SAFETY VALVE AND TANK

Description

Technical field

[0001] The present invention relates to a safety valve and a tank, in particular for a motor vehicle. State of the art

[0002] Hydrogen is becoming increasingly important as an energy carrier. Hydrogen, or gases in general, are typically stored in closed containers at a pressure greater than ambient pressure. These containers are typically equipped with safety valves to allow controlled release of the gas if the pressure inside the container exceeds a certain limit or if necessary for other reasons, such as in the event of a fire.

[0003] US Pat. No. 5,632,297, for example, describes a safety valve that triggers both in the event of overpressure and when a limit temperature is reached. The safety valve comprises a valve body with a bore, at the bottom of which a first opening is formed and on the side circumference of which a second opening is formed at a distance from the bottom, a piston guided in the bore, a compression spring, a stop piece, and a plug that melts at the limit temperature. The compression spring is supported on the piston and the stop piece. The stop piece, in turn, bears against the plug, so that the spring presses the piston sealingly against the first opening. When the plug melts, the force exerted by the spring via the stop piece and a force exerted by the gas on the piston pushes the material of the plug away, so that the piston can be lifted away from the first opening by the gas.

[0004] From DE 696 18 127 T2 a relief device is known which is activated either thermally or by pressure in order to release a pressure in a pressurised container when a predetermined temperature or such a pressure in or around the container is exceeded.

[0005] DE 603 ​​09 339 T2 shows relief devices and in particular relief valves which provide pressure relief for a pressurised fluid in a container or canister when a predetermined temperature or pressure is exceeded.

[0006] From FR 3 008 767 A1, a valve for discharging a gas is known, comprising a channel comprising an element that moves between a first position preventing gas flow, a second position allowing gas flow via a first passage section, and a third position allowing gas flow via a second passage section, wherein the second passage section has a different surface than the surface of the first flow section, wherein the device has a first and a second thrust safety device, wherein the first stop comprises a fusible link

[0007] US 2013 / 082054 A1 discloses a safety device for containers subjected to gas pressure, in particular the gas side of hydropneumatic devices such as hydraulic accumulators. This safety device is characterized by having a connection device attachable to the pressure chamber of the container to form a passage between the gas side of the container and the outside, and by a means that normally blocks the passage and can be converted under the influence of temperature into a state that allows the opening of a flow path through the passage. Disclosure of the invention

[0008] According to the invention, a safety valve having the features of claim 1 and a tank having the features of claim 10 are provided.

[0009] According to a first aspect of the invention, a safety valve is provided, in particular for a gas tank. The safety valve comprises a valve body with a guide bore defining a longitudinal axis, a first opening formed at a bottom of the guide bore, and a second opening formed along the longitudinal axis at a distance from the bottom and extending along a radial direction transverse to the longitudinal axis. A valve needle mounted axially displaceably in the guide bore of the valve body with a sealing surface facing the first opening. A compression spring device with a spring that is compressed by a preloading path, in particular relative to an unloaded state or relative to a state in which the spring rests against a stop, and thereby preloads the valve needle along the longitudinal axis into a sealing position in which the sealing surface of the valve needle seals the first opening.and a thermally activatable trigger unit, which has an extension or length along the longitudinal axis that is greater than the preload path, and which is designed to collapse upon reaching a trigger temperature, wherein the compression spring device is supported against the trigger unit. The safety valve can have a locking device with a locking body, which is displaceably mounted in a locking recess of the valve body extending in the radial direction, and a spring that preloads the locking body in the radial direction toward the longitudinal axis, wherein the second opening of the valve body is arranged between the locking recess and the base with respect to the longitudinal axis, and wherein the valve needle has a locking groove.which, in the sealing position of the valve needle, is positioned between the locking recess and the bottom of the valve body at a predetermined distance from the locking recess, and wherein the locking body, in a locking position in which it projects into the guide bore, engages in the locking groove when the valve needle is retracted by the predetermined distance from the first opening. Accordingly, a locking mechanism is provided which axially fixes the valve body in a release position, wherein, in the release position of the valve body, the sealing surface is spaced from the bottom of the guide bore and the locking groove is arranged at the level of the locking bore with respect to the longitudinal axis. This reliably prevents the sealing surface from coming into contact with the bottom of the guide bore again and sealing the first opening.When the valve needle is raised by a distance corresponding to the distance between the locking bore and the locking groove in the valve needle's sealing position, e.g., when the trigger unit has collapsed. This ensures an irreversible opening or deflation process, thus further improving the valve's reliability.

[0010] According to a second aspect of the invention, a tank, in particular for a motor vehicle, is provided. The tank comprises a container for holding a gas, in particular for holding hydrogen, and a safety valve according to the first aspect of the invention.

[0011] One idea underlying the invention is to coordinate the dimensioning of a trigger unit, which collapses when the limit temperature is reached, and the preload travel of a spring in a safety valve that triggers both when a limit pressure and a limit temperature are exceeded, in such a way that when the trigger unit has collapsed, the valve needle of the safety valve, which seals the opening to the container, can move freely axially, in particular without being subjected to a spring force. In the safety valve according to the invention, a spring of a compression spring device is compressed by a specific preload travel. This means that the spring is compressed by a specific travel compared to the relaxed state or compared to a state in which it is supported on two axially opposite stops. The valve needle is preloaded into the sealing position by the spring force.Here, the release unit is supported by the valve needle and the compression spring device, and the compression spring device is supported by a stop on the valve body. Alternatively, the compression spring device is supported directly on the valve needle and on the release unit, which in turn is supported by a stop on the valve body. In both cases, the release unit is longer than the preload travel of the spring. This means that the release unit is designed in such a way that if it breaks, for example, it releases a travel that is longer than the preload travel. This kinematically decouples the spring and the valve needle, and the valve needle is released in the axial direction.

[0012] This design releases the valve needle from its sealed position with improved reliability in the event of a temperature-related release. In particular, the force that the gas flowing through the first opening of the valve body must exert on the valve body to remove it from the sealed position is advantageously reduced, as no spring force needs to be overcome. This further improves the safety of the valve.

[0013] According to some embodiments, the locking body may be a ball. This advantageously offers a structurally simple solution.

[0014] According to some embodiments, the compression spring device may comprise a spring sleeve with a base and a collar located opposite thereto, and the spring may be configured as a spiral spring, which is supported on the collar of the spring sleeve and on a stop arranged opposite the base of the guide bore with respect to the longitudinal axis and fixed relative thereto, and wherein the trigger unit is supported on the base of the spring sleeve and on an end of the valve needle located opposite the sealing surface. The spring sleeve may, for example, comprise a sleeve body, wherein the base is arranged at a first end of the sleeve body, and the collar, which protrudes radially outward from the sleeve body, is arranged at a second end of the sleeve body.The spring sleeve is preferably positioned in the valve body such that the collar faces the bottom of the guide bore with respect to the longitudinal axis. The stop against which the spring is supported can be formed, for example, by a screw cap that is screwed to the valve body. A spiral spring offers the advantage that it is cost-effective to manufacture and, at the same time, its preload can be adjusted very precisely. The arrangement of the trigger unit such that it is supported on the valve needle and the bottom of the sleeve means that the trigger unit projects into the sleeve body. This results in a compact design in the axial direction. At the same time, the spring is spatially separated from the trigger unit by the spring sleeve, thus preventing mutual functional impairments.

[0015] According to some embodiments, the valve body may have a shoulder surface surrounding an end of the guide bore located opposite the bottom of the guide bore in the radial direction, wherein the collar of the spring sleeve faces the shoulder surface and is arranged at a distance from the shoulder surface, and wherein the collar is applied to the shoulder surface by the spring when the trigger unit is collapsed. The guide bore may, for example, open into a plenum or a cavity of the valve body in which the spring sleeve and the spiral spring are arranged. The valve body has a shoulder or stop surface which delimits the plenum with respect to the longitudinal axis and from which the guide bore extends. When the trigger unit collapses, the spring presses the spring sleeve against the stop or shoulder surface.Thus, any further movement of the spring sleeve towards the valve body is stopped by the shoulder surface and thus even more reliably prevents the valve body from being accidentally pushed into the sealing position when the trigger unit has collapsed.

[0016] According to some embodiments, an outer diameter of the valve needle and an inner diameter of the spring sleeve can be dimensioned such that the valve needle can be at least partially inserted into the spring sleeve when the trigger unit has collapsed. Thus, the valve needle can be at least partially received in the spring sleeve after the trigger unit has collapsed. This, on the one hand, achieves a compact design. On the other hand, it further facilitates the kinematic decoupling of the compression spring device and the valve needle after the trigger unit has collapsed.

[0017] According to some embodiments, it can be provided that the compression spring device has a spring carrier and the spring is designed as a disc spring which is connected to the spring carrier and is supported on an end of the valve needle located opposite the sealing surface, wherein the trigger unit is supported on the spring carrier and on a stop which is arranged opposite the bottom of the guide bore with respect to the longitudinal axis and is stationary relative to this. The spring carrier can, for example, be essentially plate-shaped. A disc spring offers the advantage of being very compact with respect to the axial direction. For example, the disc spring can have an extension with respect to the longitudinal axis in the relaxed state which lies in a range between 5% and 20%, in particular between 7% and 12% of the length of the trigger unit.Thus, the kinematic decoupling of the compression spring device and the valve needle after the release unit collapses is ensured in a very simple design.

[0018] According to some embodiments, the valve body may have an external thread with which the valve body can be screwed into an opening of a container. This facilitates a reliable coupling of the safety valve to a container.

[0019] According to some embodiments, the triggering unit can have a glass ampoule filled with a liquid. The glass ampoule can generally be an elongated, e.g. cylindrical, hollow body in which a liquid is accommodated. The glass ampoule is hermetically sealed and a wall thickness of the glass ampoule is dimensioned such that it collapses or bursts if the liquid expands as a result of increasing temperatures, causing the pressure inside the glass ampoule to exceed a limit value. This solution offers the advantage that a triggering unit with a relatively large axial extent can be realized. Nevertheless, a limit temperature at which the triggering unit is to collapse can be set very precisely, e.g. by the wall thickness of the glass ampoule and / or by the properties and / or the quantity of the liquid. A further advantage is that the liquid can continue to function or operate after the glass ampoule has collapsed.The mobility of the valve needle is not affected. Unlike plugs made of a meltable material, where there is a risk that the melted material will re-solidify in the valve body, no measures are required to expel the material or fluid from the valve body. This facilitates the placement of the actuating unit within the valve body.

[0020] With regard to directions and axes, in particular directions and axes relating to the course of physical structures, the course of an axis, a direction or a structure "along" another axis, direction or structure is understood to mean that these, in particular the tangents resulting at a respective point of the structures, each run at an angle of less than 45 degrees, preferably less than 30 degrees and particularly preferably parallel to one another.

[0021] With regard to directions and axes, in particular directions and axes relating to the course of physical structures, the term "transverse" to another axis, direction or structure is understood herein to mean that these, in particular the tangents resulting at a respective point of the structures, each run at an angle of greater than or equal to 45 degrees, preferably greater than or equal to 60 degrees and particularly preferably perpendicular to one another.

[0022] The invention is explained below with reference to the figures of the drawings. The figures show: Fig. 1 is a schematic sectional view of a safety valve according to an embodiment of the present invention, wherein a valve needle is arranged in a sealing position and the safety valve is fixed in an opening of a container; Fig. 2 shows the safety valve from Fig. 1 , wherein a trigger unit collapses and the valve needle is arranged in a release position; Fig. 3 a detailed view of the area marked by the letter Z of the Fig. 2 shown safety valve; Fig. 4 a schematic sectional view of a safety valve according to a further embodiment of the present invention, wherein a valve needle is arranged in a sealing position and the safety valve is fixed in an opening of a container; and Fig. 5 the safety valve from Fig. 4 , wherein a trigger unit collapses and the valve needle is arranged in a release position.

[0023] In the figures, the same reference symbols denote identical or functionally identical components, unless otherwise stated.

[0024] Fig. 1 shows, by way of example, a tank 200 with a container 205 for holding a gas such as hydrogen and a safety valve 100. The tank 200 can be carried, for example, in a motor vehicle (not shown) or another vehicle, e.g. a ship or an aircraft. As in Fig. 1 As shown by way of example, the container 205 has an opening 210 in which the safety valve 100 is fixed. For example, the opening 210 can be provided with an internal thread 211 into which the safety valve 100 is screwed with an external thread 19 provided on an outer circumference of a valve body 1 of the valve 100, as shown in Fig. 1 is shown as an example.

[0025] As in Fig. 1 As shown by way of example, the safety valve 100 comprises a valve body 1, a valve needle 2, a compression spring device 3 and a triggering unit 4. Optionally, a locking device 5 can also be provided, as shown in Fig. 1 is shown as an example. A closure cap 60 can also be provided optionally.

[0026] As in Fig. 1 As shown schematically, the valve body 1 may be an elongated body extending between a first end 1A and a second end 1B. As shown in Fig. 1 As shown, the valve body 1 has a guide bore 10 defining a longitudinal axis L1. A radial direction R1 extends perpendicular to the longitudinal axis L1. The valve body 1 can, for example, define a cavity extending along the longitudinal axis L1, which is delimited on one side by a shoulder surface 18a extending transversely to the longitudinal axis L1 and has an end opening 12 at the second end 1B of the valve body 1. As shown in Fig. 1 As shown by way of example, the guide bore 10 can extend from the shoulder surface 18a as a blind hole. The guide bore 10 thus extends between a bottom 11 located in the region of the first end 1A of the valve body 1 and an opposite bore opening 14. The stop surface or shoulder surface 18a thus surrounds an end of the guide bore 10 located opposite the bottom 11 of the guide bore 11 with respect to the axial direction R1.

[0027] As in Fig. 1 As further shown by way of example, the valve body 1 has a first opening 13 formed at the bottom 11 of the guide bore 10, and a second opening 15 extending along the radial direction R1 and arranged along the longitudinal axis L1 at a distance from the first opening 13 or from the bottom 11 of the guide bore 10. As shown in Fig. 1 As shown, the first opening 13 extends between the base 11 and the first end 1A or an end face of the valve body 1 forming the first end 1A. The second opening 15 extends between an inner peripheral surface defining the guide bore 10 and an outer peripheral surface of the valve body 1 located opposite thereto with respect to the radial direction R1.

[0028] As in Fig. 1 As further shown by way of example, the valve body 1 may further comprise an optional locking recess 17 extending between the inner peripheral surface and the outer peripheral surface of the valve body 1. As shown in Fig. 1 As shown by way of example, the locking recess 17 can be positioned such that the second opening 15 of the valve body 1 is arranged between the locking recess 17 and the base 11 with respect to the longitudinal axis L1.

[0029] As already mentioned, the valve body 1 can optionally have an external thread 19 formed on its outer circumferential surface. As in Fig. 1 As shown by way of example, the external thread 19 can be formed in a central region located between the first and second ends 1A, 1B.

[0030] If the safety valve 100 is fixed in the opening 210 of the container 200, e.g. by screwing the external thread 19 of the valve body 1 to the internal thread 211 of the opening 210 of the container 200, as in Fig. 1 shown as an example, the first end 1A of the valve body 1 and thus the first opening 11 of the valve body 1 facing an interior 201 of the container 200, as in Fig. 1 shown. Furthermore, the second opening 15 of the valve body 1 can be arranged in alignment with a side opening 215 of the container 200, as shown in Fig. 1 shown.

[0031] As in Fig. 1 As further shown by way of example, the valve body 1 can have, in the region of the first end 1A, a circumferential groove 16 formed on the outer circumferential surface, in which a sealing ring 7 is received. As in Fig. 1 As shown by way of example, the sealing ring 7 can rest against an inner surface of the container 205, in particular the opening 210.

[0032] The optional closure cap 60 can, for example, be screwed by means of an external thread 61 into an internal thread 62 which is formed in the area of ​​the second end 1B in the opening 12 of the valve body 1, as shown in Fig. 1 shown as an example.

[0033] The valve needle 2 can in particular be designed as a piston which extends between a first end 21 and a second end 22, as shown in Fig. 1 At the first end 21, the valve needle 2 has a sealing surface 2a, which can be formed, for example, by an end face of the valve needle 2 itself or, as in Fig. 1 shown by way of example, be formed by a sealing coating 23 connected to the end face 2a, which can be made of an elastomer material, for example. A recess 24 can be formed at the second end 22, as shown in Fig. 1 Alternatively, the end face forming the second end 22 may also be flat, as shown in Fig. 4 is shown as an example.

[0034] The valve needle 2 may further optionally have a locking groove 25 which is formed at a distance from the first end 21 on an outer peripheral surface of the piston, as shown in Fig. 1 is shown as an example.

[0035] As in Fig. 1 As shown by way of example, the valve needle 2 is guided in the guide bore 10 of the valve body 1 so as to be displaceable along the longitudinal axis L1. The sealing surface 2a of the valve needle 2 is oriented towards the bottom 11 of the guide bore 10. In Fig. 1 the valve needle 2 is shown in a sealing position in which the sealing surface 2a rests against the bottom 11 of the guide bore 10. In a release position, which is shown for example in Fig. 2 As shown, the sealing surface 2a is arranged at a distance from the bottom 11 of the guide bore 10 and exposes the first opening 13 so that gas can flow through the first opening 13 into the guide bore 10 and out of it through the second opening 15.

[0036] The compression spring device 3 has a spring 30 and may further comprise a spring sleeve 31, as shown in Fig. 1 The spring 30 can, as shown in Fig. 1 shown, for example, a spiral spring 30A. As shown in Fig. 1 As shown by way of example, the spring sleeve 31 can have a sleeve body 31C, wherein a bottom 31A is formed at a first end of the sleeve body and a collar 31B protruding radially outward from the sleeve body 31C is formed at a second end opposite thereto. The collar 31B is located facing the shoulder surface 18a or the bottom 11 of the guide bore 10.

[0037] As in Fig. 1 shown, the compression spring device 3 can be arranged in the interior or plenum of the valve body 1 between the shoulder surface 18a and the end opening 12. As in Fig. 1 As shown by way of example, the sleeve body 31C can be inserted into the spiral spring 30A, whereby the spiral spring 30A bears against the collar 31B and against the closure cap 60 or another stop 6 which is stationary with respect to the valve body 1, in particular with respect to the bottom 11 of the guide bore 10.

[0038] The trigger unit 4 is designed to be thermally activated, so that it collapses when a limit temperature is reached or exceeded. For example, the trigger unit 4 can have a glass ampoule 40 filled with a liquid, as shown in Fig. 1 is shown by way of example. If the limit temperature is reached or exceeded, the ampoule 40 bursts due to excessive pressure within it, which builds up due to thermal expansion of the liquid.

[0039] As in Fig. 1 As shown by way of example, the glass ampoule 40 or generally the trigger unit 4 may be an elongated body extending between a first end 41 and a second end 42. The trigger unit has a predetermined length or longitudinal extent between the first and second ends 41, 42. As shown in Fig. 1 As shown, the trigger unit 4 can be arranged with respect to the longitudinal axis L1 between the bottom 31A of the spring sleeve 31 and the second end 22 of the valve needle 2. In particular, the trigger unit 4 is supported on the bottom 31A of the spring sleeve 31 and on the second end 22 of the valve needle 2. For example, the second end 42 of the trigger unit 4 can be received in the recess or depression 24 formed at the second end 22 of the valve needle 2. The first end 41 of the trigger unit 4 can rest against the bottom 31A of the spring sleeve 31 and optionally also be received in a corresponding depression, as shown in Fig. 1 is shown as an example.

[0040] In the Fig. 1 In the state shown by way of example, in which the trigger unit 4 does not collapse but is mechanically intact, the trigger unit 4 kinematically couples the compression spring device 3 to the valve needle 2. In particular, the spring 30 is compressed by a preload path V, whereby the valve needle 2 is preloaded into the sealing position along the longitudinal axis L1. The extension or length I4 of the trigger unit 4 along the longitudinal axis L1 is greater than the preload path V of the spring 30. The collar 31B of the spring sleeve 31 facing the shoulder surface 18a is in the Fig. 1 shown state arranged at a distance from the shoulder surface 18a.

[0041] When a pressure inside 201 of the container 205 exceeds a certain limit value which is large enough to overcome the biasing force of the spring 30, the valve needle 2 is moved axially into the release position so that gas can flow out through the first opening 11 and the second opening 15 and, if necessary, through the side opening 215.

[0042] If the temperature reaches or exceeds the tripping temperature of the trip unit 4, the trip unit 4 collapses. This condition is shown schematically in Fig. 2 shown. By collapsing the trigger unit 4, the valve needle 2 is kinematically decoupled from the compression spring device 3, since the extension or length I4 of the trigger unit 4 along the longitudinal axis L1 is greater than the preload path V of the spring 30 and can be freely displaced axially in the guide bore 10. As in Fig. 2 As can also be seen, the collar 31B can be pressed against the shoulder surface 18a by the spring 30 when the trigger unit 4 has collapsed. The shoulder surface 18 thus forms a locking stop, which prevents the sleeve 31 from being moved further towards the valve needle 2. As in Fig. 2 As can also be seen, an outer diameter d2 of the valve needle 2 and an inner diameter d31 of the spring sleeve 31 or of the sleeve body 31C can be dimensioned such that the valve needle 2 can be at least partially inserted into the spring sleeve 31 when the trigger unit 4 has collapsed.

[0043] Fig. 2 shows purely by way of example that the valve needle 2 is locked in the release position by the optional locking device 5. This prevents the valve needle 2 from returning to the sealing position.

[0044] The optional locking device 5 is in Fig. 3 shown in detail. As in Fig. 3 As shown by way of example, the locking device 5 has a locking body 50, which can be designed as a ball, for example, and a spring 51. The locking body 50 is displaceably mounted in the locking recess 17 of the valve body 1. The spring 51, which can be implemented as a spiral spring, for example, is also received in the locking recess 17 and pretensions the locking body 50 in the direction of the guide bore 10 or in the direction of the longitudinal axis L1. For example, the spring 51 can be supported on a closure piece 52, which covers the locking recess 17 on the outer circumference of the valve body 1, as shown in Fig. 2 is shown schematically.

[0045] As in Fig. 1 As can be seen, the locking groove 25 of the valve needle 2 is positioned in a sealing position of the valve needle 2 between the locking recess 17 and the bottom 11 of the valve body 1 at a predetermined distance from the locking recess 17. When the valve needle 2 is retracted into the release position so that the sealing surface 2a is positioned at the predetermined distance from the bottom 11 of the guide bore 2, the locking groove 25 lies at the same level as the locking recess 17 with respect to the longitudinal axis L1, as shown in the Fign. 2 and 3 The spring 51 biases the locking body 50 into a locking position in which it projects into the guide bore 10 and engages in the locking groove 25, as shown in the Fign. 2 and 3 is shown.

[0046] In Fig. 4 By way of example, another safety valve 100 is shown, which is fixed in an opening 210 of a container 200. The Fig. 4 The safety valve 100 shown as an example differs from the one shown in the Fign. 1 bis 3 shown safety valve 100 only by the structure of the compression spring device 3 and the arrangement of the trigger unit 4.

[0047] As in Fig. 4 As shown by way of example, the compression spring device 3 can have a spring carrier 33 and the spring 30 can be designed as a disc spring 30B. The spring carrier 33 can be realized, for example, as a plate, wherein the disc spring 30B rests against a first surface 33a of the spring carrier 33. Optionally, the spring carrier 33 can have a recess 33C, which is formed on a second surface 33b of the spring carrier 33 opposite the first surface 33a, as shown in Fig. 4 is shown as an example.

[0048] As in Fig. 4 As shown by way of example, the disc spring 30B is supported on the second end 22 of the valve needle 2. The trigger unit 4, which can, for example, protrude into the recess 33C of the spring carrier 33, is supported on the spring carrier 33 and the closure cap 60 or another stop 6 arranged opposite to the bottom 11 of the guide bore 10 with respect to the longitudinal axis L1 and fixed relative to this.

[0049] In Fig. 4 the trigger unit 4 is mechanically intact and the valve needle 2 is arranged in its sealing position. The disc spring 30B is arranged at a distance from the shoulder surface 18a and preloads the valve needle 2 into the sealing position. If the trigger unit 4 has collapsed due to exceeding the trigger temperature, as shown in Fig. 5As shown schematically, the compression spring device 3 is kinematically decoupled from the valve needle. In this case, the compression spring device 3 can freely escape into the cavity of the valve body 1, which extends between the shoulder surface 18a and the closure cap 60. Thus, the valve needle 2 can be moved into the release position without having to work against the preload force of the spring 30.

[0050] Although the present invention has been explained above using exemplary embodiments, it is not limited thereto, but can be modified in a variety of ways. In particular, combinations of the above embodiments are also conceivable.

Claims

1. Safety valve (100), having: a valve body (1) with a guide bore (10) defining a longitudinal axis (L1), a first opening (13) formed at a bottom (11) of the guide bore (10), and a second opening (15) which is spaced apart from the bottom (11) along the longitudinal axis (L1) and extends along a radial direction (R1) extending transversely to the longitudinal axis (L1); a valve needle (2) axially displaceably mounted in the guide bore (10) of the valve body (1) with a sealing surface (2a) facing the first opening (13); a compression spring device (3) with a spring (30) which is compressed by a preloading path (V) and thereby preloads the valve needle (2) along the longitudinal axis (L1) into a sealing position, in which the sealing surface (2a) of the valve needle (2) seals the first opening (13); and a thermally activatable release unit (4), which has an extent (I4) along the longitudinal axis (L1) which is greater than the preloading path (V) and which is designed to collapse when a release temperature is reached, wherein the compression spring device (3) is supported against the release unit (4), characterized in that a locking device (5) with a locking body (50) which is mounted displaceably in a locking recess (17) of the valve body (1) extending in the radial direction (R1) and a spring (51) which preloads the locking body (50) in the radial direction (R1) towards the longitudinal axis (L1); wherein the second opening (15) of the valve body (1) is arranged with respect to the longitudinal axis (L1) between the locking recess (17) and the bottom (11); and wherein the valve needle (2) has a locking groove (25) which, in a sealing position of the valve needle (2), is positioned between the locking recess (17) and the bottom (11) of the valve body (1) at a predetermined distance from the locking recess (17), and wherein the locking body (50) engages in the locking groove (25) in a locking position, in which it protrudes into the guide bore (10) when the valve needle (2) is pulled back by the predetermined distance from the first opening (13).

2. Safety valve (100) according to Claim 1, wherein the locking body (50) is a ball.

3. Safety valve (100) according to either of the preceding claims, wherein the compression spring device (3) has a spring sleeve (31) with a bottom (31A) and a collar (31 B) positioned opposite the latter, and the spring (30) is in the form of a spiral spring (30A), which is supported on the collar (31 B) of the spring sleeve (31) and a stop (6) arranged in relation to the longitudinal axis (L1) opposite the bottom (11) of the guide bore (10) and in a fixed position relative to said bottom, and wherein the release unit (4) is supported at the bottom (31A) of the spring sleeve (31) and at an end (22) of the valve needle (2) positioned opposite the sealing surface (2a).

4. Safety valve (100) according to Claim 3, wherein the valve body (1) has a shoulder surface (18a), which surrounds an end of the guide bore (10) opposite the bottom (11) of the guide bore (11) in relation to the radial direction (R1), wherein the collar (31B) of the spring sleeve (31) is arranged facing the shoulder surface (18a) and spaced apart from the shoulder surface (18a), and wherein the collar (31B) is positioned against the shoulder surface (18a) by the spring (30) when the release unit (4) is collapsed.

5. Safety valve (100) according to Claim 3 or 4, wherein an outer diameter (d2) of the valve needle (2) and an inner diameter (d31) of the spring sleeve (31) are dimensioned such that the valve needle (2) can at least partially be inserted into the spring sleeve (31) when the release unit (4) is collapsed.