FR2720467A1 - Device allowing the rapid opening of a channel for gases under high pressure. - Google Patents

Abstract

The present invention relates to a device allowing the rapid opening of a channel for gases under high pressure, with a membrane designed as a rupture disc (1) arranged in an annular support between a high pressure chamber (11) and a chamber. at low pressure (9) of the channel, a mandrel designed in the form of a punching piston (4) to destroy the membrane (1) arranged opposite the latter in a housing in the high or low pressure chamber (11, 9) , and an acceleration device (6) for accelerating the punch piston (4) against the membrane (1), the outside diameter of this piston being only slightly less than the inside diameter of the annular support (2) and the acceleration device (6) preferably designed as a propellant charge being arranged so as to allow acceleration of the punch piston (4) such that the latter fully punches the membrane (1) along the inner periphery of the pport (2).

Description

The invention relates to a device for opening a channel for

backgrounds

  flow, preferably gases, under high pressure.

  To produce a very fast gas flow in a hypersonic aerodynamic test installation for example, it is necessary, under very precise and reproducible defined conditions, in a few milliseconds after a precise given instant, to open a passage

  by which a gas under high pressure, greater than 500 bar for example, can flow.

  This opening must be relatively large, of the order of 1 cm 2 for example.

  When using standard valves with a ball or cone shaped valve body which rests on a valve seat, due to the high pressure and the large cross-section, use a servo actuated electrically or pneumatically triggered by example. Such a servo drive is of complex construction and involves high costs and a large size. It is all the more complicated

  that the desired opening time is short.

  If, for piloting or as the gas to be handled, the combustion gases of solid propellants are used, for example, complete cleaning should be carried out after each test or after a small number of tests, since the combustion residues are deposited on surfaces exposed to gases. The more complex the valve, the more cleaning

is difficult.

  It is also known that, for the rapid opening of a channel for gases under high pressure, it is possible to use a gate valve (EP A O 513 673); high gas pressure

  again requires a servo drive because otherwise you need cylinders that are too large.

  In this case also, the cost and the volume of construction will be all the more

  great that the opening time will be short.

  A clearly less complicated solution consists in using a rupture disc which is damaged by the initiation of an explosive charge or pierced by means of a mandrel which is accelerated against it, then completely destroyed due to the stress exerted on this disc

  by the high pressure of the gas it traps.

  To damage such a rupture disc, a relatively weak force is sufficient, so that the servo drive can be dispensed with. The time interval during

  which the rupture disc is totally destroyed is also sufficiently short.

  As long as the thickness of the rupture disc is small compared to its diameter and as long as its rupture points are pre-notched, one can be sure that the disc breaks along the notches and that the remaining tongues curve on the sides under the action of pressure and remain linked to the part of the rupture disc fixed by tightening. For a rupture disc of this type to function properly, however, a notch depth is required

  very precise uniform and very precise tracing of the notches.

  However, for small diameter rupture discs, the necessary precision cannot be achieved with acceptable means. In addition, for pressures above 500 bar, the rupture discs in brass, the metal used because of the required seal, are relatively thick, so that in this case and despite the arrangement of the notches, the destruction of the disc failure is not sufficiently homogeneous and

  that the pressure build-up during opening is ultimately not reproducible.

  On the other hand, splinters and particles of the ruptured rupture disc are entrained in the gas flow and can give rise to damage or destruction of certain elements of the arranged test device which is located downstream. It should be noted that, since the flow rate obtained is relatively high, the kinetic energy of the particles entrained from the rupture disc is high even if their mass is relatively

  low. Special shields are therefore required for sensitive test facilities.

  The object of the present invention is to improve a device of this type provided with a rupture disc, with a view to obtaining better reproducibility of the profile of the pressure build-up during the opening of the rupture disc and of preventing the appearance of shards in

  the gas flow, or at least, to limit it strongly.

  On the other hand, the device according to the present invention must be easy to assemble and

to implement.

  This objective is achieved by a device allowing the rapid opening of a channel for high pressure flow media, with a membrane designed as a rupture disc arranged in an annular support between a high pressure chamber and a low chamber. pressure of the channel, a mandrel for destroying the membrane arranged opposite the latter in a housing in the high or low pressure chamber, and an acceleration device making it possible to accelerate the mandrel against the membrane, characterized in that the mandrel is designed as a punch piston whose outside diameter is only slightly smaller than the inside diameter of the annular support and that the acceleration device is arranged so as to allow acceleration of the punch piston

  that the latter fully punctures the membrane along the inner periphery of the support.

  Instead of a mandrel, which reaches the rupture disc designed as a membrane, damaging it and thus causing its irregular fragmentation into fragments, the invention provides for a punching piston, the circumference and consequently the outline of the 'punching edge, coincide with a slight undersizing, at the opening in the membrane support. The membrane, fixed to its support in a gas-tight manner, is therefore not punctually damaged as was the case until now, then then decomposed into fragments in a largely random fashion, but it is cut along a corresponding closed line. at the perimeter of its free section, the punched part of the membrane being

  kept as a heavy and coherent element.

  Unlike a punching process when cutting a sheet metal element subjected to any stress, which requires a large force, the membrane of the device according to the present invention is subjected along the contour of its support, because from the very high gas pressure exerted on it, to a prestress such that it suffices for the punch piston to exert a relatively weak impulse for the

membrane is cut.

  In this regard, the punch piston can be accelerated against the membrane as well

  by the high pressure side than by the low pressure side of said membrane.

  While using a mandrel as hitherto, it could even form small fragments capable of simply following the changes in direction of the gas flow, the coherent punched membrane portion of the device according to the invention forms a body so heavy that it is unable to follow significant changes in the direction of the gas flow. It is thus possible to provide, in the channel where the escaping gases are directed, a curvature comprising on its outer part a rebound surface intended to recover and retain the punched part of the membrane so

  to prevent it from being entrained with the gas flow.

  However, due to the high kinetic energy of the escaping gases, the guiding of the punching piston is not without problems, since it is

  likely to be driven by gas flow on an unpredictable path.

  In an alternative embodiment, the punching piston is movably arranged in a guide slide, preferably the trajectory of the piston is surrounded by a wall pierced with at least one opening for the outlet of the gases. The latter is arranged so close to the membrane that a solid bottom section of the cylindrical chamber is formed, which is large enough to receive at least the piston, or even if necessary, the device.

  acceleration expected for this one.

  When the punching piston has punched the membrane, it is then accelerated by the high pressure gas in the opposite direction to its initial movement and returned back into the aforementioned full-bottom chamber, the gas then flowing through the exhaust of the

  cylindrical chamber without further obstructing the punching piston.

  It is in principle possible, by suitable acceleration of the punching piston, to accelerate the punched part of the membrane strong enough for it to be projected inside the high pressure part in which the gas under high pressure is enclosed. , to a point where it can no longer be entrained by the escaping gas and o

  it can, if necessary, be recovered by means of a recovery device.

  However, so that the forces necessary for triggering the device remain however as low as possible, the punching piston is accelerated, in accordance with the invention, only to the extent necessary for obtaining reliable punching of the membrane. Preferably, the punched part of the membrane is then projected backwards with the punching piston which surmounts it, a housing with a solid bottom being designed so as to receive not only the punching piston and, where appropriate, its acceleration device, but also also the punched part of the membrane. The punching piston is introduced into the low pressure chamber so that it cannot be punched is introduced into the low pressure chamber so that it cannot get caught. As the punched part surmounts the front part of the punching piston, this prevents this part from getting stuck too, so that it is not only useless that the volume where the punched part of the membrane is housed is deeper than its thickness , but that we also avoid with certainty that the membrane does not get stuck during its

  movement and thus obstruct the gas flow.

  In the escaping gas, it is thus guaranteed to be able to establish a reproducible pressure with precision without being hampered by the fact that the membrane can, in certain

case, get stuck or hang.

  In principle, the high-pressure chamber also has a diameter which is at least, and preferably exactly equal to, the diameter adjacent to the membrane.

  interior of the low pressure cylindrical chamber.

  However, as in this case, during punching, the membrane initially undergoes slight penetration into the high pressure chamber of a value which depends on the rupture behavior of the membrane and which is therefore not reproducible with precision, and as the establishment of the pressure in the flow gas depends on said value, another version of the invention provides in the high pressure chamber a stop which limits the movement of the membrane inside the high chamber pressure at a value always constant, preferably essentially at the minimum value necessary for rupture

of the membrane.

  If the punch piston is to reliably punch the diaphragm, its impulse must be such that normally the punch piston and the punched part should fall into the high pressure chamber. A recovery device should be provided at this location, which should also be able to be handled. The adjustable stopper, preferably in its axial position, prevents penetration of the punched part of the membrane into the high pressure chamber, so that this part remains in the low pressure chamber, which must in any case be made accessible during operations. of discount

  in service of the device according to the present invention.

  Since a stopper arranged on the periphery would reduce the cross-section of the flow channel and since the piston which, as is known, drives on its front part the relatively flexible punched part of the membrane could become jammed, the stopper can be designed in the form of a central bolt with a circular space separating it from the wall

  high pressure chamber device.

  Since a stopper arranged on the periphery would reduce the cross-section of the flow channel, the stopper can be designed as a central bolt with space

  annular separating it from the peripheral wall of the high pressure chamber.

  To avoid buckling of the bolt, one can give a conical shape to its tip and the adjacent wall of the high pressure chamber can be widened so that one can optionally form a constant section or a narrowing section shaped

  nozzle up to the exit of the high pressure chamber blocked by the membrane.

  As described above, we form a solid bottom space which can

  receive the punched part of the membrane.

  But to avoid in all cases that the membrane is still entrained, as a result of a disturbance, by the escaping gas flow, it is possible to provide at least two gas outlet orifices in the cylindrical chamber, which respectively have a contour such that the punched part of the membrane cannot exit through one of the gas outlet orifices. In the event of a disturbance, the membrane cannot then be entrained with the gas, but it gets stuck in an outlet orifice. Even if this should be blocked, the other orifice or, if necessary, the other orifices ensure the evacuation of the gas from the chamber

low pressure.

  As an acceleration installation for the punch piston, one can for example use an electromagnetic device or a spring caliper device which has the advantage of being able to be reset by the punch piston returned, the punch piston engaging.

then in its rest position.

  Preferably, the particularly simple acceleration device propellant charge placed behind the bottom of the cylindrical chamber, which is crossed by a channel

powder gas.

  As a propellant charge, it is possible to use a commercial priming tablet which can be electrically primed with great temporal precision, that is to say within 0.1 s, and which produces only a mass of very weak gas which does not influence the setting

of the gas pressure profile.

  The chamber intended to receive the propellant charge has a channel leading towards the outside for the electrical ignition circuit; during the combustion of the propellant charge, the gas produced escapes towards the punch piston. If the latter is returned backwards, a layer of gas is formed behind the punching piston, towards the bottom of the chamber, the pressure of which is however low compared to that exerted on the front part of the punching piston, so that this gas layer is compressed to the point of not

  interfere with the recoil movement of the punch piston.

  If, however, the device according to the present invention were to be used to regulate the flow rate of a relatively low pressure flow medium, it would be advisable to eject the electric wires during the combustion of the propellant charge, so that the propellant charge chamber is open to the outside so that the gas layer can

  escape through the bores intended to receive the propellant charge.

  To allow simple fixing of the membrane, the cylindrical chamber is

  preferably arranged in a socket at the end of which the membrane can be fixed.

  The sleeve can in turn be fixed in a support, which receives the high pressure chamber and an adjustment element which surrounds the gas outlet coming from the high pressure chamber and against which the membrane bears. Provided that, for the membrane and the support or the part of the support which forms the sealing element, two different hard metals are used, the pressure exerted by the membrane against the sealing element is

certainly sufficient.

  To improve the sealing element, however, all known sealing means can be used, such as for example a flat ring between the membrane and the sealing element or an O-ring seal arranged in an annular groove in the membrane

or the sealing element.

  The edge of the membrane attached to the sleeve which remains after the punching can be removed from the support with the sleeve. In this context, it is advisable to provide the annular groove for the O-ring seal in the membrane, so that this seal can be removed and

  replaced at the same time as the membrane.

  The sleeve can be fixed in the support by a current clamping device, it should be noted for example that a knee clamping device has the advantage of handling

quick.

  Preferably, the external part of the sleeve is however provided with an external fixing thread which is screwed into a complementary internal thread provided in

the support.

  Using such a thread, it is possible without difficulty to obtain and, if necessary, adjust at will the essential pressing force between the membrane and the sealing element for

  produce the necessary seal.

  The membrane itself can for example be designed as a flat circular disc provided with tapped holes on its edges crossed by fixing screws, which make it possible to fix

  the membrane on the head of the socket.

  It is however particularly advantageous for the membrane to have the shape of a cup, in order to present an axial peripheral edge which surrounds and maintains the head of the sleeve. To accommodate this peripheral edge, a groove can be made in the front part of the sleeve; the membrane and the head of the sleeve are then crossed by a number

of radial fixing screws.

  According to a particularly practical and simple version, the periphery of the membrane has however an internal thread which is screwed into a thread

  complementary exterior of the membrane on the head of the socket.

  This internal thread is used not only to maintain the membrane, but also to ensure the seal between the membrane and the head of the socket. When the sleeve is fixed, the head of the sleeve is however preferably designed so as to come to bear against the radial part of the membrane oriented towards the sleeve; when the socket is tightened, it presses the membrane itself against the sealing element; the membrane thread is not stressed and can therefore be small, because it only has to provide the forces

  necessary to remove the rest of the membrane.

  In order to be able to remove the membrane without any problem at the same time as the sleeve, the external thread of the sleeve and the complementary internal thread of the support on the one hand, and the internal thread of the membrane and the external thread of complementary membrane of the socket head on the other hand, are in the opposite direction, so that when you unscrew the socket from the support, you cannot inadvertently unscrew the socket head

of the membrane.

  The external fixing thread is preferably in the form of usual right-hand thread and the internal membrane thread, in the form of left-hand thread: thus, to tighten the sleeve, a normal torque wrench can only be used for

tighten threads on the right.

  The aforementioned bolt forming the stop, which is placed inside the high pressure chamber and whose tip ends near the high pressure part of the membrane used, can be fixed by rivets in the support in order to ensure particularly simple attachment

and durable.

  According to another version of the invention, the bolt is however removable.

  It can thus not only be replaced by another bolt of different length or an unworn bolt but it is also possible, by removing the bolt, to remove the stopper from the

membrane, if that proves useful.

  In addition, the bolt can be adjustable in the longitudinal direction, so that the distance between the tip of the bolt and the membrane surface facing it can be adjusted,

and thus, optimized.

  It is also possible to extend this adjustment distance to such a point that the bolt becomes ineffective as a stop, so that it is then possible to push the

  punched part of the membrane inside the high pressure chamber.

  The bolt rod is designed in this case as a threaded rod passing through a wall of the support and which can be moved from the outside by means of a conventional handle.

  for adjusting or removing the bolt.

  In the assembly described so far, the space inside the support is designed as a high-pressure chamber and the cylindrical space inside the sleeve, as

low pressure chamber.

  But according to another version of the invention, it is also possible to swap the high pressure chamber and the low pressure chamber, so that the reservoir or the device for producing the gas under high pressure can be connected to the orifices of the

  socket described until now as outlet openings.

  In this case, it is advisable to remove the bolt acting as a stop in the procedure described above or to move it back from the diaphragm so that the diaphragm and, if necessary also the piston, can reach the chamber in the support. , described until now as a high-pressure chamber, since after the acceleration of the piston and the punching of the membrane, all the gas pressure weighs on

  the rear part of the piston opposite to the latter.

  But if a spring steel bolt is used, it is also possible, by choosing a suitable material and shape of a bolt, that this resiliently returns the diaphragm and the piston against the load of the gas pressure in the chamber cylindrical,

  towards the bottom thereof, the gas flow can then act freely.

  The object of the present invention is described still more precisely with the aid of the appended diagrams, which represent in FIG. 1 a longitudinal section of an experimental model, which has the device according to the invention, FIG. 2 is an enlarged longitudinal section through the socket of the device shown in FIG. 1, and in

  Fig. 3 a section along line 111-111 of FIG. 2.

  We will first examine fig. 2, which represents a socket 13 designed as a part

elongated tour.

  This sleeve 13 has a blind bore at each of its two ends.

  The blind bore starting from the end located on the right in the diagram has a larger diameter and penetrates even more inside the sleeve 13 than the blind bore starting from the left end. Between the two blind bores, there remains a crossed bottom

  by a gas inlet opening.

  The right blind bore forms a cylindrical space 9, designed as a low pressure chamber. This chamber 9 has, starting from its mouth at the end of the sleeve 13, a first section whose length roughly corresponds to its radius and whose wall

is closed.

  This section is followed by a second section, the axial length of which is almost equal to the diameter of the space 9 and the wall of which has 4 longitudinal holes 16 which

  pass through the wall of the sleeve 13 in the form of through orifices.

  These outlet orifices 16 appear with even more precision in FIG. 3.

  This section of the cylindrical space 9 limited by the orifices 16 is followed by a third section with a solid bottom, the axial length of which roughly corresponds to that of the openings 16 and therefore to the diameter of the cylindrical space 9. The section to solid bottom east

limited by a background.

  The blind bore which starts from the opposite end (on the diagram on the left) of the sleeve 13 firstly has a first section of large diameter followed by a second oblong section having an internal thread, which extends almost to the bottom of this blind bore. The two bottoms define a partition wall between the cylindrical space

and the blind bore.

  On the outer part of the sleeve 13, starting from the end in which the cylindrical space 9 opens, is shown an external left-hand thread 7 which extends in length (preferably 2 to 3 threads) over approximately two thirds of the axial length occupied by the first section of the cylindrical space 9. Starting from this external thread up to beyond the outlet orifices 1 6, the external diameter of the sleeve 1 3 increases and remains

  overall the same in the section through which the outlet orifices 16 pass.

  At the end of the longitudinal outlet holes 16 opposite the left-hand thread 7

  described, the outside diameter of the sleeve 1 3 increases and is provided with a right-hand thread 8.

  Right-hand thread 8 has a core diameter greater than all diameters

  outside of the socket 13 cited so far.

  At the left end in the drawing is a hex socket which allows the socket 13 to be tightened completely by means of a pipe wrench. Its length is planned so that

  allow the desired tightening force to be applied and the key to be suitably adapted.

  The reduced end mentioned last occupies approximately one fifth of the axial length of the sleeve, the right-hand thread 8 approximately two fifths of the axial length of the

socket 1 3.

  On the left-hand thread 7, a cup-shaped membrane 1 has been screwed in, which has a rupture wall, extending radially, forming a bottom of uniform parietal thickness, and on its edge, a rim extending axially. The inner surface of this ledge

  has a left-hand thread complementary to the left-hand thread 7.

  The axial edge of the diaphragm 1 is slightly shorter than the left-hand thread 7 of the sleeve 13 so that, when the diaphragm 1 is fully screwed onto the left-hand thread 7, its axial breaking wall is in contact with the free end of socket 1 3 in

  a fixing area in the form of a circle ring 5.

  In the cylindrical chamber 9, an axially sliding punch piston 4 has been placed, which rests on the bottom of said chamber 9 and whose front surface facing the membrane 1 is slightly recessed with respect to the adjacent axial edge of the orifices of

exit 1 6.

  In the threaded bore which leaves from the left end of the sleeve 13 is a priming disc 6, which is pressed against the bottom by a screwed confinement plug 20

  in the internal thread of the blind bore.

  The partition wall which forms the two bottoms is crossed by a channel intended

with propellants.

  The plug 20 has an internal bore which is traversed by a means of

  triggering, for example by a priming line.

  The surface of the rupture wall or of the membrane 1 opposite the sleeve 13 is designed as a flat radial surface and rests on a sealing surface of a support 10 which has a bore aligned with the cylindrical chamber 9 of the same diameter which is part

  a high pressure chamber 1 1.

  The edges of the bore in the support 10 are preferably rounded, as the

suggests the drawing.

  As can be seen in fig. 1, the sleeve 13 is screwed with the right-hand thread 8 in a threaded bore complementary to the support 10 so that the membrane 1 is pressed in leaktight manner against the sealing surface 3. The left-hand thread is thus relieved because the wall of rupture of the membrane 1 is clamped between the sealing surface 3 of the

  support 10 and the end of the sleeve 13 which rests on the inside of the membrane.

  In the case presented, the support 10 constitutes an experimental model used

  in the shock tube of a hypersonic aerodynamic test facility.

  The support or the model 10 has here an annular preliminary chamber 14 which

  surrounds the positioning bore of the sleeve 13 in the zone of the outlet orifices 16.

  This preliminary chamber 14 opens into a pilot nozzle 1 2.

  As still shown in fig. 1, the bore in the support 10 adjacent to the membrane 1 is followed by a high pressure chamber 11 of enlarged diameter in which

  opens a gas inlet, or in which a gas generator is installed.

  This generally cylindrical high pressure chamber 1 1 has a bottom crossed by a thread. In this thread is screwed the threaded rod of an adjusting bolt 15, the conical tip of which forms at the base a flange which protrudes from the rod, is rounded at the top and

  ends near membrane 1.

  The end of the threaded rod of the bolt 15 which is outside the support 10 or the high-pressure chamber 11 is provided with a socket intended to adapt a tightening wrench. The bore adjacent to the membrane 1 in the support 10 is rounded in the direction of the high-pressure chamber so as to form between the rounding and the surface of the conical tip of the bolt 15 a tight section in the form of a nozzle which s' then widens by

  again towards the membrane 1.

  In service, the high pressure chamber 11 is acted upon by a gas under a

  pressure which can exceed 500 bar.

  The inner section of the sealing surface 3, which coincides with the inner section of the cylindrical chamber 9 and of the bore adjacent to the membrane 1 in the support 10, measures approximately 1 cm2. The section of the punch piston 4 is slightly smaller. The punching piston 4 is moreover maintained in the position shown on the

  drawing by suitable means, such as by light tightening.

  When the priming pad 6 is primed, its propellant gases flow through the partition wall and accelerate against the membrane 1 the punch piston 4, which punctures the bottom of it circularly along the inner edge of the area

sealing 3.

  The distance between the membrane 1 and the top of the bolt 15 is then only calculated so as not to prevent the curvature of the membrane 1 which may appear 11 before the completion of the punching process and to allow the process of

  punching ends reliably.

  It has proven particularly useful to leave the top of the bolt flat and to blunt it only at the edges; with a bolt 15 designed in this way, the punched part of the membrane 1 remained largely undeformed and did not get stuck inside

  of the part of the membrane 1 remaining after the punching.

  Now, the punched part of the membrane 1 and the punching piston 4 which is placed thereon arrive in the rest position due to the stop against the bolt 15 and are then returned to the high pressure chamber 11 under the action of pressure until the piston 4 returns to its initial position and the punched part of the membrane rests on its punching surface. The surface of the punched part of the membrane 1 facing the high pressure chamber 11 is then exactly adjacent to the edges of the

outlet ports 1 6.

  So that the device presented can once again be ready for use, the sleeve 13 is entirely unscrewed from the support 10, the remaining annular part of the membrane 1 being necessarily removed at the same time, because because of its left-hand thread, when unscrewing the sleeve 13, it can only be tightened completely by means of the thread

  right 8, but cannot be loosened.

  From the disassembled sleeve 13, the containment plug 20 is removed, the punched part of the membrane and the annular residue of the membrane 1, the sleeve is cleaned if necessary and, after having introduced a new priming disc and a new membrane 1, it is screwed back into support 10 and is ready to be used in a new test.

  In principle, the device presented can also be used in the opposite direction, that is to say

  that is to say that the cylindrical chamber 9 used until now as a low-pressure chamber is stressed by a gas under high pressure; as a sealing surface, the installation is used between the free end of the sleeve 13 and the interior surface of the membrane 1,

  and the high pressure chamber 1 1 now constitutes the low pressure chamber.

  By means of a tool, the bolt 15 must however be spaced far enough from the membrane 1 to allow the punched part of the membrane 1 and the piston

  punch 4 to enter the chamber 1 1 at the end of the punching process.

  The whole opening process takes place in less than 10 ms and is

  reproducible with great precision.

Claims (14)

  1. Device allowing the rapid opening of a channel for high pressure flow media, with a membrane designed as a rupture disc arranged in an annular support between a high pressure chamber and a low pressure chamber of the channel, a mandrel for destroying the membrane arranged opposite the latter in a housing in the high or low pressure chamber, and an acceleration device making it possible to accelerate the mandrel against the membrane, characterized in that the mandrel is designed as a punching piston (4) whose outside diameter is only slightly smaller than the inside diameter of the annular support (2), and that the acceleration device (6) is arranged so as to allow an acceleration of the punching piston such that last fully punctures the membrane (2) along the inner periphery of the support (2).   2. Device according to claim 1, characterized in that the piston   punch (4) is movably disposed in a guide rail.   3. Device according to claim 1, characterized in that the low pressure chamber (9) is designed as an essentially cylindrical chamber, the wall close to the membrane (1) has at least one orifice for the passage of gases (16 ) and the part opposite the membrane (1) is closed by a bottom and is designed to receive the   punch piston (4) and possibly the acceleration device (6).   4. Device according to claim 3, characterized in that in the cylindrical chamber (9), between the edge opposite the membrane (1) of at least one of the gas passage orifices (16) and the edge punching the punch piston (4), when the latter is returned to the housing by the gas flow, a housing at the bottom   full to collect the punched part of the membrane (1).   5. Device according to claim 4, characterized in that, in the high pressure chamber (11) near the membrane (1), a stop (15) has been arranged which prevents the penetration of the punched part of the membrane (1) as well as, if applicable   if necessary, the punch piston (4) in the high pressure chamber (11).   6. Device according to claim 5, characterized in that the stop is designed as a central bolt (15) and that between its periphery and the gas outlet orifice of the high pressure chamber (11) closable by the membrane there is an annular space   likely to be crossed by gas flow.   7. Device according to one of claims 3 to 6, characterized in that at   at least two gas outlet orifices (16) are provided and the outline of each of these gas outlet orifices (16) is designed so as to prevent the passage of the part punched out of the membrane.   8. Device according to one of claims 2 to 7, characterized in that the   punching piston (4) is, in the rest position, at the end or near the end of the guide rail, preferably at the bottom or near the bottom of the cylindrical chamber (9) and preferably rests on the latter, that this bottom is crossed by at least one powder gas channel which opens into a chamber disposed behind the bottom intended for receive a propellant charge (6).   9. Device according to one of claims 2 to 8, characterized in that the   high pressure chamber (11) is housed in a support (10) which has a gas passage orifice with a sealing element (3) opposite to the high pressure chamber for the membrane (1), and that the slide guide or a sleeve (13) in which is housed the cylindrical chamber (9) supports at its end the membrane (1) and can be fixed in the support (10) so that the membrane (1) comes to press in a sealed manner against the sealing element (3).   10. Device according to claim 9, characterized in that the sleeve (13) has an external fixing thread (8) which, to fix said sleeve, can be screwed into   an additional internal thread executed in the support (10).   1 1. Device according to one of claims 9 or 10, characterized in that the   membrane (10) in the form of a bucket with an axial peripheral edge into which comes   fix an element on the front part of the sleeve (13) facing the membrane (1).   i12. Device according to claim 1 1, characterized in that at the inner part of the peripheral edge of the membrane (1) is an internal thread of   membrane which is screwed into an external thread complementary to the sleeve (13).   1 3 Device according to claims 8 and 1 1, characterized in that the thread   outside for fixing the sleeve (13) and the internal thread for the diaphragm (1) are in opposite directions.   14. Device according to one of claims 5 to 13, characterized in that the bolt (1 5) can be removed.   15. Device according to claim 14, characterized in that the position   axial of the bolt (15) is adjustable.   16. Device according to claim 15, characterized in that the bolt (15) has a threaded rod which passes through a thread made in the wall of the high pressure chamber (1 1) opposite the membrane (1), and qu '' by turning the threaded rod from the outside   with its point forming the stop, its distance to the membrane (1) can be adjusted.   17. Device according to one of claims 1 to 16, characterized in that the   high and low pressure chambers (11, 9) are interchangeable, so that the gas under   high pressure can be connected to the low pressure chamber (9).