Pneumatic actuator, pressure wave generator and method of operating the pressure wave generator

Abstract

A pneumatic actuator (4b) particularly for use in a pressure wave generator (1) a first piston surface (91) acting against a gaseous working medium in a first volume (41), the pressure in said first volume (41) causing an actuator force on said first piston surface (91) in a first direction; a second piston surface (92) acting against the working medium in the second volume (42), wherein the pressure in the second volume (42) generates an actuator force on the second piston surface (92) in a second direction opposite to the first direction; a throttle between said first volume (41) and said second volume (42), an inlet / outlet opening (45) of the first volume (41) for bringing the working medium into the first volume (41) and discharging the working medium from the first volume (41); wherein the first piston surface (91) is larger than the second piston surface (92). [Selected figure] Figure 3

Description

[Technical field]

[0001] The present invention relates to a pneumatic actuator, a device and a method for generating an explosion, in particular a high intensity pressure shock, according to the independent claims. In particular, the present invention relates to a pressure wave generator and a method for operating a pressure wave generator according to the preambles of the independent claims.

[0002] In pressure wave generators such as those described in WO 2007 / 028264 and especially WO 2010 / 025574, an auxiliary explosion and a main explosion are ignited in chambers separated from each other. The auxiliary explosion serves to release the closure of the main explosion chamber, either in a direct manner or via other latch / bar mechanisms, so that the subsequent main explosion does not act on the closure with sufficient force and therefore impairs or damages it. An explosion delay is therefore created between the auxiliary explosion and the main explosion. Such a delay can be created, for example, by a delay conduit through which the explosion is conducted from the auxiliary chamber to the main chamber, or by delayed ignition in both chambers via separate ignition devices present in the chambers.

[0003] The two aforementioned documents WO2007 / 028264 and WO2010 / 025574 are referred to with regard to the structure and design of the ignition and detonation delay as well as with regard to exemplary embodiments of the pressure wave generator and its method of functioning.

[0004] In particular, in the pressure wave generator of document WO2010 / 025574, the auxiliary and main explosion chambers are sealed from each other via a movable piston. The piston further closes the exhaust opening for the pressure wave generated in the main explosion chamber. The auxiliary and main explosion chambers of the pressure wave generator are filled with an explosive gas mixture, typically at overpressure, just before the ignition of the explosion. The gas explosion in the auxiliary and main explosion chambers generates very high pressures of up to 1000 bar and temperatures of up to 4000°C. Typically, the pressure is higher than 500 bar and the temperature is higher than 2000°C.

[0005] The opening should occur very quickly, on the one hand, to avoid the main explosion chamber being opened too early (otherwise the explosion energy would not be optimally utilized) and on the other hand, too late (which could destroy the device). For this reason, an actuator is needed that allows a rapid opening of the piston, but is able to cope with the prevailing conditions, operating frequencies and forces, such as those occurring with pressure wave generators.

[0006] It is therefore a possible object of the present invention to provide a pneumatic actuator suitable for use with a pressure wave generator and which at least partially meets these requirements.

[0007] Ignition in the main explosion chamber can be caused by a spark plug or an ignition conduit coming from the auxiliary explosion chamber. However, with the spark plug, there is the problem that it is heavily loaded by the explosion in the main explosion chamber and / or that it is not able to ignite certain gas-air mixtures at all, for example methane-air mixtures, at high pressure. In the case of the ignition conduit, there is the problem that under certain circumstances, especially in long ignition conduits, it can only be filled with combustible gases (e.g. methane, ethane, etc.) or oxidizers (e.g. oxygen, air, etc.), and therefore cannot lead to further explosion.

[0008] Another object of the invention is to provide a pressure wave generator of the type mentioned at the outset and a method for operating the same, which allows improved control of the detonation ignition in the main detonation chamber.

[0009] Another possible object is to provide a pressure wave generator of the above type which provides an improved seal between the auxiliary and main detonation chambers.

[0010] At least one of these objects is achieved by a pneumatic actuator, a pressure wave generator, or a method of operating a pneumatic actuator or a pressure wave generator as claimed.

[0011] According to a first aspect of the invention, there is provided a pneumatic actuator, in particular for use in a pressure wave generator according to the second aspect, comprising:

[0012] a first piston surface acting against a gaseous working medium in a first volume, the pressure in the first volume causing an actuator force on the first piston surface in a first direction;

[0013] a second piston surface acting against the working medium in the second volume, the pressure in the second volume causing an actuator force on the second piston surface in a second direction opposite the first direction.

[0014] ·Throttling between the first and second volumes

[0015] Inlet / outlet openings in the first volume for bringing the working medium into and discharging it from the first volume

[0016] · The first piston surface is larger than the second piston surface.

[0017] In an embodiment, the pneumatic actuator includes a final position damping, in particular by closing the inlet / outlet opening, so that the inlet / outlet opening is closed to the first volume.

[0018] In an embodiment, a piston closing element is arranged to close the inlet / outlet opening, so that the final position damping can be simply realised by elements of the piston itself.

[0019] In a method of operating a pneumatic actuator, the following steps are performed.

[0020] Filling the first volume with a pressurized gaseous working medium, in particular by means of a filling valve, e.g. a pressurized air valve.

[0021] Pressure compensation between a first volume and a second volume via a throttle, thereby moving an actuator in a first direction due to a surface area difference between the first piston face and the second piston face.

[0022] Discharging at least a portion of the working medium from the first volume, in particular by opening an inlet / outlet opening.

[0023] moving the actuator in the second direction with a more rapid pressure drop in the first volume than in the second volume;

[0024] Thus, with simple means (only a filling valve and an inlet / outlet opening) the back and forth movement of the actuator can be realized, which is on the one hand the result of the surface area difference between the piston surfaces and on the other hand the result of the throttling between the two volumes.

[0025] The inlet / outlet openings can be designed to be relatively large to create a rapid pressure drop within the first volume.

[0026] In an embodiment, the piston closing element is also arranged to separate the working medium filling conduit from the first volume, thereby making it possible to avoid high pressure shocks in the filling conduit.

[0027] In an embodiment, the two volumes are realised as part of a common working space of a cylinder in which a single piston is disposed and on which two piston surfaces are formed.

[0028] Here, the sealing of the piston to the (now common) cylinder is not important. A gap may exist between the piston and the cylinder. This has the function of a throttle between the two volumes. Pressure compensation is therefore carried out via this gap. This allows a further simplification of the design. The throttle in this embodiment is therefore formed by the gap between the cylinder and the piston. In this case, the usual sealing of the piston is not necessary.

[0029] In other embodiments, the two volumes and piston surfaces rest on separate pistons in separate cylinders, and the two separate pistons are mechanically coupled, and herein their motion is also coupled.

[0030] End of part pulled forward

[0031] In an embodiment, the first piston surface and the piston closing element are designed to close the inlet / outlet openings on the same piston, which allows for a particularly simple and reliable design.

[0032] In an embodiment, the pneumatic actuator comprises a cylinder discharge valve for rapidly discharging the working medium from the first volume by opening the inlet / outlet opening. The cylinder discharge valve comprises a piston surface which, when receiving the working medium, generates a force to close the cylinder discharge valve, and a valve surface which, when receiving the working medium, generates a force in the direction of opening the cylinder delivery valve, the valve surface being smaller than the piston surface, such that the two surfaces are subjected to the same pressure, thereby bringing the cylinder discharge valve into a closed position and holding it there.

[0033] In an embodiment, the pneumatic actuator includes an exhaust pilot valve for exhausting the working medium from the exhaust valve volume, which acts on the piston surface, thereby creating a brief, temporary imbalance of pressure on the two surfaces, which opens the cylinder exhaust valve.

[0034] In an embodiment, a working medium filling conduit is provided for filling the exhaust valve volume as well as the first volume with working medium at the same pressure, whereby, on the one hand, an identical pressure can be achieved in the two volumes, and, on the other hand, a temporary non-equilibrium can be realized by the filling conduit between the two volumes acting as a throttle.

[0035] The pressure in the working medium is, for example, 50 bar to 100 bar.

[0036] In an embodiment, the section of the working medium filling conduit through which the working medium is supplied to the first volume extends through the cylinder discharge valve, in particular through the shutoff body of the valve, for example, through a passage of the shutoff body that allows even a small throughflow through the valve in the combined position of the valve.

[0037] In an embodiment, the section of the working medium filled conduit through which the working medium is supplied to the first volume extends through the housing of the pressure wave generator.

[0038] In an embodiment, the linear guidance of the piston is formed by a piston surrounding the rear closure guide and being linearly movable along the rear closure guide in the direction of movement, and a hollow cylindrical piston connecting element surrounding a bearing element fastened to the rear closure guide and extending in the direction of movement away from the piston, whereby a second volume is formed between the piston, the inside of the piston connecting element, the bearing element and the rear closure guide. Typically, the rear closure guide is fixedly connected to the housing.

[0039] This allows the hollow cylindrical element to be driven as an extension of the hollow cylindrical piston connecting element, which is advantageous in certain applications, for example the case in the below described pressure wave generator with a hollow cylindrical closure element.

[0040] A pressure wave generator comprising a main explosion chamber, a closure element which in a closed position closes the main explosion chamber against the outlet and in an open position allows a flow of explosion gas from the main explosion chamber to the outlet, and ignition means for igniting an explosion in the main explosion chamber, the pressure wave generator in particular comprising a pneumatic actuator as described above, by means of which the closure element can be moved from the closed position to the open position, in particular also from the open position to the closed position, thereby achieving a pressure wave generator capable of repeatedly generating explosions and corresponding pressure waves.

[0041] In an embodiment, the pressure wave generator comprises a control designed to activate the opening movement of the closure element when the pressure in the main explosion chamber exceeds a predefined threshold. This allows the opening of the main explosion chamber to be automatically adapted to changes in conditions that affect the speed of explosion propagation. If the duration between ignition and the maximum explosion pressure is known, the opening of the main explosion chamber can also occur after a certain opening delay time. In this case, pressure measurements can be omitted. This application is provided for conditions in which the explosion propagates relatively slowly, and therefore the opening movement can start after ignition.

[0042] In an embodiment, the ignition means is an ignition means capable of constantly supplying energy, in particular a glow plug, so that the ignition of the explosion in the main explosion chamber is caused by this ignition means or glow plug, which leads to spontaneous ignition of the gas mixture depending on the pressure, temperature and composition of the gas mixture.

[0043] Thus, in an embodiment, the pressure wave generator comprises a control unit designed to actively ignite an explosion in the main explosion chamber or to detect a spontaneous ignition point, the control unit being further designed to actuate the opening movement of the closure element after completion of a settable ignition delay time after ignition.

[0044] In an embodiment, the pressure wave generator comprises a control unit designed to initiate an opening movement of the closure element and to ignite an explosion in the main explosion chamber after completion of a settable ignition delay time after the activation of the opening movement. In this application, it is envisaged for a condition in which the explosion propagates relatively quickly, so that the opening movement will already start before ignition. In this case, the ignition of the explosion in the main explosion chamber can be caused by an ignition plug.

[0045] In an embodiment, the ignition time, i.e. the time between ignition and reaching maximum pressure in the main detonation chamber, is in the range of 30 ms to 150 ms.

[0046] In an embodiment, the duration between actuation of the opening movement of the closure element, for example by actuating the exhaust solenoid valve, and maximum opening of the closure element is in the range of 20 ms to 60 ms.

[0047] The method of actuating a pressure wave generator having a primary detonation chamber occurs using a pneumatic actuator, the pneumatic actuator comprising:

[0048] a first piston surface acting against a gaseous working medium in a first volume, the pressure in the first volume causing an actuator force on the first piston surface in a first direction;

[0049] a second piston surface acting against the working medium in the second volume, the pressure in the second volume causing an actuator force on the second piston surface in a second direction opposite the first direction.

[0050] The method involves repeating the following steps:

[0051] a) filling the first volume with a gaseous working medium under pressure, in particular via a filling valve, for example a pressurized air valve;

[0052] b) a pressure compensation step between the first volume and the second volume via a restriction, whereby due to a difference in surface area between the first and second piston surfaces, the actuator is moved in a first direction, thereby moving the closure element in a closing direction and closing the main explosion chamber.

[0053] c) filling the main explosion chamber with an explosive mixture.

[0054] d) igniting an explosion in the main explosion chamber and expelling at least a portion of the working medium from the first volume, in particular by opening the inlet / outlet openings of the first volume.

[0055] e) moving the actuator in a second direction due to the more rapid pressure drop in the first volume than in the second volume, thereby moving the closure element in an opening direction to open the primary explosion chamber to the outlet and venting the explosion gas from the primary explosion chamber through the outlet.

[0056] Steps a), b) and c) can be performed simultaneously or overlapping in time. Step d) typically occurs after steps a), b) and c). With step d), the opening of the main explosion chamber, triggered by the opening of the inlet / outlet openings, directly couples to step e).

[0057] In an embodiment, ignition of the explosion in the main explosion chamber is performed prior to opening of the main explosion chamber, and in order to open the main explosion chamber, the pressure in the main explosion chamber is measured and the opening of the main explosion chamber is triggered as soon as the pressure exceeds a predefined threshold.

[0058] In an embodiment, ignition of the explosion in the primary explosion chamber is performed after the opening of the primary explosion chamber, where the opening of the primary explosion chamber is triggered first and the explosion in the primary explosion chamber is ignited after completion of a predetermined ignition delay time.

[0059] According to a second aspect of the invention, a pressure wave generator having the features of claim 22 is provided.

[0060] Thus, the pressure wave generator comprises a main explosion chamber and an auxiliary explosion chamber,

[0061] a closure element which in a closed position closes the main explosion chamber against the outlet and in an open position allows the flow of explosion gas from the main explosion chamber to the outlet

[0062] - an ignition conduit directing the explosion from the auxiliary explosion chamber to the main explosion chamber, the ignition conduit having an ignition conduit valve disposed therein

[0063] Includes.

[0064] The ignition conduit valve thus serves to block or open the conduit to the explosion from the auxiliary explosion chamber to the main explosion chamber.

[0065] This allows to control the time when the explosion in the main explosion chamber is initiated. In particular, this allows to delay the transmission of the explosion to the main explosion chamber. This allows the ignition conduit to be designed relatively short, which in turn eliminates the problem of a long ignition conduit being filled with only one gas and therefore not filled with an explosive mixture. Even with an ignition conduit of 10 cm length, this problem can lead to an explosion only after the trapped gas has exited the ignition conduit, rather than propagating through the ignition conduit first.

[0066] In an embodiment, the ignition conduit valve is an electrically actuated valve. An electrically operated valve may be actuated by an electromagnet (solenoid valve). The valve may be electrically actuated directly or indirectly via a pneumatic pilot valve.

[0067] This allows, within certain limits, a free choice of the time of the explosion in the main explosion chamber. The ignition conduit valve determines the time of the explosion and the ignition conduit provides the energy for transmitting the explosion and igniting in the main explosion chamber 2.

[0068] In an embodiment, the ignition conduit valve is mechanically actuatable by movement of a closure element. The ignition conduit valve is a mechanically operated valve. "Actuable" means that movement of the closure element causes the opening and / or closing of the ignition conduit valve. This allows for a simple means to cause a delay in ignition in the main explosion chamber.

[0069] Furthermore, it can be ensured that the opening of the ignition conduit valve is reliably coupled to the opening of the closure element, so that the main explosion can only be triggered when the closure element is already open. This is a safety-related aspect, since if there was no such positive dependence of the ignition in the main explosion chamber on the opening of the closure element, a control error could result in the main explosion being triggered without the closure element being opened. This in turn places very high demands on the pressure strength of the main explosion chamber.

[0070] In an embodiment, the element of the ignition duct valve is formed by part of the closing element or is fixedly connected to the closing element, which allows a mechanical realization of the ignition duct valve, which has few additional moving parts and is therefore less prone to malfunction.

[0071] In an embodiment, the closing element has an opening which acts as an ignition conduit or is part of the ignition conduit, which opening can be opened by moving the closing element from a closed position to an open position, which allows a particularly simple realization of the ignition conduit valve.

[0072] This opening or recess therefore also acts as part of the ignition conduit valve, in particular as a slider valve. The opening or recess can form a passage through the wall of the closure element between the main and auxiliary explosion chambers. Alternatively or additionally, a recess can be formed in the surface of the wall of the closure element, which recess forms a connection between the main and auxiliary explosion chambers when an opening movement of the closure element is provided.

[0073] In an embodiment, the closure element is brought from the closed position to the open position by the explosion in the auxiliary explosion chamber, which allows synchronization of the movement of the closure element with the explosion in the main explosion chamber by simple means, i.e. via an ignition conduit and an ignition conduit valve.

[0074] In an embodiment, the pressure wave generator comprises a spark generating ignition means, in particular a spark plug, for triggering the explosion of the auxiliary explosion chamber, and a second filling conduit for filling the auxiliary explosion chamber, which is not identical to the ignition conduit, so that the auxiliary explosion chamber can be filled without a direct connection to the main explosion chamber, which is present during filling, in particular while the ignition conduit valve is closed.

[0075] The spark generating ignition means is intermittently supplied with (electrical) energy, thereby generating a spark for inter alia igniting the gas mixture.

[0076] The spark generating ignition means is not energized during filling of the auxiliary detonation chamber, but only after filling, to activate the auxiliary detonation.

[0077] In particular, a method of operating a pressure wave generator with a primary and an auxiliary detonation chamber according to the second aspect of the invention may include carrying out the following steps:

[0078] Filling the main explosion chamber and the auxiliary explosion chamber with an explosive gas mixture, respectively.

[0079] Igniting the explosion in the auxiliary explosion chamber, in particular by means of a spark-generating ignition means

[0080] conducting an explosion from the auxiliary explosion chamber through an ignition conduit, the conducting step being blocked by an ignition conduit valve;

[0081] - opening the main explosion chamber to the outlet by opening the closure element

[0082] opening an ignition conduit valve, thereby directing the explosion to the primary explosion chamber and igniting the explosion in the primary explosion chamber;

[0083] Discharging the explosion gas from an outlet of the main explosion chamber.

[0084] In an embodiment, the pressure wave generator comprises an ignition means for igniting the explosion of the auxiliary explosion chamber, which can be energized at any time after filling, in particular a glow plug, with an ignition conduit arranged to fill the auxiliary explosion chamber from the main explosion chamber. By "always energized" it is meant that the ignition means is not only energized impulsively, as in a spark plug, but can be energized continuously, for example heated during a supply time of several seconds or minutes or more, so that it can be heated and kept at the operating temperature. For example the supply time or heating time may be at least 5 seconds or at least 10 seconds or at least 30 seconds or at least 1 minute.

[0085] The ignition means can be supplied with energy after the filling of the main explosion chamber, which allows high operating temperatures, typically above 800° C. or even up to about 1000° C. or 1300° C., while the ignition means is still in contact with the explosive mixture. Only on opening of the ignition conduit does the explosive gas mixture flow from the main explosion chamber through the ignition conduit into the auxiliary explosion chamber and is ignited on contact with the glow plug. In this case, the auxiliary explosion chamber can be designed relatively small. In particular, it can comprise only a short pipe section in which the glow element of the glow plug is arranged.

[0086] In another method for the operation of a pressure wave generator having a primary and an auxiliary detonation chamber according to a second aspect of the invention, the following steps may be carried out.

[0087] Filling the main explosion chamber with an explosive mixture.

[0088] - moving the closure element in the direction of opening

[0089] opening the ignition conduit valve, in particular by moving a closing element, thereby directing the explosive mixture from the main explosion chamber to the auxiliary explosion chamber, the auxiliary explosion chamber only comprising a space in which the heating element of the ignition means is arranged;

[0090] Igniting the explosion in the auxiliary explosion chamber, in particular by means of an ignition means which is constantly energized.

[0091] - Directing the explosion from the auxiliary explosion chamber through the ignition tube to the main explosion chamber

[0092] - moving the closure element further in the opening direction to open the main explosion chamber to the outlet by opening the closure element, and discharging the explosion gas from the main explosion chamber through the outlet.

[0093] In an embodiment, the closure element is brought from the closed position to the open position by its own actuator, in particular a pneumatic actuator, whereby independent actuation of the main explosion and of the opening movement of the closure element can be achieved.

[0094] This also allows for a relatively simple design of the sealing of the auxiliary explosion chamber, since the auxiliary explosion is only used to ignite the main explosion with high energy and not to drive the closure element.

[0095] What the above mentioned devices and methods have in common is that the explosion in the main explosion chamber can be initiated with such high energy that it immediately results in a rapid explosion or detonation in the main explosion chamber via an explosion in the auxiliary explosion chamber activated by a spark plug or glow plug via an ignition conduit. Ignition in the main explosion chamber by the spark plug initially leads to a slow explosion depending on the gas mixture.

[0096] This allows the use of relatively weakly explosive gas mixtures, such as fluid gases such as propane, which are safer to handle and subject to less stringent regulatory requirements than, for example, natural gas or ethane.

[0097] The pneumatic actuator according to the first aspect of the invention may be used with a pressure wave generator having only one primary explosion chamber, or with a pressure wave generator according to the second aspect, or with a primary explosion chamber and an auxiliary explosion chamber, or in other applications.

[0098] In an embodiment, the closure element is movable in the direction of movement and at least one plane is present, said plane being perpendicular to the direction of movement and intersecting the auxiliary and main explosion chambers, whereby a good seal can be achieved between the main and auxiliary explosion chambers, a compact structure of the device can also be achieved, and a closure element with a relatively small mass can also be achieved.

[0099] The above-mentioned arrangement of the primary explosion chamber relative to the auxiliary explosion chamber can also be realised in embodiments without an ignition conduit and even without an ignition conduit valve. According to a third aspect of the invention, there is provided a pressure wave generator having the following characteristics:

[0100] A pressure wave generator having a primary detonation chamber and an auxiliary detonation chamber,

[0101] a closure element which, in a closed position, closes the main explosion chamber against the outlet and, in an open position, allows the flow of explosion gases from the main explosion chamber to the outlet,

[0102] The closure element can be brought from the closed position to the open position by an explosion in the auxiliary explosion chamber.

[0103] The closure element is movable in a direction of movement and there is at least one plane, said plane being perpendicular to the direction of movement and intersecting the auxiliary and main explosion chambers.

[0104] In an embodiment, considered in this at least one plane, the auxiliary explosion chamber is separated from the main explosion chamber by a closure element, which allows a particularly simple design and good sealing between the two explosion chambers to be achieved. Furthermore, the arrangement of an ignition conduit through the closure element and the function of the closure element as part of a slider valve are possible here.

[0105] In an embodiment, the single connection by which the explosion can propagate from the auxiliary explosion chamber to the main explosion chamber runs through the gas spring, meaning that the gas or working medium of the gas spring stops the explosion from propagating.

[0106] There may be one or more primary explosion chambers separated from one another and one or more auxiliary explosion chambers separated from one another. A primary explosion chamber may be assigned to multiple auxiliary explosion chambers and vice versa, or a primary explosion chamber may be assigned to exactly one auxiliary explosion chamber.

[0107] In an embodiment, the primary and auxiliary detonation chambers are arranged concentrically with one another.

[0108] Here, the main and auxiliary explosion chambers can be designed to be annular or torus-shaped, in particular the main explosion chamber can surround the auxiliary explosion chamber, at least in the part extending in the direction of movement of the closure element.

[0109] The primary and auxiliary explosion chambers are arranged symmetrically with respect to the direction of movement.

[0110] In an embodiment, the primary and auxiliary detonation chambers are arranged rotationally symmetrically with respect to the direction of movement.

[0111] Here, the main and auxiliary explosion chambers can be present as a single chamber or as several chambers, at least within a sector considered along the circumference of the pressure wave generator.

[0112] Further preferred embodiments follow from the dependent claims, where features of the method claims can, where appropriate, be combined with features of the device claims and vice versa.

[0113] The subject matter of the present invention will now be described in detail by way of preferred embodiments illustrated in the accompanying drawings. [Brief description of the drawings]

[0114] [Figure 1] FIG. 1 shows a longitudinal section through a pressure wave generator. [Diagram 2]FIG. 2 shows a cross section through the pressure wave generator. [Diagram 3] FIG. 3 shows a longitudinal section through another embodiment. [Figure 4] FIG. 4 shows a section in longitudinal section of a further embodiment. [Diagram 5] Figure 5 shows a longitudinal section through a further embodiment, in which essentially identical parts are given the same reference numerals.

[0115] Detailed Description of the Invention

[0116] Figures 1 and 2 show a pressure wave generator 1 with a main explosion chamber 2 and an auxiliary explosion chamber 3. A closure element 9 is arranged which closes the main explosion chamber 2 against the outlet 15. The closure element 9 is driven by an explosion in the auxiliary explosion chamber 3 in order to open the main explosion chamber 2 against the outlet 15. A gas spring 4 is arranged to brake this opening movement of the closure element 9. The basic functioning of such a pressure wave generator 1 is explained in WO2007 / 028264 and WO2010 / 025574 cited at the beginning.

[0117] The closure element 9 is guided on a bearing element 14 that allows a linear opening and closing movement of the closure element 9. The closure element 9 surrounds the bearing element 14, which is hollow cylindrically shaped and fixedly connected to a housing 16. The direction of movement, represented by the double arrow, is typically equal to the longitudinal direction of the pressure wave generator 1 and also to the outflow direction, in which the explosion gases flow out of the outlet 15. Figure 1 shows the closure element 9 in the closed position, i.e. the main explosion chamber 2 is closed with respect to the outlet 15.

[0118] The outlet 15 serves for the directed exhaust or evacuation of the detonation gases, which can generate a pressure wave.

[0119] A first filling conduit 12 is arranged for filling the main detonation chamber 2 and a second filling conduit 13 is arranged for filling the auxiliary detonation chamber 3. The second filling conduit 13 is led to the auxiliary detonation chamber 3 through a bearing element 14. The two filling conduits may be fed in common through a fuel valve 10 or an oxidizer valve 11 as shown. Alternatively, each of the filling conduits and the detonation chamber may be fed by an individual fuel or oxidizer valve, and therefore each independently of the other filling conduit and detonation chamber.

[0120] The two explosion chambers can be filled separately from each other, for example here the combustion gas can be filled first at a relatively low pressure, for example 2 bar, and then the oxidizer, for example air, can be filled at a higher pressure, for example 20 bar.

[0121] An ignition plug 5 for igniting the auxiliary explosion chamber 3 is arranged in the bearing element 14. To this end, according to the embodiment of FIG. 1, the ignition plug 5 is arranged in the center of the area of ​​the axis of symmetry (typically in the direction of the longitudinal axis of the device) and can be connected to the auxiliary explosion chamber 3 through a connection opening 6.

[0122] An ignition conduit 8 is present to ignite the explosion in the main explosion chamber 2 with a delay relative to the explosion in the auxiliary explosion chamber 3. Two variations of the ignition conduit 8 are depicted in Figure 1, in a realization of the pressure wave generator 1 usually only one is present.

[0123] The ignition conduit 8 can be realized as an opening in the closing element 9, which is released when an opening movement of the closing element 9 is given. This can be caused by an interaction of the closing element 9 with another part of the pressure wave generator 1. Here, this is, as an example, the bearing element 14, which together with the closing element 9 forms a slider valve 71 as the ignition conduit valve 7, which is opened by the closing element 9 being moved along the bearing element 14.

[0124] The ignition conduit may be realised as a conduit 8' (shown in dashed lines) having an ignition conduit valve 7 arranged thereon. This may be a solenoid valve 72 or generally an electrically operated valve.

[0125] According to an embodiment not shown, the ignition line valve 7 is mechanically triggered on the opening movement of the closing element 9. For this purpose, a mechanical transmission device may be present, which may be adjustable so that the opening of the ignition line valve 7 takes place in different positions of the closing element 9 depending on the setting. Here, the opening of the ignition line valve 7 can be reliably coupled to the opening of the closing element 9, so that the main explosion is only triggered when the closing element 9 is already open.

[0126] The presence of the ignition conduit valve 7 makes it possible to control the point in time of transmission of the explosion from the auxiliary explosion chamber 3 to the main explosion chamber 2 .

[0127] FIG. 2 shows a concentric arrangement of a main explosion chamber 2 radially surrounding an auxiliary explosion chamber 3 and separated from it by a closure element 9, at least in a section extending in the direction of movement of the closure element 9.

[0128] The closure element 9 surrounds the bearing element 14 and the auxiliary explosion chamber 3 is formed between the closure element 9 and the bearing element 14. When the closure element 9 is displaced along the direction of movement, the volume of the auxiliary explosion chamber 3 changes. A volume of the gas spring 4, which also changes with this displacement, is formed between the closure element 9 and the housing 16. The gas spring 4 also acts as a block against the propagation of the explosion from the auxiliary explosion chamber 3 to the main explosion chamber 2.

[0129] 3 shows a pressure wave generator 1 according to another embodiment. The manner of functioning of the elements of the main explosion chamber 2, the closure element 9, the ignition conduit valve 7 or slider valve 71, the ignition conduit 8 and the outlet 15 is essentially the same as in the embodiment of FIG.

[0130] However, the auxiliary explosion chamber 3 is not arranged to drive the closure element 9, but only to generate an auxiliary explosion, the energy of which causes ignition of an explosion in the main explosion chamber 2 after the release of the slider valve 71 by the opening movement of the closure element 9.

[0131] The opening movement of the closure element 9 is produced by an active gas spring or pneumatic actuator 4b. It comprises a cylindrical working space 43 with a piston 93 which is moved inside, the movement of which is coupled to the movement of the closure element 9, in particular in the manner of a single piece, in particular by being fixedly connected to one another. In the embodiment of figures 3 and 5, the coupling is produced by a piston connecting element 94, which in figure 3 is a piston rod and in figure 5 is a hollow cylinder.

[0132] The piston 93 divides the working space 43 into a first volume 41 and a second volume 42. There is no seal between the inner cylinder wall 44 of the working space 43 and the piston 93. In particular, there may also be a small gap, referred to below as the piston gap 96. This allows gas exchange between the two volumes and acts here in particular as a throttle. In other embodiments, a separate conduit may be arranged between the first volume 41 and the second volume 42, which may be equipped with a throttle allowing gas exchange in addition to or instead of the piston gap 96. A throttle, such as the piston throttle 10, may also be realised by one or more bores through the piston 93, which likewise allow gas exchange between the two volumes.

[0133] The gas pressure of the working medium in the first volume 41 creates a force opposite to the direction of the opening movement of the closure element 9 , the effective surface area of ​​which is in this case the first piston surface 91 .

[0134] The gas pressure of the working medium in the second volume 42 generates a force in the direction of the opening movement of the closure element 9 , where the effective surface area is the second piston surface 92 .

[0135] Here, the second piston surface 92 is smaller than the first piston surface 91, for example at least 5 or 10 or 20 percent smaller.

[0136] The piston 93 is provided with a piston closing element 95 which in the course of the opening movement closes the cylinder inlet / outlet 45 or the inlet / outlet opening of the first volume 41. The cylinder inlet / outlet 45 is depicted here concentrically with respect to the working space 43, but can alternatively be arranged transversely.

[0137] The damping of the opening movement or final position damping occurs by closing the cylinder inlet / outlet. At the same time, the pressurized air valve 49 is also protected from pressure shocks via the pressurized air filling conduit 48.

[0138] The cylinder inlet / outlet 45 can be opened by means of a cylinder exhaust valve 46. The working medium flows, for example, through the exhaust or vent conduit 102. The cylinder exhaust valve 46 can have a relatively large valve cross section in comparison with the filling conduit. This allows a rapid pressure drop in the first volume 41 to be realized. The cylinder exhaust valve 46 is held closed by the pressure in the pressurized air filling conduit 48. This pressure can be reduced by opening the exhaust pilot valve 47. The opening movement of the closing element is thus triggered by the opening of the exhaust pilot valve.

[0139] The cylinder exhaust valve 46 is, in one embodiment, a seat valve with a movable shutoff body. The shutoff body has a piston surface 52 against which pressurized air from a pressurized air filled conduit 48 in the exhaust valve volume 51 impinges. The valve surface 53, which is subjected to pressure in the cylinder inlet / outlet 45, is smaller than the piston surface 52. The forces acting on the piston surface 52 and the valve surface 53 are opposite to each other. When the exhaust pilot valve 47 is closed, the gas pressure at the two surfaces is the same and the force on the piston surface 52 is greater than the force on the valve surface 53, which means that the shutoff body or cylinder exhaust valve 46 is held in the closed position.

[0140] The pressurized air charge conduit 48 also feeds the first volume 41 via section 101 of the pressurized air charge conduit 48. The pressurized air charge conduit 48 feeds through a pressurized air valve 49.

[0141] The ventilation conduit 97 provides pressure compensation between the ambient air and the intermediate cylinder, which is between the rear end of the closure element 9 and the active gas spring or pneumatic actuator 4b.

[0142] In a variant of the embodiment of FIG. 3, the working space 43 and the piston 93 are realised compactly. However, a similar function can also be realised by separate first and second volumes and separate pistons with different piston surface areas. Here, a conduit with a throttle is placed between the two volumes and the movements of the two pistons are mechanically coupled. This means that the linear movement of one of the two pistons always causes a linear movement of the other piston as well.

[0143] In the embodiment of Fig. 3 and other figures, the piston path may be, for example, 20 mm to 150 mm, in particular 30 mm to 80 mm, and the piston diameter may be, for example, 20 mm to 200 mm, in particular 40 mm to 120 mm.

[0144] 3 shows a pneumatic actuator 4b in combination with a pressure wave generator 1. However, the pneumatic actuator 4b can also be used for other applications. For this, the piston rod 94 can be coupled to another element or the movement of the piston rod can be coupled to the movement of another element.

[0145] Figure 4 shows details of a pressure wave generator 1 according to another embodiment, which is a variant of the embodiment of figure 3. The manner of functioning of the elements of the main explosion chamber 2, the closure element 9, the ignition conduit valve 7 or slider valve 71, the ignition conduit 8, the outlet 15 and the pneumatic actuator 4b is essentially identical to the embodiment of figure 3.

[0146] In this variant, the auxiliary explosion chamber 3 does not have a separate filling conduit 13. It is designed relatively small. Instead of the spark plug 5, it is equipped with a glow plug. During operation of the pressure wave generator 1, this can be supplied not only at the time of ignition, but in a constant manner, i.e. permanently or for a longer period, for example for several seconds or minutes. This allows to have a high temperature, which again introduces sufficient energy into the gas mixture, in order to cause a rapidly propagating explosion or detonation in the main explosion chamber 2. Depending on the gas mixture and pressure, this is not possible with a spark plug, which only initially activates the combustion, which leads to an explosion only after a certain time (for example 30 - 50 ms). Ignition in the main explosion chamber 2 occurs by supplying energy to the glow plug after the filling of the main explosion chamber 2, bringing the glow plug to its operating temperature. This lasts for several seconds, for example 5 or 10 seconds. When the opening movement of the closing element 9 causes the slider valve 71 to release the ignition conduit 8, the explosive gas mixture flows from the main explosion chamber 2 into the auxiliary explosion chamber 3 and comes into contact with the heated glow plug. This causes an explosion in the auxiliary explosion chamber 3 via the ignition conduit 8, and also in the main explosion chamber 2. The opening movement of the closing element 9 is caused by the pneumatic actuator 4b, as already mentioned above.

[0147] In operation of this variant, the following method steps can be performed:

[0148] If the exhaust pilot valve 47 is closed, the pressurized air valve 49 opens. This has the following effect: The pressure in the pressurized air charging conduit 48 (e.g. 70 bar) closes the cylinder exhaust valve 46. The first volume 41 is exposed to pressurized air through the pressurized air charging conduit 48 or is impinged by it. The second volume 42 is also exposed through the piston gap 96 and over time the same pressure is present in both volumes. As the first piston surface 91 is larger than the second piston surface 92, the piston 93 and thus the closing element 9 is moved to the closing position (opposite to the direction of the opening movement).

[0149] The pressurized air valve 49 is closed. The closing element 9 remains in the closed position.

[0150] · The fuel valve 10 and the oxidizer valve 11 are opened, thereby filling the main explosion chamber 2 and, in some embodiments, the auxiliary explosion chamber 3. Here, first the fuel valve 10 is opened and the oxidizer valve 11 is closed, and a controlled amount of fuel can be introduced at a first pressure. Then, given a closed fuel valve 10, the oxidizer valve 11 can be opened and an amount of oxidizer can be introduced up to a higher second pressure. The ratio of the amounts of oxidizer and fuel can be adjusted by the ratio of the first and second pressures. It is generally selected as a stoichiometric ratio depending on the chemical reaction during combustion or explosion. For example, propane can be used as fuel and air can be used as oxidizer, with a volume ratio or pressure ratio of 1:15 to 1:24.

[0151] One of the following two method variations (details below):

[0152] Triggering the spark plug 5 and then the opening movement, and then opening the ignition conduit valve 7, triggering an explosion in the main explosion chamber 2, thereby triggering an auxiliary explosion in the auxiliary explosion chamber 3.

[0153] or: triggering an opening movement, which subsequently causes an explosion in the main explosion chamber 2 by the gas mixture reaching the glow plug through the ignition conduit valve 7.

[0154] In both cases, the triggering of the opening movement is caused by opening the cylinder exhaust valve 46, in particular by opening the exhaust pilot valve 47 and reducing the pressure in the pressurized air filling conduit 48. The pressure in the first volume 41 is reduced by opening the cylinder exhaust valve 46. The pressure in the second volume 42 is reduced as well, but more slowly than in the first volume 41, due to the throttling effect of the piston gap 96. This results in a greater force on the second piston surface 82 than on the first piston surface 91. This causes a movement of the piston 93 and thus an opening movement of the closing element 9.

[0155] Before the piston 93 or the closing element 9 stops, the piston closing element 95 closes the cylinder inlet / outlet 45. The air remaining in the first volume 41 is compressed and brakes the movement of the piston 93 and the closing element 9. The pressurized air valve 49 prevents it from being loaded by pressure peaks.

[0156] The explosion gases escape through the opening released by the closing element 9.

[0157] The cylinder exhaust valve 46 is closed, in particular by closing the exhaust pilot valve 47. This can be caused by a piston surface, through which the pressurized air in the pressurized air filled conduit 48 presses the cylinder exhaust valve 46 or its shutoff body into the closed position, which surface is larger than the surface against which the pressurized air acts against the cylinder exhaust valve 46 or its shutoff body. After closing of the cylinder shutoff valve 46, the pressure in the first volume 41 is still sufficiently high (e.g. 20 bar) to retract the piston 93 after pressure compensation with the second volume 42 and thus bring the closing element 9 into the closed position.

[0158] The method can then start again with the opening of the pressurized air valve 49.

[0159] A variant of the method described above is a variant of a device having a spark plug or glow plug. The differences are as follows:

[0160] In the variant with a spark plug, ignition in the auxiliary explosion chamber 3 occurs before the opening movement is initiated, for example 50 ms before. At this point, an explosion with sufficient energy has occurred in the auxiliary explosion chamber 3, thereby causing the required rapid explosion in the main explosion chamber 2 in the course of opening the ignition conduit valve 7 or the slider valve 71 with the opening movement.

[0161] In the variant with a glow plug, if the gas mixture flows to the glow plug when the ignition conduit valve 7 or the slider valve 71 is opened, this can already provide enough energy for a rapid explosion in the main explosion chamber 2.

[0162] In both variants, thanks to the introduced ignition energy, it lasts only until the explosion propagates in the main explosion chamber 2 (for example about 2 ms). While the opening movement is already taking place, an explosion pressure is building up in the main explosion chamber 2. The maximum energy of the gas flow occurs at the outlet 15 when the explosion pressure is at a maximum at the time when the opening of the closure element 9 between the main explosion chamber 2 and the outlet 15 is also at a maximum.

[0163] In other embodiments, an ignition plug 5 or glow plug 5b is arranged to ignite the gas mixture or to cause an explosion in the main explosion chamber 2. These embodiments in particular lack the auxiliary explosion chamber 3 and the ignition conduit 82. The ignition of the explosion in the main explosion chamber 2 is synchronized by the control unit 20 with the movement of the closure element 9 in the opening direction. Here, depending on the speed at which the explosion propagates in the main explosion chamber 2 and the pressure in the main explosion chamber 2 rises, the movement of the closure element 9 can take place before or after the ignition in the main explosion chamber 2.

[0164] For example, the explosion in the main explosion chamber 2 may propagate relatively slowly. Opening under some circumstances may not occur until after ignition. In particular, the following exemplary steps are repeated herein to operate a pressure wave generator (1) having a main explosion chamber (2):

[0165] Filling the main explosion chamber (2) with an explosive mixture

[0166] Igniting an explosion in the main explosion chamber (2).

[0167] measuring the pressure in the main explosion chamber (2) and actuating the opening of the main explosion chamber (2) as soon as the pressure exceeds a predefined threshold, in particular by means of a pneumatic actuator, in particular a pneumatic actuator (4b) as described herein;

[0168] moving the closure element (9) by the pneumatic actuator (4b) in an opening direction for opening the main explosion chamber (2) relative to the outlet (15) and discharging the explosion gas from the main explosion chamber (2) through the outlet (15);

[0169] - closing the main explosion chamber (2) by displacing the closing element (9) in the closing direction by means of the pneumatic actuator (4b)

[0170] Alternatively, if the explosion propagates relatively quickly in the main explosion chamber 2, under certain circumstances the opening can already be triggered before ignition. In detail, in this document, to operate a pressure wave generator (1) having a main explosion chamber (2), the following exemplary steps are repeatedly performed:

[0171] Filling the main explosion chamber (2) with an explosive mixture

[0172] moving the closure element (9) in the opening direction, in particular by a pneumatic actuator, in particular a pneumatic actuator (4b) as described herein;

[0173] igniting an explosion in the main explosion chamber (2) after completion of a predetermined ignition delay time.

[0174] - moving the closure element (9) further in the opening direction to open the main explosion chamber (2) to the outlet (15) and to vent the explosion gases from the main explosion chamber (2) through the outlet (15);

[0175] Closing the main explosion chamber (2) by moving the closing element (9) in the closing direction by means of the pneumatic actuator (4b).

[0176] Whether the explosion propagates relatively slowly or rapidly depends, inter alia, on the applied explosive (gas) mixture, its pressure and temperature, and the applied ignition means glow (plug or spark plug), etc.

[0177] When using the pneumatic actuator 4b, as described above, movement of the closure element in the opening direction is caused by movement of the pneumatic actuator in the second direction, and movement of the closure element in the closing direction is caused by movement of the pneumatic actuator in the first direction.

[0178] Figure 5 shows an embodiment having only one main detonation chamber 2 and therefore no auxiliary detonation chamber 3 and no ignition conduit 8. Figure 5 also shows an alternative pneumatic actuator 4b which differs from the one in Figure 3. Either the complete pneumatic actuator shown in Figure 5 or, for example, only individual elements are shown.

[0179] Piston Throttle 100, and / or

[0180] a closure element 9 having a hollow cylinder instead of a piston rod as the piston connecting element 94, and / or

[0181] The cylinder exhaust valve 46 with the section 101 of the pressurized air filled conduit can be combined with a pressure wave generator 1 with an auxiliary explosion chamber 3, for example as shown in FIG.

[0182] The method of operation is essentially the same as that of the embodiment of FIG. 3, with the following differences in the implementation of the individual elements.

[0183] The piston connecting element 94, which connects the piston 93 to the closure element 9, is formed by a hollow cylinder. The piston 93 can be designed as a general cylinder, in particular a circular cylinder, along which it surrounds a rear closure guide 98 which is linearly movable in the direction of movement. The piston connecting element 94 surrounds the bearing element 14 which is fixedly connected to the housing 16. The second volume 42 is between the rear closure guide and the piston 93 and the inside of the hollow cylinder or piston connecting element 94.

[0184] The throttling between the first volume 41 and the second volume 42 is realised as a piston throttling 100 by means of one or more bores passing through the piston 93. However, additionally or alternatively, the function of the piston throttle can also be taken over by the gap between the piston 93 and the rear closure guide 98.

[0185] The section 101 of the pressurized air-filled conduit 48, through which the first volume 41 is supplied with working medium, does not pass through the housing 16 but through a blocking body of the cylinder exhaust valve 46, for example as a bore, which can also be called a piston throttle of the cylinder exhaust valve 46. The first volume 41 is therefore supplied with working medium via the exhaust valve volume 51.

[0186] 5, it is possible to dispense with end-position damping. If end-position damping is realised in the embodiment of Fig. 5, this can be effected by a protruding closure element 95 moving into the cylinder inlet / outlet 45, as in Fig. 3, or by closure by a piston 93 sliding over the cylinder inlet / outlet 45, which is guided laterally into the first volume 41 and given an opening movement.

Claims

1. A pneumatic actuator (4b) for implementing a first method of operating the pneumatic actuator (4b), comprising: The pneumatic actuator (4b) a first piston surface (91) acting against a gaseous working medium in a first volume (41), the pressure in said first volume (41) causing an actuator force on said first piston surface (91) in a first direction; a second piston surface (92) acting against the gaseous working medium in a second volume (42), wherein pressure in the second volume (42) produces an actuator force on the second piston surface (92) in a second direction opposite to the first direction; Equipped with The first method comprises: - filling said first volume (41) with a gaseous working medium under pressure by means of a filling valve; - pressure compensation between the first volume (41) and the second volume (42) via a throttle, thereby moving the pneumatic actuator in the first direction due to a surface area difference between the first piston surface (91) and the second piston surface (92); - discharging at least a portion of said gaseous working medium from said first volume (41); - moving the pneumatic actuator in the second direction by a more rapid pressure drop in the first volume (41) than in the second volume (42); Including, The step of filling the first volume (41) with a gaseous working medium under pressure is performed by a filling valve, The pneumatic actuator (4b) a throttle between the first volume (41) and the second volume (42); an inlet / outlet opening (45) of the first volume (41) for introducing the gaseous working medium into the first volume (41) and discharging the gaseous working medium from the first volume (41); Equipped with the first piston surface (91) is larger than the second piston surface (92); The filling valve is a pneumatic actuator (4b) arranged to fill the first volume (41).

2. 2. The pneumatic actuator (4b) according to claim 1, wherein a piston closing element (95) is arranged to close said inlet / outlet opening (45).

3. 3. Pneumatic actuator (4b) according to claim 2, wherein the piston closing element (95) is also arranged to separate a gaseous working medium filled conduit (48:101) for the first volume (41).

4. 2. The pneumatic actuator (4b) of claim 1, wherein the first piston surface (91) and the second piston surface (92) are formed on the same piston (93).

5. 2. The pneumatic actuator (4b) of claim 1, wherein the first piston surface (91) and the second piston surface (92) are formed on separate pistons (93) and their motions are mechanically coupled to each other.

6. 2. The pneumatic actuator (4b) according to claim 1, wherein the first piston surface (91) and a piston closing element (95) for closing the inlet / outlet opening (45) are formed on the same piston (93).

7. a cylinder exhaust valve (46) for rapidly exhausting the gaseous working medium from the first volume (41) by opening the inlet / outlet openings, the cylinder exhaust valve (46) comprising: a piston surface (52) that, when exposed to the gaseous working medium, generates a force to close the cylinder exhaust valve (46); a valve surface (53) that exerts a force in an opening direction of the cylinder exhaust valve (46) when exposed to the gaseous working medium, the valve surface (53) being smaller than the piston surface (52); The pneumatic actuator (4b) according to claim 1, comprising:

8. 8. The pneumatic actuator (4b) according to claim 7, comprising a discharge pilot valve (47) for discharging the gaseous working medium from a discharge valve volume (51) where the gaseous working medium acts on the piston surface (52).

9. 9. The pneumatic actuator (4b) according to claim 8, wherein a gaseous working medium filling conduit (48) is arranged for filling the exhaust valve volume (51) and the first volume (41) with gaseous working medium at the same pressure.

10. 10. The pneumatic actuator (4b) of claim 9, wherein a section (101) of the gaseous working medium filled conduit (48) through which the first volume (41) is supplied with gaseous working medium extends through the cylinder exhaust valve (46).

11. 7. The pneumatic actuator (4b) according to claim 6, wherein the linear guidance of the piston (93) is such that the piston (93) surrounds a rear closure guide (98) along which it is linearly movable in a direction of movement, and a hollow cylindrical piston connection element (94) extending in a direction of movement away from the piston (93) surrounds a bearing element (14) fastened to the rear closure guide (98), and the second volume (42) is formed between the piston (93), the inside of the piston connection element (94), the bearing element (14) and the rear closure guide (98).

12. A second method of actuating a pressure wave generator (1) with a main explosion chamber (2) using a pneumatic actuator (4b) according to claim 1, The pneumatic actuator (4b) a first piston surface (91) acting against a gaseous working medium in a first volume (41), the pressure in said first volume (41) causing an actuator force on said first piston surface (91) in a first direction; a second piston surface (92) acting against the gaseous working medium in a second volume (42), such that pressure in the second volume (42) produces an actuator force on the second piston surface (92) in a second direction opposite to the first direction; Equipped with The second method comprises: - filling the first volume (41) with a gaseous working medium under pressure by means of a filling valve; a pressure compensation step between the first volume (41) and the second volume (42) via a throttle, which, due to the surface area difference between the first piston surface (91) and the second piston surface (92), causes the pneumatic actuator to move in the first direction, thereby causing a closure element (9) to move in a closing direction and close the main explosion chamber (2); - filling the main explosion chamber (2) with an explosive mixture; - igniting an explosion in the main explosion chamber (2) and expelling at least a portion of the gaseous working medium from the first volume (41) by opening the inlet / outlet openings of the first volume (41), thereby opening the main explosion chamber (2); - a more rapid pressure drop in the first volume (41) than in the second volume (42) causes the pneumatic actuator to move in the second direction, thereby moving a closure element in the opening direction to open the main explosion chamber (2) to an outlet (15) and expelling the explosion gases from the main explosion chamber (2) through the outlet (15); Repeatedly execute The pressure wave generator (1) comprises: A main explosion chamber (2); a closure element (9) which in a closed position closes the main explosion chamber (2) against the outlet and in an open position allows the flow of explosion gas from the main explosion chamber (2) to the outlet; an ignition means for igniting an explosion in said main explosion chamber (2); A pneumatic actuator (4b) according to claim 1; having The closure element (9) can be moved from the closed position to the open position, in particular also from the open position to the closed position, by the pneumatic actuator (4b).

13. 13. The pressure wave generator (1) according to claim 12, comprising a control (20) designed to activate an opening movement of the closure element (9) when the pressure in the main explosion chamber (2) exceeds a predefined threshold.

14. 14. The pressure wave generator (1) according to claim 13, wherein the ignition means is an ignition means capable of being constantly supplied with energy.

15. 13. The pressure wave generator (1) according to claim 12, comprising a control (20) designed to actuate an opening movement of the closure element (9) and to ignite an explosion in the main explosion chamber (2) after completion of a settable ignition delay time after actuation of the opening movement.

16. 16. The pressure wave generator (1) according to claim 15, wherein the ignition means is a spark generating ignition means.

17. A method for operating a pneumatic actuator (4b), comprising: The pneumatic actuator (4b) a first piston surface (91) acting against a gaseous working medium in a first volume (41), the pressure in said first volume (41) causing an actuator force on said first piston surface (91) in a first direction; a second piston surface (92) acting against the gaseous working medium in a second volume (42), wherein pressure in the second volume (42) produces an actuator force on the second piston surface (92) in a second direction opposite to the first direction; Equipped with The method comprises: - filling said first volume (41) with a gaseous working medium under pressure; - pressure compensation between the first volume (41) and the second volume (42) via a throttle, thereby moving the pneumatic actuator in the first direction due to a surface area difference between the first piston surface (91) and the second piston surface (92); - discharging at least a portion of said gaseous working medium from said first volume (41); - moving the pneumatic actuator in the second direction by a more rapid pressure drop in the first volume (41) than in the second volume (42); Including, A method, wherein the step of filling the first volume (41) with gaseous working medium under pressure is performed by a filling valve.

18. A method for actuating a pressure wave generator (1) with a main explosion chamber (2) using a pneumatic actuator (4b), comprising: The pneumatic actuator (4b) a first piston surface (91) acting against a gaseous working medium in a first volume (41), the pressure in said first volume (41) causing an actuator force on said first piston surface (91) in a first direction; a second piston surface (92) acting against the gaseous working medium in a second volume (42), such that pressure in the second volume (42) produces an actuator force on the second piston surface (92) in a second direction opposite to the first direction; Equipped with The method comprises: - filling the first volume (41) with a gaseous working medium under pressure; a pressure compensation step between the first volume (41) and the second volume (42) via a throttle, which, due to the surface area difference between the first piston surface (91) and the second piston surface (92), causes the pneumatic actuator to move in the first direction, thereby causing a closure element (9) to move in a closing direction and close the main explosion chamber (2); - filling the main explosion chamber (2) with an explosive mixture; - igniting an explosion in said main explosion chamber (2) and expelling at least a portion of said gaseous working medium from said first volume (41), thereby opening said main explosion chamber (2); - a more rapid pressure drop in the first volume (41) than in the second volume (42) causes the pneumatic actuator to move in the second direction, thereby moving a closure element in the opening direction to open the main explosion chamber (2) to an outlet (15) and expelling the explosion gases from the main explosion chamber (2) through the outlet (15); Repeatedly execute A method, wherein the step of filling the first volume (41) with gaseous working medium under pressure is performed by a filling valve.

19. 19. The method according to claim 18, wherein ignition of the explosion in the main explosion chamber (2) is performed before opening of the main explosion chamber, and in order to open the main explosion chamber, the pressure in the main explosion chamber (2) is measured and the opening of the main explosion chamber (2) is activated as soon as the pressure exceeds a predetermined threshold.

20. 19. The method according to claim 18, wherein the ignition of the explosion in the main explosion chamber (2) is performed after the opening of the main explosion chamber, wherein the opening of the main explosion chamber (2) is actuated first and the explosion in the main explosion chamber is ignited after completion of a predetermined ignition delay time.

21. 13. The pressure wave generator (1) according to claim 12, further comprising an auxiliary explosion chamber (3) and an ignition conduit (8) for directing the explosion from said auxiliary explosion chamber (3) to the main explosion chamber (2), characterized in that an ignition conduit valve (7) is arranged in the ignition conduit (8).

22. 22. The pressure wave generator (1) according to claim 21, wherein the ignition conduit valve (7) is an electrically operated valve.

23. 22. The pressure wave generator (1) according to claim 21, wherein the ignition conduit valve (7) is mechanically actuatable by movement of the closing element (9).

24. 22. The pressure wave generator (1) according to claim 21, wherein the element of the ignition conduit valve (7) is formed by part of the closure element (9) or is fixedly connected to the closure element (9).

25. 25. The pressure wave generator (1) according to claim 24, wherein the closing element (9) comprises an opening or recess acting as or being part of an ignition conduit (8), the opening being releasable by movement of the closing element (9) from the closed position to the open position.

26. 22. The pressure wave generator (1) according to claim 21, wherein the closure element (9) can be moved from the closed position to the open position by an explosion in the auxiliary explosion chamber (3).

27. 27. The pressure wave generator (1) according to claim 26, comprising spark generating ignition means for activating an explosion in the auxiliary explosion chamber (3) and a second filling conduit (13) for filling the auxiliary explosion chamber (3), said second filling conduit (13) being not identical to the ignition conduit (8).

28. 27. The pressure wave generator (1) according to claim 26, comprising ignition means capable of permanently supplying energy to cause an explosion in said auxiliary explosion chamber (3), said ignition conduit (8) being arranged to fill said auxiliary explosion chamber (3) from said main explosion chamber (2).

29. The pressure wave generator (1) according to claim 21, wherein the closure element (9) can be moved from the closed position to the open position by its own actuator.

30. A method for operating a pressure wave generator (1) according to claim 21, comprising a main explosion chamber (2) and an auxiliary explosion chamber (3), comprising: - filling each of the main explosion chamber (2) and the auxiliary explosion chamber (3) with an explosive mixture; - igniting an explosion in said auxiliary explosion chamber (3); - directing said explosion from said auxiliary explosion chamber (3) through an ignition conduit (8), said directing step being interrupted by an ignition conduit valve (7); - opening said main explosion chamber (2) by opening a closure element (9) to an outlet (15); - opening the ignition conduit valve (7), thereby directing the explosion into the main explosion chamber (2) and igniting the explosion in the main explosion chamber (2); - venting the detonation gases from the main detonation chamber (2) through the outlet (15); and repeatedly performing these steps.

31. A method for operating a pressure wave generator (1) according to claim 21, having a main explosion chamber (2) and an auxiliary explosion chamber (3), comprising: - filling the main explosion chamber (2) with an explosive mixture; - moving the closure element (9) in the opening direction; - opening the ignition conduit valve (7) by moving the closing element (9) and thereby directing the explosive mixture from the main explosion chamber (2) into the auxiliary explosion chamber (3); - igniting an explosion in said auxiliary explosion chamber (3); - directing the explosion from the auxiliary explosion chamber (3) through an ignition tube (8) into the main explosion chamber (2); - moving the closure element (9) further in the opening direction to open the main explosion chamber (2) to the outlet (15) by opening the closure element (9) and allowing the explosion gases to exit the main explosion chamber (2) through the outlet (15); and repeatedly performing these steps.

32. 32. The method according to claim 31, wherein the ignition of the explosion in the auxiliary explosion chamber (3) occurs via an ignition means which can be constantly supplied with energy.

33. 18. The method of claim 17, wherein the filling valve is a pressurized air valve (49).

34. 18. The method according to claim 17, wherein the step of discharging at least a portion of the gaseous working medium from the first volume (41) is performed by opening an inlet / outlet opening of the first volume (41).

35. A method for operating a pneumatic actuator (4b), comprising: a first piston surface (91) acting against a gaseous working medium in a first volume (41), the pressure in said first volume (41) causing an actuator force on said first piston surface (91) in a first direction; a second piston surface (92) acting against the gaseous working medium in a second volume (42), such that pressure in the second volume (42) produces an actuator force on the second piston surface (92) in a second direction opposite to the first direction; Equipped with The method comprises: - filling the first volume (41) with a gaseous working medium under pressure by means of a filling valve; a pressure compensation step between the first volume (41) and the second volume (42) via a throttle, thereby moving the pneumatic actuator in the first direction due to a surface area difference between the first piston surface (91) and the second piston surface (92); - discharging at least a portion of said gaseous working medium from said first volume (41); - moving the pneumatic actuator in the second direction by a more rapid pressure drop in the first volume (41) than in the second volume (42); Including, A method in which the back and forth movement of the pneumatic actuator is achieved solely by the fill valve and the inlet / outlet openings.

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