Tank valve for a fuel gas tank and fuel gas tank

Abstract

The invention relates to a tank valve (1) for a fuel gas tank (2), comprising a valve block (3) having a bore (4) in which a non-return valve (5) is inserted, wherein the non-return valve (5) has an axially movable valve element (7) which is received directly or indirectly in the bore (4) via a valve housing (6) and is axially pretensioned against a valve seat (9) by means of the spring force of a closing spring (8), which valve seat is formed by a local cross-sectional constriction of the bore (4). The invention further relates to a fuel gas tank (2) comprising the tank valve according to the invention (1).

Description

[0001] Description

[0002] title

[0003] Tank valve for a as well as

[0004] The invention relates to a tank valve for a fuel gas tank. The tank valve is intended to control the filling of the fuel gas tank with fuel gas and the removal of fuel gas from the fuel gas tank. The fuel gas can be, in particular, hydrogen or natural gas.

[0005] The invention further relates to a fuel gas tank with a tank valve according to the invention.

[0006] The preferred field of application of the invention is vehicles powered by a fuel gas, such as hydrogen or natural gas.

[0007] State of the art

[0008] Hydrogen produced in a climate-neutral manner is becoming increasingly important as an environmentally friendly energy source, for example as a power source for fuel cell systems or combustion engines, but also for stationary applications. High-pressure gas tanks with pressures of up to 700 bar are used to store hydrogen. Tank valves are usually screwed onto these tanks, which control both the filling and withdrawal of hydrogen. For this purpose, a bore is formed within the tank valve that is divided into two paths: a filling path through which the hydrogen enters the gas tank during a refueling process, and a withdrawal path through which hydrogen flows when hydrogen is withdrawn from the gas tank and fed to the consuming system. The two paths are interconnected within the valve.To prevent hydrogen from escaping uncontrollably via the refueling path when the withdrawal path is blocked or during withdrawal, the refueling path is locked with a check valve. The check valve has a valve element that is accommodated in a housing bore for axial movement and a closing spring whose spring force acts on the valve element in the direction of a valve seat. The valve seat is usually formed by an elastic seat element that is mechanically fixed in the housing bore. As a rule, fixing is achieved with the help of a valve housing that is screwed into the housing bore, with the elastic seat element being clamped axially between the valve housing and a shoulder in the housing bore. However, settling effects that occur over time can lead to a loss of height of the seat element, so that the axial force in the screw connection decreases.To prevent the screw joint from loosening, an adhesive is typically applied to the threaded area when screwing in the valve housing. However, the adhesive also prevents the check valve from being easily removed for replacement.

[0009] The present invention is concerned with the object of demonstrating a possibility of integrating a check valve in a tank valve, which makes it possible to dispense with a thread adhesive in order to avoid the disadvantages described above.

[0010] To achieve this objective, the tank valve having the features of claim 1 is proposed. Advantageous further developments of the invention are set forth in the subclaims. Furthermore, a fuel gas tank with a tank valve according to the invention is specified.

[0011] Disclosure of the invention

[0012] The tank valve proposed for a fuel gas tank comprises a valve block with a bore in which a check valve is inserted, wherein the check valve has an axially movable valve element received directly or indirectly via a valve housing in the bore, which is axially prestressed by means of the spring force of a closing spring against a valve seat which is formed by a local cross-sectional constriction of the bore.

[0013] In the proposed tank valve, the valve block itself forms the valve seat, eliminating the need for a separate seat element. This also eliminates the need for mechanically securing the seat element within the valve block. Eliminating the separate seat element also eliminates an elastic intermediate element in the screw connection between the valve housing—if present—and the valve block. This means that over time, no settling effects can occur that could lead to the screw connection becoming loose. This is because the screw connection consists exclusively of the valve housing and the valve block. Consequently, the use of adhesive in the screw connection area is unnecessary.

[0014] Since the elimination of the separate seat element also eliminates the need for a valve housing for mechanically securing the seat element, a valve housing is also no longer required, further reducing the number of components. This reduced number of components, in turn, helps save installation space and costs.

[0015] Further advantages arise. For example, by locally narrowing the cross-section of the bore in the valve block, the spring force required to close the check valve can be reduced, allowing the use of a smaller closing spring. This further reduces the space required for the check valve.

[0016] Preferably, the bore formed in the valve block has an inner diameter on both sides of the local cross-sectional constriction that is larger than the seat diameter of the valve seat. Ideally, the bore has the smallest flow cross-section in the area of ​​the valve seat. This means that, on the one hand, a sufficiently large flow cross-section is available outside the area of ​​the valve seat, which helps reduce pressure losses. On the other hand, a bore section is formed that is sufficiently large to accommodate the check valve.

[0017] In a further development of the invention, it is proposed that the valve element, at least in the region of a sealing contour interacting with the valve seat, be made of a material whose modulus of elasticity is lower than that of the material from which the valve block is made. The material of the valve element can, for example, be a high-strength plastic that allows minimal local deformation of the valve element. In this way, the tightness of the check valve in the closed position can be improved. Preferably, the valve element has at least one guide area on the outer circumference, via which it is guided in the bore of the valve block or in the valve housing. The guidance of the valve element is achieved either directly via the valve block or via the valve housing inserted into the valve block. The latter assumes that a valve housing is present, which is not absolutely necessary.

[0018] Furthermore, the valve element preferably has an axial bore designed as a blind hole, which is connected via at least one further bore extending transversely or obliquely thereto to an annular space formed between the valve element and the valve block or between the valve element and the valve housing. When the check valve is open, gas flows through the valve seat into the annular space and from there via the at least one transverse or oblique bore into the axial bore. This enables circumferential outer circumferential guidance of the valve element within the valve block or within the valve housing.

[0019] Furthermore, it is proposed that the closing spring be axially supported on the valve element on one side and on the valve housing on the other. This requires a valve housing to be present. If this is the case, this can also be used to support the closing spring. The valve housing is preferably screwed into the bore of the valve block. When screwing the valve housing into the bore, the spring preload and thus the spring force of the closing spring can be adjusted via the screw-in depth.

[0020] Alternatively, it is proposed that the closing spring be axially supported on one side by the valve element and on the other side by a clamping sleeve. In this case, the clamping sleeve replaces the valve housing. The clamping sleeve is preferably screwed into the bore of the valve block. Similar to the screwed-in valve housing, the spring preload and thus the spring force of the closing spring can be adjusted by adjusting the screw-in depth.

[0021] According to a preferred embodiment of the invention, the valve block is made of metal. The valve block is thus particularly robust. Furthermore, precise internal threads can be manufactured in the valve block, for example, to create a screw connection with a valve housing or a clamping sleeve. Furthermore, the valve housing screwed into the bore of the valve block or the clamping sleeve screwed into the bore of the valve block is preferably also made of metal, so that the screw connection is a purely metallic screw connection.

[0022] It is further proposed that a refueling path be provided through the bore formed in the valve block. This means that the check valve inserted into the bore is integrated into the refueling path. The check valve can thus be used to lock the refueling path.

[0023] Furthermore, a fuel gas tank with a tank valve according to the invention is proposed, since the advantages of the tank valve according to the invention are particularly evident in this application. The small installation space requirement of the check valve of the tank valve according to the invention is particularly advantageous. If the check valve is integrated into a refueling path of the tank valve, the check valve can be used to block the refueling path to prevent uncontrolled escape of fuel gas from the fuel gas tank.

[0024] The tank valve is preferably inserted into the fuel gas tank in sections, in particular screwed in. The tank valve is thus firmly connected to the fuel gas tank.

[0025] drawing

[0026] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings. These show:

[0027] Fig. 1 shows a section of a longitudinal section through a first tank valve according to the invention in the area of ​​a check valve integrated into a refueling path and

[0028] Fig. 2 shows a section of a longitudinal section through another tank valve according to the invention in the area of ​​a check valve integrated into a refueling path. Detailed description of the drawings

[0029] Figure 1 shows a first tank valve 1 according to the invention, the illustration of which is essentially limited to the area of ​​a refueling path 15 with integrated check valve 5. A fuel gas tank 2 can be filled with fuel gas via the refueling path 15.

[0030] The refueling path 15 leads in the refueling direction via a filter 18 and a shut-off valve 17, which are integrated into a valve block 3 of the tank valve 1. The refueling path 15 then branches off into a bore 4 formed in the valve block 3, in which bore the check valve 5 is accommodated. The check valve 5 opens under pressure control, so that during refueling the higher pressure prevailing upstream of the check valve 5 in the refueling direction causes the check valve 5 to open. When the check valve 5 is open, fuel gas flows into a filling lance 16, via which the fuel gas is introduced in an oriented manner into the fuel gas tank 2.

[0031] The check valve 5 of the tank valve 1 shown in Figure 1 has a valve housing 6 which is screwed into the bore 4 of the valve block 3. A valve element 7 is accommodated and guided in the valve housing 6 so as to be axially movable. For this purpose, the valve element 7 has two guide regions 10 on its outer circumference. Furthermore, the valve housing 6 accommodates a closing spring 8 which is axially supported on the one hand on the valve element 7 and on the other hand on the valve housing 6. The spring force of the closing spring 8 axially preloads the valve element 7 against a valve seat 9. The valve seat 9 is formed by a local cross-sectional constriction of the bore 4 so that the valve seat 9 has a seat diameter SD which is smaller than an inner diameter I Di which the bore 4 has upstream of the valve seat 9 in the refueling direction.The seat diameter SD is also smaller than an inner diameter ID2, which the bore 4 has in the refueling direction downstream of the valve seat 9, wherein ID2 is again significantly larger than ID1, since the check valve 5 is arranged in this area of ​​the bore 4.

[0032] Since the valve seat 9 is formed by the valve block 3, a separate seat element, which must be inserted into the bore 4 and mechanically fixed within the bore 4 by means of the valve housing 6, is unnecessary. Eliminating the separate seat element reduces the installation space required for the check valve 5. Furthermore, it ensures that the screw connection created via the valve housing 6 with the valve block 3 does not contain any elastic elements. This, in turn, eliminates the need for a threadlocker to permanently secure the screw connection.

[0033] Since the valve element 7 of the tank valve 1 of Figure 1 is externally guided, the valve element 7 has an axial bore 11 designed as a blind hole, which is connected via further bores 12 running transversely thereto to an annular space 13 into which the fuel gas flows when the check valve 5 opens. From the annular space 13, the fuel gas then flows via the bores 12 into the axial bore 11 and subsequently into the filling lance 16.

[0034] Figure 2 shows another tank valve 1 according to the invention. Since this differs from the tank valve 1 of Figure 1 only with regard to the design of the check valve 5, the illustration in Figure 2 is limited to this.

[0035] In the check valve 5 of Figure 2, the valve housing 6 is replaced by a clamping sleeve 14. In this way, the installation space requirement of the check valve 5 can be further reduced. The clamping sleeve 14 is also screwed into the bore 4 of the valve block 3. Since the valve block 3 and the clamping sleeve 14 are each made of metal, the two together form a purely metallic screw connection. The clamping sleeve 14 serves to axially support the closing spring 8 and to guide the axially movable valve element 7 in a first guide area 10. The valve element 7 is guided in the bore 4 of the valve block 3 via a further guide area 10. The valve seat 9 is also formed in Figure 2 by a local cross-sectional constriction of the bore 4, so that a seat diameter SD is created that is smaller than the inner diameters I Di and ID2.When the check valve 5 is open, fuel gas flows through the valve seat 9 into an annular space 13, which is formed between the valve element 7 and the valve block 3 due to the absence of a valve housing 6. The connection of the annular space 13 to the axial bore 11 of the valve element 7, which is designed as a blind hole, is achieved in this case via bores 12 running at an angle thereto.

Claims

Claims 1. Tank valve (1) for a fuel gas tank (2), comprising a valve block (3) with a bore (4) in which a check valve (5) is inserted, wherein the check valve (5) has an axially movable valve element (7) which is received directly or indirectly via a valve housing (6) in the bore (4) and which is axially prestressed by means of the spring force of a closing spring (8) against a valve seat (9) which is formed by a local cross-sectional constriction of the bore (4).

2. Tank valve (1) according to claim 1, characterized in that the bore (4) has on both sides of the local cross-sectional constriction an inner diameter (IDi, ID2) which is larger than a seat diameter (SD) of the valve seat (9).

3. Tank valve (1) according to claim 1 or 2, characterized in that the valve element (7) is made, at least in the region of a sealing contour cooperating with the valve seat (9), of a material whose modulus of elasticity is lower than that of the material from which the valve block (3) is made.

4. Tank valve (1) according to one of the preceding claims, characterized in that the valve element (7) has at least one outer peripheral guide region (10) via which it is guided in the bore (4) of the valve block (3) or in the valve housing (6).

5. Tank valve (1) according to one of the preceding claims, characterized in that the valve element (7) has an axial bore (11) designed as a blind hole, which is connected via at least one further bore (12) running transversely or obliquely thereto to an annular space (13) which is formed between the valve element (7) and the valve block (3) or between the valve element (7) and the valve housing (6).

6. Tank valve (1) according to one of the preceding claims, characterized in that the closing spring (8) is axially supported on the one hand on the valve element (7) and on the other hand on the valve housing (6), wherein preferably the valve housing (6) is screwed into the bore (4) of the valve block (3).

7. Tank valve (1) according to one of claims 1 to 5, characterized in that the closing spring (8) is axially supported on the one hand on the valve element (7) and on the other hand on a clamping sleeve (14), wherein the clamping sleeve (14) is preferably screwed into the bore (4) of the valve block (3).

8. Tank valve (1) according to one of the preceding claims, characterized in that the valve block (3) is made of metal, wherein preferably the valve housing (6) screwed into the bore (4) of the valve block (3) or the clamping sleeve (14) screwed into the bore (4) of the valve block (3) is also made of metal.

9. Tank valve (1) according to one of the preceding claims, characterized in that a refueling path (15) leads via the bore (4) formed in the valve block (3).

10. Fuel gas tank (2) with a tank valve (1) according to one of the preceding claims, wherein the tank valve (1) is preferably inserted, in particular screwed, into the fuel gas tank (2) in sections.

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