Check valve for a tank valve, and tank valve

Abstract

The invention relates to a check valve (1) for a tank valve, comprising a valve housing (2) and a closure element (3) which is accommodated in the valve housing so as to be capable of reciprocating motion and which is biased towards a valve seat (4) by the spring force of a spring (5), wherein the reciprocating motion of the closure element in the opening direction is limited by a stop element (6) in which a pressure chamber (7) is formed, the pressure chamber being pneumatically connected to a main flow path (11) of the check valve via a channel (8) and a stop-forming sealing seat (9) such that, when the check valve is fully open, the closure element closes off the sealing seat and a mass flow passing through the main flow path generates a reduced pressure in the pressure chamber which draws the closure element against the sealing seat. The invention also relates to a tank valve comprising a check valve according to the invention.

Description

[0001] R.417057

[0002] - 1 -

[0003] Description

[0004] Check valve for a tank valve and tank valve

[0005] The invention relates to a check valve for a tank valve and to a tank valve with a check valve according to the invention. The tank valve can be used, for example, to fill a fuel gas tank with fuel gas and to withdraw fuel gas from the fuel gas tank. The fuel gas can be, in particular, hydrogen or natural gas.

[0006] The preferred application area of ​​the invention is mobile tank systems for vehicles powered by fuel gas, for example hydrogen or natural gas.

[0007] State of the art

[0008] A tank valve for a fuel gas tank typically consists of a base body with a threaded "neck" and sealing rings, allowing the valve to be screwed into the threaded connection of the fuel gas tank. The base body also features a connection for filling and venting the fuel gas tank. This connection is divided within the base body into a filling path and a venting path. Furthermore, the base body usually integrates various valves with shut-off and / or control functions, as well as at least one sensor, particularly a temperature sensor.

[0009] The various valves of a tank valve typically include a check valve integrated into the refueling path with a closing element that is acted upon by the spring force of a spring towards a valve seat. During refueling, the closing element is lifted out of the valve seat by the pressure of the incoming fuel gas against the spring force of the spring, thus opening the refueling path. After refueling, when the pressure before and after the R.417057

[0010] - 2 -

[0011] Once the check valve is balanced, the closing element is returned to the valve seat by the spring. In the closed position, the check valve must be airtight to prevent fuel gas from escaping the fuel tank. If the pressure in the fuel tank is higher than the pressure upstream of the check valve in the refueling direction, the valve seals reliably because, in addition to the spring force, a pneumatic force acts on the closing element.

[0012] Pressure pulsations during the refueling process can cause instabilities that may lead to the undesired closing of the check valve. This must be prevented. The present invention therefore addresses the problem of keeping the check valve stably open during refueling.

[0013] To solve the problem, a check valve with the features of claim 1 is proposed. Advantageous embodiments of the invention are described in the dependent claims. Furthermore, a tank valve with a check valve according to the invention is described.

[0014] Disclosure of the invention

[0015] A check valve for a tank valve, comprising a valve body and a closing element movably mounted within the valve body, which is acted upon by the spring force of a spring in the direction of a valve seat. The stroke of the closing element is limited in the opening direction by a stop element in which a pressure chamber is formed. The pressure chamber is pneumatically connected to a main flow path of the check valve via a channel and a stop-forming sealing seat, so that when the check valve is fully open, the closing element seals the sealing seat and a mass flow guided via the main flow path creates a vacuum in the pressure chamber, which draws the closing element into the sealing seat.

[0016] The invention utilizes a physical effect also known as the Venturi effect. This effect is based on the fact that in a constricted flow path, the flow velocity and dynamic pressure increase, while the static pressure decreases. In this way, a negative pressure is generated, which can be used, for example, to draw in a medium (“Venturi nozzle”). In the proposed check valve, the effect described above is utilized.

[0017] - 3 -

[0018] The negative pressure created by the physical effect is used to hold the closing element stably in the open position when the check valve is fully open. If the check valve is not fully open, gas flows from the main flow path into the pressure chamber via the sealing seat, so that the pressure in the pressure chamber is essentially the same as in the main flow path. A negative pressure in the pressure chamber therefore only occurs when the closing element rests against the stop element and seals the sealing seat, i.e., when the check valve is fully open.

[0019] According to a preferred embodiment of the invention, the main flow path leads through at least one flow channel arranged radially outside the pressure chamber, which is formed in the stop element and / or bounded by the stop element and the valve housing. The flow channel forms a cross-sectional termination of the main flow path, resulting in the physical effect described above. Preferably, several flow channels are provided, which are further preferably arranged at equal angular intervals from one another, so that the stop element is uniformly subjected to, around, and / or through the flow. An eccentrically arranged axial bore can be formed in the stop element to create the at least one flow channel. Alternatively or additionally, the stop element can have an axially extending groove and / or a chamfer on its outer circumference.The flow channel is then limited by the stop element and the valve housing.

[0020] Furthermore, it is proposed that the channel connecting the pressure chamber to the main flow path is essentially radial. A radially extending channel enables the connection of the pressure chamber to the main flow path in the region of the at least one flow channel, which is arranged radially outward with respect to the pressure chamber. In the region of the flow channel, the main flow path experiences a cross-sectional narrowing, thus achieving the Venturi effect. In a further development of the invention, it is therefore proposed that the channel connects the pressure chamber to the flow channel. The radially extending channel can, for example, be designed as a simple radial bore in the stop element.

[0021] According to a further preferred embodiment of the invention, the channel for connecting the pressure chamber to the main flow path runs essentially axially. In this case, the channel can be designed as a simple axial bore in the stop element R.417057

[0022] - 4 -

[0023] To achieve the desired physical effect, it is important that the pressure chamber is connected to the main flow path via the axially extending channel.

[0024] Furthermore, it is proposed that the spring be housed within the pressure chamber. In the open position of the check valve, the spring housed within the pressure chamber is optimally protected from the incoming gas, since the closing element seals the sealing seat and the mass flow is directed radially outside the stop element.

[0025] According to a preferred embodiment of the invention, the stop element is essentially cup-shaped. The cup shape results in the formation of a pressure chamber open on one side, with the opening of the pressure chamber preferably oriented towards the valve seat. The opening then forms the sealing seat for the closing element, providing a stop. Such a stop element is simple and inexpensive to manufacture.

[0026] Preferably, the stop element is inserted into the valve housing, preferably by pressing or screwing it in. This allows for easy installation of the stop element. The stroke of the closing element can be adjusted via the press-fit or screw-in depth. The axial position of the stop element is also secured by the press-fit or screw connection. To create the press-fit or screw connection, the stop element has a press fit or an external thread in at least one section.

[0027] The sealing seat is preferably arranged coaxially with respect to the valve seat, so that the stroke of the closing element brings it into sealing contact with the sealing seat. Alternatively or additionally, it is proposed that the sealing seat be designed as a flat seat or a cone. Depending on the shape of the closing element, a linear sealing contour can thus be formed, enabling high sealing forces.

[0028] The locking element is preferably spherical. This applies in particular if the sealing seat is designed as a flat seat or cone. The sealing seat then allows for self-centering of the spherical locking element with respect to the sealing seat. R.417057

[0029] - 5 -

[0030] This is achieved. Furthermore, an advantageous linear sealing contour is formed between the closing element and the sealing seat.

[0031] Furthermore, it is proposed that the valve seat be conical. This is particularly advantageous if the closing element is spherical, because then the valve seat and the closing element together form a linear sealing contour that enables a high sealing force. Moreover, the conical valve seat allows for self-centering of the closing element with respect to the valve seat when the check valve closes.

[0032] Preferably, the valve seat is formed by a separate seat element. This separate seat element facilitates the installation of the check valve. Preferably, the separate seat element is axially attached to the valve housing. When the check valve is inserted into a bore of a tank valve body with the seat element leading, the seat element can be pressed against a shoulder within the bore by the valve housing and thus secured within the bore.

[0033] Furthermore, a tank valve for a fuel gas tank, in particular a hydrogen tank, is proposed, which includes a check valve according to the invention. The advantages of the check valve according to the invention are particularly evident when used in a tank valve, since the check valve remains constantly open during refueling and there is no unwanted throttling of the fuel gas mass flow in the area of ​​the valve.

[0034] Preferably, the check valve is inserted into a bore in the base body of the tank valve, in particular by screwing or pressing it in. This allows for easy installation of the check valve.

[0035] Furthermore, preferably a refueling path leads via the main flow path of the check valve. The check valve thus secures the refueling path. This means that during refueling, it opens under pressure control against the spring force and, after refueling, is held closed by the spring force and the pressure in the fuel gas tank. R.417057

[0036] - 6 -

[0037] Brief description of the drawings

[0038] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings. These show:

[0039] Fig. 1 shows a longitudinal section through a first preferred embodiment of a check valve according to the invention in the open position,

[0040] Fig. 2 shows a longitudinal section through a second preferred embodiment of a check valve according to the invention in the open position and

[0041] Fig. 3 shows a schematic representation of a tank valve with a check valve according to the invention.

[0042] Detailed description of the drawings

[0043] Figure 1 shows a first preferred embodiment of a check valve 1 according to the invention for a tank valve 10. Figure 1 shows the check valve 1 in an open position.

[0044] The illustrated check valve 1 comprises a valve housing 2 in which a spherical closing element 3 is movably mounted. The closing element 3 is subjected to the spring force of a spring 5 in the direction of a valve seat 4. The valve seat 4 is formed by a separate seat element 13, which is axially attached to the valve housing 2. The stroke of the closing element 3 is limited by a stop element 6, which is inserted, preferably pressed, into the valve housing 2. The stop element 6 forms a pressure chamber 7, which is connected, or can be connected, to a main flow path 11 of the check valve 1 via a channel 8 and a sealing seat 9. When the check valve 1 is fully open, the closing element 3 seals against the sealing seat 9. The connection between the pressure chamber 7 and the main flow path 11 then exists only via the channel 8, which is designed as a radial bore in Figure 1.The radial bore or channel 8 opens into a flow channel 12, through which the main flow path 11 passes and which is formed as an outer circumferential groove in the stop element 6. The flow channel 12 is thus delimited by the stop element 6 and the valve housing 2. ImR.417057.

[0045] - 7 -

[0046] In the area of ​​flow channel 12, the main flow path experiences a cross-sectional narrowing, so that when the valve is open, the flow velocity in the area of ​​flow channel 12 increases. Simultaneously, the dynamic pressure increases, while the static pressure decreases. This creates a negative pressure, which draws gas located in pressure chamber 7 into flow channel 12. The negative pressure in pressure chamber 7 then causes the closing element 3 to be drawn into the sealing seat 9, and the check valve 1 remains constantly open.

[0047] The check valve 1 shown in Figure 1 is inserted, preferably screwed in, into a bore 14 of a base body 15 of the tank valve 10 with the seat element 13 facing forward. The screw-in depth is selected such that the seat element 13 is pressed against a shoulder 19 of the base body 15 via the valve housing 2. A refueling path 16 of the tank valve 10 can, in particular, lead through the bore 14 (see Figure 3 for an example), so that the main flow path 11 through the check valve 1 is simultaneously the refueling path 16.

[0048] Figure 2 shows a second preferred embodiment of a check valve 1 according to the invention. In contrast to the embodiment of Figure 1, the channel 8, through which the pressure chamber 7 is connected to the main flow path 11, is designed here not as a radial bore, but as an axial bore. Since the connection of the pressure chamber 7 to the main flow path 11 is also ensured here via the channel 8, a negative pressure can be created in the pressure chamber 7 when the check valve 1 is fully open, which draws the closing element 3 into the sealing seat 9, so that the check valve 1 remains constantly open.

[0049] A check valve 1 according to the invention is particularly suitable for use in a tank valve 10. Figure 3 therefore shows an exemplary tank valve 1 in which a check valve 1 according to the invention is integrated in the area of ​​a refueling path 16. Furthermore, the tank valve 10 has a withdrawal path 17 through which fuel gas can be withdrawn from a fuel gas tank 18 connected to the tank valve 10. The illustrated tank valve 10 also has further valves with shut-off and / or control functions as well as sensors. Since these are not part of the invention, they will not be discussed in more detail here.

Claims

R.417057 - 8 - Claims 1. Check valve (1) for a tank valve (10), comprising a valve housing (2) and a closing element (3) movably mounted in the valve housing (2), which is acted upon in the direction of a valve seat (4) by the spring force of a spring (5), wherein the stroke movement of the closing element (3) in the opening direction is limited by a stop element (6) in which a pressure chamber (7) is formed, which is pneumatically connected to a main flow path (11) of the check valve (1) via a channel (8) and a stop-forming sealing seat (9), so that when the check valve (1) is fully open the closing element (3) closes the sealing seat (9) and a mass flow guided via the main flow path (11) generates a negative pressure in the pressure chamber (7) which draws the closing element (3) into the sealing seat (9).

2. Check valve (1) according to claim 1, characterized in that the main flow path (11) leads via at least one radially external flow channel (12) arranged in relation to the pressure chamber (7), which is formed in the stop element (6) and / or is limited by the stop element (6) and the valve housing (2).

3. Check valve (1) according to claim 1 or 2, characterized in that the channel (8) for connecting the pressure chamber (7) to the main flow path (11) runs essentially radially, wherein preferably the channel (8) connects the pressure chamber (7) to the flow channel (12).

4. Check valve (1) according to claim 1 or 2, characterized in that the channel (8) for connecting the pressure chamber (7) to the main flow path (11) runs essentially axially.

5. Check valve (1) according to one of the preceding claims, characterized in that the spring (5) is received in the pressure chamber (7). R.417057 - 9 - 6. Check valve (1) according to one of the preceding claims, characterized in that the stop element (6) is essentially cup-shaped and / or is inserted into the valve housing (2), preferably pressed in or screwed in.

7. Check valve (1) according to one of the preceding claims, characterized in that the sealing seat (9) is arranged coaxially with respect to the valve seat (4) and / or is designed as a flat seat or cone.

8. Check valve (1) according to one of the preceding claims, characterized in that the closing element (3) is spherical.

9. Check valve (1) according to one of the preceding claims, characterized in that the valve seat (4) is conical and / or is formed by a separate seat element (13) which is preferably axially attached to the valve housing (2).

10. Tank valve (10) for a fuel gas tank, in particular a hydrogen tank, comprising a check valve (1) according to one of the preceding claims, wherein preferably the check valve (1) is inserted into a bore (14) of a base body (15) of the tank valve (10), in particular screwed in or pressed in.

11. Tank valve (10) according to claim 10, characterized in that a refueling path (16) leads over the main flow path (11) of the check valve (1).

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