25a can from the consumer 24 via the pressure-output line 26, the first pressure outlet 2b, then via an outer axial bore 43 of the core 12, an interior 29 of the armature 7, in which preferably also z. B. the inner armature spring 13 is provided, and are guided over the axial gap 22 of the open second valve 10,11 and the bore 14a of the second core 14 to the second pressure outlet 2c and thus to the pressure outlet 27 for venting. The second valve 10, 11 is thus open, since the second valve seat 11 is separated from the second valve seal 10 by the axial gap 22.

In the second anchor position II, ie the ventilation position of the Fig. 10 , the first valve 8, 9 is open, ie the axial gap 22 is formed between the first valve seat 9 and the first valve seal 8. Accordingly, that is second valve 10, 11 closed by the second valve seat 11 rests on the second valve seal 10. Compressed air 25a is thus from the compressed air supply 25 via the compressed air supply line 23, the pressure inlet 2a, the inner bore 42, the open first valve 8, 9, the axial gap 22, the radially outer bore 43 to the first pressure outlet 2b and thus to the Consumer 24 led.

The bores 42, 43 in the first core 12 are advantageously formed by the first core 12 is formed with an inner tube 12 a and an outer tube 12 b, between which at least in some areas of the circumference, the outer axial bore 43 is formed; the inner bore 42 is formed by the central bore of the inner tube 12a.

The armature 7 is formed according to the embodiment shown here by a first anchor part 7a and a second anchor part 7b, the z. B. be joined together by press fitting; the armature spring 13 presses the valve seals 8 and 10 apart axially. The armature 7 can thus be joined with an armature interior 29 which, as described above, serves as an air duct for the ventilation.

List of Reference Numerals (part of the description)

1

bistable solenoid valve

2a

pressure input

2 B

first pressure outlet to pressure connection line / output line

2c

second pressure outlet for venting

3, 4

Compressed air supply line and compressed air outlet line

5

bistable solenoid valve device

6

Armature guide tube

7

anchor

7a

first anchor part

7b

second anchor part

8th

first valve seal to anchor 7

9

first valve seat

10

second valve seal to anchor 7

11

second valve seat

12

first core

12a

Inner tube of the first core 12

12b

outer tube of the first core 12

13

inner armature spring in armature 7 between the valve seals 8 and 10th

14

second core

15

Magnet means

16

Permanent magnet means

16a, b, c, d

rod-shaped permanent magnets

16e

Permanent magnet ring

17

Electromagnet means

18

first coil

19

second coil

20

Jochtopf

20a

pot base

20b

pot wall

21

yoke disc

22

air gap

23

Compressed air supply

24

consumer

25

Air Supply

25a

compressed air

26

Pressure output line

27

pressure outlet

28

Pole tube for radial field line transition

29

Anchor interior

30

Circuitry of the Fig. 6 for ramp control

35

Circuitry of the Fig. 7 for separate coil control

40

control device

42

central bore in the first core 12

43

outer bore in the first core 12, between the tubes 12a, 12b

50

fluid system

61a, b

Coil terminals of the first coil 18 to the circuit arrangement

62a, b

Coil terminals of the second coil 19 to the circuit arrangement

Tr1, Tr2, Tr3, Tr4

Transistors of the circuit arrangement 30

T1, T2, T3, T4, T5, T6

Transistors of the circuit arrangement 35

uv

supply voltage

GND

Dimensions

D1 to D6

diodes

A

Axis, axial direction

R

radial direction

PM

Total magnetic field

PM1

first permanent magnetic field

PM2

second permanent magnetic field

EM1

first electromagnetic field

EM2

second electromagnetic field

N, S

North Pole, South Pole

I

Current in series connection

I1

first current through the first coil 18th

I1_s

switching first current

I1_k

compensating first current

I2

second current through the second coil 19th

I2_s

switching second stream

I2_k

compensating second stream

S1

first drive signal of the ramp control

S2

second drive signal of the ramp control

S3

third drive signal of the ramp control

S4

fourth drive signal of the ramp control

Si1

first hiside control signal

Si2

second Hiside control signal

Si3

third loside control signal

Si4

fourth loside control signal

Si5

fifth loside control signal

si6

sixth loside control signal

SV1

Reset switching operation, first switching operation

SV2

Anchor switching process, second switching operation

Claims (19)

Circuit arrangement (30, 35) for driving a bistable solenoid valve (1) for a fluid system (50),
wherein the circuit arrangement (30, 35) comprises switching devices (T1, T2, T3, T4, T5, T6, Tr1, Tr2, Tr3, Tr4) and a control device (40) for activating the switching devices (T1, T2, T3, T4, T5 , T6, Tr1, Tr2, Tr3, Tr4) for a first switching operation (SV1) and a second switching operation (SV2),
wherein the control means (40) controls the switching means (T1, T2, T3, T4, T5, T6, Tr1, Tr2, Tr3, Tr4) in such a way that
in a first switching operation (SV1), a first electromagnetic device (18) is energized with a switching first current (I1_s) for forming a first electromagnetic field (EM1) adjusting the armature (7) from a second armature position (II) to a first armature position (I) )
in a second switching operation (SV2), a second electromagnetic means (19) is energized with a switching second current (I2_s) for forming a second electromagnetic field (EM2) adjusting the armature (7) from the first armature position (I) to the second armature position (II) )
characterized in that
the control device (40) is designed in such a way for activating the switching devices (T1, T2, T3, T4, T5, T6, Tr1, Tr2, Tr3, Tr4) that the two electromagnetic devices (18, 19) are in each case in both the first switching operation ( SV1) as well as in the second switching process (SV2) are energized. Circuit arrangement (30, 35) according to claim 1, characterized in that the two electromagnet devices (18, 19) are connected in parallel or in series and by the control device (40) for the first switching operation (SV1) in a first direction and for the second switching operation (SV2) can be energized in a second direction opposite to the first direction. Circuit arrangement (35) according to claim 1 or 2, characterized in that the control device (40) is designed in such a way for driving the switching devices (T1, T2, T3, T4, T5, T6) that in the second switching operation (SV2) the first Electromagnetic device (18) for at least partially compensating a first permanent magnetic field (PM1) with a smaller compensating first current (I1_k) and the second electromagnet means (19) for amplifying a second permanent magnetic field (PM2) is energized with a larger switching second current (I2_s), and
in the first switching operation (SV1), the second electromagnetic means (19) for at least partially compensating the second permanent magnetic field (PM1) with a smaller compensating second current (I2_k) and the first electromagnet means (18) for amplifying the first permanent magnetic field (PM2) with a larger one is energized switching first current (I1_s). Circuit arrangement (30, 35) according to one of Claims 1 to 3,
characterized in that the switching devices (T1, T2, T3, T4, T5, T6; TR1, Tr2, Tr3, Tr4) are connected as highside drivers (T1, T1, T2) connected between an upper supply voltage (Uv) and the electromagnetic devices (18, 19). T2, Tr1, Tr2), and between the solenoid means (18, 19) and a lower supply voltage, e.g. Ground (GND), switched lowside drivers (T3, T4, T5, T6, Tr3, Tr4) are provided. Circuit arrangement (30, 35) according to claim 4, characterized in that the control device (4) pulsed signals (Si3, Si4, Si5, Si6), in particular pulse width modulation signals, for adjusting the compensating lower currents (I1_k, I2_k) and the switching larger currents (I1_s, I2_s), in particular to the low-side drivers (Tr3, Tr4). Circuit arrangement (35) according to one of the preceding claims,
characterized in that the control device (4) controls the switching devices (T1, T2, T3, T4, T5, T6, TR1, Tr2, Tr3, Tr4) in such a way that the compensating first current (I1_k) of the second switching process (SV2) corresponds to the switching first current (I1_s) of the first switching operation (SV1) is opposite and smaller in magnitude, and
the compensating second current (I2_k) of the first switching operation (SV1) is opposed to the switching second current (I2_s) of the second switching process (SV2) and smaller in magnitude. Solenoid valve device (5) having a circuit arrangement (30, 35) according to one of the preceding claims and a solenoid valve (1),
wherein the solenoid valve (1) comprises: a between the first anchor position (I) and second anchor position (II) adjustable anchor (7), a first core (12) for mounting the armature (7) in the first armature position (I) and a second core (14) for mounting the armature (7) in the second armature position (II), wherein the armature (7) for conditioning is provided on each of the cores (12, 14) forming an air gap (22) to the other core (14, 12), a permanent magnet device (16) for forming a first permanent magnetic field (PM1), which passes over a magnetic yoke (20, 21), the first core (12) and the armature (7), and a second permanent magnetic field (PM2) passing over the magnetic yoke (20, 21), the second core (14) and the armature (7), a in the first armature position (I) closed first valve means (8, 9) and in the second armature position (II) closed second valve means (10, 11), a first electromagnet device (18) for forming a first electromagnetic field (EM1) displacing the armature (7) in the first switching process (SV1) into the first armature position (I) and a second electromagnet device (19) for forming an armature (7) in FIG the second switching operation (SV2) in the second armature position (II) adjusting second electromagnetic field (EM2), wherein the circuit arrangement (30, 35) is provided for driving the first electromagnetic device (18) and the second electromagnetic device (19). Solenoid valve device (5) according to claim 7, characterized in that the two electromagnetic fields (EM1, EM2) respectively between the radially outer yoke (20, 21) and the radially inner armature (7) in the radial direction (R) through the permanent magnet device (16). Solenoid valve device (5) according to claim 7 or 8, characterized in that the permanent magnet device (16) in the radial direction is magnetized relative to an axial direction (A). Solenoid valve device (5) according to one of claims 7 to 9, characterized in that the permanent magnet device (16) is positioned radially outside the armature (7) and between the first coil (18) and the second coil (19). Solenoid valve device (5) according to one of claims 7 to 10,
characterized in that
the solenoid valve (1) is designed as a 3/2-way valve with a pressure input (2a), a first pressure outlet (2b) and a second pressure outlet (2c),
wherein the first pressure outlet (2b) in the two armature positions (I, II) is respectively connected to either the pressure inlet (2a) or the second pressure outlet (2c) and the respective other port (2c, 2a) is blocked. Solenoid valve device (5) according to one of claims 7 to 11, characterized in that in the armature (7) an armature interior (29) is formed in exactly one of the armature positions (I) in the air path between the open terminals ( 2b, 2c) is provided and / or flows through the air. Method for switching a bistable solenoid valve (1) for a fluid system (50), in which
in a first switching operation (SV1) an armature (7) from a second armature position (II) in the first armature position (I) is adjusted by a first solenoid device (18) is energized with a switching first current (I1_s) to form a den Anchor (7) adjusting the first electromagnetic field (EM1),
in a second switching operation (SV2) the armature (7) in the second armature position (II) is adjusted by a second electromagnet means (19) with a switching second current (I2_s) is energized to form a armature (7) adjusting the second electromagnetic field (EM1)
the armature being held in the first armature position (I) by a first permanent magnetic field (PM1) and in the second armature position (II) by a second permanent magnetic field (PM2),
characterized in that
the two electromagnetic devices (18, 19) are respectively energized in both the first switching process (SV1) and in the second switching process (SV2). A method according to claim 13, characterized in that in the first switching operation (SV1), the second electromagnet means (19) is energized with a compensating second current (I2_k) for forming a holding the second permanent magnetic field (PM2) at least partially compensating second electromagnetic field (EM2). .
in the second switching operation (SV2), the first electromagnetic device (18) is energized with a compensating first current (I1_k) for forming a first electromagnetic field (EM1) at least partially compensating the first permanent magnetic field (PM1). A method according to claim 14, characterized in that the compensating first current (I1_k) of the second shift (SV2) the switching first current (I1_s) set of the first switching operation (SV1) against and is smaller in magnitude, and
the compensating second current (I2_k) of the first switching operation (SV1) is opposed to the switching second current (I2_s) of the second switching process (SV2) and smaller in magnitude. A method according to claim 15, characterized in that the first and second current (11, I2) by pulse modulation, z. B. by means of PWM clocking, can be adjusted. A method according to claim 13 or 14, characterized in that the compensating current (I_K, I_K1, I_k2) is time-varying and / or increasing in time in the switching electromagnetic means (18, 19) is controlled and only after a start-up period (Δ_t1) a maximum current value (I_max) reached. A method according to claim 17, characterized in that the armature (7) in the respective armature position (II) against the holding core (12, 14), passes through which the holding permanent magnetic field (PM1, PM2), and the armature (7) is moved away from the holding core (12, 14) in each switching operation (SV1, SV2) even before reaching the maximum current value (I_max) of the compensating current (I_k), forming an air gap (22) between the Anchor (7) and the holding core (12, 14) for attenuating the sustaining permanent magnetic field (PM1, PM2) and the compensating electromagnetic field. A method according to claim 17 or 18, characterized in that in the reset switching operations (SV1, SV2) of the compensation current (I_k) in each case with a time-delayed, steady and / or sudden increase to the maximum current value (I_max) is raised.

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