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 body (3) which is accommodated in the valve housing (2) and is preloaded 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).

Description

The present invention relates to a check valve device for a refueling path of a tank system, in particular of a hydrogen pressure vessel, and to a tank system having such a check valve device.Prior ArtHydrogen obtained in a neutral climate as an environmentally friendly energy carrier for fuel cells and internal combustion engines as a drive for mobile and stationary applications is becoming increasingly important. High pressure gas containers are used for storing the hydrogen. These tanks are usually screwed onto so-called "multifunction tank valves", by means of which both the refueling and the removal for the consumer are controlled.Within the tank valve, the bore via which hydrogen can pass from the tank valve into the connecting line and vice versa is divided into two paths: the tank filling path via which the hydrogen reaches the gas container during the tank filling operation and the extraction path via which hydrogen flows when hydrogen is extracted from the gas container and fed to the consuming system. There are both valves which have two external high-pressure connections (refueling and extraction separated) and valves with only one high-pressure connection via which refueling or extraction takes place depending on the operating state. The two paths are connected to one another within the valve.However, all switching concepts have the common feature that the filling path is locked with a check valve (RSV for short). This prevents hydrogen from escaping from the tank in an uncontrolled manner during the shutdown of the system and in the event of removal.For example, DE 10 2014 214 182 A1 describes a method for adjusting the opening pressure of a valve, having 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 interacting with the valve seat and movable with respect to the valve seat is located, and having a valve spring which loads the valve closing body in a direction closing the valve and is supported for this purpose on a counter bearing connected to the valve housing. A shank 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-friction ring lies.The friction ring is generally used for damping axial oscillations of the valve closing body. Often, the friction ring in the prior art is designed as an open friction ring made of a flexurally elastic material.When the valve is open, a gas flow through the valve is established. The gas flows through a gap between the valve seat and the valve closing body lifted from the valve seat. The opening pressure of the valve is determined by the prestress of the spring, which is in turn determined by the position of the counter bearing with respect to the valve seat in the valve housing.Disclosure of the InventionThe invention provides a check valve device for a filling path of a tank system, in particular of 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 of 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 oscillations 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 brings about a radial clamping force on the valve closing body.According to a second aspect of the invention, a tank system is provided. The tank system comprises a tank filling path having a check valve device according to the first aspect of the invention.An idea on which the present invention is based is to reduce, in particular to avoid, axial oscillation of the valve closure member or what is known as ringing, which can be excited by system-intrinsic pressure oscillations in the tank system. The check valve device is mechanically designed, i.e. the valve closing body is axially movable, for example, and has a correspondingly effective seat diameter on the valve seat and the counteracting spring device or closing spring for providing a hold-closed adjusting force. The valve closing body can be designed as a piston, ball or the like. The piston can be formed hollow, in particular, at least in sections. The check valve device can be opened when an overpressure, i.e. an opening pressure, between the tank system and a reservoir bottle or the static pressure difference which is present directly before and after the check valve device and which is established by flow and absolute pressure losses is at least in equilibrium with the appropriately adjusted spring force setting.Downstream of the check valve device, the tank system may have, for example, a filling pipe, which may also be called a filling lance. The fill tube may disperse an incoming fluid in the tank system to obtain a uniform temperature distribution, for example. For example, the check valve device can be integrated within a screw-in shank of a bottle neck.The spring device can be provided within the valve housing and designed to press the valve closure body in the direction of the valve seat in order to close a flow opening, so that in the basic position a pressure medium connection between two working connections can be controlled in a predetermined flow direction. For example, the spring device is designed as a compression spring, in particular as a helical compression spring or helical spring. The valve housing can be designed conically in the region of the valve seat. The valve closing body can have a conical end for planar contact with the valve seat.In the design of the check valve device, the following conflict of goals is fundamentally produced.If the check valve device is closed or in a blocking direction, an operating state "Shut-down" is present, for example. In this operating state, the tank system is pressureless outside a gas cylinder or with a lower pressure. The functional requirement of the seat tightness is provided by sufficient surface pressure. In this case, the greatest possible clamping force, which is provided in particular by the mechanical spring device, is required for a predefined seat diameter. This can be effected, for example, by means of a prestressed helical compression spring.If the check valve device is open, a "refueling" operating state is present, for example. The first function requirement of the throttling, i.e. a minimum total pressure loss due to flow friction, of the check valve device is required so that a high mass flow is ensured for short tank times. For this purpose, for example, a valve lift that is as large as possible, in particular of the order of magnitude of the inflow and outflow cross sections, can be provided. The second functional requirement for the stable positioning of the valve closing body independently of the stroke position, i.e. also before reaching the stroke stop in an undefined intermediate position, is demanded. This can be effected by the friction device by preventing the axial oscillation of the valve closure member, the so-called chatter.Due to the check valve device or friction device according to the invention, these axial valve closing body oscillations cannot couple back to the tank system. Thus, control circuits and other assemblies cannot be adversely affected, severe guide wear cannot be induced in the check valve device, and acoustic disturbances cannot be triggered.Due to the axial spring force application and the deflection of the force on the conical contact surface of the valve housing, the friction device narrows tangentially elastically and thus induces a radial clamping force, which ultimately leads to a mechanical friction damping of the valve closing body.A further advantage of the present invention is that the assembly capability of the friction device into the valve housing can be improved. In particular, in comparison with non-circumferential, i.e. open, friction rings, tilting, tilting or a spiral-shaped spreading of the ends of the open friction ring can be reduced, in particular avoided. Moreover, a hooked connection of the end section of the spring device with the groove of the non-circumferential friction ring can be avoided. Furthermore, a uniform force distribution and deflection can be effected by the friction device. Consequently, clamping and thus frictional forces from specimen to specimen and from stroke to stroke can be less scattered as a result of a twisting action of the spring device. In this way, high requirements for a geometrical accuracy, for example a diameter and a maximum permissible spreading of the end sections, for setting force conditions with low scattering can be avoided.It is also advantageous that the friction device can be produced on the basis of cost-effective injection molding without an additional manufacturing step.Advantageous embodiments and refinements emerge from the further dependent claims and from the description with reference to the figures of the drawing.According to a further development of the invention, the friction device is designed to be rotationally symmetrical. An axis of rotation of the friction device corresponds, for example, to a longitudinal axis of the valve closing body. In particular, the friction device is designed, for example, as a closed friction ring.According to a further development of the invention, the friction device axially supports an end section of the spring device. The friction device can be inserted, for example, between the spring device, in particular between the end section of the spring device, and the valve housing.According to a further development of the invention, the friction device has a multiplicity of flexible spring elements which are arranged circumferentially and are substantially flexible along a radial direction. This means that a plurality of recesses can be formed between the plurality of bending spring elements. For example, the bending spring elements are substantially identical.According to a further development of the invention, the plurality of bending spring elements is six, eight or ten bending spring elements which are arranged uniformly distributed over the circumference of the spring device. Alternatively, the plurality of flexure spring elements may be any even or odd number of flexure spring elements, for example, three, five, seven or nine flexure spring elements.According to a further development of the invention, the plurality of flexible spring elements are shaped such that they taper conically at least in sections in such a way that an envelope of the plurality of flexible spring elements corresponds to the conically designed contact surface of the valve housing.According to a further development of the invention, free ends of the plurality of bending spring elements each have a friction surface for anti-slip contact with a lateral surface of the valve closing body.According to a further development of the invention, the friction device is produced from an elastic material, in particular from polytetrafluoroethylene. For example, the friction device can be made at least in sections from a flexurally elastic material.Optionally, by means of a geometric adaptation of the bending elasticity, for example a length, a bending beam shape, a resistance moment or the like, the optimum clamping force can be applied very effectively in a simulative and experimental manner.According to a further development of the invention, the tank system is designed as a pressure vessel for storing hydrogen.Brief Description of the DrawingsThe invention is explained below with reference to the figures of the drawings. Of the figures, FIG. 1 shows a schematic sectional view of a check valve device for a filling path of a hydrogen pressure vessel according to an exemplary embodiment of the invention; FIG. 2 shows a schematic perspective view of a friction device according to a further exemplary embodiment of the invention.In the figures, the same reference numerals designate identical or functionally identical components, unless indicated to the contrary. The numbering of method steps is for clarity and is generally not intended to imply a particular chronological order. In particular, a plurality of method steps can also be carried out simultaneously.DESCRIPTION OF THE EMBODIMENTSFurther advantages, features and details of the invention will become apparent from the following description, in which various exemplary embodiments are described in detail with reference to the drawing.FIG. 1 shows a schematic sectional view of a check valve device 1 for a filling path of a hydrogen pressure vessel.The illustrated check valve device 1 includes a valve housing 2, a valve closing body 3, a spring device 5 and a friction device 6.The valve closing body 3 is accommodated in the valve housing 2 and, in a basic position, is prestressed 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 closure member 3 in the direction of the valve seat 4 in order to close a throughflow opening. Thus, in the basic position, a pressure medium connection between two working connections A, B can be closed in a predetermined flow direction X. By way of example, the valve closing body 3 is formed hollow in sections.The spring device 5 is designed, for example, as a helical compression spring or helical spring. The valve housing 2 can be designed conically in the region of the valve seat 4. The valve closing body 3 can have a conical end for planar contact with the valve seat 4.The friction device 6 is suitable for damping axial oscillations of the valve closing body 3. Furthermore, the friction device 6 is designed to be circumferential and is arranged in a conically designed contact surface 7 of the valve housing 2, so that an axially acting spring force FA elastisch the friction device 6 in such a way that the friction device 6 brings about a radial clamping force FKon the valve closing body 3.The exemplary friction device 6 axially supports an end portion of the spring device 5. Moreover, the friction device 6 is made of, for example, an elastic material.FIG. 2 shows a schematic perspective view of a friction device 6.The friction ring 6 illustrated here has substantially the same features as the friction device 6 from FIG. 1. Moreover, the friction ring 6 of FIG. 2 can be used in a check valve device 1 in the same manner as described in FIG. 1. The friction device 6 is designed to be rotationally symmetrical. An axis of rotation of the friction device 6 corresponds, for example, to a longitudinal axis of the valve closure member 3. Furthermore, the friction device 6 has eight flexible spring elements 8, which are arranged circumferentially and are substantially flexible along a radial direction. For example, the eight bending spring elements 8 are substantially identical.As can be seen in FIG. 2, eight recesses 9 are formed between the eight bending spring elements 8.The eight flexible spring elements 8 are shaped such that they taper conically at least in sections in such a way that an envelope of the plurality of flexible spring elements 8 corresponds to the conically designed contact surface 7 of the valve housing 2. Free ends 8 aof the plurality of bending spring elements 8 each have a friction surface for anti-slip contact with a lateral surface of the valve closing body 3.As a result of the axially acting spring force FA, the bending spring elements 8 are pressed radially inward via the conically designed contact surface 7 or the deflection cone and thus induce a clamping force FKon the individual friction surfaces.Although the present invention has been explained above by way of example with reference to exemplary embodiments, it is not restricted thereto, but can be modified in a variety of ways. In particular, combinations of the above exemplary embodiments are also conceivable.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2014 214 182 A1

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Claims

Check valve device (1) for a filling path of a tank system, in particular of a hydrogen pressure container, having: a valve housing (2); a valve closing body (3) which is accommodated in the valve housing (2) and, in a basic position, is prestressed against a valve seat (4) by a spring device (5); and a circumferential friction device (6) for damping axial oscillations of the valve closing body (3), wherein the friction device (6) is arranged in a conically designed contact surface (7) of the valve housing (2), such that an axially acting spring force (FA) elastically deforms the friction device (6) in such a way that the friction device (6) brings about a radial clamping force (FK) on the valve closing body (3).Check valve device (1) according to Claim 1, wherein the friction device (6) is of rotationally symmetrical design.The check valve device (1) according to claim 1 or 2, wherein the friction means (6) axially supports an end portion of the spring means (5).The check valve device (1) according to any of the preceding claims, wherein the friction means (6) comprises a plurality of bending spring elements (8) arranged circumferentially and being substantially flexible along a radial direction.The check valve device (1) according to claim 4, wherein the plurality of flexure spring elements (8) is six, eight or ten flexure spring elements (8) arranged evenly distributed over the circumference of the spring device (5).The nonreturn valve device (1) according to claim 4 or 5, wherein the plurality of flexible spring elements (8) are shaped such that they taper conically at least in sections in such a way that an envelope of the plurality of flexible spring elements (8) corresponds to the conically designed contact surface of the valve housing (2).The nonreturn valve device (1) according to one of claims 4 to 6, wherein free ends (8a) of the plurality of bending spring elements (8) each have a friction surface for anti-slip contact with a lateral surface of the valve closing body (3).The 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.A tank system having a refueling path comprising a check valve device (1) according to any of the preceding claims.Tank system according to Claim 9, which is designed as a pressure vessel for storing hydrogen.

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