Stop valve for compressed gas container, compressed gas container having stop valve

Abstract

The invention relates to a shut-off valve (1) for a compressed gas container, comprising:-a main valve having a main valve seat (2) and a reciprocally movable main valve part (3),-a control valve for controlling the reciprocation of the main valve part (3), the control valve having a reciprocally movable valve tappet (4), the valve tappet can be coupled to a reciprocating armature (5) and is acted upon by a spring force of a closing spring (7) in the direction of a control valve seat (6) formed in the main valve part (3), and an electromagnetic coil (8) for acting on the armature (5). According to the invention, the armature (5) is decoupled from the valve tappet (4) and is preloaded against a housing-side stop (10) by the spring force of a compression spring (9) when the electromagnetic coil (8) is not energized, the compression spring (9) being supported on the armature (5) on the one hand and on the main valve part (3) on the other hand. The invention also relates to a compressed gas container having a shut-off valve (1) according to the invention.

Description

Field of the Invention

[0001] The present invention relates to a shut-off valve for a compressed gas container having the features of the preamble of claim 1. Furthermore, the present invention relates to a compressed gas container having a shut-off valve according to the present invention.

[0002] The compressed gas container can in particular be a container for storing combustible gases such as hydrogen or natural gas. Such combustible gases are particularly necessary for vehicles having a fuel cell or a gas engine. Therefore, a more preferred field of application of the present invention is mobile applications. However, stationary applications are not excluded. Background Art

[0003] Compressed gas containers for storing fuel gases such as hydrogen or natural gas are subject to legal safety regulations. These compressed gas containers are provided, for example, with an automatically closing shut-off valve.

[0004] Such a shut-off valve is known, for example, from DE 10 2018 221 602 A1. It can be controlled electromagnetically by means of an electromagnetic coil, the magnetic force of which acts on a actuating valve element reciprocating along the longitudinal axis. In the case where the electromagnetic coil is not energized, a spring presses the actuating valve element against a valve seat constructed on the housing side.

[0005] Furthermore, indirectly and / or multi-stage opening shut-off valves are known, which include a main valve and a control valve. By means of the control valve, a small opening cross-section is first released during opening, thereby reducing the force required for opening. As the control valve opens, the pressure ratio on the main valve changes, with the result that the main valve also opens. In order to support the opening of the main valve, a mechanical actuating member can be arranged between the control valve and the main valve.

[0006] The object of the present invention is to provide an electromagnetically actuable shut-off valve for a compressed gas container, which can be opened with a minimum of magnetic force, so that the solenoid and thus the size of the shut-off valve can be made smaller. Summary of the Invention

[0007] To solve this task, a shut-off valve having the features of claim 1 is proposed. Advantageous refinements of the present invention can be derived from the dependent claims. Furthermore, the present invention also provides a compressed gas container having a shut-off valve according to the present invention.

[0008] The proposed shut-off valve for a compressed gas container comprises:

[0009] - a main valve having a main valve seat and a reciprocating main valve element,

[0010] - A control valve for controlling the reciprocating movement of a main valve member, wherein the control valve has a valve tappet capable of reciprocating movement, the valve tappet can be coupled to an armature capable of reciprocating movement and is loaded by the spring force of a closing spring in the direction towards a control valve seat formed in the main valve member, and

[0011] - An electromagnetic coil for acting on the armature.

[0012] According to the present invention, in the case where the electromagnetic coil is not energized, the armature is decoupled from the valve tappet and pre-tightened towards the housing-side stop by the spring force of a pressure spring. Here, the pressure spring is supported on the armature on the one hand and on the main valve member on the other hand.

[0013] The terminal orientation of the armature is pre-given by the pressure spring and the housing-side stop, and this terminal orientation is the initial position of the armature when the shut-off valve is open. In this initial position, the armature is not coupled to the valve tappet, so that the armature can move relative to the valve tappet or perform a free stroke. With the armature abutting against the valve tappet, this free stroke ends. The valve tappet is thus only temporarily coupled to the armature. The coupling is achieved by the stop.

[0014] To open the shut-off valve, the electromagnetic coil is energized, thereby forming a magnetic field, and the magnetic force of this magnetic field acts on the armature. The armature disengages from the housing-side stop and starts to move, wherein the armature first performs a defined free stroke. When the stop is on the valve tappet, the armature transmits an impulse acting in the opening direction, and this impulse disengages the valve tappet from the control valve seat, so that the control valve opens. Here, the impulse causes such a large temporary opening force that the electromagnetic coil can be dimensioned smaller.

[0015] With the opening of the control valve, the pressure ratio on the main valve member of the main valve changes until the force acting in the opening direction becomes dominant and the main valve also opens. Here, this opening is supported by the spring force of a pressure spring arranged between the main valve member and the armature. Because with the opening movement of the armature relative to the still-closed main valve member, the pressure spring is tensioned, so that as the armature stroke increases, an increasing opening spring force acts on the main valve member. Therefore, the pressure spring facilitates the opening of the main valve.

[0016] If the energization of the electromagnetic coil ends, the closing spring resets the valve tappet and (indirectly via the valve tappet) the main valve member back into the corresponding valve seat. Here, the valve tappet drives the armature. However, due to the free stroke, the complete reset of the armature to its initial position is not achieved by the carrying movement of the valve tappet, but by the pressure spring pressing the armature towards the housing-side stop. Therefore, the armature is reliably reset to its initial position by the pressure spring. Therefore, the initial position of the armature is always the same, thus ensuring stable and reproducible valve opening.

[0017] When resetting by means of a compression spring, the armature disengages from the valve tappet, so that the armature and the valve tappet are decoupled again. This has the advantage that the seat load in the seats of the main valve and the control valve is reduced. Because the closing impulse of the relatively heavy armature is reduced by the housing-side stop and not by the valve seat.

[0018] According to a preferred embodiment of the invention, the armature has a preferably hollow cylindrical section which sectionally surrounds the main valve element in such a way as to form an annular space, wherein the compression spring is accommodated in this annular space. Thus, the compression spring is guided by the armature and / or the main valve element when tensioned. This prevents the spring from bending. Furthermore, a compact arrangement which requires little structural space is achieved in this way.

[0019] The annular space accommodating the compression spring can have a constant or variable width in the axial direction (depending on the configuration of the armature and / or the main valve element). In the circumferential direction, the width is preferably the same all around, so that the armature and the main valve element are arranged concentrically with each other.

[0020] Furthermore, it is proposed that the compression spring is supported on the one hand on an annular flange extending radially inwards of the preferably hollow cylindrical section of the armature and on the other hand on an annular flange extending radially outwards of the main valve element. Each annular flange forms a spring seat, through which the spring force of the compression spring is evenly transmitted to the armature or the main valve element.

[0021] The annular flange of the preferably hollow cylindrical section of the armature and / or the annular flange of the main valve can form a circumferentially closed ring or a ring interrupted several times, in particular a segmented ring. Furthermore, at least one annular flange can be formed by an additional structural element which is connected to the armature or the main valve element in a force-locking, form-locking and / or material-locking manner.

[0022] Furthermore preferably, the valve tappet is at least sectionally accommodated in the armature and has an annular flange extending radially outwards and accommodated in the armature for coupling with the armature. Thus, the valve tappet can be guided by the armature. For accommodating the valve tappet, a hole is formed in the armature, which hole is preferably configured as a stepped hole, so that a shoulder is formed which cooperates with the annular flange.

[0023] Based on the free stroke traveled by the armature during reciprocating motion, the stroke of the armature is greater than the stroke of the valve tappet. Preferably, the stroke of the armature is delimited on the one hand by a stop on the housing side and on the other hand by a stroke stop, so that the armature moves back and forth between two end positions. In the limitation of the stroke, there is a risk of causing the armature to impact. The impact tendency of the armature is usually attributed to: as the stroke increases and the working air gap decreases, the magnetic force acting in the opening direction in the magnetic circuit increases, while the aerodynamic force acting in the closing direction decreases. As the excess force in the opening direction increases, the armature is accelerated, which results in repeated stops at the stroke stop and the formation of disturbing and perceptible noise. However, in the proposed shut-off valve, the impact tendency of the armature is significantly reduced because the reciprocating motion of the armature is braked by a stop and impulse transfer on the valve tappet. Further braking of the armature is achieved by a tensioned pressure spring, thereby further reducing the risk of impact.

[0024] The pressure spring can have a linear or progressive spring characteristic curve. For example, the pressure spring can be implemented as a simple helical pressure spring with a linear spring characteristic curve, so that the spring force increases linearly as the pressure spring is tensioned. However, a pressure spring with a progressive spring characteristic curve is considered particularly advantageous because in this case, the valve force characteristic curve can be optimally matched to the magnetic force characteristic curve. This in turn makes it possible to further reduce the electromagnetic coil and thus miniaturize the shut-off valve. At the same time, the risk of impact is also further minimized.

[0025] Therefore, in an improvement of the present invention, it is proposed that the pressure spring is a helical pressure spring, the coils of which have:

[0026] - a varying wire diameter,

[0027] - a varying coil diameter, and / or

[0028] - a varying pitch height,

[0029] so that the pressure spring has a progressive spring characteristic curve.

[0030] In addition, a compressed gas container with a shut-off valve according to the present invention is proposed. Such a compressed gas container can be used, for example, for storing fuel gases, especially hydrogen or natural gas, because the legal safety requirements for such a storage can be met by means of the shut-off valve according to the present invention. In addition, the shut-off valve has an electromagnetic coil with a very small size design, so that the structural space requirement is small. Therefore, the shut-off valve can be integrated into the narrow neck of a bottle-shaped compressed gas container in a simple manner.

[0031] For example, in a fuel cell vehicle, a bottle-shaped compressed gas container is used to store hydrogen. To protect the fuel cell, a pressure reducer is usually provided between the compressed gas container and the fuel cell, and the pressure reducer reduces the high pressure existing in the compressed gas container to a medium pressure level. When using a compressed gas container having a shut-off valve according to the present invention, the pressure reducer is protected against an inadmissible high pressure shock, since the spring stiffness of the pressure spring and the stroke of the armature can be set very precisely to the maximum pressure shock when the main valve opens. Thus, the load on the pressure reducer and the load on the downstream medium pressure system containing the fuel cell are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. These drawings show:

[0033] Figure 1 A schematic longitudinal section showing the shut-off valve according to the present invention in the closed position,

[0034] Figure 2 A schematic longitudinal section showing the shut-off valve when the electromagnetic coil is energized and the armature abuts against the valve tappet Figure 1

[0035] Figure 3 A schematic longitudinal section showing the shut-off valve when the electromagnetic coil is energized and the armature abuts against the stroke stop (control valve open) Figure 1

[0036] Figure 4 A schematic longitudinal section showing the shut-off valve when the electromagnetic coil is energized and the main valve is open Figure 1

[0037] Figure 5 A schematic longitudinal section showing the shut-off valve when the electromagnetic coil is not energized and the main valve and the control valve are closed, and Figure 1

[0038] Figure 6 A schematic longitudinal section showing another shut-off valve according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0039] In Figures 1 to 5 shown, the shut-off valve 1 according to the present invention is used to extract fuel gas, such as hydrogen, from a compressed gas container (not shown).

[0040] ​​​​The shut-off valve 1 shown includes a main valve and a control valve. The main valve has a main valve seat 2 and a reciprocating main valve member 3. The control valve has a control valve seat 6 formed in the main valve member 3 and a reciprocating valve tappet 4. The control valve is electromagnetically actuated. For this purpose, an electromagnetic coil 8 is provided, which acts on an armature 5 that can be coupled to the valve tappet 4. To open the control valve, the electromagnetic coil 8 is energized. With the end of the energization of the electromagnetic coil 8, a closing spring 7 supported on the valve tappet 4 returns the valve tappet 4 to the control valve seat 6. The spring force of the closing spring 7 is sized such that with the return of the valve tappet 4, the armature 5 and the main valve member 3 are returned simultaneously. The shut-off valve 1 shown is thus implemented as a normally closed valve (stromlos geschlossenes Ventil).

[0041] To couple with the armature 5, the valve tappet 4 has an annular flange 15, which is received in a hole of the armature 5, and the hole is implemented as a stepped hole 18. Thus, depending on the stroke of the armature 5, the annular flange 15 of the valve tappet 4 abuts against a step 19 of the armature 5. In the closed state of the shut-off valve 1, the end positions of the main valve member 3 and the valve tappet 4 are pre-given by the respective valve seats 2, 6. The end position of the armature 5 is determined by a housing-side stop 10. The armature is pressed against this stop 10 by the spring force of a pressure spring 9, which is received in an annular space 12 between a hollow cylindrical section 11 of the main valve member 3 and the armature 5, and is supported on the one hand on an annular flange 13 of the hollow cylindrical section 11 and on the other hand on an annular flange 14 of the main valve member 3. Since the spring force of the pressure spring 9 is less than the spring force of the closing spring 7, the closing spring 7 keeps the shut-off valve 1 closed when the electromagnetic coil 8 is not energized. In this closed state, the armature 5 and the valve tappet 4 are decoupled. That is, an axial gap is left between the step 19 and the annular flange 15, and this axial gap defines the free stroke h of the armature 5 F 。

[0042] The following is based on the attached Figures 2 to 5 to illustrate the working mode of the shut-off valve 1.

[0043] If the electromagnetic coil 8 is energized to open the shut-off valve 1, a magnetic field is formed, and the magnetic force of this magnetic field attracts the armature 5 in the direction of the stroke stop 16. Therefore, the armature 5 disengages from the housing-side stop 10 and moves in the direction of the stroke stop 16. With the passage of the free stroke h F , the armature 5 collides with the valve tappet 4 (see Figure 2 ), whereby the armature 5 transfers an opening impulse to the valve tappet 4, causing the valve tappet to disengage from the control valve seat 6 and open the control valve (see Figure 3) At the same time, the armature 5 is braked by impulse transfer, thereby reducing the risk of impact on the stroke stop 16. Another braking effect is achieved in such a way that as the stroke of the armature 5 increases, the pressure spring 9 is tensioned. In addition, the tensioning of the pressure spring 9 causes an opening force on the main valve member 3, so that once the opening spring force is greater than the closing pneumatic force on the main valve member, the main valve member opens. Through the already opened control valve, a changed pneumatic pressure ratio appears on the main valve, which results in a continuous further decrease in the pneumatic closing force. Because when the control valve is open, the combustion gas flows from the compressed gas container with pressure p1 to the outlet 20 with a pressure p2 that is less than p1. However, increased pressure compensation is achieved through the opened control valve. Therefore, once the pneumatic closing force reduced due to the pressure difference on the main valve member is less than the opening spring force of the tensioned pressure spring 9 (see Figure 4 ), the main valve opens. By appropriately designing the opening spring force, the so-called opening pressure difference on the main valve member can be precisely determined, because this opening pressure difference is directly obtained from the quotient of the spring force and the area of the effective main valve seat diameter. Therefore, the pressure shock when opening the main valve member can be limited to a well - tolerable level almost independently of the tank pressure, which significantly reduces the subsequent component loads, especially those of the pressure reducer.

[0044] To close the shut - off valve 1, the energization of the electromagnetic coil 8 is ended, so that the closing spring 7 resets the valve tappet 4 into the control valve seat 6. At the same time, since this control valve seat is constructed in the main valve member 3, the main valve member 3 is reset into the main valve seat 2 by the valve tappet 4 (refer to Figure 5 ). Since the valve tappet 4 is coupled to the armature 5, the armature is also driven in the direction of the housing - side stop 10. However, the full reset of the armature 5 to its initial position (see Figure 1 ) is achieved by means of the pressure spring 9. Therefore, the initial position of the armature 5 is always the same when opening through the pressure spring 9, so that the armature 5 travels through a free stroke h F in order to transfer the desired opening impulse to the valve tappet 4. This opening impulse enables a smaller size of the electromagnetic coil 8, because the opening can be achieved with a reduced magnetic force.

[0045] In Figure 6 , another preferred embodiment of the shut - off valve 1 according to the present invention is shown. Different from the shut - off valve 1 in Figures 1 to 5 , another pressure spring 9 is used in this shut - off valve 1. This other pressure spring is also constructed as a helical pressure spring with coils 17. However, the coils 17 have a varying coil diameter, so that the pressure spring 9 has a progressive spring characteristic curve. The progressive spring characteristic curve enables an even better matching of the valve force characteristic curve and the magnetic force characteristic curve, so that the electromagnetic coil 8 can be further reduced in size.

[0046] Figure 6 The working principle of the globe valve 1 corresponds to Figures 1 to 5 the working principle of the globe valve 1, and thus reference is made to the above description.

Claims

1. A stop valve (1) for a compressed gas container, comprising: - A main valve having a main valve seat (2) and a reciprocating main valve element (3), - A control valve for controlling the reciprocating movement of the main valve element (3), wherein the control valve has a reciprocating valve tappet (4) which can be coupled to a reciprocating armature (5) and is loaded by the spring force of a closing spring (7) in the direction of a control valve seat (6) formed in the main valve element (3), and - An electromagnetic coil (8) for acting on the armature (5), Characterized in that, when the electromagnetic coil (8) is not energized, the armature (5) is decoupled from the valve tappet (4) and pre-tensioned by the spring force of a pressure spring (9) against a housing-side stop (10), wherein the pressure spring (9) is supported on the one hand on the armature (5) and on the other hand on the main valve element (3).

2. The stop valve (1) according to claim 1, characterized in that The armature (5) has a preferably hollow cylindrical section (11) which sectionally surrounds the main valve element (3) in such a way as to form an annular space (12), wherein the pressure spring (9) is received in the annular space (12).

3. The stop valve (1) according to claim 2, characterized in that The pressure spring (9) is supported on the one hand on an annular flange (13) extending radially inwards of the preferably hollow cylindrical section (11) and on the other hand on an annular flange (14) extending radially outwards of the main valve element (3).

4. The stop valve (1) according to claim 3, characterized in that The annular flange (13) and / or the annular flange (14) form a circumferentially closed ring or a ring which is interrupted a plurality of times, in particular a segmented ring.

5. The stop valve (1) according to any one of the preceding claims, characterized in that The valve tappet (4) is at least sectionally received in the armature (5) and has an annular flange (15) extending radially outwards and received in the armature (5) for coupling to the armature (5).

6. The stop valve (1) according to any one of the preceding claims, characterized in that The stroke of the armature (5) is greater than the stroke of the valve tappet (4), wherein the stroke of the armature (5) is delimited on the one hand by the housing-side stop (10) and on the other hand by a stroke stop (16).

7. The stop valve (1) according to any one of the preceding claims, characterized in that The pressure spring (9) has a linear or progressive spring characteristic curve.

8. The stop valve (1) according to any one of the preceding claims, characterized in that The pressure spring (9) is a helical pressure spring, the coils (17) of which have: - A varying wire diameter, - A varying coil diameter, and / or - A varying pitch height.

9. A compressed gas container having the stop valve (1) according to any one of the preceding claims.

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