DE102018120291B3 - Process for producing a lightweight pressure vessel forming a lightweight pressure tank and lightweight pressure vessel - Google Patents

Abstract

Method for producing a lightweight pressure vessel (1; 1 ') forming a lightweight pressure tank from a metal material with two curved container bottoms (12, 14; 12', 14 '), the curved vessel bottoms (12, 14; 12', 14 ') are connected to one another or with at least one cylindrical container section (10) or are integrally formed, characterized in that at least the respective container base (12, 14; 12', 14 ') is seamlessly produced from a metal material by additive manufacturing by means of a thermal spraying process The production of the respective curved container bottom (12, 14) takes place with the following steps: a) provision of a first, cylindrical formwork form (2), b) layer-by-layer application of the metal material by a spray jet (32) by means of at least one spray nozzle (30) according to the thermal spraying process onto the inner peripheral surface (21) of the first, cylindrical formwork form (2) with a unidirectional shape parallel to the cylinder axis (Z) reducing the inner diameter (d) to form an annular blank (4), c) machining the annular blank (4) in such a way that a cross-sectionally Y-shaped ring body (44) with a cylindrical outer wall (45) and one of the brim (46) extending radially inward at an acute angle (a) is formed, d) machining the radially inner peripheral edge (46 ') of the brim (46) such that the wall thickness of the brim (46) is radial inner circumferential edge (46 ') tapers, as a result of which a wall section (47) with an oblique cross section is formed as a chamfer on the surface of the brim (46) facing away from the acute angle (α), e) removing the y-shaped ring body (44) from the first formwork form (2), f) providing a second formwork form (6) which has a concave or convex curved surface (60), g) placing the cross-sectionally y-shaped ring body (44) on the edge (64) of the second shalu ngsform (6) such that the brim (46) of the ring body (44) lies on the curved mold surface (66) and covers the edge thereof, the sloping wall section (47) of the brim (46) away from the mold surface (66) , h) layer-by-layer application of the metal material by a spray jet (32 ') by means of at least one spray nozzle (30') according to the thermal spraying method onto the inclined wall section (47) of the ring body (44) and onto the mold surface (66) of the second formwork form (6) to form a central, arched dome section (49) which adjoins the brim (46) and is integrally formed therewith, and i) removing the unit comprising the dome section (49) and ring body (44) forming the container bottom (12, 14) from the second form of formwork (6).

Description

TECHNICAL AREA

The present invention relates to a method for producing a lightweight pressure tank forming a lightweight pressure tank according to the preamble of claim 1. It also relates to a tank bottom produced using this method and, overall, also to a lightweight pressure tank. Such a method according to the invention is used, for example, to produce a satellite, spacecraft or rocket tank, so that a lightweight pressure tank produced using this method forms, for example, a satellite, spacecraft or rocket tank.

BACKGROUND OF THE INVENTION

Pressure vessels that have to withstand a high internal pressure against a lower external pressure are generally known. Pressure vessels of this type are usually produced from sheet steel, which are welded to form a cylindrical container section, dome-like container bottoms being attached to the open sides of this cylinder. These dome-like container bottoms are mostly made from triangular or trapezoidal sheets that are bent and welded together to form a spatial shape. The connection of the container bottoms to the cylinder section of the pressure container is either done either by welding or by means of flanges. The quality of the weld seam is critical in the case of pressure vessels having such weld seams, since it must be avoided in any case that the pressurized pressure vessel tears and bursts at the weld seams which may form weak points. For this reason, these weld seams must be manufactured with the greatest care and the pressure vessel must be subjected to regular pressure tests.

Lightweight pressure vessels, such as those used as fuel tanks in space technology, represent a particular challenge. With these tanks, the weight has to be reduced to a minimum, so that it has become customary here to design the container with a very thin container wall and, if appropriate, a support structure connected to this thin container wall on the inside or outside of the container. For this purpose, so much material is removed from a thick wall material in the machining process, for example by milling, on the inside of the container that a thin wall skin with reinforcing elements, such as longitudinal ribs and frames, adjoining it on the inside (or the outside) is formed , It is obvious that such a manufacturing process is time-consuming and costly. The triangular or trapezoidal segments for the production of the respective container base are also milled from the solid in this way. The flat components obtained in this way are then shaped, for example by means of shot peening, into spatially curved triangles or trapezoids, which are then welded together to form the dome-like container bottom. Where welding seams are provided, a thicker wall thickness must be maintained during machining to enable welding and to compensate for the low material strength in the weld seam. This locally thicker wall in turn increases the mass and thus the weight of the pressure vessel.

The welding of the individual components is usually done by tungsten inert gas welding or by friction stir welding, for which special welding systems are required, which have to be adapted to the geometry and the diameter of the tank bottoms to be welded and which have to be manufactured as special machine construction at high costs.

In the conventional procedure for the production of lightweight pressure vessels, in particular rocket tanks, it is disadvantageous that the production of the individual components (including the cylindrical tank body) by milling from the solid as well as welding the parts to one another is very time-consuming and costly. In addition, the individual bodies in the area of the weld seam must have a thicker wall thickness than would be required without a weld seam. This manufacturing process requires very large machines that have to be manufactured individually for a single pressure vessel type. Therefore, the costs of manufacturing such pressure vessels (e.g. rocket tanks) are extremely high and due to the long lead time for the design and manufacture of the special welding systems to be carried out, a very long lead time is required before a tank construction developed on the drawing board is implemented in a first prototype can.

A rocket tank made in such a conventional manner is shown in 1 shown. It can be seen that the cylindrical container section 110 from a variety of curved panels 110 ' . 110 ' . 110 '' . 110 "" is assembled by welding. The cylindrical container section 110 is with the peripheral edge of a curved container bottom 112 welded, as on the weld 113 can be seen. Building the one with a manhole 114 provided container bottom 112 is in 2 shown in side view. On a flange ring 115 (Y-ring) are individual spatially curved trapezoidal floor segments 116 . 116 ' . 116 ' . 116 '' welded with its wide base, as through the annular weld 117 is represented symbolically. Also the individual arched floor segments 116 . 116 ' . 116 ' . 116 '" are welded together at their lateral contact edges, as through the weld seams 118 . 118 ' . 118 ' is represented symbolically. The bottom segments are at their respective inner free ends 116 . 116 ' . 116 ' . 116 '" with an annular manhole flange 119 welded as it is by the annular weld 119 ' is represented symbolically. A lid 120 is provided to the manhole 114 to close.

STATE OF THE ART

Thermal spray processes, such as cold gas spraying, are usually used to coat surfaces. A cold gas spraying method for coating surfaces, in which the gas is first compressed and heated and then accelerated by relaxing in a nozzle, in which particles introduced into the gas jet are shot onto a previously heated substrate, is known from DE 10 2006 044 612 A1 known.

From the WO 2009/109016 A1 it is also known to use the method of cold gas spraying for the production of pipes, the material particles which later form the pipe being sprayed onto a carrier element in order to produce the pipe. The support element is then removed from the tube.

From the DE 10 2010 060 362 A1 it is known to adjust the inclination of the spray nozzle, that is to say the spray angle, relative to the surface to be coated when producing a tube by means of a thermal spraying process, and thereby to change the adhesive tensile strength of the material layer produced on its surface. The spray angle is chosen so that there is adhesion that is sufficient for the coating material to adhere to the carrier element, and at the same time is so small that the tube can be more easily detached from the carrier element after completion without the use of costly process steps.

The DE 10 2015 017 026 A1 describes methods for the production of pressure vessels without the use of molds, in which the pressure vessel is produced entirely or partially from metal by means of a sintering or powder printing method. A layer-by-layer melting of metal powder contained in a metal powder supply takes place by electron beam melting or by selective laser melting. Alternatively, it is stated that the pressure vessel is produced from liquid plastic material by means of multi-jet modeling, the plastic material emerging from the nozzle being hardened immediately after the outlet by means of an energy source. It is explicitly pointed out that a molding device can be completely dispensed with in these methods.

PRESENTATION OF THE INVENTION

The object of the present invention is therefore to specify a method with which a lightweight pressure vessel forming a lightweight pressure tank can be produced more quickly and more cost-effectively.

This object is achieved by a method with the features of claim 1. Furthermore, the object is also achieved by a lightweight pressure vessel with the features of claim 14.

1. a) Bereitstellen einer ersten, zylindrischen Schalungsform,
2. b) schichtweises Auftragen des Metallmaterials durch einen Spritzstrahl mittels zumindest einer Spritzdüse gemäß dem thermischen Spritzverfahren auf die Innenumfangsfläche der ersten, zylindrischen Schalungsform mit einem sich in einer Richtung parallel zur Zylinderachse verringernden Innendurchmesser zur Bildung eines ringförmigen Rohlings,
3. c) Bearbeiten des ringförmigen Rohlings derart, dass ein im Querschnitt y-förmiger Ringkörper mit einer zylindrischen Außenwand und einer von dieser unter einem spitzen Winkel radial schräg nach innen verlaufenden Krempe entsteht,
4. d) Bearbeiten des radial inneren Umfangsrands der Krempe derart, dass sich die Wandstärke der Krempe zum radial inneren Umfangsrand hin verjüngt, wodurch auf der vom spitzen Winkel abgewandten Oberfläche der Krempe ein im Querschnitt schräg verlaufener Wandabschnitt als Fase ausgebildet wird,
5. e) Entnehmen des y-förmigen Ringkörpers aus der ersten Schalungsform,
6. f) Bereitstellen einer zweiten Schalungsform, die eine konkav oder konvex gewölbte Formoberfläche aufweist,
7. g) Aufsetzen des im Querschnitt y-förmigen Ringkörpers auf den Rand der zweiten Schalungsform derart, dass die Krempe des Ringkörpers auf der gewölbten Formoberfläche aufliegt und deren Rand bedeckt, wobei der schräg verlaufende Wandabschnitt der Krempe von der Formoberfläche weg weist,
8. h) schichtweises Auftragen des Metallmaterials durch einen Spritzstrahl mittels zumindest einer Spritzdüse gemäß dem thermischen Spritzverfahren auf den schräg verlaufenden Wandabschnitt des Ringkörpers und auf die Formoberfläche der zweiten Schalungsform zur Bildung eines sich nahtlos an die Krempe anschließenden und mit dieser integral ausgebildeten zentralen, gewölbten Domabschnitts und
9. i) Entnehmen der den Behälterboden bildenden Einheit aus Domabschnitt und Ringkörper aus der zweiten Schalungsform.

In a method for producing a lightweight pressure tank forming a lightweight pressure tank from a metal material, in particular a satellite, spacecraft or missile tank, with two curved tank bottoms and preferably at least one cylindrical tank section, the curved tank bottoms with one another or with the at least one cylindrical one Container section are connected or integrally formed, according to the invention, at least the respective container bottom and preferably also the at least one cylindrical container section are seamlessly produced from metal material by additive manufacturing by means of a thermal spraying process, the respective curved container bottom being produced with the following steps:

1. a) providing a first, cylindrical formwork form,
2. b) layer-by-layer application of the metal material by means of a spray jet by means of at least one spray nozzle in accordance with the thermal spraying method to the inner circumferential surface of the first, cylindrical formwork with an inner diameter which decreases in one direction parallel to the cylinder axis to form an annular blank,
3. c) machining the annular blank in such a way that an annular body with a Y-shaped cross section is formed with a cylindrical outer wall and a brim which extends radially inward at an acute angle therefrom,
4. d) machining the radially inner peripheral edge of the brim in such a way that the wall thickness of the brim tapers towards the radially inner peripheral edge, as a result of which a wall section with an oblique cross section is formed as a chamfer on the surface of the brim facing away from the acute angle,
5. e) removing the y-shaped ring body from the first form of formwork,
6. f) providing a second formwork form which has a concave or convex arched form surface,
7. g) placing the cross-sectionally y-shaped ring body on the edge of the second formwork form such that the brim of the ring body rests on the curved mold surface and covers its edge, the obliquely extending wall section of the brim pointing away from the mold surface,
8. h) layer-by-layer application of the metal material by means of a spray jet by means of at least one spray nozzle according to the thermal spraying method onto the oblique wall section of the ring body and onto the mold surface of the second form of form in order to form a central, arched dome section which adjoins seamlessly and is formed integrally therewith
9. i) Removing the unit forming the container bottom from the dome section and ring body from the second form of formwork.

In particular, the production takes place by means of a cold gas spraying process as a thermal spraying process.

BENEFITS

By means of the additive manufacturing of at least the container bottoms according to the invention, these pressure vessel components, which have hitherto been produced in complicated manufacturing steps from a large number of elements, can each be produced in one piece as an integral component. There are no longer any component-specific manufacturing machines to be manufactured in special machine construction, such as, for example, special welding systems, so that the manufacturing machines required for the method of the invention are independent of the geometry and the diameter of the pressure vessel to be manufactured. The costs conventionally required for special machine construction and the lead time for the production of these special machines no longer apply to the method according to the invention. Both the manufacturing costs and the time required for manufacturing are thus significantly reduced in the method of the invention compared to the prior art.

With these steps, the curved container bottoms, for example as tank bottoms of a spacecraft tank, can be manufactured sequentially quickly and precisely, which enables a high utilization of the machines required for the manufacture. The layered application of the metal material by means of the spray nozzle (s) to the sloping wall section of the brim of the ring body creates an integral connection of the ring body with the arched dome section, so that a uniform workpiece is formed without a joint and thus without a weak point.

In principle, it is also possible (and encompassed by the invention) to first produce the curved dome sections and to produce the annular blank for producing the y-shaped annular body - in an oblique manner, analogously to the manufacturing method described above according to steps a) to i) To form the peripheral wall section of the dome section and then to process it mechanically. In this case, steps analogous to steps f) to i) are carried out first, with the circumferential edge of the form analogous to the step before the dome section is removed from the formwork d ) is processed. Steps a) to c) are then carried out. Alternatively, the dome sections can also be formed by applying the metal material in layers on a convexly curved formwork form.

Further preferred and advantageous design features of the method according to the invention are the subject of subclaims 2 to 13.

A cold gas spraying method is preferably used as the thermal spraying method.

It is particularly advantageous if the second form of form has a central recess for receiving a manhole flange, if the manhole flange has an annular wall section in the region of its outer circumference, which is obliquely cross-sectionally, whereby the wall of the manhole flange tapers towards the outer circumferential edge of the manhole flange, whereby the sloping wall section is designed as a chamfer if the manhole flange is inserted into the recess of the second formwork form before step h) in such a way that the sloping wall section points away from the mold surface and if in step h) the metal material is also on the sloping one Wall section of the manhole flange is applied to integrally mold this in the dome section. Here, too, the layered application of the metal material by means of the spray nozzle (s) to the inclined wall section of the manhole flange also integrally integrates the manhole flange into the material structure of the dome section, so that a uniform workpiece is also formed here without a joint and thus without a weak point.

A further development of the method according to the invention is particularly preferred, according to which the characteristic properties of the spray jet of the at least one spray nozzle are changed when it moves from the inclined wall section of the The brim and / or the manhole flange moves further and strikes the mold surface on which no material has yet been applied by means of the thermal spray process, and according to which the characteristic properties of the spray jet are changed back when it is removed from the mold surface on which no material has yet been applied had been applied by means of the thermal spraying process, migrates further and strikes the sloping wall section of the manhole flange and / or the brim. This change in the characteristic properties of the spray jet, for example the speed of impact of the metal material particles and / or the angle of impact on the substrate, ensures that in the area of the respective inclined wall section there is a firm and intimate material connection to the wall section here, which is made of the material of the inclined wall section The substrate formed takes place while there is no firm and intimate material connection to the substrate formed here by the material of the mold surface or a release agent located there, where the spray jet strikes the mold surface from which the workpiece, i.e. the container bottom, has to be detached again later to make it easier to remove the finished container bottom from the formwork form.

Surface treatment of the container base, in particular of the central curved dome section, is preferably carried out after step i). Such a surface treatment can be used, for example, for surface compaction or surface hardening (e.g. by shot peening).

It is also advantageous if a thermal treatment of the container bottom is carried out after step i). Such a thermal treatment can be used to make structural changes in the metal material in the workpiece produced by means of the additive manufacturing according to the invention which, for example, change the toughness of the material and make the workpiece more elastic.

• a') Bereitstellen einer dritten, zylindrischen Schalungsform,
• b') schichtweises Auftragen des Metallmaterials auf die Innenfläche oder die Außenfläche der dritten, zylindrischen Schalungsform zur Bildung einer zylindrischen Behälterhaut,
• c') schichtweises lokales Auftragen des Metallmaterials durch einen Spritzstrahl mittels der zumindest einen Spritzdüse auf die Innenfläche beziehungsweise die Außenfläche der zylindrischen Behälterhaut zur Erzeugung einer mit der Zylinderhaut integral ausgebildeten Versteifungsstruktur zur Bildung eines zylindrischen Rohrkörpers,
• d') Entnehmen des den zylindrischen Behälterabschnitt bildenden bearbeiteten zylindrischen Rohrkörpers aus der dritten Schalungsform.

In a further preferred embodiment of the method, which can be combined with other embodiments, the at least one cylindrical container section is produced with the following steps:

• a ') providing a third, cylindrical formwork form,
• b ') layer-by-layer application of the metal material to the inner surface or the outer surface of the third, cylindrical formwork form to form a cylindrical container skin,
• c ') layer-by-layer local application of the metal material by means of a spray jet by means of the at least one spray nozzle onto the inner surface or the outer surface of the cylindrical container skin in order to produce a stiffening structure integrally formed with the cylinder skin to form a cylindrical tubular body,
• d ') removing the machined cylindrical tubular body forming the cylindrical container section from the third form of formwork.

The same advantages apply to the additive manufacture of the cylindrical container section as to the manufacture of the container bottoms by means of the method according to the invention. Compared to the already known additive manufacturing of pipes, according to the invention in a first additive manufacturing step only a very thin wall, referred to as a cylinder skin, is produced, onto which a ribbing stiffening structure is then locally applied additively, so that an integral cylinder structure is formed Cylinder skin and stiffening structure results, whereby there is a firm and intimate mutual material connection between the cylinder skin and the stiffening structure and thus a uniform, integral workpiece is formed without a joint and thus without a weak point. The cylindrical container section can in principle be produced by layer-wise application of the metal material to the inner circumferential surface or the outer circumferential surface of a cylindrical formwork form, the stiffening structure being built up on the inside or the outside of the cylinder skin which is initially formed. Such a stiffening structure is created by ribs formed integrally with the cylinder skin.

• c'1) Planen der radial inneren Flächen der Versteifungsstruktur mittels mechanischer Bearbeitung, und/oder
• c'2) Planen der seitlichen Flächen der Versteifungsstruktur mittels mechanischer Bearbeitung.

It is advantageous if at least one of the following steps is carried out after step c):

• c'1) planning the radially inner surfaces of the stiffening structure by means of mechanical processing, and / or
• c'2) Planning the lateral surfaces of the stiffening structure by means of mechanical processing.

Through at least one of these mechanical processing steps, unnecessary material is removed from the ribs and the mass of the cylindrical tubular body is reduced and thereby optimized. It is advantageous to carry out these mechanical processing steps of the cylindrical tubular body in or on the third form of form because the forces acting on the cylindrical tubular body during mechanical processing are supported over a large area by the third form of form, so that the cylindrical tubular body is not subject to deformation due to mechanical processing.

The stiffening structure is preferably designed in the form of an orthogrid, that is to say in the form of a grid with longitudinal ribs and ribs running at right angles to one another, but grid structures with other angles, for example diamond-shaped stiffening structures, are also encompassed by the invention.

The stiffening structure designed as an orthogrid preferably has longitudinal ribs running parallel to the cylinder axis and spaced apart from one another in the circumferential direction, and frames extending in the circumferential direction and spaced apart in the axial direction.

An alternative embodiment in which the stiffening structure is designed in the form of an isogrid is also advantageous.

Advantageously, after the step d ' ) surface processing of the cylindrical container section is carried out. The same advantages apply here as for the corresponding processing step of the container bottom.

It is also an advantage if after the step d ' ) a thermal treatment of the cylindrical container section is carried out. The same advantages apply here as for the corresponding processing step of the container bottom.

In a preferred embodiment of the method according to the invention, the at least one cylindrical container section and the two container bases are seamlessly produced separately from one another by means of the thermal spraying method and then joined together. For example, the cylindrical container section is welded to the respective container base. Several cylindrical container sections can also be welded together to form a cylinder tube, which is then welded to the container bottoms. Alternatively, a flange connection is possible.

In an alternative advantageous embodiment, the at least one cylindrical container section and at least one of the two container bases are integrally produced seamlessly by means of the thermal spraying process. In such an additive manufacturing, a container base is first produced as described, the annular connecting edge of the container base being designed in the same way as an inclined wall section, as has already been described above in connection with the brim of the y-shaped ring body, and wherein the cylindrical container section is formed from this inclined edge section by additive manufacturing, as has already been described above for the separately manufactured cylindrical container section. If one of the container bases is provided with a manhole, the cylindrical container section can also be seamlessly molded between two existing container bases by the additive manufacturing according to the invention if the spray nozzle and other processing tools are introduced through the manhole into the interior of the cylindrical formwork.

In an alternative method, the two curved container bottoms are seamlessly produced by additive manufacturing using the thermal spraying process as an integral, preferably spherical or spherical, spatial body by layer-by-layer application of the metal material by means of a spray jet by means of at least one spray nozzle onto the outer surface of a fourth formwork form which is initially provided. The formwork form, which in this case is designed as a so-called “lost formwork”, is then removed from the interior of the space body through at least one opening provided in the resulting spatial body, for example melted or broken out.

In this way, the method according to the invention can be used, for example, to manufacture spherical or spherical lightweight pressure vessels such as are used, for example, as satellite tanks.

The invention is also directed to a lightweight pressure vessel, in particular a satellite, spacecraft or rocket tank, which has been produced by means of a method according to one of the preceding claims. In particular, the invention also relates to a lightweight pressure vessel, in particular a satellite, spacecraft or rocket tank, with at least one tank bottom seamlessly produced by means of the thermal spraying process.

Even if a satellite, spacecraft or rocket tank is mentioned above as an application for a lightweight pressure vessel according to the invention, the invention is not restricted to this. A lightweight pressure vessel according to the invention can be used for many other purposes in which the weight of the pressure tank must be kept low, for example as a gas or hydrogen tank in a motor vehicle or a rail vehicle, an aircraft or a water vehicle. The invention also includes a stationary use of the lightweight pressure vessel according to the invention.

Preferred exemplary embodiments of the invention with additional design details and further advantages are described and explained in more detail below with reference to the accompanying drawings.

list of figures

• 1 einen herkömmlichen Raketentank,
• 2 einen sphärischen Behälterboden eines herkömmlichen Raketentanks,
• 3 eine bereitgestellte erste, zylindrische Schalungsform zur Durchführung des erfindungsgemäßen Verfahrens (Schritt a),
• 4 den Schritt des Auftragens von Metallmaterial auf die erste, zylindrische Schalungsform zur Erzeugung eines ringförmigen Rohlings (Schritt b),
• 4A die Einzelheit IV aus 4,
• 5 den Schritt der mechanischen Bearbeitung des ringförmigen Rohlings (Schritt c und d),
• 5A die Einzelheit V aus 5,
• 6 das Entnehmen des Ringkörpers aus der ersten, zylindrischen Schalungsform (Schritt e),
• 7 das Einsetzen des Ringkörpers in eine zweite, konkav gewölbte Schalungsform (Schritt g),
• 8 das Auftragen des Metallmaterials auf die zweite Schalungsform (Schritt h),
• 9 einen Ausschnitt aus dem so gebildeten Behälterboden gemäß Einzelheit IX aus 8,
• 10 das Entnehmen des Behälterbodens aus der zweiten Schalungsform (Schritt i),
• 11 das Auftragen des Metallmaterials auf die Innenseite einer dritten, zylindrischen Schalungsform zur Bildung einer zylindrischen Behälterhaut (Schritt b'),
• 12 das Auftragen des Metallmaterials auf die Innenseite der Zylinderhaut zur Ausbildung eines zylindrischen Rohrkörpers mit einer Versteifungsstruktur aus Spanten und Längsrippen auf der Innenseite der zylindrischen Behälterhaut (Schritt c'),
• 12A eine vergrößerte Ausschnitt-Darstellung des oberen Randes des zylindrischen Rohrkörpers aus 12,
• 12B den Schritt gemäß 12 in vergrößerter Darstellung,
• 13 den Schritt des mechanischen Bearbeitens der Spanten und Längsrippen (Schritt c'1),
• 13A den Verfahrensschritt aus 13 in vergrößerter Darstellung,
• 14 den Verfahrensschritt der mechanischen Bearbeitung der zwischen den Längsrippen und Spanten gebildeten Taschen (Schritt c'2),
• 14A den Verfahrensschritt der 14 in vergrößerter Darstellung,
• 15 das Entnehmen des fertigen zylindrischen Behälterabschnitts aus der dritten Schalungsform (Schritt d'),
• 16 einen teilweise geschnittenen zylinderartigen Leichtbau-Druckbehälter gemäß der Erfindung,
• 17 einen teilweise geschnittenen kugelartigen Leichtbau-Druckbehälter gemäß einem alternativen Verfahren und
• 18 eine alternative Versteifungsstruktur in Form eines Isogrids.

It shows:

• 1 a conventional rocket tank,
• 2 a spherical container bottom of a conventional rocket tank,
• 3 a provided first, cylindrical formwork form for performing the method according to the invention (step a )
• 4 the step of applying metal material to the first, cylindrical formwork to produce an annular blank (step b )
• 4A the detail IV out 4 .
• 5 the step of mechanical processing of the annular blank (step c and d )
• 5A the detail V out 5 .
• 6 the removal of the ring body from the first, cylindrical formwork form (step e )
• 7 inserting the ring body into a second, concave formwork form (step G )
• 8th applying the metal material to the second formwork form (step H )
• 9 a section of the container bottom thus formed according to the detail IX out 8th .
• 10 the removal of the container bottom from the second formwork form (step i )
• 11 applying the metal material to the inside of a third, cylindrical form of form to form a cylindrical container skin (step b ' )
• 12 the application of the metal material on the inside of the cylindrical skin to form a cylindrical tubular body with a stiffening structure made of frames and longitudinal ribs on the inside of the cylindrical container skin (step c ' )
• 12A an enlarged detail of the upper edge of the cylindrical tube body 12 .
• 12B the step according 12 in an enlarged view,
• 13 the step of mechanically machining the frames and longitudinal ribs (step c'1 )
• 13A the procedural step 13 in an enlarged view,
• 14 the process step of mechanical processing of the pockets formed between the longitudinal ribs and frames (step c'2 )
• 14A the procedural step of 14 in an enlarged view,
• 15 the removal of the finished cylindrical container section from the third formwork form (step d ' )
• 16 a partially cut cylinder-like lightweight pressure vessel according to the invention,
• 17 a partially cut spherical lightweight pressure vessel according to an alternative method and
• 18 an alternative stiffening structure in the form of an isogrid.

PRESENTATION OF PREFERRED EMBODIMENTS

The 1 and 2 show, as has already been mentioned, a rocket tank manufactured in a conventional manner.

The manufacture of the in 16 shown lightweight pressure vessel according to the invention 1 , for example a rocket tank, with a cylindrical container section 10 , an upper arched container bottom 12 and a lower arched container bottom 14 from a metal material by additive manufacturing by means of a thermal spraying process, in particular by means of a cold gas spraying process 3 to 15 described.

In 3 is a first, cylindrical formwork form 2 shown that on a work platform P lies. On the inner circumferential surface 21 the first, cylindrical formwork form 2 is already a separation layer 22 has been applied, which consists for example of a release agent, which is a later easy removal of the formwork form 2 from a created workpiece. As in 3 the first, cylindrical formwork form can be seen 2 from several cylinder segments, of which in 3 the segments 20 . 20 ' and 20 " are shown. These segments later make it easier to remove the formwork form 2 from a created workpiece.

In 4 is shown as a thermal sprayer 3 inside in front of the inner peripheral surface of the first cylindrical form 2 is positioned and works according to step b). This sprayer 3 can be attached to a robot arm, for example.

From a spray nozzle 30 the thermal sprayer 3 a spray jet occurs 32 from that on the inner peripheral surface 21 the first, cylindrical formwork form 2 is directed. The spray jet 32 consists of a high-speed gas jet, which in the sprayer 3 Particles of a metal material are supplied. The gas jet with the metal particles contained therein is accelerated in a known manner to a preferably supersonic speed by means of a Laval nozzle, so that the metal particles with a very high kinetic energy on the inner peripheral surface 21 or on the release agent layer provided there 22 incident. By moving the spray nozzle 30 having spraying device 3 in the direction parallel to the cylinder axis Z the cylindrical formwork and possibly also in the circumferential direction and by simultaneous rotation of the processing platform P around one with the cylinder axis Z coaxial axis of rotation D layer by layer, an essentially homogeneous material application of the metal material on the inner peripheral surface 21 the first, cylindrical formwork form 2 get like it in 4 is shown, whereby an annular blank 4 is obtained.

This ring-shaped blank 4 has a pentagon shape when viewed vertically, as shown in 4A is shown enlarged. One of the inner peripheral surface 21 the first, cylindrical formwork form 2 adjacent section of the blank 4 is about the axial extent of the blank 4 on both axial faces 41 . 42 of the blank 4 same thickness. From these two faces 41 . 42 the same wall thickness reduces the inner diameter d of the annular blank 4 towards a narrowest inner diameter d ₁ , which relates to the axial extent of the blank 4 asymmetrical (about 20:80% of the axial extent of the blank 4 ) is located.

In 5 is shown as in the process steps c) and d) the annular blank 4 is mechanically processed, for example with a rotating milling tool 50 having milling machine 5 , To carry out the mechanical processing of the ring-shaped blank 4 and the y-shaped ring body 44 becomes the blank 4 before starting mechanical processing in the first, cylindrical formwork form 2 fixed in a manner known to the person skilled in the art.

This mechanical machining and, if necessary, also grinding the blank 4 and the resulting surfaces first become a ring body in step c) 44 generated, the wall of which is Y-shaped in cross section, as in 5A is shown enlarged. This in cross section y-shaped ring body 44 has a cylindrical outer wall 45 as well as one of this cylindrical outer wall 45 Brim running radially inward at an acute angle α 46 on. That brim 46 is a wall section running radially inward at an acute angle α, which is curved into the cylindrical outer wall 45 of the ring body 44 transforms.

The radially inner peripheral edge 46 ' the brim 46 then in the crotch d ) using, for example, the milling tool 50 of the router 5 processed in such a way that the wall thickness of the brim 46 to the radially inner peripheral edge 46 ' tapered towards. As a result, the brim is on the surface facing away from the acute angle α 46 a cross-sectionally sloping wall section 47 formed in the form of a chamfer.

That way from the annular blank 4 worked out y-shaped ring body 44 is then from the first, cylindrical formwork form 2 taken as it is in 6 is shown (process step e).

Next in step f) is a second form of formwork 6 on the processing platform P (or on another corresponding processing platform P ' ) provided. This second form of formwork 6 points to their from the editing platform P ' a concave curved surface 60 with an upper annular rim 64 on.

In the example of the 7 is the second form of formwork 6 also with a central recess 62 to accommodate a manhole flange 48 Mistake.

The y-shaped ring body 44 is removed from the first formwork form 2 rotated by 180 ° around a transverse axis and with the acute angle α between the cylindrical outer wall 45 and the brim 46 formed gap space 43 to the top 64 the second form of formwork 6 so that the brim 46 of the y-shaped ring body 44 on the concave arched surface 60 the second form of formwork 6 as it is in 8th is shown. The brim 46 covers the upper edge 64 the curved surface of the mold 60 and the sloping wall section 47 the brim 46 points from the mold surface 60 path.

In 8th The method step h) is shown, in which by a spray jet 32 ' a spray nozzle 30 ' a sprayer 3 ' the metal material in layers on the mold surface 60 is applied. The sprayer 3 ' can be the same spraying device as the spraying device used in step b), but it can also, if the production steps at different workplaces, for example at a different one processing platform 6 ' , be carried out, another sprayer.

The metal material is from the spray nozzle 30 ' according to the same spraying method as in step b) in layers on the mold surface 60 and the sloping wall section 47 of the ring body 44 applied so that starting from the brim 46 of the annular body 44 a domed section of the cathedral 49 on the mold surface 60 forms, which is integral with the y-shaped ring body 44 is trained. The processing platform is also used in this process step P ' with the second form of formwork 6 about an axis of rotation D ' that are coaxial with the axis of symmetry Z ' the second form of formwork 6 and from their mold surface 60 is rotating during the spraying process.

In 8th is also shown, as is the manhole flange 48 , also in the area of its outer circumference an annular wall section which runs obliquely in cross section 48 ' has, whereby the wall 48 " of the manhole flange 48 to the outer peripheral edge 48 '' of the manhole flange 48 tapered, also from the spray nozzle 30 ' with the metal material, so that the manhole flange 48 integral to the cathedral section 49 is involved. The unit created in this way from the cathedral section 49 , the ring body 44 and the manhole flange 48 forms the upper container bottom 12 of the lightweight pressure vessel 1 ,

In the event that no manhole opening is required, the second form of formwork 6 without the central recess 62 trained and the cathedral section 49 ' extends continuously in this area and forms a uniform spherical or flattened-spherical surface, as in 16 based on the bottom of the container 14 you can see. This unit of ring body and dome section then forms the lower container bottom 14 of in 16 shown lightweight pressure vessel 1 ,

9 shows the detail IX out 8th , which shows that the brim 46 on its inclined wall section, which is shown here as an example 47 continuously into the wall of the domed section 49 transforms. The former surface of the sloping wall section shown here 47 is in the finished unit from the y-shaped ring body 44 and the cathedral section 49 no longer ascertainable and therefore in 9 only drawn in dashed lines.

In 10 is shown as the finished container bottom 12 from the formwork form 6 is removed (step i).

11 shows a platform P ", which is another platform or one of the platforms P or P ' can act. On this platform P "is a third, cylindrical formwork form 7 provided that like the first cylindrical formwork form 2 also consists of a plurality of segments. This third, cylindrical formwork form 7 is provided on the inside with a release layer or a release agent to facilitate later removal of the workpiece formed in the mold.

Furthermore, in 11 to see how a sprayer 3 ' that have a spray nozzle 30 " has, by means of a spray jet 32 " Metal material on the cylindrical inner surface 70 the third, cylindrical formwork form 7 applies in layers. Even the sprayer 3 ' can be another spray device or one of the spray devices 3 or 3 ' his.

During the layered application of the metal material on the inner surface 70 while moving the sprayer 3 ' in the axial direction and possibly also in the circumferential direction, the processing platform P " with the third, cylindrical formwork clamped on it 7 about an axis of rotation D " that with the cylinder axis Z " the third form of formwork 7 is coaxial, rotates. By applying the metal material in layers on the inner surface 70 the third form of formwork is on the inner surface 70 a cylindrical container skin 80 to form a thin-walled cylindrical tubular body which is formed in the third form of formwork 8th generated (step b ' ). This container skin 80 is in relation to the inner radius R the third, cylindrical formwork form 7 extremely thin. The wall thickness of the cylindrical container skin 80 is at a radius R of, for example, 2.5 m, only about 1.5 mm to 2.5 mm, preferably 2 mm.

In 12 is shown as by means of the sprayer 3 ' on the inside of the crotch b ' ) formed cylindrical container skin 80 in a next step c ' ) by local application of the metal material in layers using the spray jet 32 " parallel to the cylinder axis Z " extending and circumferentially spaced longitudinal ribs 82 as well as in the circumferential direction and in the axial direction spaced frames 84 can be applied in layers. The spraying device also moves here 3 ' in the axial direction and possibly also in the circumferential direction and at least when applying the frames 84 rotates the processing platform P " with the third cylindrical formwork clamped on it 7 , The longitudinal ribs 82 and the frames 84 together form one with the skin of the container 80 integrally formed stiffening structure 87 the container skin 80 out.

Also, in step b ' ) or c ' ) the upper edge area 81 and the lower margin 86 the container skin 80 formed with a thicker wall thickness, as in 12 A is seen to be from the cylindrical tubular body 8th manufactured cylindrical container section 10 in this area with a respective container bottom 12 . 14 or to be able to weld another cylindrical container section. The very thin wall thickness of the cylinder skin 80 go to a transition area 81 ' . 86 ' gradually into the thicker wall thickness of the assigned edge area 81 . 86 about. The marginal areas 81 . 86 are preferably not with longitudinal ribs 82 or frames 84 strengthened. The longitudinal ribs running parallel to the axis 82 go, preferably while reducing their radial extent, in the respective transition area 81 ' . 86 ' about.

12B shows enlarged, like in step c ' ) the metal material by the spray jet 32 " the sprayer 3 ' locally spaced from each other on the previously made container skin 80 is applied to the longitudinal ribs 82 or the frames 84 to create. This symbolic representation applies both to the creation of the longitudinal ribs 82 as well as for the production of the frames 84 to, so in the example of the 12A the arrangement of the longitudinal ribs at right angles to one another 82 and the frames 84 is not shown.

13 shows a first mechanical processing step c'1 ) of the steps b ' ) and c ' ) generated cylindrical tube body 8th with a milling tool 50 ' of a router 5 ' , which is also the milling tool 50 of the router 5 can act, which was used in processing steps c) and d). The milling tool 50 ' machined on the inside of the cylindrical tube body 8th the radially inner surfaces 83 the longitudinal ribs 82 and the radially inner surfaces 85 the frame 84 such that they become flat and have a predetermined dimension in the radial direction. This step d ' planning the radially inner surfaces 83 . 85 is in 13A schematically shown enlarged. Here, too, is the right-angled arrangement of the longitudinal ribs 82 and the frames 84 not shown to each other for the sake of simplicity.

14 shows the process step c'2 ), in which the side surfaces 83 ' . 83 " respectively 85 ' . 85 " the longitudinal ribs 82 or the frames 84 by means of the milling tool 50 ' be milled to obtain a flat (i.e. flat) side surface and the distances between adjacent longitudinal ribs 82 and neighboring frames 84 to bring each to a predetermined level, as in 14A which is a schematic representation in the same way as that 13A , The milling tool used for this 50 ' is preferably a torus cutter rounded on the circumference of its cutting edge.

Mechanical processing of the cylindrical tube body 8th in the third form 7 in steps c'1 ) and c'2 ) has the advantage that the formwork form the tubular body 8th supports against the forces of the milling tool. The same advantage arises in the mechanical processing of the annular blank 4 in the first form 2 in steps c) and d).

Finally in 15 the procedural step d ' ) shown in which of the cylindrical tube body 8th worked out cylindrical container section 10 is removed.

This finished cylindrical container section 10 can now - like the container bottoms 12 . 14 - be subjected to surface treatment and / or thermal treatment.

16 shows one from the upper tank bottom 12 , the bottom of the tank 14 and the cylindrical container section 10 formed finished lightweight pressure vessel 1 , The two container bottoms 12 . 14 are with the cylindrical container section 10 welded, as by the two welds indicated 11 . 13 is represented symbolically. The lightweight pressure vessel 1 However, as described above, it can also have been produced fully integrally or partially integrally by means of the method according to the invention and have no or only one circumferential weld seam.

17 shows a partially cut open spherical lightweight pressure vessel 1' in the form of one with at least one nozzle 13 ' provided spherical body 1" , which like two essentially hemispherical curved container bottoms 12 ' . 14 ' by the additive manufacturing by means of the thermal spraying process according to the invention integral with a uniform spherical wall 10 ' of the spatial body 1" is trained. The metal material is sprayed 32 '' by means of at least one spray nozzle 30 '' a sprayer 3 '' according to the thermal spraying process on the outer surface 90 a fourth, spherical or spherical form of formwork 9 applied in layers. The fourth form of formwork 9 determines the internal volume of this alternative lightweight pressure vessel 1' , 17 shows an example of an opening 11 ' of the lightweight pressure vessel 1' by a cylinder neck 13 ' is surrounded, which is also integral with the wall by additive manufacturing 10 ' is trained. A plurality of such openings and / or sockets can also be provided, which then also attach the lightweight pressure vessel 1' can serve. The spherical or spherical formwork form 9 will after the Production of the spherical body 1" smashed and / or melted and through the opening (s) 11 ' dissipated. This ball-like lightweight pressure vessel 1' with the spherical body 1" can be, for example, a satellite tank.

Even if in the 12 to 16 one on the radially inner side of the container skin 80 trained stiffening structure 87 as an orthogrid with longitudinal ribs running at right angles to each other 82 and frames 84 the invention is not limited to this. Alternatively, the stiffening structure can also be formed on the radially outer side of the container skin if the container skin has been formed on the outside of the third, cylindrical formwork form. It is also possible to apply stiffening structures on the radially inner and on the radially outer side of the container skin if appropriate formwork forms are made available.

In addition, the invention is not limited to an orthogrid as a stiffening structure, but the stiffening ribs can also be at a different angle to one another and, for example, be designed in the form of a diamond pattern.

A modified stiffening structure 87 ' is in 18 shown, in which the stiffening ribs are arranged in the form of an isogrid and thereby isogrid ribs 88 form that in isogrid nodes 89 are interconnected.

Reference symbols in the claims, the description and the drawings serve only for a better understanding of the invention and are not intended to limit the scope of protection.

LIST OF REFERENCE NUMBERS

1

zylinderartiger Leichtbau-Druckbehälter

1'

kugelartiger Leichtbau-Druckbehälter

1"

kugelförmiger Raumkörper

2

erste, zylindrische Schalungsform

3

Spritzvorrichtung

3'

Spritzvorrichtung

3"

Spritzvorrichtung

3"'

Spritzvorrichtung

4

ringförmiger Rohling

5

Fräser

5'

Fräser

6

zweite Schalungsform

7

dritte, zylindrische Schalungsform

8

zylindrischer Rohrkörper

9

vierte Schalungsform

10

zylindrischer Behälterabschnitt

10'

Wandung

11'

Öffnung

12

oberer Behälterboden

12'

oberer Behälterboden (Abschnitt des kugelförmigen Raumkörpers)

13'

Stutzen

14

unterer Behälterboden

14'

unterer Behälterboden (Abschnitt des kugelförmigen Raumkörpers)

20

Segment

20'

Segment

20"

Segment

21

Innenumfangsfläche

22

Trennmittelschicht

30

Spritzdüse

30'

Spritzdüse

30"

Spritzdüse

30'"

Spritzdüse

32

Spritzstrahl

32'

Spritzstrahl

32"

Spritzstrahl

32'"

Spritzstrahl

41

axiale Stirnfläche

42

axiale Stirnfläche

43

Spaltraum

44

y-förmiger Ringkörper

45

zylindrische Außenwand

46

Krempe

46'

Umfangsrad der Krempe

47

Wandabschnitt

48

Mannlochflansch

48'

Wandabschnitt

48"

Außenumfangsrand

48'"

Außenumfangsrand

49

Domabschnitt

49'

Domabschnitt

50

Fräswerkzeug

50'

Fräswerkzeug

60

konkav gewölbte Formoberfläche

62

zentrale Ausnehmung

64

oberer Rand

70

Innenfläche von 7

80

zylindrische Behälterhaut

81

oberer Randbereich von 8

81'

Übergangsbereich

82

Längsrippe

83

radial innere Fläche

83'

seitliche Fläche

83"

seitliche Fläche

84

Spante

85

radial innere Fläche

85'

seitliche Fläche

85"

seitliche Fläche

86

unterer Randbereich von 8

86'

Übergangsbereich

87

Versteifungsstruktur

87'

Versteifungsstruktur

88

Isogridrippe

89

Isogridknoten

90

Oberfläche der vierten Schalungsform

d

Durchmesser des ringförmigen Rohlings

d₁

Innendurchmesser des ringförmigen Rohlings

D

Drehachse

D'

Drehachse

D"

Drehachse

P

Bearbeitungsplattform

P'

Bearbeitungsplattform

P"

Bearbeitungsplattform

Z

Zylinderachse

Z'

Zylinderachse

Z"

Zylinderachse

Designate it:

1

cylindrical lightweight pressure vessel

1'

spherical lightweight pressure vessel

1"

spherical body

2

first, cylindrical formwork form

3

sprayer

3 '

sprayer

3 '

sprayer

3 ''

sprayer

4

ring-shaped blank

5

milling cutter

5 '

milling cutter

6

second formwork form

7

third, cylindrical formwork form

8th

cylindrical tubular body

9

fourth form of formwork

10

cylindrical container section

10 '

wall

11 '

opening

12

upper tank bottom

12 '

upper tank bottom (section of the spherical body)

13 '

Support

14

lower tank bottom

14 '

lower container bottom (section of the spherical body)

20

segment

20 '

segment

20 "

segment

21

Inner circumferential surface

22

Release layer

30

nozzle

30 '

nozzle

30 "

nozzle

30 ''

nozzle

32

spray jet

32 '

spray jet

32 "

spray jet

32 ''

spray jet

41

axial face

42

axial face

43

gap

44

y-shaped ring body

45

cylindrical outer wall

46

brim

46 '

Circumferential wheel of the brim

47

wall section

48

manway flange

48 '

wall section

48 "

Outer peripheral edge

48 ''

Outer peripheral edge

49

dome section

49 '

dome section

50

milling tool

50 '

milling tool

60

concave curved surface

62

central recess

64

upper edge

70

Inner surface of 7

80

cylindrical container skin

81

upper edge area of 8th

81 '

Transition area

82

longitudinal rib

83

radially inner surface

83 '

side surface

83 "

side surface

84

joists

85

radially inner surface

85 '

side surface

85 "

side surface

86

lower edge area of 8th

86 '

Transition area

87

stiffening structure

87 '

stiffening structure

88

Isogridrippe

89

Isogridknoten

90

Surface of the fourth form of formwork

d

Diameter of the ring-shaped blank

d ₁

Inner diameter of the annular blank

D

axis of rotation

D '

axis of rotation

D "

axis of rotation

P

processing platform

P '

processing platform

P "

processing platform

Z

cylinder axis

Z '

cylinder axis

Z "

cylinder axis

Claims (15)

Method for producing a lightweight pressure vessel (1; 1 ') forming a lightweight pressure tank from a metal material with two curved container bottoms (12, 14; 12', 14 '), the curved vessel bottoms (12, 14; 12', 14 ') are connected to one another or with at least one cylindrical container section (10) or are integrally formed, characterized in that at least the respective container base (12, 14; 12', 14 ') is seamlessly produced from a metal material by additive manufacturing by means of a thermal spraying process The production of the respective curved container bottom (12, 14) takes place with the following steps: a) provision of a first, cylindrical formwork form (2), b) layer-by-layer application of the metal material by a spray jet (32) by means of at least one spray nozzle (30) according to the thermal spraying process on the inner circumferential surface (21) of the first, cylindrical formwork form (2) with one in one direction direction parallel to the cylinder axis (Z) reducing the inner diameter (d) to form an annular blank (4), c) machining the annular blank (4) in such a way that a cross-sectionally Y-shaped ring body (44) with a cylindrical outer wall (45) and one of the brim (46), which extends radially inward at an acute angle (a), d) machining the radially inner peripheral edge (46 ') of the brim (46) such that the wall thickness of the brim (46) increases radially inner circumferential edge (46 ') tapers, as a result of which a wall section (47) with an oblique cross section is formed as a chamfer on the surface of the brim (46) facing away from the acute angle (a), e) removing the y-shaped ring body (44 ) from the first formwork form (2), f) providing a second formwork form (6) which has a concave or convex arched form surface (60), g) placing the ring body (44) which is Y-shaped in cross section onto the edge (64) the second n Formwork form (6) such that the brim (46) of the ring body (44) rests on the curved mold surface (66) and covers the edge thereof, the oblique wall section (47) of the brim (46) from the mold surface (66) h) layer-by-layer application of the metal material by a spray jet (32 ') by means of at least one spray nozzle (30') according to the thermal spraying method onto the inclined wall section (47) of the ring body (44) and onto the mold surface (66) of the second Formwork form (6) for forming a central, arched dome section (49) which seamlessly adjoins the brim (46) and is formed integrally therewith, and i) removing the unit comprising the dome section (49) and ring body ( 44) from the second form of formwork (6). Procedure according to Claim 1 , characterized in that a cold gas spraying process is used as the thermal spraying process. Procedure according to Claim 1 or 2 , characterized in that the second form of formwork (6) has a central recess (62) for receiving a manhole flange (48), that the manhole flange (48) has an annular wall section (48 ') with an oblique cross section in the region of its outer circumference, whereby the wall (48 ") of the manhole flange (48) tapers towards the outer peripheral edge (48 '") of the manhole flange (48), the inclined wall section (48') being designed as a chamfer that the manhole flange (48) in front of the Step h) is inserted into the recess (62) of the second formwork mold (6) such that the inclined wall section (48 ') points away from the mold surface (66) and that in step h) the metal material also points onto the inclined wall section (48 ') of the manhole flange (48) is applied in order to form it integrally into the dome section (49). Procedure according to Claim 1 . 2 or 3 , characterized in that characteristic properties of the spray jet of the at least one spray nozzle are changed if it continues to migrate from the inclined wall section (47; 48 ') of the brim (46) and / or the manhole flange (48) and onto the mold surface (66) occurs, on which no material has yet been applied by means of the thermal spraying process, and that the characteristic properties of the spray jet are changed back when it continues to migrate from the mold surface (66) on which no material has yet been applied by means of the thermal spraying process and strikes the sloping wall section (48 '; 47) of the manhole flange (48) and / or the brim (46). Procedure according to one of the Claims 1 to 4 , characterized in that after step i) a surface treatment of the container bottom is carried out. Procedure according to one of the Claims 1 to 5 , characterized in that after step i) a thermal treatment of the container bottom (12, 14) is carried out. Method according to one of the preceding claims, characterized in that the at least one cylindrical container section (10) is produced with the following steps: a ') providing a third, cylindrical formwork form (7), b') layer-by-layer application of the metal material by means of a spray jet (32 ") by means of at least one spray nozzle (30") on the inner surface (70) or the outer surface of the third, cylindrical formwork form (7) to form a cylindrical container skin (80), c ') layer-by-layer local application of the metal material by the spray jet ( 32 ") by means of the at least one spray nozzle (30") onto the inner surface or the outer surface of the cylindrical container skin (80) to produce a stiffening structure (87; 87 ') with ribs (82, 84) which is integrally formed with the container skin (80) to form a cylindrical tubular body (8), d ') removing the cylindrical container section (10) machined cylindrical tubular body (8) from the third form (7). Procedure according to Claim 7 , characterized in that at least one of the following steps is carried out after step c '): c'1) planning of the radially inner surfaces (83; 85) of the stiffening structure (87; 87') by means of mechanical processing, and / or c ' 2) Planning the lateral surfaces (83 ', 83 ";85',85") of the stiffening structure (87; 87 ') by means of mechanical processing. Procedure according to Claim 7 or 8th , characterized in that, the stiffening structure (87) is designed in the form of an orthogrid. Procedure according to Claim 7 or 8th , characterized in that, the stiffening structure (87 ') is designed in the form of an isogrid. Procedure according to one of the Claims 7 to 10 , characterized in that after step d ') a surface treatment and / or a thermal treatment of the cylindrical container section (10) is carried out. Method according to one of the preceding claims, characterized in that the at least one cylindrical container section (10) and the two container bases (12, 14) are seamlessly produced separately from one another by means of the thermal spraying process and then joined together. Procedure according to one of the Claims 1 to 11 , characterized in that the at least one cylindrical container section (10) and at least one of the two container bases (12, 14) are produced seamlessly integrally with one another by means of the thermal spraying process. Lightweight pressure vessel (1; 1 ') manufactured by means of a method according to one of the preceding claims. Lightweight pressure vessel (1; 1 ') after Claim 14 with at least one by means of the thermal Spraying process seamlessly produced container bottom (12, 14; 12 ', 14').

Images