EP3086335B1 - Magnet valve device for a fluid system and method for switching a solenoid valve - Google Patents

Description

The invention relates to a solenoid valve device with a bistable solenoid valve for a fluid system, in particular a compressed air system in a vehicle, and a method for switching a bistable solenoid valve.

As a bistable solenoid valve, in particular a 3/2-way valve may be provided which applies a first pressure output in a first position or 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 position, 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. Depending on the design of the air gap, a first permanent magnetic field is via the first core or a second permanent magnetic field via the second Core stronger or weaker than the other permanent magnetic field. 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.

Inset to the prior art

EP 1 331 426 A2 discloses a pulse driven solenoid, particularly for a solenoid valve, including a coil for generating a magnetic field in a magnetic circuit having a magnetically conductive core, a magnetically conductive core, and an armature cooperating with the core. Furthermore, the electromagnet contains a releasably attached permanent magnet whose magnetic field is at least partially superimposed on the coil.

In order to operate the electromagnet without complex conversion with or without permanent magnets, the permanent magnet is arranged outside of the magnetic circuit.

DE 26 50 810 A1 discloses a solenoid valve having means for permanently magnetic locking in a first position and an arrangement for electromagnetic reversal from the first to another position.

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

This object is achieved by a solenoid valve device and a method suitable for switching or for driving the solenoid valve according to the independent claims. The method can be carried out in particular using the solenoid valve device.

The solenoid valve device in this case has the bistable solenoid valve, a circuit arrangement and a control device.

Thus, a partial or complete compensation of the armature-holding permanent magnetic field is effected by a compensating electromagnetic field of the electromagnetic device, which is also provided for switching. The compensating current inputted to the electromagnet means for compensation is opposite to the current input to switch into the electromagnet means, so that the switching electromagnetic field is opposed to the compensating one.

The compensating current is preferably input here with a time change, in particular with a time increase, z. B. via a ramp. This is z. B. a continuous increase from zero to a maximum current value possible. Alternatively or additionally, a jump to an average current value is possible, for. B. after a first period of time. Thus, a maximum current value by jumps and / or a continuous increase, z. B. as a time ramp.

According to the invention, it is recognized that the resetting switching operation can be improved by the compensating energization. As a result of the at least partial compensation, the magnetic holding force of the holding permanent magnetic field is thus already reduced, and the switching electromagnetic field can be dimensioned smaller with respect to its magnetic field strength or the formation of ampere-turns in order to enable the switching process by amplifying the second permanent magnetic field.

Thus, without additional equipment overhead or with low circuit overhead for z. B. a bridge circuit an additional use of an already used for switching electromagnet device, for. B. coil, possible.

According to the invention is further preferably recognized that the complementary design of a compensating electromagnetic field depending on the dynamics and position of the armature can also be problematic, since the respective restoring force is limited and serving for compensation "compensating" electromagnetic field due to the lack of air gap to the holding anchor quickly large can. So z. B. if too fast or too strong energization, the compensating first electromagnetic field (or the electromagnetic flux) may be so great that it not only compensates the permanent magnetic field, but overcompensated so much that results in a total magnetic field that of Amount ago is greater than the restoring force.

In order to avoid such overcompensation and thus a missing switching operation, preferably a temporally variable energization of the compensating electromagnetic device or coil is provided, in particular with a time increase within a rise time. This can be z. B. by a time control, in which the current is not immediately driven to its maximum value, but is ramped up via a switch-on, which allows 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 electromagnetic field in the turn-on ramp initially compensates for the air gap-loosely-holding permanent magnetic field until the restoring force has overcome the holding force and an air gap is formed between the armature and the retaining core, which attenuates the sustaining permanent magnetic field. Thus, the armature can be pulled in the desired manner in the other switching position, before the first permanent magnetic field is overcompensated.

The restoring device for forming the restoring force, ie for returning the armature in its first armature position, according to a non-claimed embodiment may be a mechanical spring device, for. B. a coil spring, which is thus switched between their states "tense" and "not tense".

The reset device is formed by a solenoid device. For a switching operation, the electromagnet 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 or the smaller permanent flux due to the air gap.

The first electromagnetic field and the first permanent magnetic field thus form a first overall magnetic field, accordingly the second electromagnetic field and the second permanent magnetic field thus form a second overall magnetic field.

In the embodiment with two electromagnetic devices in particular a symmetrical design of the solenoid valve with respect to armature, permanent magnet and the two electromagnetic devices is possible with a specific, z. B. unbalanced valve training. In this case, the currents can be controlled in combination by the two electromagnetic devices, z. B. as a series circuit or parallel connection of the two electromagnetic devices. Thus, the switching current of the one solenoid device and the compensating current of the other solenoid device can be formed and controlled together. Thus, the coils for each switching operation can be switched together, wherein the current directions for the respective switching operations are reversed accordingly, so that in each case an electromagnetic field as compensating, ie to compensate for the stronger permanent magnetic field (or permanent magnet flux) and the other magnetic switching, ie for the active circuit is used.

As an alternative to the combined control and separate controls of the two electromagnetic devices are possible, wherein z. B. the high-side driver circuits for the two electromagnetic devices can be formed separately, with common low-side drive to ground. In a separate control can z. B. the compensating electromagnetic field can be formed by a smaller current than the switching electromagnetic field.

Preferably, in each solenoid device, the compensating current of the one switching operation is set against the switching current from the current direction inputted by this electromagnetic device in the other switching operation.

In the embodiment with two electromagnetic devices, the solenoid valve may have a permanent magnet device with radial magnetization. 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 an axial end via the first core to the armature, or at the other end run second core to the armature, wherein in each of the two positions in each case an axial air gap is provided by the armature to one of the two cores.

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.

Fig. 1

ein bistabiles Magnetventil gemäß einer Ausführungsform mit zwei Spulen in geschnittener Darstellung;

Fig. 2

eine Darstellung des Verlaufs der Magnetfeldlinien in Fig. 1;

Fig. 3

eine Schaltungsanordnung zur Ansteuerung der Spulen gemäß einer Ausführungsform mit Reihenschaltung beider Spulen;

Fig. 4

eine Schaltungsanordnung zur Ansteuerung der Spulen gemäß einer Ausführungsform mit Parallelschaltung beider Spulen;

Fig. 5

ein Zeitdiagramm des Spulenstroms gemäß einer Ausführungsformen mit Rampen-Ansteuerung;

Fig. 6

ein Zeitdiagramm des Spulenstroms gemäß einer weiteren Ausführungsformen mit Rampen-Ansteuerung;

Fig. 7

ein Schnittbild des bistabilen Magnetventils gemäß einer Ausführungsform mit zwei Spulen in der ersten Ankerstellung;

Fig. 8

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

Fig. 9

ein Schnittbild des bistabilen Magnetventils gemäß einer nicht-beanspruchten mit Feder-Rückstellung in der ersten Ankerstellung;

Fig. 10

das bistabile Magnetventil aus Fig. 9 bei dem Anker-Schaltvorgang in die zweite Ankerstellung;

Fig. 11

das bistabile Magnetventil aus Fig. 9 bis 10 in der zweiten Ankerstellung;

Fig. 12

das bistabile Magnetventil aus Fig. 9 bis 11 bei dem Rückstell-Schaltvorgang in die erste Ankerstellung; und

Fig. 13

ein Zeitdiagramm des Spulenstroms der Ausführungsform der Fig. 9 bis 12 bei Rampen- Ansteuerung.

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 with two coils in a sectional view;

Fig. 2

a representation of the course of the magnetic field lines in Fig. 1 ;

Fig. 3

a circuit arrangement for driving the coils according to an embodiment with series connection of both coils;

Fig. 4

a circuit arrangement for driving the coils according to an embodiment with parallel connection of both coils;

Fig. 5

a timing diagram of the coil current according to a embodiments with ramp drive;

Fig. 6

a timing diagram of the coil current according to another embodiments with ramp drive;

Fig. 7

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

Fig. 8

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

Fig. 9

a sectional view of the bistable solenoid valve according to a non-claimed with spring return in the first armature position;

Fig. 10

the bistable solenoid valve off Fig. 9 in the armature switching operation in the second armature position;

Fig. 11

the bistable solenoid valve off Fig. 9 to 10 in the second anchor position;

Fig. 12

the bistable solenoid valve off Fig. 9 to 11 in the return switching operation in the first armature position; and

Fig. 13

a timing diagram of the coil current of the embodiment of the Fig. 9 to 12 with ramp control.

Fig. 1 shows a bistable solenoid valve 1, which is designed for use in a fluid system 50, in particular a compressed air system 50, in particular as a 3/2 solenoid valve with three ports, preferably a pressure input 2a, a first pressure outlet 2b and a second pressure outlet 2c, the z. B. can serve as a vent. Thus, the bistable solenoid valve 1 in the compressed air system 50, 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 connect in the second armature position II connected to the pressure input 2a compressed air supply line 1 to the first pressure outlet 2b, as further below with reference to FIGS. 7 and 8 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 to the plant comes on a second valve seat 11, z. B. for closing the second pressure output 2c.

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 a total electromagnet means 17, wherein the one total electromagnet means 17 in turn with a first electromagnet means or first coil 18 and a second electromagnet means or second coil 19 is formed. The entire magnet device 15 is received in a magnetic yoke 20, 21, which is formed by a yoke pot 20 with pot bottom 20a and cylindrical pot wall 20b and the yoke cup 20 to a 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 shown first position I, 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 is formed between the armature 7 and the second core 14; 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 22 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, d. H. the magnetization and thus the magnetic flux lines of the permanent magnetic field PM extend in the radial direction R, z. B. radially outward, d. H. perpendicular to the axis A. In the figures, the magnetic field is shown in part simplified by lines; In principle, the magnetic flux formed by the magnetic field is relevant to the magnetic effects.

Here, different configurations of the permanent magnet device 16 are possible, for. Example, by individual permanent magnets or a permanent magnet disc, which is designed as a ring or disc and in this case is magnetized in the radial direction.

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 proceeds according to Fig. 2 in the radial direction R through the permanent magnet device 16 and subsequently through the yoke 20, 21, wherein it extends axially in both directions, ie -A and A, ie along the pot wall 20b as a first permanent magnetic field PM1 and second permanent magnetic field PM2, wherein the permanent magnetic fields PM1, PM2 then extend at the axial ends radially downwards along the pot base 20b and the yoke disc 21 to the cores 12, 14, and subsequently axially, ie in the direction 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 thus forms z. B. a double torus or is 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 most 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, wherein the electromagnetic fields EM1 and EM2 are superimposed 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 in accordance with the first permanent magnetic field PM1, in particular in rotationally symmetrical design of the permanent magnetic field PM1:
The first electromagnetic field EM1 initially extends 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 current is applied to the second coil 19, the second electromagnetic field EM2 is similar to the second permanent magnetic field PM2, ie, depending on polarity, from the second core 14 in the axial direction A to the armature 7, or in the opposite direction from the armature 7 to the second core 14, and radially in each case radially outward 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 are advantageously carried out by energizing each of both coils 18 and 19. For the second switching operation SV2 of the first armature position I of Fig. 1 a first electromagnetic field EM1 of the first coil 18 is set up, which is opposite to the first permanent magnetic field PM1 and this partially compensated in particular, so that the magnetic holding force of the armature 6 on the first core 12 is 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 shifted to the left, whereby 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 a circuit arrangement 30, which represents in particular an output stage. 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, ie in Fig. 1 the 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 total second field EM2 + PM2.

Therefore, in both switching operations, at least the compensating current I1_k or I2_k is in each case increased with a time delay, advantageously via a ramp. In the case of a series connection of the two currents I1, I2, both currents can thus be ramped up with a time delay. 3 and 4 show embodiments of a circuit arrangement 30 for such ramp controls.

The coils 18 and 19 can according to Fig. 3 be connected in a series circuit. Thus, the circuit arrangement 30 according to Fig. 3 four transistors, preferably circuit MOSFETs Tr1, Tr2, Tr3 and Tr4, which are connected as an output stage H-bridge, so that according to Fig. 3 via control signals S1, S2, S3, S4, a current supply either Tr1 = ON, Tr4 = ON and Tr2 = OFF, Tr3 = OFF is present 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.

Alternatively, a parallel connection is after Fig. 4 intended.

The H bridge of the 3 or 4 is here to form a temporal ramp according to Fig. 5 or 6 suitable, in which the coil current I, ie in the series circuit of Fig. 3 the common coil current I1 = I2 = I, is switched on at the time t1 and ramped up to a maximum current value I_max, which it reaches at a time t2. To a subsequent one At 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 takes place depending on the tolerance position of the individual components in the valve between the times t1 and t2.

Fig. 6 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. 5 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 t2 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.

FIGS. 7 and 8 show a detailed design of a solenoid valve 1 accordingly Fig. 1 , The permanent magnet device 16 is here opposite for illustrative purposes Fig. 1 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. At the second pressure output 2c, as Venting is a pressure outlet 27 is attached directly or indirectly via a line.

In the first anchor position I, ie the venting position of Fig. 7 , 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. 8 , 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, the 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 holes 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 the circumference of 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.

Fig. 9 to 12 show a non-claimed embodiment with a solenoid valve 101 with spring return by a spring device 70, here as a helical spring between the armature 7 and the yoke, z. B. the yoke disc 21, is provided. Thus, the spring means 70 in the second anchor position II of Fig. 11 curious and in the first anchor position I the Fig. 9 relaxed.

In Fig. 9 Thus, the second permanent magnetic field PM2 is weakened by the air gap 22 and therefore too small to overcome the spring force.

In the second switching operation or armature switching operation SV2 of Fig. 10 the switching electromagnetic field EM2_s is superimposed reinforcing or constructive with the second permanent magnetic field PM2, so that the spring force is overcome and the armature 7 is moved upward.

In Fig. 11 the armature 7 is held in the second anchor position II to the holding core 14 (or second core or holding core), since the holding permanent magnetic field or second permanent magnetic field PM2 due to the lack of air gap 22 is strong enough, even without Supported by the second electromagnetic field EM2 to hold the armature 7 against the spring action of the spring device 70.

In Fig. 12 is then the holding permanent magnetic field or second permanent magnetic field PM2 weakened by at least partial compensation by the compensating second electromagnetic field EM2_k, so that the spring restoring force of the spring device 70, the magnetic holding force, which is determined by the amount of the difference of the holding second permanent Magnetic field PM2 and the compensating second electromagnetic field EM2_k is exceeded. Thus, the resetting switching operation SV1 or first switching operation takes place in the first armature position I, which in turn forms the air gap 22 between the holding core or holding core 14 and the armature 7.

Fig. 13 shows a circuit arrangement or power amplifier 130, respectively Fig. 3 is constructed with only the switching solenoid device or second coil 19 is energized. Here again the time diagrams of the Fig. 5 or 6 be set.

List of Reference Numerals (part of the description)

1, 101

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, 105

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, holding core

15

Magnet means

16, 116

Permanent magnet means

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, 130

circuitry

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

70

Return spring

Tr1, Tr2, Tr3, Tr4

Transistors of the circuit arrangement 30

uv

supply voltage

GND

Dimensions

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, reset electromagnetic field

EM2

second electromagnetic field, armature electromagnetic field

EM2_k

second compensating electromagnetic field

EM1_k

first compensating electromagnetic field

N, S

North Pole, South Pole

I

Current in series connection

i_s

switching current

I_k

compensating current

I1

first current through the first coil 18th

I1_s

switching first current

I1_k

compensating first current

I_mid

mean current value

i_max

maximum current value

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

SV1

Reset switching operation, first switching operation

SV2

Anchor switching process, second switching operation

Claims (15)

1. Bistable solenoid valve device (5, 105) for a fluid system (50), having a solenoid valve (1, 101), a circuit arrangement (30, 130) and a control device (40) for actuating the circuit arrangement (30, 130), wherein the solenoid valve (1, 101) has:

   an armature (7), which can be displaced between a first armature position (I) and a second armature position (II), and valve means (8, 9, 10, 11), which can be displaced by way of the armature (7) and which are in various valve positions in the first and second armature position (I, II),

   a permanent-magnet device (16, 116) for forming a holding permanent magnetic field (PM2), which holds the armature (7) in the second armature position (II),

   a switching electromagnet device (19) for forming a switching electromagnetic field (EM2) for an armature switching process (SV2) from the first armature position (I) to the second armature position (II), and

   a return device (12, 18; 70) for returning the armature (7) in a return switching process (SV1) to the first armature position (I), wherein the circuit arrangement (30, 130) is designed to actuate the switching electromagnet device (19) in the armature switching process (SV2) by way of a switching current (I2_S),

   wherein

   the control device (40) is designed to actuate the circuit arrangement (30, 130) in such a way that the switching electromagnet device (19) in the return switching process (SV1) is energized by way of a compensation current (I_k) to form a compensating electromagnetic field (EM2_k) for at least partial compensation of the holding permanent magnetic field (PM2), wherein

   the solenoid valve (1, 101) has a magnetic yoke (20, 21) and a holding core (14) for positioning the armature (7) in the second armature position (II),

   wherein

   an air gap (22) is formed between the armature (7) and the holding core (14) in the first armature position (I), and

   the holding permanent magnetic field (PM2) and the switching electromagnetic field (EM2) run over the magnetic yoke (20, 21), the holding core (14) and the armature (7), wherein

   the return device (12, 18) has a first core (12) for positioning the armature (7) in the first armature position (I) and a first electromagnet device (18),

   which is energized in the return switching process (SV1) to form a first electromagnetic field (EM1),

   wherein the first electromagnetic field (EM1) and a first permanent magnetic field (PM1) of the permanent-magnet device (16) run over the magnetic yoke (20, 21),

   the first core (12) and the armature (7), wherein in the first armature position (I) the first permanent magnetic field (PM1) holds the armature (7) on the first core (12) and the air gap (22) is formed between the armature (7) and the holding core (14), wherein the control device (40) is designed to actuate the circuit arrangement (30) in such a way that the first electromagnet device (18) in the armature switching process (SV2) is energized by way of a compensation current (I_k) to form a temporally increasing compensating electromagnetic field for at least partial compensation of the first permanent magnetic field (PM1).
2. Solenoid valve device (5, 105) according to Claim 1, characterized in that a current direction of the compensation current (I_k) in the switching electromagnet device (19) is opposite to a current direction of the switching current (I2_S) in the switching electromagnet device (19).
3. Solenoid valve device (5, 105) according to Claim 1 or 2, characterized in that the compensation current (I_k) during the return switching process (SV1) is temporally variable and has a maximum current value (I_max) only after a start-up period (Δ_t1).
4. Solenoid valve device (5, 105) according to Claim 3, characterized in that a maximum current value (I_max) of the compensation current (I_k) during the return switching process (SV1) lies below a switching current value of the switching current (I2_S).
5. Solenoid valve device (5, 105) according to Claim 3 or 4, characterized in that the compensation current (I_k) during the return switching process (SV1) has a temporally delayed steady and/or rapid increase to the maximum current value (I_max) of the compensation current (I_k).
6. Solenoid valve device (5, 105) according to Claim 5, characterized in that the temporally delayed increase of the compensation current (I_k) has at least a steady temporal ramp profile (Δt1) and/or a rapid profile to an average current value (I_mid) with a subsequent increase to the maximum current value (I_max).
7. Solenoid valve device (5, 105) according to one of the preceding claims, characterized in that the solenoid valve (1, 101) is formed as a 3/2 directional control valve with a pressure input (2a), a first pressure output (2b) and a second pressure output (2c), wherein the first pressure output (2b) in both armature positions (I, II) is connected in each case to either the pressure input (2a) or the second pressure output (2c) and the respective other connection (2c, 2a) is blocked.
8. Solenoid valve device (5) according to Claim 1, characterized in that the two electromagnet devices (18, 19) are connected as a series circuit or parallel circuit and are both able to be energized jointly in both switching processes (SV1, SV2).
9. Solenoid valve device (5) according to Claim 1 or 8, characterized in that the two electromagnet devices (18, 19) are able to be energized by way of the control device (40) for the return switching process (SV1) in a first direction and for the armature switching process (SV2) in a second direction opposite to the first direction.
10. Solenoid valve device (5, 105) according to one of the preceding claims, characterized in that the circuit arrangement (30) has:

    high-side drivers (Tr1, Tr2), for example transistors,

    which are connected between an upper supply voltage (Uv) and the two electromagnet devices (18, 19), and

    low-side drivers (Tr3, Tr4), for example transistors,

    which are connected between the two electromagnet devices (18, 19) and a lower supply voltage, for example ground (GND), wherein the high-side drivers (Tr1, Tr2) and the low-side drivers (Tr3, Tr4) are able to be switched, in particular able to be switched over in alternation, for the switching processes (SV1, SV2).
11. Method for switching a bistable solenoid valve (1, 101), in which a switching electromagnet device (19) is energized by way of a switching current (I2s) in an armature switching process (SV2) to form a switching electromagnetic field (EM2), by way of which an armature (7) is displaced from a first armature position (I) to a second armature position (II), wherein valve means (8, 9, 10, 11) are displaced by way of the armature (7),
    wherein the armature (7) is held in the second armature position (II) by way of a holding permanent magnetic field (PM2) of a holding permanent-magnet device (16, 116), and
    the armature (7) is returned to the first armature position (I) by a return device (12, 18; 70) in a return switching process (SV1), wherein
    the switching electromagnet device (19) is energized in the return switching process (SV1) by way of a compensation current (I_K) to form a compensating electromagnetic field (EM2_k) for at least partial compensation of the holding permanent magnetic field (PM2), wherein the compensation current (I_k) and the switching current (I2_S) are oriented in opposite directions, wherein the compensation current (I_K) is introduced into the switching electromagnet device (19) in a temporally variable and/or temporally increasing manner and reaches a maximum current value (I_max) only after a start-up period (Δ_t1), wherein the armature (7) bears against a holding core (14) in the second armature position (II), through which holding core the holding permanent magnetic field (PM2) runs, and the armature (7) is moved away from the holding core (14) in the return switching process (SV1) even before the maximum current value (I_max) of the compensation current (I_k) is reached so as to form an air gap (22) between the armature (7) and the holding core (14) to weaken the permanent magnetic field (PM2) and the compensating electromagnetic field.
12. Method according to Claim 11, characterized in that the compensation current (I_k) is raised in the return switching process (SV1) with a temporally delayed steady and/or rapid increase to the maximum current value (I_max).
13. Method according to Claim 12, characterized in that the temporally delayed increase has at least a steady ramp profile and/or a rapid profile to an average current value (I_mid).
14. Method according to one of Claims 11 to 13, characterized in that the return device (12, 18) has a first electromagnet device (18),
    wherein the first electromagnet device (18) is energized in the return switching process (SV1) so as to form a first electromagnetic field (EM1), which pulls the armature (7) into the first armature position (I),
    wherein the armature (7) is held in the first armature position (I) by way of a first permanent magnetic field (PM1),
    wherein the first electromagnet device (18) is energized in the armature switching process (SV2) to form a first compensating electromagnetic field (EM1_k) for at least partial compensation of the first permanent magnetic field (PM1), preferably with corresponding energization in both switching process (SV1, SV2).
15. Method according to Claim 14, characterized in that the two electromagnet devices (18, 19), connected in series or in parallel, are energized jointly in both switching processes (SV1, SV2).

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