Method for producing a tubular body with reduced internal stress by using 3D printing, and a tubular body with reduced internal stress

Abstract

A method for producing a tubular body with reduced internal stress uses 3D printing. The tubular body has an outer wall with a stiffening structure extending along at least part of the outer wall. The method sets a printing plane for 3D printing with a 3D printer, and prints a tubular body layer in the printing plane with the 3D printer. The tubular body layer has an outer wall layer and a stiffening structure layer extending in the printing plane along a periphery of the outer wall layer. The stiffening structure layer has at least two portions spaced apart from one another. The method produces an outer wall with a stiffening structure for a tubular body with reduced internal stress.

Claims

1. A method for producing a tubular body with reduced internal stress by using 3D printing, the tubular body having an outer wall with a stiffening structure, the stiffening structure extending along at least part of the outer wall, the method comprising the steps of: a) setting a printing plane for 3D printing with a 3D printer; b) printing a tubular body layer in the printing plane with the 3D printer, the tubular body layer having an outer wall layer and a stiffening structure layer, the stiffening structure layer extending in the printing plane along a periphery of the outer wall layer, and the stiffening structure layer having at least two portions spaced apart from one another; and c) repeating steps a) and b) to produce an outer wall with a stiffening structure for a tubular body with reduced internal stress, wherein a number of stiffening structure layers form the stiffening structure by intersecting on the outer wall of the tubular body to form a hexagonal rib-like network structure with a plurality of hexagons lying on the outer wall of the tubular body.

2. The method according to claim 1, wherein the outer wall layer and the stiffening structure layer are in one piece.

3. The method according to claim 1, wherein the stiffening structure extends around the outer wall outside the tubular body.

4. The method according to claim 1, wherein the stiffening structure forms an irregularly hexagonal rib-like network structure on the outer wall of the tubular body.

5. The method according to claim 1, wherein step b) comprises the sub step of: b1) printing the tubular body layer from metal.

6. The method according to claim 5, wherein the metal comprises titanium.

7. The method according to claim 1, wherein step b) comprises the sub step of: b2) printing the tubular body layer from plastic.

8. The method according to claim 1, wherein step c) comprises the substep of: c1) repeating steps a) and b) until a first tubular body layer is at a distance from a last tubular body layer of between 50 mm and 1000 mm.

9. The method according to claim 1, wherein step a) comprises the substep of: a1) setting a printing plane for 3D printing with a laser 3D printer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention are described below on the basis of an embodiment that is given by way of example by means of the appended drawing, in which:

(2) FIG. 1 shows a schematic representation of a tubular body with a stiffening structure;

(3) FIG. 2 shows a schematic cross-sectional representation of the tubular body that corresponds to a tubular body layer;

(4) FIG. 3 shows a schematic representation of a 3D printer;

(5) FIGS. 4a and 4b show schematic representations of tubular body layers;

(6) FIG. 5 shows a schematic representation of an aircraft; and

(7) FIGS. 6a and 6b show schematic flow diagrams of the method.

DETAILED DESCRIPTION

(8) The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.

(9) FIG. 1 shows a schematic representation of a tubular body 10 in the form of a manifold, which has been produced by means of 3D printing. The tubular body 10 should be understood here as merely given by way of example, since any desired component that has a tendency to suffer from cracks or ruptures due to internal stress can be produced by the method according to the disclosure.

(10) The tubular body 10 comprises an outer wall 12 and a stiffening structure layer 10. The stiffening structure 14 extends along the outer wall 12. As shown in FIG. 1, the stiffening structure 14 may in this case only cover part of the outer wall 12. Alternatively, the stiffening structure 14 may extend over the entire outer wall 12.

(11) The stiffening structure 14 stiffens the outer wall 12. The outer wall 12 can therefore be made thinner than without a stiffening structure 14.

(12) Furthermore, in a first embodiment given by way of example, the tubular body 10 may consist of titanium.

(13) In a second embodiment given by way of example, the tubular body 10 may consist of a high-performance plastic, for example polyetheretherketone or polyetherimide.

(14) The tubular body 10 may be made up of at least two tubular body layers 20. In FIG. 2, a tubular body layer 20 is shown along the section A-A.

(15) The tubular body layer 20 comprises an outer wall layer 16 with a periphery 17 and a stiffening layer 18, 19. The stiffening layer 18, 19 extends along the periphery 17 of the outer wall layer 16. Furthermore, the stiffening layer 18, 19 has at least two portions, which are spaced apart from one another. One portion of the stiffening layer 18, 19 is denoted in FIG. 2 by the reference numeral 18, the other portion of the stiffening layer 18, 19 is denoted by the reference numeral 19.

(16) The two portions of the stiffening layer 18, 19 do not have any direct connection to one another. They are only connected to one another indirectly by way of the outer wall layer 16.

(17) The stiffening layer 18,19 has the effect that the outer wall layer 16 can have a smaller width 11 than without a stiffening layer 18, 19. Since the internal stress may be proportional to the width 11 of the outer wall layer 16, the internal stresses in the outer wall layer 16 are reduced. By reducing the internal stresses in the outer wall layer 16, the internal stresses in the outer wall 12 are also reduced. As a result, cracks or ruptures of the tubular body 10 at the outer wall 12 are avoided.

(18) In FIG. 3, a 3D printer 30 is shown. The 3D printer 30 is represented in this case in the form of a laser 3D printer, which by means of a laser 32 focuses a laser beam on a focal point 36 in a printing plane 38. The 3D printer 30 also comprises a printing platform 34, on which a tubular body 10 is printed.

(19) In FIG. 3 there can also be seen part of an outer wall 12 and part of a stiffening structure 14, both of which are not yet completed, i.e. are still being printed. In the printing plane 38, a tubular body layer 20 is applied to the tubular body 10 by the laser beam of the laser 32. An outer wall layer 16 is thereby applied and attached on the outer wall 12 and a stiffening structure layer 18, 19 is thereby applied and attached on the stiffening structure 14. The attachment of the outer wall layer 16 and the stiffening layer 18, 19 on the outer wall 12 and the stiffening structure 14, respectively, can be carried out in this case by means of a melting process, by the energy of the laser at the focal point 36. The focal point 36 of the laser 32 thereby travels in the printing plane 38 to the positions at which the tubular body layer 20 is to be applied.

(20) When one tubular body layer 20 has been completed, the printing plane 38 can be adjusted. The adjustment may in this case be performed such that the printing plane 38 is moved away perpendicularly in relation to the plane of the tubular body layer 20 that was last completed, and forms a parallel plane in relation to the tubular body layer 20 outside the tubular body 10. Then, a new tubular body layer 20 can be produced on the previous tubular body layer 20. In the case of a laser 3D printer, the adjustment of the printing plane may for example take place by means of adjusting the platform 34 and/or displacing the focal point 36 of the laser 32.

(21) By repeatedly displacing the printing plane 38 and producing the tubular body layer 20 with the outer wall layer 16 and the stiffening layer 18, 19, a tubular body 10 with an outer wall 12 that has a stiffening structure 14 can be produced layer by layer.

(22) Also shown in FIG. 3 are a first tubular body layer 21 and a last tubular body layer 23, it also being possible that the last tubular body layer 23 is only just being produced. The first tubular body layer 21 and the last tubular body layer 23 may be at a distance 15, which may be between 50 mm and 1000 mm, preferably between 300 mm and 800 mm, more preferably between 350 mm and 600 mm, and most preferably at 400 mm. This allows for example overall heights of up to 1000 mm to be achieved for the tubular body 10 by means of the laser 3D printer 30. The overall height of the tubular body 10 is in this case only limited by the height of the printing space in the laser 3D printer 30.

(23) FIG. 4a shows here an exemplary embodiment in which the outer wall layer 16 and the stiffening layer 18, 19 were applied individually and only after their completion were connected to one another to form the tubular body layer 20. It can also be seen here that the outer wall layer 16 does not have any kinks or folds, but rather has a smooth periphery 17. This means that the tubular body layer 20 has a greater width 11 at the positions at which the portions of the stiffening layer 18, 19 are connected to the outer wall layer 16 than between the portions of the stiffening layer 18, 19.

(24) FIG. 4b shows a further exemplary embodiment, in which the outer wall layer 16 and the stiffening layer 18, 19 are formed in one piece. This means that there is no seam between the outer wall layer 16 and the stiffening layer 18, 19. The outer wall layer 16 and the stiffening layer 18, 19 are in this case produced in one step. Together, they form the tubular body layer 20.

(25) If, for example, a laser 3D printer is used for the production of the tubular body layer 20 according to FIG. 4b, the focal point 36 of the laser beam of the laser 32 can travel back and forth directly between the outer wall layer 16 and one of the portions of the stiffening layer 18, 19, and thereby form the outer wall layer 16 and the corresponding portion of the stiffening layer 18, 19.

(26) FIG. 5 shows an aircraft 40. The aircraft 40 has a wing 46 and two propulsion elements 48. The propulsion elements 48 are supplied with fuel from a tank 44 by way of a system of pipes 42. The system of pipes 42 is connected to a tubular body 10, which in this example is connected to the outlet opening of the tank 44. The tubular body 10 and the system of pipes 42 are in this case connected to one another in a fluid-communicating manner, so that the fuel can be delivered from the tank 44 through the tubular body 10 and the system of pipes 42 to the propulsion elements 48.

(27) FIG. 6a shows a first exemplary embodiment of the method 100 for producing a tubular body with reduced internal stress by using 3D printing. The tubular body has in this case an outer wall with a stiffening structure. In this case, the stiffening structure extends along at least part of the outer wall.

(28) In a first step a), a printing plane 38 is set 101 by means of a 3D printer 30. This may take place by displacing a printing platform 34 of the 3D printer 30. In a substep a1), the printing plane 38 may be set 104 by means of a 3D printer. In this case, the setting of the printing plane 38 may take place by setting a focal point 36 of a laser beam of a laser 32. The printing plane 38 is in this case set such that it is free from parts of the 3D printer 30 and from the tubular body 10 to be produced.

(29) In a second step b), a tubular body layer 20 is printed 102 in the printing plane 38 by means of the 3D printer. The tubular body layer 20 has in this case an outer wall layer 16 and a stiffening structure layer 18, 19. The stiffening structure layer 18,19 extends in the printing plane 38 along a periphery 17 of the outer wall layer 16. The stiffening structure layer 18, 19 also has at least two portions, which are spaced apart from one another.

(30) In a first embodiment that is given by way of example, the tubular body layer may be printed 105 from metal according to step b1). Titanium may preferably be used for this. However, other metals are also possible. In this way, a tubular body 10 can be produced from titanium by means of the method 100.

(31) In a second embodiment that is given by way of example, the tubular body layer may be printed 107 from plastic according to step b2). In this case, the plastic may be a high-performance plastic, such as for example polyetheretherketone or polyetherimide. However, other types of plastic are also possible. For printing with plastics, a laser 3D printer is not absolutely necessary.

(32) In a third step c), steps a) and b) may be repeated 103 until an outer wall 12 with a stiffening structure 14 for a tubular body 10 with reduced internal stress has been produced. In this case, the repetition 103 of steps a) and b) has the effect that the printing plane 38 is moved successively away from the tubular body layer 20 first produced, so that new tubular body layers 20 can be successively applied to the old tubular body layers 20.

(33) In a substep c1), steps a) and b) may be repeated 106 until a first tubular body layer 21 is at a distance 15 from a last tubular body layer 20 of between 50 mm and 1000 mm. The distance may preferably lie between 300 mm and 800 mm, more preferably between 350 mm and 600 mm, and most preferably at 400 mm. This means that the method 100 can be used to produce a component which has at least in one dimension a measure of up to 1000 mm, this component having a low internal stress and consequently being of a very stable configuration.

(34) While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope defined by the claims, which includes known equivalents and foreseeable equivalents at the time of filing this patent application.