Check-valve device for a refueling path of a tank system, and tank system

Abstract

The invention relates to a check-valve device for a refueling path of a tank system, and to a tank system. The check-valve device (1) is equipped with: a valve housing (2); a valve closing element (3) which is accommodated in the valve housing (2) and, in an initial position, is biased against a valve seat (4) by means of a spring mechanism (5); and a circumferential friction device (6) for damping axial oscillations of the valve closing element (3), the friction device (6) being located in a conical abutment face (7) of the valve housing (2) so that an axially acting spring force (FA) elastically deforms the friction device (6) in such a way that the friction device (6) exerts a radial clamping force (FK) on the valve closing element (3).

Description

[0001] Description

[0002] Title and

[0003] The present invention relates to a check valve device for a refueling path of a tank system, in particular a hydrogen pressure vessel, and to a tank system with such a check valve device.

[0004] State of the art

[0005] Climate-neutrally produced hydrogen as an environmentally friendly energy source for fuel cells and combustion engines as a power source for mobile and stationary applications is becoming increasingly important. High-pressure gas cylinders are used to store the hydrogen. So-called "multifunctional tank valves" are typically screwed onto these cylinders, which control both refueling and withdrawal for the consumer.

[0006] Within the tank valve, the hole through which hydrogen can flow from the tank valve into the connecting line and vice versa is split into two paths: the refueling path, through which the hydrogen flows into the gas tank during the refueling process, and the withdrawal path, through which hydrogen flows when hydrogen is withdrawn from the gas tank and fed to the consuming system. There are valves that have two external high-pressure connections (separate refueling and withdrawal), as well as valves with just a single high-pressure connection through which refueling or withdrawal takes place depending on the operating state. The two paths are interconnected within the valve. However, all switching concepts have in common that the refueling path is locked with a check valve (RSV for short). This prevents uncontrolled hydrogen from escaping from the tank when the system is shut down or when it is being withdrawn.

[0007] For example, DE 10 2014 214 182 A1 describes a method for adjusting the opening pressure of a valve with a valve housing having a valve inlet and a valve outlet, on which a valve seat is formed and in which a valve closing body is located that interacts with the valve seat and is movable relative to the valve seat. The valve closing body is provided with a valve spring that loads the valve closing body in a direction that closes the valve and is supported on a counterbearing connected to the valve housing. A shaft of the valve closing body has a circumferential collar in which a circumferential groove is located, in which a friction ring in the form of an O-ring is located.

[0008] The friction ring is typically used to dampen axial vibrations of the valve closing body. In the prior art, the friction ring is often designed as an open friction ring made of a flexible material.

[0009] When the valve is open, gas flows through the valve. The gas flows through a gap between the valve seat and the valve closing element, which is lifted from the valve seat. The opening pressure of the valve is determined by the preload of the spring, which in turn is determined by the position of the counter bearing relative to the valve seat in the valve housing.

[0010] Disclosure of the invention

[0011] The invention provides a check valve device for a refueling path of a tank system, in particular a hydrogen pressure vessel, having the features of claim 1 and a tank system having the features of claim 9. According to a first aspect of the invention, a check valve device is provided for a refueling path of a tank system, in particular a hydrogen pressure vessel.The check valve device comprises a valve housing and a valve closing body which is accommodated in the valve housing and is prestressed in a basic position against a valve seat by a spring device. Furthermore, the check valve device comprises a circumferential friction device for damping axial vibrations of the valve closing body, wherein the friction device is arranged in a conically designed contact surface of the valve housing, so that an axially acting spring force elastically deforms the friction device in such a way that the friction device effects a radial clamping force on the valve closing body.

[0012] According to a second aspect of the invention, a tank system is provided. The tank system comprises a refueling path having a check valve device according to the first aspect of the invention.

[0013] One idea underlying the present invention is to reduce, and in particular to avoid, axial oscillation of the valve closing body or so-called rattling, which can be caused by system-inherent pressure oscillations in the tank system. The check valve device is mechanically designed, i.e. the valve closing body is, for example, axially movable and has a correspondingly effective seat diameter on the valve seat and the counteracting spring device or closing spring for providing a locking setting force. The valve closing body can be designed as a piston, ball or the like. The piston can in particular be hollow, at least in sections. The check valve device can open when there is an overpressure, i.e. an opening pressure, between the tank system and a storage bottle orThe static pressure difference immediately upstream and downstream of the check valve device, which is established due to flow and absolute pressure losses, is at least in equilibrium with the correspondingly adjusted spring force setting. Downstream of the check valve device, the tank system can, for example, have a filling pipe, which can also be called a filling lance. The filling pipe can distribute or mix an inflowing fluid within the tank system, for example, to achieve a uniform temperature distribution. For example, the check valve device can be integrated within a screw-in stem of a bottle neck.

[0014] The spring device can be provided within the valve housing and configured to press the valve closing body toward the valve seat to close a flow opening, so that, in the basic position, a pressure medium connection between two working ports can be controlled in a predetermined flow direction. For example, the spring device is designed as a compression spring, in particular as a spiral compression spring or helical spring. The valve housing can be conical in the region of the valve seat. The valve closing body can have a conical end for surface contact with the valve seat.

[0015] When designing the check valve device, the following conflict of objectives arises.

[0016] If the check valve device is closed or in a blocking direction, for example, a "shut-off" operating state exists. In this operating state, the tank system outside of a gas cylinder is depressurized or at a lower pressure. The functional requirement of seat tightness is provided by sufficient surface pressure. The greatest possible locking force, which is provided in particular by the mechanical spring device, is required for a given seat diameter. This can be achieved, for example, by means of a preloaded helical compression spring.

[0017] If the check valve device is open, for example, a "refueling" operating state exists. The first functional requirement of dethrottling, i.e. minimal total pressure loss due to flow friction, of the check valve device is required to ensure a high mass flow for short refueling times. This can be achieved, for example, by providing the largest possible valve stroke, particularly in the order of magnitude of the inlet and outlet cross sections. The second functional requirement of stable positioning of the valve closing body independent of the stroke position, i.e. even before the stroke stop is reached in an undefined intermediate position. This can be achieved by the friction device by avoiding axial oscillation of the valve closing body, the so-called rattling.

[0018] Thanks to the check valve device or friction device according to the invention, these axial valve closing body vibrations cannot feed back into the tank system. Thus, control circuits and other components are not negatively affected, severe guide wear is not induced in the check valve device, and acoustic disturbances are not triggered.

[0019] Due to the axial spring force imprint and the force deflection on the conical contact surface of the valve housing, the friction device is elastically constricted tangentially and thus induces a radial clamping force, which ultimately leads to a mechanical friction damping of the valve closing body.

[0020] A further advantage of the present invention is that the mountability of the friction device in the valve housing can be improved. Particularly in comparison with non-rotating, i.e., open friction rings, tilting, canting, or spiral spreading of the ends of the open friction ring can be reduced, and in particular prevented. Furthermore, jamming of the end section of the spring device with the groove of the non-rotating friction ring can be prevented. Furthermore, a uniform force distribution and redirection can be achieved by the friction device. Consequently, clamping and thus friction forces can vary less from one specimen to another and from one stroke to another due to a twisting effect of the spring device.In this way, high demands on geometric accuracy, such as a diameter and maximum permissible spread of the end sections, for achieving low-variance force ratios can be avoided. Another advantage is that the friction device can be manufactured using a cost-effective injection molding process without any additional production steps.

[0021] Advantageous embodiments and further developments emerge from the further subclaims and from the description with reference to the figures of the drawing.

[0022] According to a further development of the invention, the friction device is rotationally symmetrical. A rotational axis of the friction device corresponds, for example, to a longitudinal axis of the valve closing body.

[0023] In particular, the friction device is designed, for example, as a closed friction ring.

[0024] According to a further development of the invention, the friction device axially supports an end portion of the spring device. The friction device can, for example, be inserted between the spring device, in particular between the end portion of the spring device, and the valve housing.

[0025] According to a further development of the invention, the friction device comprises a plurality of spiral spring elements arranged circumferentially and flexible substantially along a radial direction. This means that a plurality of recesses can be formed between the plurality of spiral spring elements. For example, the spiral spring elements are designed substantially identically.

[0026] According to a further development of the invention, the plurality of spiral spring elements comprises six, eight, or ten spiral spring elements, which are evenly distributed over the circumference of the spring device. Alternatively, the plurality of spiral spring elements can comprise any even or odd number of spiral spring elements, for example, three, five, seven, or nine spiral spring elements.

[0027] According to a further development of the invention, the plurality of spiral spring elements are at least partially shaped to taper conically such that an envelope of the plurality of spiral spring elements corresponds to the conically shaped contact surface of the valve housing.

[0028] According to a further development of the invention, free ends of the plurality of spiral spring elements each have a friction surface for anti-slip contact with a lateral surface of the valve closing body.

[0029] According to a further development of the invention, the friction device is made of an elastic material, in particular polytetrafluoroethylene. For example, the friction device can be made, at least in sections, of a flexurally elastic material.

[0030] Optionally, the optimal clamping force can be easily applied by simulating and testing the bending elasticity, for example by adjusting the length, the shape of the bending beam, the section modulus, or the like.

[0031] According to a further development of the invention, the tank system is designed as a pressure vessel for storing hydrogen.

[0032] Short description of the drawings

[0033] The invention is explained below with reference to the figures of the drawings. The figures show:

[0034] Fig. 1 is a schematic sectional view of a check valve device for a refueling path of a hydrogen pressure vessel according to an embodiment of the invention;

[0035] Fig. 2 is a schematic perspective view of a friction device according to a further embodiment of the invention.

[0036] In the figures, the same reference numerals designate identical or functionally equivalent components, unless otherwise stated. The numbering of process steps is for clarity and generally does not imply a specific chronological order. In particular, several process steps can be performed simultaneously.

[0037] Description of the embodiments

[0038] Further advantages, features and details of the invention will become apparent from the following description, in which various embodiments are described in detail with reference to the drawing.

[0039] Fig. 1 shows a schematic sectional view of a check valve device 1 for a refueling path of a hydrogen pressure vessel.

[0040] The illustrated check valve device 1 contains a valve housing 2, a valve closing body 3, a spring device 5 and a friction device 6.

[0041] The valve closing body 3 is accommodated in the valve housing 2 and, in a basic position, is preloaded against a valve seat 4 by a spring device 5. In other words, the spring device 5 is provided within the valve housing 2 and is designed to press the valve closing body 3 toward the valve seat 4 to close a flow opening. Thus, in the basic position, a pressure medium connection between two working ports A, B can be controlled in a predetermined flow direction X. For example, the valve closing body 3 is hollow in sections.

[0042] The spring device 5 is designed, for example, as a spiral compression spring or helical spring. The valve housing 2 can be conical in the region of the valve seat 4. The valve closing body 3 can have a conical end for surface contact with the valve seat 4.

[0043] The friction device 6 is suitable for damping axial vibrations of the valve closing body 3. Furthermore, the friction device 6 is circumferentially formed and arranged in a conically shaped contact surface 7 of the valve housing 2, so that an axially acting spring force FA elastically deforms the friction device 6 such that the friction device 6 exerts a radial clamping force FK on the valve closing body 3.

[0044] The exemplary friction device 6 axially supports an end portion of the spring device 5. Furthermore, the friction device 6 is made, for example, of an elastic material.

[0045] Fig. 2 shows a schematic perspective view of a friction device 6. In particular, Fig. 2 shows a closed, rotationally symmetrical friction ring 6 with circumferentially arranged, radially effective bending spring elements 8.

[0046] The friction ring 6 illustrated here has essentially the same features as the friction device 6 of Fig. 1. Furthermore, the friction ring 6 according to Fig. 2 can be used in a check valve device 1 in the same manner as described in Fig. 1.

[0047] The friction device 6 is rotationally symmetrical. A rotational axis of the friction device 6 corresponds, for example, to a longitudinal axis of the valve closing body 3. Furthermore, the friction device 6 has eight spiral spring elements 8 that are arranged circumferentially and are flexible essentially along a radial direction. For example, the eight spiral spring elements 8 are essentially identical.

[0048] As can be seen in Fig. 2, eight recesses 9 are formed between the eight bending spring elements 8.

[0049] The eight spiral spring elements 8 are tapered, at least in sections, such that an envelope of the plurality of spiral spring elements 8 corresponds to the conically shaped contact surface 7 of the valve housing 2. Free ends 8a of the plurality of spiral spring elements 8 each have a friction surface for anti-slip contact with a lateral surface of the valve closing body 3.

[0050] As a result of the axially acting spring force FA, the bending spring elements 8 are pressed radially inwards via the conical contact surface 7 or the deflection cone and thus induce a clamping force FK on the individual friction surfaces.

[0051] Although the present invention has been explained above using exemplary embodiments, it is not limited thereto but can be modified in a variety of ways. In particular, combinations of the above embodiments are also conceivable.

Claims

Claims 1 . A check valve device (1) for a refueling path of a tank system, in particular a hydrogen pressure vessel, comprising: a valve housing (2); a valve closing body (3) which is received in the valve housing (2) and is prestressed in a basic position against a valve seat (4) by a spring device (5); and a circumferential friction device (6) for damping axial vibrations of the valve closing body (3), wherein the friction device (6) is arranged in a conically shaped contact surface (7) of the valve housing (2) such that an axially acting spring force (FA) elastically deforms the friction device (6) such that the friction device (6) effects a radial clamping force (FK) on the valve closing body (3).

2. Check valve device (1) according to claim 1, wherein the friction device (6) is rotationally symmetrical 3. Check valve device (1) according to claim 1 or 2, wherein the friction device (6) axially supports an end portion of the spring device (5).

4. Check valve device (1) according to one of the preceding claims, wherein the friction device (6) comprises a plurality of spiral spring elements (8) which are arranged circumferentially and are flexible substantially along a radial direction.

5. Check valve device (1) according to claim 4, wherein the plurality of spiral spring elements (8) is six, eight or ten spiral spring elements (8) which are arranged evenly distributed over the circumference of the spring device (5).

6. Check valve device (1) according to claim 4 or 5, wherein the plurality of spiral spring elements (8) are at least partially shaped to taper conically such that an envelope of the plurality of spiral spring elements (8) corresponds to the conically shaped contact surface of the valve housing (2).

7. Check valve device (1) according to one of claims 4 to 6, wherein free ends (8a) of the plurality of spiral spring elements (8) each have a friction surface for anti-slip contact with a lateral surface of the valve closing body (3).

8. Check valve device (1) according to one of the preceding claims, wherein the friction device (6) is made of an elastic material, in particular of polytetrafluoroethylene.

9. Tank system with a refueling path which has a check valve device (1) according to one of the preceding claims.

10. Tank system according to claim 9, which is designed as a pressure vessel for storing hydrogen.

Images