Pressure control unit for a hydrogen supply system of an internal combustion engine, method for producing the pressure control unit, and hydrogen supply system

Abstract

A pressure control unit (30) for a hydrogen supply system (10) for controlling the pressure of and feeding gaseous hydrogen from a high-pressure tank (12) to a consumer (42), comprising a housing (52), an inlet stub (54) and an outlet stub (56), a fluid duct (58) which extends through the housing (52) from the inlet stub (54) to the outlet stub (56), and at least one valve (32, 36), by which a throughflow of the hydrogen through the fluid duct (58) can be throttled or can be shut off, wherein the valve (32, 36) has a valve body (101) which fixes a valve seat (102) and in which a valve element (103) is received movably, wherein the valve body (101) is arranged in a bore (104), connected fluidically to the fluid duct (58), of the housing (52), and wherein a first sealing point (111) which is configured as welded seam (120) is provided between the bore (104) and the valve body (101), and a second sealing point (112) is formed which comprises an O-ring (121).

Description

[0001] Description

[0002] title

[0003] Pressure control unit for a hydrogen supply system of an internal combustion engine, method for producing the pressure control unit and hydrogen supply system

[0004] State of the art

[0005] The invention relates to a pressure control unit for a hydrogen supply system of an internal combustion engine for supplying and controlling the pressure of hydrogen.

[0006] From the subsequently published DE 10 2022 212 773 A1 of the applicant, a pressure control unit is already known which comprises a housing and a pressure control valve arranged in the housing, wherein the housing comprises a steel material and is connected to the pressure control valve in a fluid-tight manner by welding.

[0007] Disclosure of the invention

[0008] The present invention develops the previously published prior art mentioned at the beginning.

[0009] According to the invention, in a pressure control unit for a hydrogen supply system for pressure control and supply of gaseous hydrogen from a high-pressure tank to a consumer, the pressure control unit comprises a housing, an inlet nozzle, and an outlet nozzle. The inlet nozzle and the outlet nozzle can, for example, be mounted directly on the housing or on a component that is itself directly or indirectly fixed to the housing. According to the invention, the pressure control unit further comprises a fluid channel that extends from the inlet nozzle to the outlet nozzle through the housing, and at least one valve by which a flow of hydrogen through the fluid channel can be throttled or blocked.

[0010] The at least one valve can therefore be a shut-off valve, for example, a switching valve, or a pressure control valve, for example, a proportional valve. Alternatively, the pressure control unit can also comprise a pressure control valve and a shut-off valve, or two pressure control valves, which are connected in parallel, for example, and additionally comprise a shut-off valve. All of these valves, or only a subset of these valves, can have the properties associated with the component referred to herein simply as a "valve."

[0011] The invention further provides that the valve has a valve body that fixes a valve seat. The valve seat can thus be part of the valve body or be rigidly connected to the valve body. The invention further provides that a valve element is movably accommodated in the valve body. For example, the valve element can be acted upon by an elastic spring and / or can experience forces in the opening and / or closing direction from an electromagnet that cooperates with the valve, resulting in corresponding movements of the valve element.

[0012] It is further provided according to the invention that the valve body is arranged in a bore of the housing which is fluidically connected to the fluid channel, wherein a first sealing point is provided between the bore and the valve body, which is designed as a weld seam, and a second sealing point is formed which comprises an O-ring.

[0013] The first sealing point, designed as a weld seam, creates a permanent connection through a material bond. Its strength can be improved compared to a screw connection, for example. Its tightness can be high, for example, equivalent to helium tightness. The first sealing point, designed as a weld seam, also enables a compact design of the pressure control device and effectively prevents electrochemical infiltration of the first sealing point, which is generally exposed to environmental influences.

[0014] The type of weld and the circumstances of its production are not necessarily limited by the invention. It can, for example, be a weld produced by laser radiation ("laser welding") or a weld based on heating the joining position with electric current ("resistance welding", "CE welding"). In the latter case, different welding geometries are generally possible, for example, ring projection welding and / or ring edge welding.

[0015] The first sealing point seals in particular the bore and the fluid channel to the outside so that the hydrogen passed through the pressure control unit cannot escape from the hydrogen supply system.

[0016] The second sealing point comprises an O-ring, resulting in a flexible connection. This connection can accommodate relative movements between the housing and the valve body, for example, resulting from the welding process or from temperature fluctuations, or can shift accordingly within the bore.

[0017] The second sealing point seals in particular between the valve body and the fluid channel in such a way that a bypass around the valve within the fluid channel is reliably excluded.

[0018] The first sealing point can be provided, in particular, in the area of ​​the bore's exit, i.e., at the location on the outer surface of the housing where a twist drill would have first cut the housing during the intended drilling. This is where the bore starts, and this is the area where it exits.

[0019] For example, the hole may have a chamfer in its starting area.

[0020] The valve body can then be inserted into the bore more easily.

[0021] The housing and valve body can be made of steel, for example stainless steel.

[0022] The weld seam can be produced, for example, by means of capacitor discharge press-fit welding, which has advantages as explained in more detail below.

[0023] A pressure control unit which is further developed in that the valve body tapers via an annular shoulder pointing away from the housing, wherein the annular shoulder is coplanar with the outer surface of the housing in the region of the outlet of the bore, is particularly suitable for introducing a magnetic flux, which is generated by an electromagnet cooperating with the valve, through the valve body into the housing.

[0024] Such a pressure control unit can be manufactured using the following steps or the valve can be joined in the bore using the following steps:

[0025] - The valve and the housing are initially provided separately from each other, with an O-ring already mounted on the valve body, then

[0026] - the valve body is initially incompletely inserted into the bore due to a radial oversize that it has compared to the bore, then

[0027] - an electrode is placed on the ring shoulder, then

[0028] - an electric current is introduced into the housing via the electrode and the valve body, so that the valve body and / or the housing melts in the area of ​​the first sealing point, and at the same time

[0029] - a force is introduced into the valve body via the electrode, which acts in the direction of the housing, so that the valve body is inserted further into the bore until the electrode hits a mechanical stop, where

[0030] - the O-ring moves along the fluid channel as the valve body is further inserted into the bore.

[0031] Finally, the electromagnet can be mounted on the tapered part of the valve body

[0032] - i.e., spatially outside the housing - mounted, for example, by pressing. Such a pressure control unit can be manufactured, or the valve can be joined in the bore, using the following steps:

[0033] - The valve and the housing are initially provided separately from each other, with an O-ring already mounted on the valve body, then

[0034] - the valve body is initially incompletely inserted into the bore due to a radial oversize that it has compared to the bore, then

[0035] - a flat electrode is placed on the ring shoulder in such a way that it projects radially beyond the ring shoulder, then

[0036] - an electric current is introduced into the housing via the electrode and the valve body, so that the valve body and / or the housing melts in the area of ​​the first sealing point, and at the same time

[0037] - a force is introduced into the valve body via the electrode, which acts in the direction of the housing, so that the valve body is inserted further into the bore until the electrode hits the outer surface of the housing, whereby

[0038] - the O-ring moves along the fluid channel as the valve body is further inserted into the bore.

[0039] Finally, the electromagnet can be mounted on the tapered part of the valve body

[0040] - i.e. spatially outside the housing - mounted, for example pressed.

[0041] It can be provided that the bore has a first diameter in the region of the first sealing point and a second diameter in the region of the second sealing point. If the ratio of the first diameter to the second diameter is selected such that it is not less than 1.05 and not greater than 1.4, the effect is that the O-ring mounted on the valve body, which lies sealingly in the bore in the region of the second sealing point, can be easily inserted into the bore beyond the region of the first sealing point.

[0042] It can be provided that the second sealing point is arranged within the bore at a distance in the bore direction from the bore outlet, and that the bore has a first diameter in the region of the first sealing point. If the ratio of the first diameter to the distance in the bore direction from the bore outlet is not less than 0.7 and not greater than 1.4, this has the technical effect that the O-ring is at least far enough away from the weld seam that the amount of heat introduced into the valve housing during the weld seam reliably does not damage the O-ring.

[0043] It can be provided that the bore has a second diameter in the area of ​​the second sealing point, and that the valve housing has a housing diameter in the area of ​​the second sealing point. If the housing diameter is smaller than the second diameter, an electrical shunt between the valve housing and the housing is avoided, for example, during resistance welding.

[0044] Embodiments of the present invention are explained below with reference to the accompanying drawings, in which:

[0045] Figure 1 is a schematic representation of a fuel supply system for supplying an internal combustion engine with gaseous fuel having a pressure control unit with two pressure control valves;

[0046] Figure 2 is a schematic perspective view of the pressure control unit of Figure 1;

[0047] Figure 3 is a schematic perspective view of an alternative pressure control unit with only a single pressure control valve;

[0048] Figure 4 shows a schematic longitudinal section through the pressure control unit of Figure 3;

[0049] Figure 5 is a schematic longitudinal section through a modified embodiment of the pressure control unit of Figure 3, and Figure 6 is a detail of the areas of the pressure control units of Figures 4 and 5 in which valves are connected to the housing by welding.

[0050] A fuel supply system is designated overall by reference numeral 10 in Figure 1. It serves to supply an internal combustion engine (not shown) with a gaseous fuel, in this case, for example, with gaseous hydrogen.

[0051] The hydrogen is stored under high pressure, for example, below 700 bar, in a tank-like fuel storage unit 12. This can be filled via a filling connection 14. Furthermore, an integrated unit 16 consisting of a tank valve for filling and discharging hydrogen into and from the fuel storage unit 12 and a temperature sensor for detecting the temperature of the hydrogen coming from the fuel storage unit 12 is arranged on the fuel storage unit 12.

[0052] The hydrogen first flows via a pressure line 18 to a filter 20 and from there to a high-pressure pressure regulator 22. This reduces the pressure of the gaseous hydrogen to, for example, a pressure in the range of 40 bar. The pressure line 18 leads from the high-pressure pressure regulator 22 to a pressure sensor 24, another filter 26, and an optional temperature control device 28, finally to a low-pressure pressure regulator unit 30 (short: "pressure regulator unit").

[0053] The low-pressure pressure control unit 30 comprises, in the present example, two hydraulically parallel pressure control valves 32, a low-pressure pressure sensor 34, and a safety valve in the form of a shut-off valve device 36. The two pressure control valves 32 are identically constructed and, in the present case, are proportional control valves. The low-pressure pressure control unit 30 further reduces the pressure in the pressure line 18 from the inlet-side pressure of approximately 40 bar, in the present example, to a pressure of, for example, approximately 15 bar. Downstream of the low-pressure pressure control unit 30, the pressure line 18 leads to a fuel distribution device 38, which can be designed, for example, as an elongated tube in the manner of a typical fuel rail, as is known from gasoline and diesel fuel systems. The gas pressure prevailing in the fuel distribution device 38 is detected by a pressure sensor 40.

[0054] Connected to the fuel distribution device 38 are several injectors 42, which inject the gaseous hydrogen directly into combustion chambers 44 of the internal combustion engine, as an example here. The gaseous hydrogen is mixed with atmospheric oxygen in the combustion chambers 44, and this mixture is ignited by a respective ignition device 46. Typically, the internal combustion engine is a 2-stroke or 4-stroke piston internal combustion engine of a largely conventional design. For example, such an internal combustion engine is used to power a motor vehicle. However, it can also be used stationary, for example, to drive a generator for power generation.

[0055] The fuel supply system 10 and its components are controlled by an electronic control and regulating device 48, which has one or more corresponding microprocessors, a memory for program code, etc. The control and regulating device 48 receives signals from, among others, the temperature sensor (installed in the integrated unit 16), the pressure sensor 24, the pressure sensor 34, the pressure sensor 40, etc. The control and regulating device 48 controls various components of the fuel supply system 10, including the low-pressure pressure regulating device 30, the safety valve 36 and the ignition devices 46. Furthermore, a control device 50 is also controlled by the control and regulating device 48, which in turn specifically controls or regulates the operation of the fuel storage device 12.

[0056] Figure 2 shows the low-pressure pressure control unit 30 in greater detail. It comprises a block-like housing 52 with an inlet-side connection piece 54 and an outlet-side connection piece 56. In the illustrated installation position, the two pressure control valves 32 are arranged with their longitudinal direction essentially vertically. Hydraulically, the two pressure control valves 32 are connected in parallel, as already mentioned above. The outlet-side connection 56 leads to the fuel distribution device 38. It can be seen that in the exemplary embodiment shown here, the low-pressure pressure control unit 30 forms an integrated unit that includes the two pressure control valves 32, the shut-off valve device 36, and the pressure sensor 34. This integrated unit is also referred to as a HIPR (Hydrogen Injection Pressure Regulator).

[0057] The housing 52 is made of a steel material, in this case, for example, stainless steel. As will be shown below, the two pressure control valves 32 are connected to the housing 52 of the pressure control unit 30 in a fluid-tight manner by welding. Likewise, the connecting pieces 54 and 56 and the housing of the shut-off valve device 36 can be welded to the housing 52 in a fluid-tight manner. The pressure sensor 34 can also be welded to the housing 52 in a fluid-tight manner. The welds can be produced by capacitor discharge welding (KEEP process) or by laser welding.

[0058] The alternative embodiment of a pressure control unit 30 shown in Figure 3 is basically identical to that of Figure 2, but it comprises only a single pressure control valve 32. Further details of the pressure control unit 30 of the embodiment of Figure 3 are explained below with reference to Figures 4 and 5, these details also applying to the embodiment shown in Figure 2.

[0059] In Figure 4, from left to right, one can schematically see first the inlet-side connection piece 54, then the shut-off valve device 36, then the housing 52, into which the pressure sensor 34 and, next to it, the pressure regulating valve 32 are inserted in regions from above, and finally the outlet-side connection piece 56. In the housing 52, a fluid channel 58 is drawn schematically and only in regions, which extends from the inlet-side connection piece 54 via the shut-off valve device 36, the pressure sensor 34 and the pressure regulating valve 32 to the outlet-side connection piece 56. For the partial accommodation of the pressure sensor 34 and pressure regulating valve 32 in the housing 52, the latter comprises receiving openings 60 and 62, the longitudinal axes 64 and 66 of which, in the present case, run orthogonally to a longitudinal axis 68 of the fluid channel 58, for example.The shut-off valve device 36, the pressure sensor 34, and the pressure control valve 32 have respective housings 70, 72, and 74, which, however, are only shown schematically in Figure 4. At least the housing 74 of the pressure control valve 32 is preferably also made of a steel material or stainless steel.

[0060] In the embodiment of a pressure control unit 30 shown in Figure 4, only the pressure control valve 32 with its housing 74 is welded to the housing 52 of the pressure control unit 30. The connecting pieces 54 and 56, however, are connected to the housing 52 by screw connections (not shown). The seal between the inlet-side connecting piece 54 and the housing 70 of the shut-off valve device 36 (the housing 70 of the shut-off valve device 36 forms, in this case, for example, a section of the housing 52 of the pressure control unit 30) is achieved by an annular sealing element 78, which in this case can be, for example, a flat sealing ring. Analogously, the seal between the outlet-side connecting piece 56 and the housing 52 is achieved by an annular sealing element 80, which in this case can also be, for example, a flat sealing ring.EPDM or FKM (EPDM = ethylene propylene diene (monomer) rubber, FKM = fluororubber) can be used as a material for the flat sealing ring.

[0061] In the exemplary embodiment shown in Figure 4, the connection of the housing 70 to the remaining area of ​​the housing 52 is also achieved by a screw connection (not shown in detail). The fluid seal between the housing 70 and the remaining area of ​​the housing 52 is achieved in the area of ​​the fluid channel 58 by a sealing element 82, in the present case, for example, in the form of an O-ring. EPDM or FKM, for example, can again be used as a material for the O-ring. The pressure sensor 34 can, in the present case, for example, form a metallic seal with the housing 52. For example, the housing 72 of the pressure sensor 34 can have a biting edge (not shown) that interacts with the housing 52. However, it is also possible for a sealing element to be used to seal between the pressure sensor 34 and the housing 52.

[0062] The embodiment of a pressure control unit 30 shown schematically in Figure 5 differs from that of Figure 4, among other things, in that not only the pressure control valve 32, but also the two connecting pieces 54 and 56 are welded fluid-tight to the housing 52. Preferably, the two connecting pieces 54 and 56 are also made of a steel material, in particular a stainless steel, preferably the same material as the housing 52.

[0063] Furthermore, in the embodiment of Figure 5, the shut-off valve device 36 is also inserted from above into a receiving opening 84 of the housing 52 and is also welded to the housing 70 in a fluid-tight manner on the housing 52. Thus, in the embodiment shown in Figure 5, separate sealing elements, for example in the form of O-rings or flat sealing rings, can be completely dispensed with.

[0064] It is understood that in an embodiment not shown, the pressure control unit 30 may also comprise only the housing, pressure control valve 32, and connecting pieces 54, 56. The connecting pieces 54, 56 could also be manufactured integrally with the housing 52 of the pressure control unit 30.

[0065] Figure 6 shows again in detail the connection of a valve (namely the pressure control valve 32 from Figure 4 or Figure 5 or the shut-off valve device 36 from Figure 5) to the housing 52.

[0066] Accordingly, it is provided that the valve 32, 36 has a valve body 101 which fixes a valve seat 102 and in which a valve element 103 is movably received. The valve body 101 is arranged in a bore 104 of the housing 52 which is fluidically connected to the fluid channel 58 and which, in Figure 6, extends vertically into the housing 52, starting from the outer surface 52E of the housing 52. A first sealing point 111, which is designed as a weld seam 120, is provided between the bore 104 and the valve body 101. In Figure 6, it is located above the fluid channel 58 at the outlet 104A of the bore 104 and seals the fluid channel 58 from the exterior 100 of the pressure control unit 30.

[0067] Furthermore, a second sealing point 112 comprising an O-ring 121 is formed between the bore 104 and the valve body 101. This sealing point 112 is located in a part of the fluid channel 58 that runs vertically in Figure 6 and ensures that there is no bypass to the valve 32, 36 within the fluid channel 58.

[0068] The valve 32, 36 has a valve body 101, in the lower part of which in Figure 6 a valve seat body 102K is accommodated. The valve seat body 102K has an axially central through-channel 106 and a valve seat 102 is formed on it.

[0069] Furthermore, a valve element 103 is accommodated in the valve body 101 and is displaceable between a lower position in Figure 6, in which the valve element 103 rests against the valve seat 102 of the valve seat body 102K and thus closes the through-channel 106, and an upper position in Figure 6, in which the valve 32, 36 is open.

[0070] The valve body 101 is tapered by an annular shoulder 101 R pointing away from the housing 52, wherein the annular shoulder 101 R is coplanar with the outer surface 52E of the housing 52 in the region of the outlet 104A of the bore 104.

[0071] An electromagnet 105, which cooperates with the valve 32, 36 and which, viewed in the longitudinal direction, is mounted only at the level of the tapered part of the valve body 101, is shown only schematically in Figure 6.

[0072] A valve 32, 36, which is designed as shown in Figure 6, can be mounted in a housing 52 as follows:

[0073] - The valve 32, 36 and the housing 52 are initially provided separately from each other, with an O-ring 112 already mounted on the valve body 101, then

[0074] - the valve body 101 is initially incompletely inserted into the bore 104 according to a radial oversize that it has compared to the bore 104, then

[0075] - an electrode is placed on the ring shoulder 101 R, then

[0076] - an electric current is introduced into the housing 52 via the electrode and the valve body 101, so that the valve body 101 and / or the housing 52 melt in the area of ​​the first sealing point 111, and at the same time

[0077] - a force is introduced into the valve body 101 via the electrode, which acts in the direction of the housing 52, so that the valve body 101 is inserted further into the bore 104, whereby

[0078] - the O-ring 121 moves along the fluid channel 58 during further insertion of the valve body 101 into the bore 104.

[0079] Finally, the electromagnet 105 can be mounted, for example pressed, on the tapered part of the valve body 101 - i.e. spatially outside the housing 52 and the bore 104.

[0080] The valve body 101 can be inserted into the bore 104 with a travel limiter. The travel limiter can be achieved by an actuator advancing the electrode stopping the advancement of its own accord or according to its electronic control.

[0081] Alternatively, the insertion path of the valve body 101 into the bore 104 can be limited by a mechanical stop. This can be a stop formed in the bore 104 or temporarily introduced, against which the valve body 101 strikes, or a stop formed on the pressure control unit 30, against which the electrode strikes or against which the actuator advancing the electrode strikes. Alternatively, it can also be a stop separate from the pressure control unit 30, against which the electrode strikes or against which the actuator advancing the electrode strikes.

[0082] Advantageously, the stop not only stops the mechanical advance of the valve body 101 into the bore 104, but also creates an electrical shunt past the first sealing point 111, so that a current flow through the sealing point 111 and the associated heat generation - and thus the welding process - comes to a standstill. In the example, the bore 104 has a first diameter dk in the area of ​​the first sealing point 111, which is, for example, 24 mm, and a second diameter ds in the area of ​​the second sealing point 112, which is, for example, 21 mm. The valve housing 101 has a housing diameter db in the area of ​​the second sealing point 112, which is, for example, 18 mm. The second sealing point 112 is arranged within the bore at a distance Is in the bore direction from the outlet of the bore 104, which is 20 mm.

[0083] A valve 32, 36, which is designed as shown in Figure 6, can be mounted in a housing 52 as follows, according to an example:

[0084] - The valve 32, 36 and the housing 52 are initially provided separately from each other, with an O-ring 112 already mounted on the valve body 101, then

[0085] - the valve body 101 is initially incompletely inserted into the bore 104 according to a radial oversize that it has compared to the bore 104, then

[0086] - a flat electrode is placed on the ring shoulder 101 R in such a way that it projects radially beyond the ring shoulder 101 R, then

[0087] - an electric current is introduced into the housing 52 via the electrode and the valve body 101, so that the valve body 101 and / or the housing 52 melt in the area of ​​the first sealing point 111, and at the same time

[0088] - a force is introduced into the valve body 101 via the electrode, which acts in the direction of the housing 52, so that the valve body 101 is inserted further into the bore 104 until the electrode strikes the outer surface 52E of the housing 52, whereby

[0089] - the O-ring 121 moves along the fluid channel 58 during further insertion of the valve body 101 into the bore 104.

[0090] Finally, the electromagnet 105 can be mounted, for example pressed, on the tapered part of the valve body 101 - i.e. spatially outside the housing 52 and the bore 104.

Claims

Claims 1. Pressure control unit (30) for a hydrogen supply system (10) for pressure control and supply of gaseous hydrogen from a high-pressure tank (12) to a consumer (42), comprising a housing (52), an inlet nozzle (54) and an outlet nozzle (56), a fluid channel (58) extending from the inlet nozzle (54) to the outlet nozzle (56) through the housing (52), and at least one valve (32, 36) by means of which a flow of hydrogen through the fluid channel (58) can be throttled or blocked, wherein the valve (32, 36) has a valve body (101) which fixes a valve seat (102) and in which a valve element (103) is movably received, wherein the valve body (101) is arranged in a bore (104) of the housing (52) which is fluidically connected to the fluid channel (58), and wherein between the bore (104) and the valve body (101) a first sealing point (111) is provided, which is designed as a weld seam (120),and a second sealing point (112) is formed which comprises an O-ring (121)., 2. Pressure control unit (30) according to claim 1, wherein the valve (32, 36) is a shut-off valve or a proportional valve.

3. Pressure control unit (30) according to claim 1 or 2, characterized in that the first sealing point (111) is provided in the region of the outlet (104A) of the bore (104).

4. Pressure control unit (30) according to claim 1, 2 or 3, characterized in that the second sealing point (112) is provided in the fluid channel (58).

5. Pressure control unit (30) according to one of the preceding claims, characterized in that the bore (104) has a chamfer (104F) in its outlet region (104A).

6. Pressure control unit (30) according to one of the preceding claims, characterized in that the weld seam (120) results from capacitor discharge press-in welding.

7. Pressure control unit (30) according to one of the preceding claims, characterized in that the housing (52) and the valve body (101) are made of steel.

8. Pressure control unit (30) according to one of the preceding claims, wherein the bore (104) in the region of the first sealing point (111) has a first diameter (dk) and wherein the bore (104) in the region of the second sealing point (112) has a second diameter (ds) and wherein the ratio of the first diameter (dk) to the second diameter (ds) is not less than 1.05 and not greater than 1.

4.

9. Pressure control unit (30) according to one of the preceding claims, wherein the second sealing point (112) is arranged within the bore (104) at a distance (Is) in the bore direction from the outlet of the bore (104) and wherein the bore (104) has a first diameter (dk) in the region of the first sealing point (111) and wherein the ratio of the first diameter (dk) to the distance (Is) in the bore direction from the outlet of the bore (104) is not less than 0.7 and not greater than 1.

4.

10. Pressure control unit (30) according to one of the preceding claims, wherein the bore (104) has a second diameter (ds) in the region of the second sealing point (112) and wherein the valve housing (101) has a housing diameter (db) in the region of the second sealing point (112) and wherein the housing diameter (db) is smaller than the second diameter (ds).

11. Pressure control unit (30) according to one of the preceding claims, characterized in that the valve body (101) tapers via an annular shoulder (101 R) pointing away from the housing 52, wherein the annular shoulder (101 R) is coplanar with the outer surface (52E) of the housing (52) in the region of the outlet of the bore (104A).

12. Pressure control unit (30) according to the preceding claim, characterized in that the valve (32, 36) cooperates with an electromagnet (105) which, viewed in the longitudinal direction, is mounted only at the level of the tapered part of the valve body (101).

13. A method for producing a pressure control unit (30) according to one of the preceding claims, characterized in that for joining the valve (32, 36) in the bore (104), - the valve (32, 36) and the housing (52) are initially provided separately from one another, with an O-ring (121) already mounted on the valve body (101), then - the valve body (101) is initially incompletely inserted into the bore (104) according to a radial oversize which it has in comparison to the bore (104), then - an electrode is placed on the valve body (101), then - an electric current is introduced into the housing (52) via the electrode and via the valve body (101), so that the valve body (101) and / or the housing (52) melt in the region of the first sealing point (111), and at the same time - a force is introduced into the valve body (101) via the electrode, which force acts in the direction of the housing (52), so that the valve body (101) is inserted further into the bore (104) until the electrode or the valve body (101) or an actuator pushing the electrode strikes a stop, whereby - the O-ring (121) moves along the fluid channel (58) during further insertion of the valve body (101) into the bore (104).

14. A method for producing a pressure control unit (30) according to one of the two claims 11 and 12, characterized in that for joining the valve (32, 36) in the bore (104), - The valve (32, 36) and the housing (52) are first provided separately from each other, with an O-ring (121) already mounted on the valve body (104), then - the valve body (101) is initially incompletely inserted into the bore (104) according to a radial oversize which it has in comparison to the bore (104), then - a flat electrode is placed on the ring shoulder (101 R) in such a way that it projects radially beyond the ring shoulder (101 R), then - an electric current is introduced into the housing (52) via the electrode and via the valve body (101), so that the valve body (101) and / or the housing (52) melt in the region of the first sealing point (111), and at the same time - a force is introduced into the valve body (101) via the electrode, which force acts in the direction of the housing (52), so that the valve body (101) is inserted further into the bore (104) until the electrode strikes the outer surface (52E) of the housing (52), whereby - the O-ring (121) moves along the fluid channel (58) during further insertion of the valve body (101) into the bore (104).

15. Hydrogen supply system (10) with a pressure control unit (30) according to one of claims 1 to 12, wherein upstream of the pressure control unit (30) a high-pressure tank (12) is provided and downstream of the pressure control unit (30) a consumer, for example a fuel distribution device (38) with one or more injectors (42), is provided.

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