SOLENOID VALVE AND HYDROGEN TANK SYSTEM WITH SOLENOID VALVE

Description

[0001] The invention relates to a solenoid valve, in particular a shut-off valve for hydrogen tank systems. Furthermore, the invention relates to a hydrogen tank system with a solenoid valve according to the invention as a shut-off valve. State of the art

[0002] For solenoid valves with large strokes, such as shut-off valves for hydrogen tank systems, solenoid actuators with plunger plungers are typically used. With these, the magnetic force decreases less with increasing distance between the armature and its fixed stop than with flat-armature designs.

[0003] DE 10 2018 221 602 A1 discloses, by way of example, a tank device for storing hydrogen with an electromagnetically actuated valve device, which has a movable valve element that interacts with a valve seat for opening and closing an outlet opening. The valve element is acted upon by the spring force of a spring in the direction of the valve seat, so that when the solenoid coil is de-energized, the valve device is closed. In the open position, the valve element exposes an outlet opening with a diameter and an adjoining passageway. The valve element simultaneously forms a solenoid armature that operates according to the solenoid plunger principle. When the solenoid coil is energized, a magnetic field is formed that surrounds the coil, the field lines of which extend over an outer pole body, an inner pole body, and the solenoid armature.The field lines run across a radial and an axial air gap between the magnet armature and the outer pole piece. The magnetic force generated in the axial air gap can lift the magnet armature or valve element from the sealing seat against the spring force, causing the solenoid valve to open.

[0004] In a solenoid valve with a plunger, as described in DE 10 2018 221 602 A1, the field coupling via the radial air gap leads to a weakening of the magnetic field in the axial air gap. The result is a reduction in the magnetic force acting on the armature in the opening direction. This means that a larger solenoid coil is required, which increases the installation space requirement.

[0005] US 2014 / 239207 A1 discloses a solenoid valve, in particular a shut-off valve suitable for a gas tank, comprising a liftable solenoid armature coupled to a liftable valve member.

[0006] US 2018 / 038507 shows a valve device comprising a main valve element that divides the space of a valve element of a housing into the first and second pressure chambers.

[0007] DE 10 2018 221600 A1 discloses a method for operating a tank device for storing compressed fluids with a tank, a valve device, a supply line, a flow element arranged in the supply line and a control unit.

[0008] WO 2020 / 158728 A1 shows a solenoid valve for gas, which is provided with a housing having a first connection, a second connection and a valve opening.

[0009] US 2015 / 184805 A1 discloses a fluid control valve comprising a main valve body with a first flow channel mounted at an inlet through which a supplied gas flows.

[0010] US 6 675 831 B2 shows a high pressure tank device consisting of a high pressure tank in which a high pressure gas is located and a valve mechanism which is provided at an outlet of the high pressure tank.

[0011] The present invention attempts to remedy this situation by providing a solenoid valve with optimized field line guidance. The solenoid valve has the features of claim 1. Advantageous developments of the invention can be found in the subclaims. Furthermore, a hydrogen tank system with a solenoid valve according to the invention is specified. Disclosure of the invention

[0012] The proposed solenoid valve, in particular a shut-off valve for hydrogen tank systems, comprises a liftable solenoid armature that is or can be coupled to a liftable valve member. The solenoid armature is biased in the direction of the valve member by means of a spring. The solenoid valve further comprises an annular solenoid coil for acting on the solenoid armature, wherein the solenoid coil surrounds the solenoid armature in sections. According to the invention, the solenoid armature has a section designed as a solenoid armature and a section designed as a flat armature, wherein the section designed as a solenoid armature delimits a pressure chamber within the solenoid coil, which is pneumatically connected, preferably via a throttle, to a control chamber that can be relieved by opening a control valve that can also be actuated by means of the solenoid coil.

[0013] The surface of the solenoid armature that borders the pressure chamber acts as a pressure surface, so that the pressure in the pressure chamber exerts a pneumatic force on the solenoid armature in the closing direction or in the direction of a sealing seat. The pressure surface is connected on the opposite side to the valve chamber into which the solenoid armature extends. The pressure in the valve chamber thus exerts a pneumatic force on the solenoid armature in the opening direction. When the pressure in the pressure chamber and the valve chamber is the same, the resulting force of the force couple on the opposite pressure surfaces is zero. This means that they cancel each other out. The invention is based on the idea that the pressure in the pressure chamber can be reduced compared to the valve chamber.

[0014] In the proposed solenoid valve, therefore, not only the magnetic force generated by the solenoid coil acts on the solenoid armature, but also an opening pneumatic force resulting from a pressure difference between the reduced pressure in the pressure chamber within the solenoid coil and the pressure in the valve chamber. The pressure in the pressure chamber is reduced via the pressure reduction in the adjacent control chamber, which is pneumatically connected to the pressure chamber, with the connection advantageously being designed in the form of a throttle. The pressure reduction in the control chamber, in turn, occurs by actuating a control valve, which for this purpose is preferably connected to a pressure system, in particular a line system, which serves, for example, to supply a fuel cell or an internal combustion engine with fuel.The pneumatic separation from the valve chamber required to reduce the pressure in the pressure chamber can be achieved by means of a correspondingly tight guide for the solenoid armature, by means of sealing elements in the guide area and / or by means of diaphragm seals. In order to ensure that the main valve can close reliably after the activation has ended and the control valve is closed, it is necessary to enable backfilling of the pressure or control chamber. This can be achieved by a pneumatic connection between the valve chamber and the pressure chamber in the form of a throttle bore, the so-called inlet or Z-throttle. When using the guide of the solenoid armature for pneumatic separation, the guide itself can be designed as a Z-throttle in an advantageous embodiment of the invention.

[0015] The solenoid valve is therefore designed as a servo-controlled solenoid valve, with the solenoid coil not only operating the control valve but also acting on the solenoid armature of the main valve. The design of the solenoid armature as a plunger and a flat armature is advantageous. With appropriate magnetic circuit design, the field lines can be directed more strongly through the flat armature section, which has a larger magnetic interface than the plunger armature section due to its larger diameter. For example, the solenoid coil can be designed in some areas, particularly in an area facing the plunger armature section, so that this area exhibits increased magnetic resistance and, in extreme cases, even reaches saturation.

[0016] The design of the solenoid armature as a plunger and flat armature thus enables optimized field line guidance, with the field lines of the magnetic circuit predominantly guided through axial working air gaps. This results in a high force acting on the solenoid armature of the main valve and—depending on the design of the control valve—also on its solenoid armature.

[0017] According to a preferred embodiment of the invention, the stroke of the magnet armature is limited by a stroke stop. The magnet armature thus performs defined stroke movements between two end positions. In particular, the section of the magnet armature designed as a flat armature can interact with the stroke stop, so that no additional part connected to the magnet armature by force, form, and / or material engagement is required. The stroke stop itself can be formed by the magnet coil or another component of the magnetic circuit, for example, a pole body accommodating the magnet coil.

[0018] Furthermore, the magnet armature, in particular the portion of the magnet armature designed as a plunger, is preferably guided via a sleeve. Guidance via the plunger section is particularly easy to implement. For example, the guide can be formed by a sleeve-shaped portion of a pole body accommodating the magnet coil. A separate sleeve can thus be omitted.

[0019] Furthermore, it is proposed that the magnet armature, in particular the section of the magnet armature designed as a plunger armature, and the sleeve jointly delimit at least one flow channel that connects the pressure chamber to a valve chamber in which the valve member is accommodated. In this case, the at least one flow channel serves as an inlet or Z-throttle. For secure connection of the flow channel or the Z-throttle, in particular in the event that the magnet armature rests against the stroke stop, the magnet armature and / or the sleeve can have at least one recess extending in the axial direction, for example a ground portion and / or a groove. Alternatively or additionally, the guide play in the area of ​​the guide of the magnet armature can be increased. This also has the advantage that radial field coupling during energization of the magnet coil is made more difficult.

[0020] In a further advantageous embodiment of the invention, a sealing element is provided between the magnet armature and the sleeve, and the pressure chamber is connected via a flow channel to a valve chamber accommodating the valve member, which is formed as a bore, in particular as a throttle bore, in the magnet armature or in the sleeve. This means that the Z-throttle is not formed by the guide of the magnet armature, but rather by a separate flow channel designed as a bore or throttle bore.

[0021] The pneumatic connection between the pressure chamber and the valve chamber, established via at least one flow channel, simultaneously ensures a connection between the valve chamber and the control chamber of the control valve, since the pressure chamber is connected to the control chamber - preferably via a throttle. In the closed position of the control valve, the same pressure prevails in all three chambers. The pneumatic connection of the chambers ensures reliable closing of the control valve.

[0022] In the case of a stroke stop limiting the stroke of the magnet armature, this is preferably designed to be non-sealing so as not to interrupt the pneumatic connection between the valve chamber and the pressure chamber. In a further development of the invention, it is therefore proposed that the magnet armature, in particular the section of the magnet armature designed as a flat armature, and the stroke stop jointly limit at least one flow channel that connects the valve chamber to the pressure chamber via the flow channel, which is preferably designed as a Z-throttle. The at least one further flow channel can in particular be designed as a substantially radially extending recess, in particular a groove, in the magnet armature and / or in the stroke stop.

[0023] Alternatively or additionally, it is proposed that the magnet armature, in particular the section of the magnet armature designed as a flat armature, be penetrated by at least one flow opening. A pneumatic connection between the valve chamber and the pressure chamber can also be established via the at least one flow opening. The at least one flow opening can be designed, for example, as a bore extending axially or obliquely through the section designed as a flat armature.

[0024] In a further development of the invention, it is proposed that the magnet armature, in particular the section of the magnet armature designed as a solenoid armature, has a circumferential cross-sectional reduction. In the area of ​​the circumferential cross-sectional reduction, the magnet armature therefore has a reduced outer diameter, so that the radial air gap between the magnet armature and the guide increases in this area. The magnetic resistance in this area increases accordingly. This in turn leads to a reduction in the radial and strengthening of the axial field lines. The cross-sectional reduction can be realized, for example, by a recess in the solenoid armature section. Preferably, the cross-sectional reduction is arranged adjacent to the section of the magnet armature designed as a flat armature in order to guide the field lines more intensively across the axial working air gap.

[0025] Alternatively or additionally, it is proposed that the sleeve, preferably the sleeve-shaped portion of the pole body, have a circumferential section made of a non-magnetic material. The non-magnetic material also leads to an increase in the radial air gap, so that this measure has a similar effect to the previously proposed cross-sectional reduction of the magnet armature in the section designed as a plunger armature.

[0026] Preferably, the circumferential section made of a non-magnetic material is arranged at the level of the cross-sectional reduction of the armature when the armature is at full stroke. In this case, the non-magnetic section of the sleeve and the cross-sectional reduction of the armature act together as a field line switch. When the main valve is still closed, the field line switch allows the field lines to couple radially into the armature, resulting in a high force to open the control valve due to the very low magnetic resistance in the magnetic circuit. When the main valve is opening or open, the area of ​​the cross-sectional reduction is brought into overlap with the non-magnetic section of the sleeve, so that the radial self-coupling of the field lines is reduced or even completely prevented. This is because the field lines detach radially and pivot towards the flat armature section, where the magnetic resistance is lower.The field line switch thus enables the operation of two working air gaps with one solenoid coil without one air gap reducing the magnetic flux in the other. This allows for the production of very cost-effective, energy-efficient, and space-saving solenoid valves.

[0027] The control valve of the proposed solenoid valve preferably has a magnet armature designed, at least in part, as a flat armature. The stroke of the control valve can thus be kept small. Accordingly, the air gap at the magnet armature of the control valve is minimized, which has a positive effect on the dimensioning of the solenoid coil. Advantageously, the magnet armature of the control valve also forms a valve closing element that interacts with a sealing seat. The control valve can therefore be implemented relatively simply and in a space-saving manner.

[0028] The solenoid armature of the control valve is preferably preloaded in the direction of the sealing seat by means of a control valve spring. This means that the control valve has its own closing spring. The control valve spring can thus be designed independently of the spring of the main valve. In particular, the spring force of the control valve spring can be selected to be smaller than the spring force of the main valve spring, so that the control valve can be opened with reduced force. This has a positive effect on the dimensioning of the solenoid coil and thus on the installation space required for the solenoid valve. The solenoid coil only needs to be dimensioned large enough that the forces acting in the opening direction are greater than the sum of the pneumatic closing force on the control valve and the control valve spring force. This not only achieves a compact design, but also reduces the energy consumption of the solenoid valve.

[0029] The solenoid armature of the control valve preferably has at least one flow opening for connecting the pressure chamber to the control chamber. This applies in particular to a solenoid armature that is designed at least partially as a flat armature. The at least one flow opening can in particular open into a chamber upstream of the pressure chamber, which is connected to the pressure chamber via the throttle. The throttle ensures that a pressure drop occurs in the control chamber when the control valve is opened, since less gas flows in through the throttle than escapes through the sealing seat of the control valve. At the same time, the gas flowing in through the throttle ensures the necessary closing and sealing force to keep the control valve closed when the control valve is closed.

[0030] Furthermore, it can be provided that the valve member of the main valve is preloaded in the direction of the solenoid armature by means of a valve member spring. The task of the valve member spring is to ensure that the main valve opens against the pressure in the valve chamber. The valve member spring makes it possible to set an opening pressure difference between the valve chamber and the piping system very precisely when the main valve opens, thereby effectively preventing high pressure surges in the system. This allows safety devices for protecting downstream components, such as a pressure reducer and / or a medium-pressure system, to be designed more simply and therefore more cost-effectively. The spring force of the valve member spring is smaller than the spring force of the spring that preloads the solenoid armature in the direction of the valve member. This ensures that the solenoid armature and the valve member are safely returned to their respective starting positions when closing.

[0031] A preferred application area of ​​a solenoid valve according to the invention is hydrogen tank systems, so that a hydrogen tank system is further proposed that comprises at least one compressed gas container and a solenoid valve according to the invention for shutting off the compressed gas container. The hydrogen tank system can be used in particular in a fuel cell vehicle or in a vehicle with hydrogen combustion.

[0032] Preferred embodiments of the invention and their advantages are explained in more detail below with reference to the accompanying drawings. These show: Figure 1 a)-f) each a schematic longitudinal section through a first solenoid valve according to the invention in different switching positions, Figure 2 a)-f) each a schematic longitudinal section through a second solenoid valve according to the invention in different switching positions and Figure 3 a)-f)each a schematic longitudinal section through a third solenoid valve according to the invention in different switching positions. Detailed description of the drawings

[0033] The Figure 1 a)-f) The illustrated solenoid valve 1 has an annular solenoid coil 5 housed in a pole body 12. With the aid of the solenoid coil 5, a magnetic force can be generated that acts on the one hand on a solenoid armature 19 of a control valve 9 and, on the other hand, on a solenoid armature 2 of the main valve. The two solenoid armatures 2, 19 are arranged coaxially and move in opposite directions.

[0034] The magnetic armature 19 of the control valve 9 is designed, at least in part, as a flat armature and is preloaded toward a sealing seat 20 by a control valve spring 21. The magnetic armature 19 simultaneously forms a valve closing element that interacts with the sealing seat 20. Oblique flow openings 22 are formed in the section of the magnetic armature 19 designed as a flat armature.

[0035] The solenoid armature 2 of the main valve has a first section 2.1, which is designed as a plunger armature, and a second section 2.2, which is designed as a flat armature. The solenoid armature 2 can be coupled to a valve member 3, which interacts with a sealing seat 24. The spring force of a spring 4 biases the solenoid armature 2 toward the valve member 3. The guidance of the solenoid armature 2 is achieved by means of a sleeve 11, which in this case is formed by a sleeve-shaped section of a pole body 2 accommodating the solenoid coil 5.

[0036] In the Figure 1a) the solenoid valve 1 is shown with the solenoid coil 5 de-energized and therefore in the closed state. High pressure prevails in the control chamber 8 and in a valve chamber 14 in which the valve member 3 of the main valve is accommodated. This is because a gas line 25, which is preferably connected to a storage volume of a compressed gas container (not shown), opens into the valve chamber 14. The valve chamber 14, in turn, is connected via the guide of the solenoid armature 2 to a pressure chamber 6, which is connected to the control chamber 8 via a throttle 7. Low pressure prevails outside the solenoid valve 1, i.e. in a gas line 26. In addition to the spring forces of the control valve spring 21 and the spring 4, pneumatic closing forces also act on the solenoid armature 19 and the valve member 3 of the main valve.

[0037] To open the solenoid valve 1, the control valve 9 is first opened. For this purpose, the solenoid coil 5 is energized, so that a magnetic field is built up, the magnetic force of which lifts the magnet armature 19 from the sealing seat 20. The magnet armature 19 then comes into contact with the pole body 12 (see Figure 1b )). The flow openings 22 formed in the magnet armature 19 ensure that the control chamber 8 remains connected to the pressure chamber 6. This results in not only the pressure in the control chamber 8, but also the pressure in the pressure chamber 6 falling. Supported by the magnetic forces generated by the magnet coil 5, the forces acting on the magnet armature 2 in the opening direction now predominate, so that the latter moves in the direction of the magnet coil 5 until it comes to rest against a stroke stop 10 (see Figure 1cThe volume displacement required for an opening movement of the magnet armature occurs on the main valve side by an inflow from the compressed gas container into the valve chamber 14 and on the control valve side by an outflow from the pressure chamber 6, preferably via a throttle 7, into the control chamber 8 and from there via the open sealing seat 20 into the gas line 26. However, when the magnet armature 2 is to be closed, the sealing seat 20 is closed by switching off the magnetic force, which means that the volume displacement on the control valve side can no longer occur via the sealing seat 20. In this case, the volume displacement on the control valve side occurs through a corresponding pneumatic inflow via the pneumatic connection designed as a Z-throttle between the valve chamber 14 and the pressure chamber 6.To ensure the connection, the magnet armature 2 has flow channels 13, 15 and at least one flow opening 16, via which a pneumatic connection is established even when the magnet armature 2 rests against the stroke stop 10.

[0038] The stroke of the magnet armature 2 is therefore achieved with the help of pneumatic and magnetic forces, whereby the special design of the magnet armature 2, comprising a plunger armature section 2.1 and a flat armature section 2.2, not only leads to an increase in the magnetic forces, but also enables an optimization of the field line guidance. In particular, the magnetic circuit can be designed such that the field lines lead more strongly via the flat armature section 2.2. The radial field line coupling, which weakens the magnetic field, is minimized in this way. For example, the play in the area of ​​the guide of the magnet armature 2 can be increased, so that the magnetic resistance in the radial air gap increases. Alternatively or additionally, the magnetic resistance can be increased by changing the material.

[0039] During the stroke of the magnet armature 2, it separates from the valve member 3, so that the spring force of the spring 4 no longer exerts any influence on the valve member 3. Instead, a valve member spring 23 unfolds its effect and lifts the valve member 3 from the sealing seat 24 when the opening pressure difference between the gas line 26 and the valve chamber 14 is reached (see Figure 1d )). Solenoid valve 1 is open.

[0040] When the solenoid valve 1 is open, pressure equalization occurs in the gas lines 25 and 26 via the valve chamber 14. With complete pressure equalization, the main valve and the control valve 9 are held open purely magnetically against the spring force of the springs 4, 21. Due to the minimal air gap, this is also possible with a lower so-called holding current at the solenoid coil 5. Typically, a temporarily higher current, the so-called pull-in current, is selected for opening. Once the valve is open, the switch can be made from the pull-in current to the lower holding current.

[0041] To close the solenoid valve 1, the current supply to the solenoid coil 5 is stopped, so that the control valve spring 21 returns the magnet armature 19 of the control valve 9 to the sealing seat 20 (see Figure 1e)). When the control valve 9 is closed, the control chamber 8 fills with gas from the valve chamber 14, so that the pressure in the control chamber 8 rises again. The same applies to the pressure in the pressure chamber 6, which is filled via the Z-throttle between the valve chamber 14 and the pressure chamber 6, so that the pressure in the pressure chamber 6 also rises. This leads to the forces acting on the magnet armature 2 in the closing direction predominating and returning the magnet armature 2 to its initial position. The magnet armature 2 then comes into contact with the valve element 3 and presses it into the sealing seat 24 (see Figure 1f )).

[0042] Further optimization of the field line guidance can be achieved through further development measures. Preferred measures are described below based on the Figure 2 and 3 described.

[0043] The solenoid valve 2 of the Figure 2 a)-f)has a main valve with a modified solenoid armature 2. This is because in the area of ​​section 2.1 designed as a plunger armature, the solenoid armature 2 has a cross-sectional reduction 17. This contributes to the field lines of the magnetic field running more strongly through section 2.2 designed as a flat armature, since in the area of ​​the cross-sectional reduction 17 the radial air gap is enlarged and thus the magnetic resistance is increased. The cross-sectional reduction 17 can be easily implemented by a recess on the solenoid armature 2. Preferably, the cross-sectional reduction 17 is arranged directly adjacent to section 2.2 designed as a flat armature, so that flow channels 15 and / or flow openings 16 formed in the flat armature section 2.2 can open into this area in order to establish the necessary pneumatic connection between the valve chamber 14 and the pressure chamber 6.

[0044] The operation of the solenoid valve 1 of the Figure 2corresponds to that of solenoid valve 1 of the Figure 1 . The Figure 2a ) shows the solenoid valve 1 with the solenoid coil 5 de-energized, i.e. in the closed state. To open, the solenoid coil 5 is energized, so that a magnetic field is built up, the magnetic force of which lifts the magnet armature 19 of the control valve 9 from the sealing seat 20 (see Figure 2b )). When the control valve 9 is open, gas flows from the control chamber 8 into the gas line 26, so that the pressure in the control chamber 8 drops. The same applies to the pressure in the pressure chamber 6, which is connected to the control chamber 8 via the throttle 7. The pressure drop in the pressure chamber 6 relieves the load on the solenoid armature 2 of the main valve, so that the forces acting in the opening direction predominate and move the solenoid armature 2 towards the solenoid coil 5 until the flat armature section 2.2 comes into contact with the stroke stop 10 (see Figure 2c)). Since the magnet armature 2 is released from the valve member 3, the valve member spring 23 is able to lift the valve member 3 from the sealing seat 24 with increasing filling of the gas line 26 via the control valve 9 when the opening pressure difference is reached (see Figure 2d )). In the event that the gas line 26 and the valve chamber 14 are pressure-equalized before the start of energization, the valve member 3 opens immediately upon opening of the control valve 9 and the subsequent opening of the magnet armature 2. The main valve is now also open. To close, the energization of the magnet coil 5 is terminated, so that the control valve spring 21 returns the magnet armature 19 to the sealing seat 20 (see Figure 2e)). When the control valve 9 is closed, the pressure in the control chamber 8 rises again, as it is pneumatically connected to the valve chamber 14. In the same way, the pressure in the pressure chamber 6 also rises via the Z throttle, so that the forces acting on the solenoid armature 2 in the closing direction predominate and the latter moves towards the sealing seat 24. In this case, the solenoid armature 2 comes into contact with the valve member 3, so that the solenoid armature 2 presses the valve member 3 into the sealing seat 24. The solenoid valve 1 is thus closed (see Figure 2f )).

[0045] The solenoid valve 1 of the Figure 3To optimize the field line guidance, in addition to the cross-sectional reduction 17 of the magnet armature 2, it has a sleeve 11 serving to guide the magnet armature 2, which sleeve has a section 18 made of a non-magnetic material. The section 18 interacts with the cross-sectional reduction 17 to form a field line switch. The field line switch facilitates the actuation of the control valve 9 and the main valve with only one solenoid coil 5. In particular, the magnetic flux in one air gap does not lead to a reduction of the magnetic flux in the other air gap, thus creating a particularly cost-effective and energy- and space-optimized solenoid valve 1.

[0046] Since in the Figure 3The sleeve 11 is formed by a sleeve-shaped section of the pole body 12, which has the section 18 made of a non-magnetic material. Due to the use of a non-magnetic material, the section 18 leads to an enlargement of the radial air gap, which acts as a field line switch, in particular, when the cross-sectional reduction 17 is brought into overlap with the section 18 by the stroke of the magnet armature 2 (see Figure 3c )). Previously, that is, with the main valve closed (see Figure 3a )), the field line switch allows field lines of the magnetic field to be coupled via the radial air gap into the section 2.1 of the solenoid armature 2, which is designed as a plunger armature. Since the magnetic resistance here is greater than in the area of ​​the axial air gap between the solenoid armature 19 of the control valve 9 and the pole body 12, a high magnetic force is generated, which can be used to open the control valve 9 (see Figure 3b)). Only when the armature 2 of the main valve opens or is opened is the area of ​​the cross-sectional reduction 17 brought into overlap with the section 18 of the sleeve 11, so that a radial coupling of the field lines is prevented or greatly reduced. The field lines are thereby radially separated and pivot towards the flat armature section 2.2 of the armature 2, which represents the lower magnetic resistance for the field lines. Since the armature 2 detaches from the valve member 3 during its stroke, the latter is lifted out of the sealing seat 24 by the valve member spring 23 (see Figure 3d)). For closing - analogous to the Figure 1 and 2 - the current supply to the solenoid coil 5 is stopped, so that first the control valve 9 (see Figure 3e )) and then close the main valve (see Figure 3f )).

Claims

1. Solenoid valve (1), in particular shut-off valve suitable for a gas tank, comprising a lifting magnet armature (2), which is coupled to a lifting valve member (3), wherein the magnet armature (2) is preloaded in the direction of the valve member (3) by means of a spring (4), further comprising an annular solenoid coil (5) for acting on the magnet armature (2), wherein the solenoid coil (5) surrounds the magnet armature (2) in portions, wherein the magnet armature (2) has a portion (2.1) embodied as a solenoid plunger, wherein the portion (2.1) embodied as a solenoid plunger within the solenoid coil (5) delimits a pressure chamber (6) which by way of a restrictor (7) is pneumatically connected to a control chamber (8), characterized in that the magnet armature (2) has a portion (2.2) embodied as a flat armature, and that the control chamber (8) can be relieved by opening a control valve (9) which can also be operated by means of the solenoid coil (5).

2. Solenoid valve (1) according to Claim 1, characterized in that the stroke of the magnet armature (2) is delimited by a stroke travel stop (10), wherein preferably the portion (2.2) of the magnet armature (2) embodied as a flat armature interacts with the stroke travel stop (10).

3. Solenoid valve (1) according to Claim 1 or 2, characterized in that the magnet armature (2), in particular the portion (2.1) of the magnet armature (2) embodied as a solenoid plunger, is guided over a sleeve (11) which is preferably formed by a sleeve-shaped portion of a pole body (12) receiving the solenoid coil (5).

4. Solenoid valve (1) according to Claim 3, characterized in that the magnet armature (2), in particular the portion (2.1) of the magnet armature (2) embodied as a solenoid plunger, and the sleeve (11) conjointly delimit at least one flow duct (13),which connects the pressure chamber (6) to a valve chamber (14) in which the valve member (3) is received.

5. Solenoid valve (1) according to Claim 3, characterized in that a sealing element is present between the magnet armature (2) and the sleeve (11), and the pressure chamber (6) is connected via a flow duct to a valve chamber (14) that receives the valve member (3) and is formed as a bore, in particular as a throttle bore, in the magnet armature (2) or in the sleeve (11).

6. Solenoid valve (1) according to Claim 4 or 5, characterized in that the magnet armature (2), in particular the portion (2.2) of the magnet armature (2) embodied as a flat armature, and the stroke travel stop (10) conjointly delimit at least one flow duct (15) which connects the pressure chamber (6) to the valve chamber (14).

7. Solenoid valve (1) according to one of the preceding claims, characterized in that the magnet armature (2), in particular the portion (2.2) of the magnet armature (2) embodied as a flat armature, is penetrated by at least one flow opening (16).

8. Solenoid valve (1) according to one of the preceding claims, characterized in that the magnet armature (2), in particular the portion (2.1) of the magnet armature (2) embodied as a solenoid plunger, has an encircling cross-sectional reduction (17), which is preferably disposed adjacent to the portion (2.2) of the magnet armature (2) embodied as a flat armature.

9. Solenoid valve (1) according to one of Claims 3 to 8, characterized in that the sleeve (11), preferably the sleeve-shaped portion of the pole body (12), has an encircling portion (18) of a non-magnetic material, wherein preferably the portion (18) is disposed so as to be level with the cross-sectional reduction (17) of the magnet armature (2) when the magnet armature (2) is at full lift.

10. Solenoid valve (1) according to one of the preceding claims, characterized in that the control valve (9) has a magnet armature (19) embodied at least in portions as a flat armature, which preferably simultaneously forms a valve closing element that interacts with a seal seat (20).

11. Solenoid valve (1) according to Claim 10, characterized in that the solenoid armature (19) of the control valve (9) is preloaded in the direction of the seal seat (20) by means of a control valve spring (21).

12. Solenoid valve (1) according to Claim 10 or 11, characterized in that the magnet armature (19) of the control valve (9) has at least one flow opening (22) for connecting the pressure chamber (6) to the control chamber (8).

13. Solenoid valve (1) according to one of the preceding claims, characterized in that the valve member (3) is preloaded in the direction of the magnet armature (2) by means of a valve member spring (23), wherein the spring force of the valve member spring (23) is smaller than the spring force of the spring (4) that preloads the magnet armature (2) in the direction of the valve member (3).

14. Hydrogen tank system comprising at least one pressurized gas tank and a solenoid valve (1) according to one of the preceding claims for shutting off the pressurized gas tank.