Shut-off valve and hydrogen tank system equipped with shut-off valve

Abstract

The present invention relates to a shut-off valve (1) for a hydrogen tank system, comprising a main valve (2) with a swivelable main valve piston (3) which defines a control chamber (6) at one end and cooperates with a main valve seat (4) at the other end and is biased by a spring force of a spring (5) in a direction towards the main valve seat (4), a control valve (7) for controlling the swivel movement of the main valve piston (3), the control valve (7) comprising a control valve armature (8) which is arranged coaxially with and axially spaced from the main valve piston (3) and is biased by a spring force of the spring (5) or another spring (9) in a direction towards a control valve seat (10), and the shut-off valve (1) further comprises an annular magnet coil (11) for operating the control valve (7) and for acting on an end section (12) of the main valve piston (3) configured as a cylindrical armature. The present invention also relates to a hydrogen tank system equipped with a shutoff valve (1) according to the present invention.

Description

[Technical field]

[0001] The present invention relates to a shut-off valve for a hydrogen tank system. Furthermore, the present invention relates to a hydrogen tank system equipped with a shut-off valve according to the invention. [Background technology]

[0002] For solenoid valves with large strokes, as is the case for example in shutoff valves for hydrogen tank systems, magnetic actuators with immersed armature are generally used, in which the magnetic force decreases more slowly with increasing distance between the armature and its stationary stop than in flat armature designs.

[0003] EP 1 399 633 A1 discloses, for example, a tank arrangement for storing hydrogen with an electromagnetically operable valve arrangement, which has a movable valve element cooperating with a valve seat for opening and closing an outlet orifice. The valve element is biased towards the valve seat by the spring force of a spring, so that the valve arrangement is closed when the magnet coil is not energized. In the open position, the valve element opens an outlet orifice having a given diameter as well as a flow path leading to said outlet orifice. The valve element simultaneously forms a magnet armature which operates according to the immersed armature principle. When the magnet coil is energized, a magnetic field is formed which surrounds the coil, the magnetic flux lines of which extend through the inner pole body, the outer pole body and the magnet armature. In this case, the magnetic flux lines extend through the radial and axial air gaps between the magnet armature and the outer pole body. By means of the magnetic force generated in the axial air gap, the magnet armature or valve element can be lifted from the sealing seat against the spring force of the spring, whereby the solenoid valve opens.

[0004] In solenoid valves with an immersed armature, as described for example in US Pat. No. 5,999,563, the magnetic field coupling through the radial air gap weakens the magnetic field in the axial air gap. As a result, the magnetic force acting on the magnet armature in the opening direction is reduced. This means that a larger magnet coil is required, which increases the energy requirements and the installation space. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] DE 102018221602 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention in particular seeks to take measures which allow the use of smaller magnet coils. [Means for solving the problem]

[0007] To achieve this object, a shut-off valve is proposed having the features of claim 1. Advantageous developments of the invention can be read from the dependent claims. Furthermore, a hydrogen tank system is provided which is provided with a shut-off valve according to the invention.

[0008] The proposed shutoff valve for the hydrogen tank system is: a main valve having a stroking main valve piston, the main valve piston defining a control chamber at one end and cooperating with a main valve seat at the other end, the main valve piston being biased by a spring force in a direction toward the main valve seat; a control valve for controlling the stroke movement of the main valve piston, the control valve including a control valve armature, the control valve armature being coaxially disposed with respect to the main valve piston and axially spaced therefrom, and biased by a spring or a separate spring in a direction toward the control valve seat; Furthermore, the shut-off valve has an annular magnetic coil for operating the control valve and for acting on an end section of the main valve piston which is configured as a cylindrical armature. Effect of the Invention

[0009] Indirect control of the main valve by the control valve allows the use of a smaller magnetic coil, since it only has to provide the force required to open the control valve. The opening of the control valve reduces the pressure in the control chamber, and therefore the pneumatic force acting on the main valve piston in the closing direction. At the same time, the end section of the main valve piston facing the control chamber is designed as an immersed armature, so that an additional magnetic force acts on the main valve piston. The combination of pneumatic force and magnetic force thus results in the opening of the main valve.

[0010] Therefore, a smaller magnet coil can be used since only a smaller magnetic force is required to open the shut-off valve, which can result in energy and installation space savings.

[0011] According to a preferred embodiment of the invention, the control chamber can be loaded with gas from the accumulator volume via an inlet throttle, Z throttle for short, and can be relieved via the control valve seat when the control valve is opened. In this case, the control valve seat or a bore connected downstream of the control valve seat acts as an outlet throttle, A throttle for short. When the control valve is opened, gas flows from the accumulator volume via the Z throttle into the control chamber and from this control chamber via the A throttle into the outlet region. The control chamber is thus located pneumatically between the accumulator volume and the outlet region. A pressure level between the accumulator pressure and the outlet pressure is thus generated in the control chamber. After closing of the control valve and the associated closure of the A throttle, pressure can be generated again in the control chamber via the inlet throttle. Insofar as this shut-off valve is used in a hydrogen tank system, the gas is preferably hydrogen gas. That is to say, the control chamber is loaded via the inlet throttle with hydrogen, which is preferably supplied from the accumulator volume of a pressurized gas container of the hydrogen tank system, so that the control chamber is loaded with the accumulator pressure. The control chamber is filled with high pressure, whereas a lower pressure prevails on the control end depending on the operating point, for example in the case of quantity take-off due to the valve seat throttling of the main valve. This pressure difference generates an air force which, together with the spring force of at least one spring, ensures that the shut-off valve is closed and kept closed at de-energized magnet coils. Even at operating points where there is no quantity take-off and therefore no pressure drop at the main valve seat, the main valve is reliably closed or kept closed by the spring force.

[0012] The remaining guide gap between the end section of the main valve piston configured as a submerged armature and the housing-side guide section receiving this end section can be used as the inlet throttle. In this case, no further measures are required for creating the inlet throttle. Alternatively or additionally, the end section of the main valve piston configured as a submerged armature can have at least one longitudinal groove and / or flattened section for creating the inlet throttle. In this way, a larger and / or defined throttle cross section can be provided. In another preferred embodiment, a sealing element is provided in the guide region, which pneumatically separates the control chamber from the accumulation pressure. In this case, the inlet throttle is realized via an additional throttle connection between the accumulation volume and the control chamber, for example via a throttle bore on the housing side, the valve side or the seal side.

[0013] The control valve armature is preferably configured as a flat armature. In order to optimize the magnetic flux guidance, it is further proposed that the flat armature is spaced radially and annularly from the housing of the shut-off valve. This spacing causes that when the magnet coil is energized, a magnetic field is formed, the magnetic flux lines of which are guided mainly by the axial working air gap, and as a result, high forces act on the control valve armature.

[0014] At least one spring of the shut-off valve is accommodated in a suitable manner in the control chamber, so that the control chamber simultaneously serves as a spring chamber. If only one spring is provided, this spring can bear against the main valve piston on the one hand and against the control valve armature on the other hand. If only one spring is provided, the number of components is reduced. Of course, the spring force of the spring must be adapted to the force required to close the main valve, so that in order to close the control valve, the spring is sometimes overdesigned. This force must be provided by the magnet coil to open the control valve. It is therefore advantageous if a second spring is provided which is adapted to the control valve and is therefore smaller, in order to enable the magnet coil to be designed even more compactly. To accommodate the two springs, the control chamber is preferably divided by an intermediate wall with a through-flow opening, so that two spring chambers connected via the through-flow opening are formed. Furthermore, the intermediate wall serves to support the housing side of the two springs.

[0015] It is further proposed that the main valve piston has or constitutes an annular collar with a stop surface, in which at least one flow passage, preferably extending in the radial direction, is formed. The annular collar forms a stroke stop together with the stop surface on the housing side. When abutting against the stroke stop, the at least one flow passage extending in the radial direction ensures that the inlet throttle is pneumatically connected to the pressure-accumulator volume. The annular collar can be formed, for example, by a local thickening of the main valve piston. Alternatively, the main valve piston can have a separate ring- or sleeve-shaped part, which is arranged on the outer peripheral area of ​​the main valve piston and is connected to it in a frictional, positive and / or material-tight manner.

[0016] In a further development of the invention, it is proposed that the main valve piston has a section configured as a flat armature, in which at least one through-flow opening and / or radially extending flow passage is formed. Due to its larger diameter, the section of the main valve piston configured as a flat armature has a larger magnetic interface surface than the section configured as a submerged armature, which allows higher forces to be applied to the main valve piston. By configuring the main valve piston as a submerged armature and a flat armature, the magnetic flux guidance can thus be further optimized, in which case the magnetic flux lines of the magnetic circuit are guided mainly by the axial working air gap. The opening of the main valve piston is achieved by the ratio of the applied pneumatic pressures as well as the magnetic forces acting on the two armature sections.

[0017] It is further proposed that the magnet coil has an increased reluctance in the area where it cooperates with the section of the main valve piston configured as a flat armature. Due to the increased reluctance, the magnetic flux lines are again amplified and guided by the section of the main valve piston configured as a flat armature, so that increased forces are obtained at the flat armature. In extreme cases, this area may even become saturated.

[0018] The section of the main valve piston configured as a flat armature can simultaneously form a stop surface which cooperates with a stop surface on the housing side to form a stroke stop. In this case, the flat armature takes the place of an annular flange. At least one through-flow opening configured in the flat armature and / or at least one radially extending flow passage formed in the flat armature pneumatically ensures the connection of the inlet throttle to the accumulator volume.

[0019] The control valve armature preferably has at least one through-flow opening for relieving the control chamber, which ensures that the control chamber can be relieved via the open control valve during the entire stroke of the control valve armature. The at least one through-flow opening can be designed, for example, as a tilted bore, via which the control chamber is connected to the control valve seat.

[0020] Since a preferred area of ​​application of the shut-off valve according to the invention is a hydrogen tank system, furthermore, a hydrogen tank system is proposed which comprises at least one pressurized gas container as well as a shut-off valve according to the invention for isolating the pressurized gas container, which can be used in particular in fuel cell vehicles or vehicles with a hydrogen combustion device. [Brief description of the drawings]

[0021] [Figure 1] 3 a) to 3e) respectively show schematic longitudinal sections of a first shut-off valve according to the invention in different switching positions. [Diagram 2] 3 a) to 3e) respectively show schematic longitudinal sections of a second shut-off valve according to the invention in different switching positions. [Diagram 3] 3 a) to 3e) respectively show schematic longitudinal sections of a third shut-off valve according to the invention in different switching positions. [Figure 4] 3 a) to 3e) respectively show schematic longitudinal sections of a fourth shut-off valve according to the invention in different switching positions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The preferred embodiments of the present invention and their advantages are explained in detail below with reference to the accompanying drawings.

[0023] The shut-off valve 1 shown in FIGS. 1a) to 1e) has a main valve 2 with a swivelable main valve piston 3 which cooperates with a main valve seat 4 and is biased towards it by the force of a spring 5. At its end opposite to the main valve seat 4, the main valve piston 3 defines a control chamber 6 to which gas is connected via an inlet throttle 13 from an accumulator volume of a pressure gas container (not shown). From the accumulator volume of the pressure gas container, the gas passes via a gas line 26 into a valve chamber 27 and from there into the control chamber 6 via the inlet throttle 13. The inlet throttle 13 is here formed via a guide play of a guide section on the housing side for guiding the main valve piston 3. As a result, a storage pressure or high pressure prevails in the control chamber 6 as well as in the valve chamber 27. On the other hand, on the control end side, i.e. in the gas line 25, a pressure level that is normally reduced with respect to the storage pressure prevails. Thus, the applied pneumatic pressure ratio as well as the spring force of the spring 5 presses the main valve piston 3 against the main valve seat 4, thereby closing the main valve 2.

[0024] To open the main valve 2, an annular magnet coil 11 acts on the control valve armature 8, which is configured as a flat armature of the control valve 7. When the magnet coil 11 is energized, a magnetic field is generated which has a magnetic force that lifts the control valve armature 8 from the control valve seat 10, so that the control valve 7 opens (see FIG. 1b). Due to the control valve armature 8 being configured as a flat armature, a high magnetic force acts on this control valve armature 8. Furthermore, the guidance of the magnetic flux lines in the magnetic circuit is optimized by the flat armature being spaced at a radial distance a from the housing 14, so that the magnetic flux lines are mainly guided by the axial working air gap.

[0025] When the control valve 7 is open, gas flows out of the control chamber 6 into the gas line 25, so that the pressure in the control chamber 6 decreases. In this case, the through-flow opening 24 formed in the control valve armature 8 ensures that gas can flow out of the control chamber 6 even during the entire stroke of the control valve armature 8.

[0026] The pressure drop in the control chamber 6 causes the main valve piston 3 to be decompressed while the pressure rises on the control end side or in the gas line 25. The end section 12 of the main valve piston 3 facing the control chamber is designed as a cylindrical armature, so that the magnetic force of the magnet coil 11 acts on this end section 12 at the same time, resulting in a combination of pneumatic and magnetic forces for finally opening the main valve 2 (see FIG. 1c). An annular flange 17 with abutment surface 18 designed on the main valve piston 3 limits the opening stroke of the main valve piston 3. A radially extending flow passage 19 formed in the annular flange 17 ensures that during the entire opening stroke of the main valve piston 3, the inlet throttle 13 remains connected to the valve chamber 27 and thus to the accumulator volume of the pressurized gas container.

[0027] To close the main valve 2, the magnet coil 11 is de-energized, which causes the spring 5 to move the control valve armature 8 back to the control valve seat 10 and close the control valve 7 (see FIG. 1d). Since gas can no longer flow out of the control chamber 6, it fills with gas via the inlet throttle 13, so that the pressure in the control chamber 6 rises again. The pneumatic pressure ratio generates a pneumatic force which, together with the spring force of the spring 5, moves the main valve piston 3 back to its seat 4, so that the main valve 2 closes (see FIG. 1e).

[0028] 2a) to 2e) show another preferred embodiment of the shutoff valve 1 according to the invention. This shutoff valve 1 differs from FIGS. 1a) to 1e) in particular in that the main valve piston 3 not only has an end section 12 designed as a cylindrical armature, but also a section 20 designed as a flat armature. Furthermore, the magnet coil 11 has an increased magnetic resistance in the area 23 which cooperates with the flat armature, by which the magnetic flux lines are amplified and guided by the section designed as a flat armature. As a result, an increased magnetic force acts on the main valve piston 3. In addition, the section 20 designed as a flat armature replaces the annular flange 17, so that the section 20 constitutes a stroke stop. During the full opening stroke of the main valve piston 3, a pneumatic connection between the inlet throttle 13 and the valve chamber 27 is ensured by at least one through-flow opening 21 and a flow passage 22 formed in the flat armature section.

[0029] The function of the shut-off valve 1 in Figs. 2a) to 2e) corresponds to the function of the shut-off valve 1 in Figs. 1a) to 1e). Fig. 2a) shows the shut-off valve 1 in the de-energized state of the magnet coil 11, i.e. in the closed state. For opening, the magnet coil 11 is energized, which creates a magnetic field with a magnetic force that lifts the control valve armature 8 of the control valve 7 from the control valve seat 10 (see Fig. 2b). With the control valve 7 open, gas flows out of the control chamber 6 into the gas line 25, which reduces the pressure in the control chamber 6. The reduced pressure in the control chamber 6 relieves the main valve piston 3, so that a force acting on the main valve piston 3 in the opening direction prevails and the main valve 2 opens (see Fig. 2c). For closing, the magnet coil 11 is de-energized, which causes the spring 5 to return the control valve armature 8 to the control valve seat 10 (see Fig. 2d). With the control valve 7 closed, the pressure in the control chamber 6 rises again. This is because the control chamber 6 is pneumatically connected to the valve chamber 27 via the inlet throttle 13. In a similar manner, the pressure in the pressure chamber 6 also increases, so that a force acting on the main valve piston 3 in the closing direction prevails, and the main valve piston 3 is forced back into its main valve seat 4 (see FIG. 2e).

[0030] The shut-off valve 1 according to the invention shown in FIGS. 3a) to 3e) represents a development of the shut-off valve 1 of FIGS. 1a) to 1e). Instead of one common spring 5, two springs 5, 9 are accommodated in the control chamber 6. The control chamber 6 is divided into two spring chambers by an intermediate wall 15 with a central through-flow opening 16, so that the two springs 5, 9 can be supported on the intermediate wall 15. The further spring 9 can be designed smaller than the spring 5, since it only has to close the control valve 7. Correspondingly, the magnetic force required to open the control valve 7 is reduced, so that a smaller magnet coil 11 can be used. In other respects, the functional form of the shut-off valve 1 of FIGS. 3a) to 3e) corresponds to the functional form of the shut-off valve 1 of FIGS. 1a) to 1e). In order to avoid a repetitive explanation, reference is therefore made to the corresponding explanation.

[0031] The shut-off valve 1 according to the invention shown in Figs. 4a to 4e) represents a development of the shut-off valve 1 of Figs. 2a to 2e). Here too, instead of one common spring 5, two springs 5, 9 are accommodated in the control chamber 6. The control chamber 6 is divided into two spring chambers by an intermediate wall 15 with a central through-flow opening 16, so that the two springs 5, 9 can be supported on the intermediate wall 15. The further spring 9 can be designed smaller than the spring 5, since only the control valve 7 has to be closed. Correspondingly, the magnetic force required to open the control valve 7 is reduced, so that a smaller magnet coil 11 can be used. In other respects, the functional form of the shut-off valve 1 of Figs. 4a to 4e) corresponds to the functional form of the shut-off valve 1 of Figs. 2a to 2e). In order to avoid a repetitive explanation, reference is therefore made to the corresponding explanation. [Explanation of symbols]

[0032] 1. Shutoff valve 2 Main valve 3 Main valve piston 4 Main valve seat 5. Spring 6. Control Room 7. Control valve 8 Control valve armature 9. Another Spring 10 Control valve seat 11 Magnet coil 12 Termination section 13 Inflow restriction 14 Housing 15 Intermediate Wall 16 Through-flow opening 17 Annular brim 18 Contact surface 19 Flow Path 20 Sections configured as flat movers 21 Through-flow opening 22 Flow Path 23 areas 24 Through-flow opening 25 Gas Pipeline 26 Gas Pipeline 27 Valve chamber

Claims

1. A shutoff valve (1) for a hydrogen tank system, comprising: The valve includes a main valve (2) having a main valve piston (3) capable of stroking, the main valve piston (3) defining a control chamber (6) at one end and cooperating with a main valve seat (4) at the other end, and biased by a spring (5) in a direction toward the main valve seat (4), a control valve (7) for controlling the stroke movement of the main valve piston (3), the control valve (7) including a control valve armature (8) arranged coaxially with the main valve piston (3) at an axial distance therefrom and biased in a direction toward a control valve seat (10) by a spring force of the spring (5) or another spring (9); a ring-shaped magnet coil (11) for operating the control valve (7) and for acting on an end section (12) of the main valve piston (3) configured as a cylindrical armature; Shut-off valve for hydrogen tank system (1).

2. 2. The shutoff valve (1) according to claim 1, characterized in that the movement of the main valve piston (3) and the movement of the control valve armature (8) are in opposite directions to each other.

3. 3. The shut-off valve (1) according to claim 1 or 2, characterized in that the control chamber (6) can be loaded with gas, preferably hydrogen, from a pressure accumulator volume via an inlet throttle (13) and can be relieved via the control valve seat (10) when the control valve (7) is opened.

4. 4. The shut-off valve (1) according to claim 3, characterized in that the end section (12) of the main valve piston (3) configured as an immersed armature has at least one longitudinal groove and / or flattened portion for forming the inlet throttle (13).

5. 5. The shut-off valve (1) according to claim 1, wherein the control valve armature (8) is configured as a flat armature, which is preferably radially and annularly spaced (a) relative to the housing (14).

6. 6. The shut-off valve (1) according to claim 1, wherein the at least one spring (5, 9) is received in a control chamber (6), the control chamber (6) being divided in a suitable manner by an intermediate wall (15) provided with a through-flow opening (16).

7. 7. The shut-off valve (1) according to claim 1, wherein the main valve piston (3) has or constitutes an annular collar (17) with an abutment surface (18), in which at least one radially extending flow passage (19) is formed in a suitable manner.

8. 8. The shut-off valve (1) according to claim 1, characterized in that the main valve piston (3) has a section (20) configured as a flat armature, in which at least one through-flow opening (21) and / or a radially extending flow passage (22) is formed.

9. 9. The shut-off valve (1) according to claim 8, characterized in that the magnet coil (11) has an increased magnetic resistance in a region (23) cooperating with the section (20) of the main valve piston (3) configured as a flat armature.

10. 10. The shut-off valve (1) according to any one of claims 1 to 9, characterized in that the control valve armature (8) has at least one through-flow opening (24) for relieving pressure in the control chamber (6).

11. A hydrogen tank system comprising at least one pressurized gas container and a shut-off valve (1) according to any one of claims 1 to 10 for isolating the pressurized gas container.

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