Check valve for valve assembly, valve assembly and gas tank

Abstract

The invention relates to a check valve (1) for a valve assembly (2), comprising a piston (4), which is received in a bore (3) and is guided in an axially displaceable manner via the bore (3), which piston interacts with a valve seat (5). According to the invention, the piston (4) is non-spring-loaded and has at least one outer circumferential groove (6), outer circumferential flats (7) and / or bores (8) extending substantially in the longitudinal direction for forming a flow channel which is arranged outside the inner diameter (IDS) of the valve seat (5) in the radial direction. The invention further relates to a valve assembly (2) for a gas tank (11) and to a gas tank (11).

Description

Technical Field

[0001] The invention relates to a non-return valve for a valve assembly. In addition, the invention relates to a valve assembly having a non-return valve according to the invention and a gas tank having a valve assembly according to the invention. The gas can be hydrogen or natural gas, in particular, which is stored under high pressure in the gas tank.

[0002] A preferred field of application of the invention is fuel cell vehicles and / or gas vehicles which are powered by gas. Background Art

[0003] Mobile gas tank systems with at least one gas tank are known, which are used to store gas, such as hydrogen or natural gas. In this case, the gas tanks are usually designed as high-pressure tanks. Tank valves are usually screwed onto these tanks, via which not only the filling of the gas but also the extraction of the gas is controlled. Therefore, two gas paths are constructed in the tank valve, namely a filling path and an extraction path. For the two paths, the tank valve has its own high-pressure attachment end or a common high-pressure attachment end. In the latter case, the two paths are interconnected with the help of a valve so that the filling path or the extraction path is connected to the high-pressure attachment end depending on the switching state.

[0004] Usually, a non-return valve is integrated into the withdrawal path, which prevents the stop valve, which is also integrated into the withdrawal path, from flowing through in the opposite direction of the withdrawal during filling. In this way, water should be prevented from entering the stop valve, since water may freeze and clog the stop valve.

[0005] Known spring-loaded non-return valves include a valve element that is pressed against a valve seat by the spring force of a closing spring in the filling direction. In the case of an open stop valve, the non-return valve downstream of the stop valve causes throttling of the withdrawal amount in this way. Summary of the invention

[0006] The invention relates to the following object: to provide a non-return valve for a valve assembly, in particular for a tank valve, which does not lead to throttling of the withdrawal amount. At the same time, the non-return valve should be as simple and compact as possible in order to reduce production costs and keep the structural requirements low.

[0007] In order to achieve this object, a non-return valve according to the invention and a valve assembly according to the invention are provided. Advantageous further developments of the invention can be seen from the description. In addition, a gas tank having a valve assembly according to the invention is provided.

[0008] The non-return valve for the valve assembly comprises a piston which is received in a bore and guided via the bore in an axially displaceable manner, the piston cooperating with a valve seat. According to the invention, the piston is non-spring-loaded and has at least one substantially longitudinally extending piston.

[0009] - grooves on the outer circumference,

[0010] - flattened areas on the outer circumference and / or

[0011] -hole,

[0012] For forming a flow channel which is arranged in a radial direction outside the inner diameter of the valve seat.

[0013] The piston of the proposed non-return valve is non-spring-loaded, i.e. not spring-loaded. Therefore, no spring, in particular no closing spring, acts on the piston by means of which the piston is prestressed against the valve seat. In a preferred application, i.e. when the non-return valve is integrated into a tank valve for a gas tank, the closing and opening of the non-return valve is thus caused only by means of pneumatic forces acting on the piston. Since no spring force needs to be overcome in order to open or keep the non-return valve open, only low forces are required for this purpose. At the same time, due to the saving of springs, the number of components is reduced, so that the proposed non-return valve is of simple and compact construction.

[0014] In the proposed nonreturn valve, the arrangement of at least one flow channel formed in the piston is selected such that it is arranged outside the inner diameter of the valve seat or radially outside the inner diameter of the valve seat. This ensures that a sufficiently large sealing surface remains on the piston, which seals the valve seat securely in the closed position.

[0015] The piston embodiment with at least one groove and / or flattened portion on the outer circumference for forming the flow channel has the advantage that the laborious internal machining of the piston can be omitted. The flow channel is then limited radially on the outside by the hole or the hole inner wall.

[0016] The embodiment of the piston with at least one bore for forming the flow channel has the advantage that the piston can be guided over its entire outer circumference, since the outer circumference is not interrupted by grooves and / or flattened portions.

[0017] In the simplest embodiment, the non-return valve can consist only of a piston, a bore and a valve seat. The piston is guided via the bore. The non-return valve is opened and closed pneumatically.

[0018] In order to further simplify the non-return valve, it is proposed that the valve seat is designed as a flat seat. The valve seat can be formed by a shoulder in the hole. Alternatively, a component forming the valve seat can be inserted into the hole. The component can be in particular a component of another valve, in particular a component of a stop valve integrated into the withdrawal path. The non-return valve and the other valve can be arranged in a particularly space-saving manner in this way.

[0019] Preferably, the piston of the non-return valve has an end face, which forms a sealing surface cooperating with the valve seat. This end face can also be implemented flat, so that the manufacture of the piston is further simplified.

[0020] Furthermore, preferably, a stop is constructed in the hole to limit the stroke of the piston. Thus, the axial displaceability of the piston is limited on the one hand by the valve seat and on the other hand by the stop. That is to say, the piston can only move back and forth between the valve seat and the stop. By the position of the stop, the stroke of the piston can be adjusted in such a way that no throttling of the gas flow through the non-return valve occurs. The stop can be realized, for example, by a shoulder in the hole that receives the piston. In order to avoid throttling of the gas flow in the area of ​​the stop, the shoulder should have an inner diameter that is greater than the inner diameter of the valve seat, so that it is ensured that when the piston is in contact with the stop, at least one flow channel constructed in the piston continues to remain open.

[0021] Alternatively or additionally, it is proposed that at least one flow channel formed in the piston extends obliquely relative to the longitudinal axis A of the piston, wherein at least one flow channel has a radial spacing a1 from the longitudinal axis at its end close to the valve seat, which is greater than the radial spacing a2 at the end of the piston away from the valve seat. In this configuration of the at least one flow channel, the stop limiting the stroke of the piston can also have an inner diameter that is smaller than the inner diameter of the valve seat.

[0022] If the at least one flow channel is formed by a groove, the at least one groove preferably has a groove bottom which runs obliquely to the longitudinal axis A of the piston.

[0023] If the at least one flow channel is formed by a flattened portion, the at least one flattened portion preferably forms a surface which runs obliquely to the longitudinal axis A of the piston.

[0024] If the at least one flow channel is formed by a bore, the at least one bore preferably extends obliquely to the longitudinal axis A of the piston.

[0025] Furthermore, the piston preferably has a plurality of grooves and / or flattened portions which are arranged on the outer circumference and extend in the longitudinal direction and are arranged at equal angular distances from one another. When the non-return valve is open, the piston is circumvented as evenly as possible by the gas flow, so that transverse forces acting on the piston are avoided.

[0026] If the piston has a plurality of holes, these holes are preferably also arranged at the same angular spacing from one another. It is further proposed that the plurality of holes merge into a central hole. When the nonreturn valve is open, the gas flow through the piston then flows out via this central hole. This allows the stop surface of the stroke-limiting stop to be maximized.

[0027] In addition, a valve assembly for a gas cylinder is proposed, wherein the valve assembly comprises a non-return valve according to the invention. The non-return valve is preferably integrated into a valve block of the valve assembly, and more preferably into a withdrawal path formed in the valve block, which withdrawal path is used to withdraw gas from the gas cylinder. The advantages of the non-return valve according to the invention also extend to the valve assembly. In particular, a simple and compact embodiment of the non-return valve has proven to be advantageous, since the available installation space in the valve assembly for the gas cylinder is usually very limited.

[0028] Preferably, a filling path connected to the withdrawal path is formed in the valve block for filling the gas tank with gas, and the non-return valve is arranged upstream of the actuable valve integrated into the withdrawal path for withdrawing gas in the filling direction. When the gas tank is filled with gas, the other valve integrated into the withdrawal path can then be protected from water ingress by means of the non-return valve.

[0029] Since the preferred application area of ​​the valve assembly according to the invention is gas cylinders, a gas cylinder having the valve assembly according to the invention is also proposed. The compactness of the non-return valve integrated into the valve assembly reduces the structural space requirement of the valve assembly, so that the valve assembly can be inserted into the gas cylinder in the area of ​​the bottleneck. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. These drawings show:

[0031] Figure 1 shows a schematic longitudinal section through a first non-return valve according to the invention during a filling process, the first non-return valve being integrated into a valve assembly for a gas tank,

[0032] Figure 2 Show Figure 1 Schematic longitudinal section of a non-return valve during the extraction process,

[0033] Figure 3 Show Figure 1 and Figure 2 Top view of the piston of the check valve,

[0034] Figure 4shows a longitudinal section through a second piston for a non-return valve according to the invention,

[0035] Figure 5 A perspective view showing a third piston for a non-return valve according to the invention,

[0036] Figure 6 shows a longitudinal section through a fourth piston for a non-return valve according to the invention, and

[0037] Figure 7 A schematic diagram of a gas cylinder with a valve assembly is shown. DETAILED DESCRIPTION

[0038] from Figure 1 1 shows a non-return valve 1 according to the invention, which is integrated into a valve block 12 of a valve assembly 2 for a gas tank 11. The non-return valve 1 has a piston 4, which is received and guided in a bore 3 of the valve block 12 in an axially displaceable manner. A further valve 15 is integrated into the bore 3, which serves to extract gas from the gas tank 11. For this purpose, an extraction path 13 is guided through the bore 3 and the further valve 15. A filling path 14 branches off from the extraction path 13, via which the gas tank 11 can be filled with gas. The non-return valve 1 is integrated into the extraction path 13 between the further valve 15 and the branched filling path 14, so that when filling the gas tank 11, the non-return valve prevents gas and thus also water from entering the further valve 15.

[0039] The piston 4 of the nonreturn valve 1 cooperates with a valve seat 5 which in the present case is formed by a further valve 15. The valve seat 5 is designed as a flat seat with an inner diameter ID S The end face 9 of the piston 4 forms a sealing surface which, in the closed position of the non-return valve 1 (see Figure 1 ) lies flat against the valve seat 5 and thus closes the valve seat 5. During filling (see Figure 1 ), the piston 4 is held in the closed position only via the pneumatic force exerted on the piston 4. Therefore, no closing spring is required, so that the check valve 1 is simple and compact in structure.

[0040] In order to extract gas from the gas tank 11, the further valve 15 is opened so that the gas flows out of the gas tank 11 and lifts the piston 4 from the valve seat 5. The stroke of the piston 4 is limited by the stop 10, which is formed by a shoulder of the hole 3 (see Figure 2 In the open position of the non-return valve 1, the piston 4 rests against the stop 10 and the gas is removed via at least one flow channel which is formed by a groove 6 of the piston 4 which is arranged on the outer circumference and extends in the longitudinal direction (see also Figure 3). Here, the flow channel is limited radially on the outside by a valve block 12 which is provided with a hole 3. In order that the flow channel is not blocked by the stopper 10, the stopper 10 has an inner diameter ID A , which is larger than the inner diameter ID of the valve seat 5 S Therefore, the flow channel is within the inner diameter ID of the stopper 10. A Internal termination.

[0041] exist Figures 4 to 6 The Figure 3 Variations of the piston 4 are described below.

[0042] Figure 4 The piston 4 also has a groove 6 for forming a flow channel, but the groove 6 has a groove bottom 16 extending obliquely to the longitudinal axis A of the piston 4. That is, the flow channel has a radial spacing a1 from the longitudinal axis A at its end close to the valve seat, which is greater than the radial spacing a2 at the end of the piston 4 away from the valve seat. Here, the end close to the valve seat is defined by the end face 9 of the piston 4, which forms a sealing surface that cooperates with the valve seat 5.

[0043] Instead of slot 6, Figure 5 The piston 4 has a flattened portion 7. The flattened portion 7 forms a surface 17 extending obliquely to the longitudinal axis A, so that here the flow channel also has a radial spacing a1 from the longitudinal axis A at its end close to the valve seat, which is greater than the radial spacing a2 at the end of the piston 4 remote from the valve seat. Here, the end surface 9 defines the end close to the valve seat.

[0044] Figure 6 The piston 4 has a bore 8 for forming a flow channel, wherein the bore 8 extends obliquely to the longitudinal axis A of the piston 4 and ends in a centrally arranged further bore 18. The further bore is located at the inner diameter ID of the stop 10. A The stopper 10 is provided inside so as to prevent the gas flow from being throttled during extraction.

[0045] For example, from Figure 7 1 shows a valve assembly 2 connected to a gas tank 11. The valve assembly 2 has a valve block 12, which is inserted in sections, in particular screwed into the gas tank 11. A withdrawal path 13 and a filling path 14 are formed in the valve block 12. A valve 15 is integrated into the withdrawal path 13, which is opened to withdraw gas from the gas tank 11. A check valve 1 is arranged downstream of the valve 15 in the withdrawal direction, which should prevent water from penetrating into the valve 15 when the gas tank 11 is filled with gas via the filling path 14. Preferably, the check valve 1 is embodied according to the invention so that only pneumatic forces act on the piston 4 of the check valve 1. This has the advantage that, in particular in the case of small withdrawal quantities, the pressure difference applied to the piston 4 of the check valve 1 is also small.

[0046] Figure 7 The valve assembly 2 shown has a plurality of further components, in particular a further valve 19 and a filter 20 , which are not essential to the invention and are therefore not described in greater detail.

Claims

1. A non-return valve (1) for a valve assembly (2), comprising a piston (4) which is received in a bore (3) and guided via the bore (3) in an axially displaceable manner, the piston cooperating with a valve seat (5), It is characterized in that The piston (4) is non-spring-loaded and has at least one groove (6) extending substantially in the longitudinal direction on the peripheral side, - at least one flattened portion (7) on the outer circumference and / or - at least one hole (8), For constructing a flow channel, the flow channel is arranged in the radial direction on the inner diameter (ID) of the valve seat (5) S ) besides.

2. The check valve (1) according to claim 1, It is characterized in that The valve seat (5) is implemented as a flat seat.

3. The check valve (1) according to claim 1 or 2, It is characterized in that The piston (4) has an end face (9) which forms a sealing surface cooperating with the valve seat (5).

4. The non-return valve (1) according to any one of the preceding claims, It is characterized in that A stop (10) is formed in the bore (3), which limits the stroke of the piston (4) and is realized, for example, by a shoulder.

5. The non-return valve (1) according to any one of the preceding claims, It is characterized in that At least one flow channel constructed in the piston (4) extends obliquely relative to the longitudinal axis (A) of the piston (4), wherein the at least one flow channel has a radial spacing (a1) from the longitudinal axis (A) at its end close to the valve seat, and the radial spacing is greater than the radial spacing (a2) at the end of the piston (4) away from the valve seat.

6. The non-return valve (1) according to any one of the preceding claims, It is characterized in that The at least one groove (6) has a groove bottom (16) which extends obliquely to the longitudinal axis (A) of the piston (4).

7. The non-return valve (1) according to any one of the preceding claims, It is characterized in that The at least one flattened portion (7) forms a surface (17) extending obliquely to the longitudinal axis (A) of the piston (4).

8. The non-return valve (1) according to any one of the preceding claims, It is characterized in that The at least one hole (8) extends obliquely to the longitudinal axis (A) of the piston (4).

9. The non-return valve (1) according to any one of the preceding claims, It is characterized in that The piston (4) has a plurality of grooves (6) and / or flattened portions (7) which are arranged on the outer circumference and extend in the longitudinal direction and are arranged at equal angular distances from one another.

10. The non-return valve (1) according to any one of the preceding claims, It is characterized in that The piston (4) has a plurality of holes (8) which are arranged at equal angular distances from one another and / or merge into a central hole.

11. A valve assembly (2) for a gas cylinder (11), comprising a non-return valve (1) according to any one of the preceding claims, wherein: The non-return valve (1) is preferably integrated into a valve block (12) of the valve assembly (2), and is also preferably integrated into a withdrawal path (13) formed in the valve block (12) for withdrawing gas from the gas tank (11).

12. The valve assembly (2) according to claim 11, It is characterized in that A filling path (14) connected to the withdrawal path (13) is constructed in the valve block (12) for filling the gas tank (11) with gas, and the non-return valve (1) is arranged upstream of a controllable valve (15) in the filling direction, the controllable valve being integrated into the withdrawal path (13) for withdrawing gas.

13. A gas cylinder (11) having a valve assembly (2) according to claim 11 or 12.

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