DE102012013289B4 - Manufacturing method for a pipe and arrangement for manufacturing the pipe - Google Patents

Abstract

Production method for a pipe (13), in particular a ventilation or air conditioning pipe, wherein a pipe body at least partially forming the pipe (13) is produced from a curable fiber composite material (P), with an inner surface of a first one during the curing of the fiber composite material (P) of the pipe body Ring segment (11) of the tubular body, pressurized from the outside, is pressed against an outer surface of a mandrel (4) inserted into the first ring segment (11), and a second ring segment (12) of the tubular body, in particular adjoining the first ring segment (11) pressurized from the inside against an inner surface of a tool (2, 3) that encircles at least the second ring segment (12), with a radially encircling pressure piece (5, 6) overlapping with the mandrel (4) on the outside of the first ring segment (11) ) is attached, and wherein the first ring segment (11) is pressed against the mandrel (4) by thermal expansion of the pressure piece (5, 6) approx.

Description

The invention relates in particular to a production method for a pipe made from a fiber composite material, as well as an arrangement for producing the pipe.

Pipes made of fiber composite materials are used in particular because of the weight savings that can be achieved with them, for example in aircraft in the area of ventilation and air conditioning piping. With regard to the piping and assembly effort, there is definitely still room for improvement in the known pipes made of fiber composite materials.

From the U.S. 5,525,288 A There is known a method of manufacturing a hose having an expanded portion and a compression molded portion including making the expanded portion and the compression molded portion integrally and almost simultaneously. The manufacturing process is simple and easy, and the number of manufacturing steps is reduced and the cost can be reduced. The process forms the expanded section and the compression molded section from a tube. A rigid central core element is inserted into at least one end portion of the tube. This structure is then assembled between mold sections that have an expanded internal cavity when closed. The mold sections are then closed and the end between the central core member and the opposing inner surface of the mold sections are compressed and molded. The tube is then expanded in the mold to conform the tube to the cavity surface by introducing pressurized fluid into the interior of the tube. The customized tube is removed from the molded sections as a tube with expanded and compression molded sections.

From the DE 693 07 056 T2 a method of manufacturing a laminated hose is known.

From the DE 198 03 965 A1 a method for producing hollow bodies from thermoplastics with long and / or continuous fiber reinforcement is known. A preform or multi-layer, flat semi-finished product is provided with an inflatable polymer bladder inside, heated in its flat state above the melting temperature of the thermoplastic and shaped into a hollow body by applying internal pressure to the polymer bladder. This can be done both in a tool, on the inner surface of which the semi-finished product is molded by the internal pressure in the polymer bubble, and also in polymer films which are capable of stretching against the counter pressure and which surround the hollow body.

From the U.S. 4,182,019 A discloses a method of making an improved collapse-resistant corrugated tube of flexible elastomeric material having a tubular structure, preferably comprising a single layer of textile reinforcement which may be of knitted construction. The tubular structure is formed to an outer diameter, substantially that of the maximum diameter of the mold cavity, then placed therein and vulcanized under heat and pressure to thermally form cylindrical end portions and a corrugated central portion. A pre-formed wire insert is then placed in the troughs of the internal corrugations to provide resistance to collapse when the hose is subjected to a vacuum or bend. The hose is particularly suitable for vehicle cooling systems.

Proceeding from this, the present invention is based on the object of specifying a production method for a pipe made of a fiber composite material which enables particularly advantageous piping and assembly. In addition, an arrangement for producing a corresponding pipe is to be specified.

This object is achieved by a manufacturing method with the features of claim 1 and by an arrangement with the features of claim 11. Refinements of the invention emerge in particular from the respective subclaims.

According to claim 1, a manufacturing method for a pipe is provided in which a pipe body at least partially forming the pipe is made from a curable fiber composite material. The pipe is in particular a ventilation and air conditioning pipe, in particular for use in aircraft or airplanes, i. H. So in the aviation sector.

The term “a pipe body at least partially forming the pipe” should be understood in particular to mean that the pipe body forms a, not necessarily contiguous, section of the entire pipe wall of the pipe, and in particular at least one segment, in particular a ring segment, particularly preferably at least one axially includes end ring segment.

The fiber composite material can be, for example, a fabric impregnated with a curable plastic material, such as resin. For example, glass, carbon fibers and / or others can be used as the fabric Reinforcement fibers into consideration. The fiber composite material can also comprise a plastic matrix mixed with fibers, in particular glass fibers, carbon fibers or other reinforcing fibers. So-called prepregs are particularly suitable.

The term “curing” and related terms are to be understood in particular to mean measures with which the initially still flexible, uncured plastic material is cured, in particular solidified. In particular, these measures can include application of temperature and / or pressure.

According to the method, it is provided that during the hardening of the fiber composite material of the tubular body, an inner surface, in particular a segment of the inner side, of a, in particular end-side or terminal, first ring segment of the tubular body is pressurized from the outside against an outer surface of a mandrel introduced into the first ring segment . is pressed.

The phrase “pressurized from the outside” is intended to mean in particular that the first ring segment is subjected to a pressure from the outside, which causes the wall of the pipe segment to be pressed or pressed in the direction of, in particular on the, mandrel.

Furthermore, it is provided according to the production method that a second ring segment, in particular adjoining the first ring segment, is pressurized from the inside against an inner surface of a tool encircling at least the second ring segment.

According to the method, the inside or inside surface of the first ring segment is pressed against the outside surface of the mandrel during curing. It can thereby be achieved that the inner surface or inner side of the first ring segment is given a roughness that can be defined by the surface roughness of the outer surface of the mandrel. The same applies to the tool in connection with the outside of the second ring segment.

If, for example, mandrels or tools made of metal are used, can compared to areas in which the tubular body during curing z. B. is pressurized with a hose or a pressure piece, comparatively low surface roughness can be generated.

The advantage of the proposed method is in particular that a defined, comparatively smooth inner surface can be generated in the first ring segment, and a defined, comparatively smooth outer surface can be generated in the second ring segment. Are the first and second ring segments matched in diameter, i. H. If the outside diameter of the second ring segment is in the range of the inside diameter of the first ring segment, a pipe system can be provided which enables a simple connection of two successive pipes by plugging a first pipe segment into a second pipe segment of a subsequent pipe.

The comparatively smooth surfaces achieved during hardening by pressing against the mandrel or the tool, i.e. H. Outer surfaces of the second ring segments or inner surfaces of the first ring segments enable a comparatively tight, in particular airtight, connection between two successive tubes. With the proposed manufacturing method, a pipe system made of pipes made of fiber composite materials can thus be provided, in which two pipes can be connected to one another in a simple manner in the manner of a plug-in system.

Additional measures, such as union sleeves and the like, for sealing or securely connecting two pipes, in particular pipe ends, can, but do not necessarily have to be taken.

In the production method it can be provided that a fiber-plastic composite material, in particular a fiber-resin composite material, is used as the fiber composite material. In particular, the fiber composite material can be semi-finished products known under the term “prepreg”, ie in particular prepreg materials.

In the production method it is provided that a radially circumferential pressure piece is attached to the outside of the first ring segment, overlapping with the mandrel, and that the first ring segment is pressed against the mandrel by thermal expansion of the pressure piece.

The use of such a pressure piece has the advantage that it can be supported against the inside of a tool used in any case in the manufacture of the pipe. The first ring segment can be pressed against the outer surface or the outer jacket of the mandrel in a particularly simple manner with the formation of sufficient pressure forces with a corresponding pressure piece.

The properties of the pressure piece are preferably selected in such a way that it can be fitted or inserted into a tool in a simple manner in the state before the pipe was cured, in particular in the cold state. Furthermore, the pressure piece is preferably designed in such a way that the pressure piece expands during the hardening of the fiber composite material with an increase in temperature due to thermal expansion in such a way that the first ring segment is pressed against the mandrel, while the pressure piece on the side facing away from the ring segment at a fixed point, for example an inside of a tool or a tool half is supported. This means in particular that the pressure piece fills the free space formed between the tool and the mandrel in the cold state so that the first ring segment is pressurized.

The pressure piece, which can in particular also be referred to as a printed supplement, can in particular comprise several individual elements. In this respect, the pressure piece can be or will be composed of several elements, in particular individual elements, when carrying out the production process.

The individual elements are preferably adapted to one another in such a way that the pressure piece can be placed around the outside of the first ring segment in a completely ring-shaped manner and essentially without gaps. The pressure piece preferably comprises two half-shells, in particular with a symmetrical structure. The use of a two-part or multi-part pressure piece can be advantageous with regard to simplified production.

According to a variant of the manufacturing method, it is provided that the second ring segment is pressurized from the inside by a flexible hose, in particular a silicone hose. In this case, the application of pressure can be achieved in that the hose or the pipe, in particular the region of the pipe comprising the hose, is subjected to an overpressure or underpressure during curing. With both procedures it can be achieved that the hose inflates or expands, so that the wall of the hose is pressed against the inside of the second ring segment. In particular, when there is sufficient pressure applied, it can be achieved that the wall of the tubular body of the second ring segment is pressed or pressed against an inner surface of the tool. As a result, as already mentioned, a defined, comparatively smooth outer surface for the second segment can be achieved through a defined inner surface of the tool.

In a particularly preferred variant, the pressure hose is designed in such a way and when the method is carried out is arranged in such a way that the pressure hose extends through the second ring segment and the mandrel. For this purpose, the mandrel preferably has an axially central opening through which the pressure hose can be passed. The penetration through the second ring segment can in particular be made possible by the fact that the tool is covered with the fiber composite material in the area of the second ring segment on an inner surface, so that, to a certain extent, an inner cavity results at least in the area of the second ring segment.

The variant in which the tube penetrates both the mandrel and the second segment is advantageous with regard to a quick and efficient implementation of the manufacturing process. As far as the penetration through the mandrel is concerned, the pressure hose only presses against an inner wall of the mandrel, which is inherently dimensionally stable, in particular made of metal. With a pressure hose which also extends through the mandrel, transition areas between the first ring segment and further segments, in particular intermediate segments, of the tubular body, in particular the second ring segment, can be obtained, particularly with regard to shape and structure.

According to an advantageous embodiment of the manufacturing method, the mandrel on the outside and inside mold surfaces, in particular two pressure half-shells, of the tool are covered separately with the fiber composite material. Furthermore, it is provided that the loaded mandrel, in particular with a pressure piece, is inserted into a radially expanded segment of the tool directly adjoining the occupied mold surfaces.

In order to insert the mandrel, for example in the case of a two-part design of the pressure piece, a first half of the pressure piece can first be inserted into the tool. The occupied mandrel and then a second half of the pressure piece can then be inserted or fitted so that the first ring segment is completely separated from the pressure piece, i.e. H. is surrounded or rotated by the halves of the pressure piece.

In a variant of the manufacturing process that can be used in particular with the procedure described above, provision can also be made for the mandrel with pressure piece to be clamped between two tool halves of the tool by preferably inserting the mandrel with pressure piece into a first tool half, and then one for the mandrel and Pressure piece encompassing the second tool half is connected to the first tool half.

The variants described for covering and assembling the tool for the production and curing of the pipe enable particularly simple and inexpensive production processes with high quality of the pipes at the same time, in particular the inner surfaces of the first segment and the outer surfaces of the second segment.

In particular when using a tool as described above, it can be advantageous if, in particular before the connection of the, in particular two, tool halves, or also after connection of the, in particular two, tool halves, the pressure hose in a tool covered on the inside with fiber composite material and the mandrel, which is covered on the outside with fiber composite material, is or will be inserted or drawn in or introduced through axially centrally penetrating pipe cavity. The tube cavity can in particular be a cylindrical, free interior or cavity in the interior of the tool. This means in particular that the pressure hose can be inserted or retracted either before the tool halves are assembled or after the tool halves are assembled, and in particular connected.

It has been shown in particular that the proposed method can be used to produce a pipe, in particular a pipe system, which enables a particularly simple connection of two consecutive pipes. In particular, two pipes produced according to the manufacturing method can be connected by inserting a second segment of one pipe into a first segment of a subsequent pipe. Due to the proposed location of the printing surfaces, i. H. the outer surface of the mandrel or the inner surface of the tool result in comparatively smooth pipe surfaces, which in particular enable an airtight connection between two pipes in the plug-in connection.

A pipe is provided, in particular a ventilation and / or air conditioning pipe, preferably for aviation or aviation applications. The tubular body of the tube, which is to be understood in accordance with the above explanations, is manufactured in particular according to a manufacturing method proposed according to the invention and / or configurations and variants thereof. For advantages and advantageous effects, reference is made to the above statements.

In the case of the pipe produced according to the production method or an embodiment of the same, it may be possible that this comprises a first ring segment at the end and a, in particular adjoining, second ring segment, the first ring segment as a, in particular radially widened, socket, in particular an outer socket, in particular socket, is formed. In particular, widened sleeves are particularly well suited for the implementation of plug-in systems in which, in order to connect two pipes, sleeves of successive pipes that correspond to one another, in particular that are complementary to one another, are plugged into one another.

In the case of the pipe variant with an outer sleeve described above, it can be advantageous if the second ring segment, in particular an outer side of the second ring segment, is designed as an inner sleeve, optionally with a reduced diameter, on a side of the pipe facing away from the first ring segment.

If the diameter of the outer sleeve of the first ring segment and the inner sleeve of the second ring segment are matched to one another, in particular as indicated above, a pipe can be connected to another pipe in a simple manner by a plug connection. This facilitates the assembly of piping systems, in particular ventilation and / or air conditioning piping. For further advantages, reference is made in particular to the statements above.

According to claim 11, an arrangement for producing a pipe, in particular one of the pipes proposed above, is provided. The arrangement can also be used when carrying out the manufacturing method described above.

The arrangement comprises a tool with a first half-shell and a second half-shell, a mandrel and a pressure piece. The first and second half-shells are designed such that they can be connected to one another to form a cylindrical cavity. The arrangement provides that an inner surface of the tool composed of the first and second half-shells comprises a radially widened segment extending in the axial direction over a certain length, into which the mandrel and the pressure piece can at least partially be inserted. The radially expanded segment is preferably located at an axial end of the tool, or in other words, it is advantageous if the radially expanded segment is formed at an axial end region of the tool after the tool, which can optionally be composed of several halves or segments, has been assembled or will. In particular, this allows pipes to be produced with axially end outer sleeves.

The proposed modular arrangement enables a particularly simple and rapid production of a corresponding pipe. First, the tool halves and the mandrel can be covered with the fiber composite material. Reference is also made to the above statements. The mandrel with the pressure piece can then be inserted into one half of the tool. Is preferred or the mandrel is covered with fiber composite material in such a way that the fiber composite material placed on the mandrel, in particular in a protruding area or overlap area, overlaps with directly adjoining fiber material of the occupied tool. In this way, a fixed connection between the fiber material of the loaded mandrel and the fiber material of the loaded tool is possible in particular.

After inserting the mandrel and, if necessary, the pressure piece, the second half-shell can be connected to the first half-shell of the tool. At this stage or, if necessary, before the pressure piece is fully inserted or before the second half-shell is fastened or placed on, the pressure hose can, as already stated, be inserted or introduced. Reference is also made here to the above statements.

According to a variant of the arrangement, the pressure piece is formed from at least two half-shells, and the assembled half-shells have an inner diameter which essentially corresponds to an outer diameter of an outer shaped surface of the mandrel. Such a pressure piece can and can be inserted into the tool in a simple manner.

In the case of a two-part pressure piece, in particular, one half of the pressure piece can be inserted into the tool, followed by inserting the loaded mandrel and a further step of inserting the second half of the pressure piece.

For further advantages and refinements, reference is made to the above statements, which are used mutatis mutandis here.

According to a variant of the arrangement, the mandrel is designed in the manner of a hollow cylinder and, at one axial end, preferably has a radially outwardly extending, in particular circumferential, flange. Due to the hollow-cylindrical configuration, for example, the pressure hose can be easily inserted into the tool. Reference is also made to the above statements. The circumferential flange can be useful in particular for aligning the mandrel on the tool, in particular on each of the tool halves. In addition, the flange can be used or serve to mold any radially extending flanges or tabs onto the first ring segment. Because of further advantages and advantageous effects, reference is made in particular to the statements above and below.

The invention described herein makes it possible, in particular in the end area of an FRP pipe (FRP = fiber-reinforced plastic), or a pipe that is similar in structure and construction, to create a smooth pipe end area. In particular, it is possible to produce a defined inner surface in the pipe end area, whereas the part of the pipe running away from the pipe end area in the axial direction at least for the most part, preferably essentially completely, depicts a defined outer area, i.e. H. has a defined outer surface. Defined inner surface and outer surface are intended to mean that corresponding surfaces have in particular defined or essentially defined values with regard to surface roughness, etc.

In order to produce the tubes, it is provided in particular that the tube end region is laminated onto a mandrel, which is then embedded in the tool. The pressure on the component is applied in the end area preferably via a pressure insert that preferably encircles the pipe end area from the outside and that expands under temperature.

By using an inner mandrel with an outer pressure insert, it is possible to produce a one-piece climatic tube with a smooth inner surface at one or more tube ends. Such pipes can be used to create a pipeline using the plug-in concept (plug-socket system). In particular, with a corresponding configuration, several tubes can be plugged into one another at the ends, the smooth inside of one tube end coming into contact with the smooth outside of the subsequent or preceding tube end.

Due to the defined surfaces, the pipes connected in this way can achieve a comparatively high level of tightness.

The pipe ends can be glued together in a subsequent step for further sealing.

Segments with a defined outside (plug) are preferably produced using the "NDS" (low pressure hose) technique, and segments with a defined inside (sleeve) are preferably produced using a vacuum lamination technique using a mandrel.

A combined tool concept is proposed which depicts defined inner surfaces in certain partial areas of the pipe and defined outer surfaces in other areas.

Advantages result in particular from the achievable lighter construction, a reduced throughput time in production, and the lower number of individual parts.

In particular, an advantageous integrated design of a tool with silicone pressure coating and "NDS technology" can be implemented for the formation of smooth inner surfaces in the area of the component sleeves. The combination of mandrel and hose in one tool is particularly advantageous.

• 1 einen Axialschnittschnitt einer zur Herstellung eines Rohrs ausgebildeten Werkzeuganordnung; und
• 2 einen Querschnitt durch ein entsprechend hergestelltes Rohr.

The production of a pipe proposed herein and a corresponding pipe and a tool arrangement are explained in more detail below with reference to the figures. Show it:

• 1 an axial sectional view of a tool arrangement designed to produce a pipe; and
• 2 a cross section through a correspondingly manufactured pipe.

It should be noted that the representation of the figures is not necessarily true to scale. Furthermore, the distances and dimensions of elements or components can be shown larger than absolutely necessary for reasons of clearer recognizability.

The tool arrangement 1 includes a tool base 2 , a tool head 3 , a thorn 4th , a first half-shell 5 and a second half-shell 6th comprehensive pressure piece. The arrangement also comprises a connection plate to be attached axially at the end 7th and an end plate to be attached to an axially remote side 7a . The tool arrangement 1 further comprises a pressure hose 8th .

The pipe can be produced by the following method, with particular reference to FIG 1 is taken.

First of all, the mandrel released from the tool assembly 4th and separately from each other the upper part of the tool 3 as well as the lower part of the tool 2 with a semi-finished product made of a fiber composite material, in particular with so-called prepregs P , be occupied. The order in which they are assigned can essentially be chosen freely.

An outer surface of the mandrel becomes concrete 4th and respective inner surfaces of the tool base 2 and tool head 3 separately covered with prepreg material. The lower part of the tool 2 and tool head 3 are in each case in mold surfaces intended for curing 9 with prepreg material P occupied, while at the axial ends existing radially recessed surfaces, which have a radially expanded segments 10 not with prepreg material P be occupied.

The thorn 4th is so with prepreg material P occupied so that this axially from the mandrel 4th survives, and with the arrangement of the occupied mandrel 4th in the tool, as in the 1 shown with the prepreg material P of the upper part of the tool 3 and lower part of the tool 2 in an overlap area U overlaps. By covering the respective outer surface of the mandrel 4th and the respective inner surfaces of the lower tool part 2 and tool head 3 with sufficient overlap U it can be achieved that the separately coated segments are securely connected to one another during curing.

The finished mandrel 4th can then, possibly together, or after inserting the first half-shell 5 of the pressure piece into the expanded segment 10 into the fully occupied lower part of the tool 2 can be used. Then, if not already together with the mandrel 4th happen the second half-shell 6th of the pressure piece on the mandrel 4th be placed in such a way that this is axially aligned with the first half-shell 5 comes to rest.

After the appropriate arrangement and alignment of the components mentioned, the occupied upper tool part 3 on the one with thorn 4th and pressure piece provided lower tool part 2 placed on, and connected to this, in particular screwed.

Next can the pressure hose 8th in the tool assembly 1 formed cylindrical tube cavity, which the two tool halves and the mandrel 4th axially penetrates, are used. Inserting the pressure hose 8th can also be done at a different point in time, for example before the upper part of the tool is attached 3 , respectively.

As a further step, the connection plate 7th and the end plate 7a be attached, with which the tool arrangement for curing the prepreg material P is completely assembled.

For curing the prepreg material P this is subjected to a suitable curing temperature and pressure. Pressurization of the inside wall of the upper part of the tool 3 and lower part of the tool 2 adjacent prepreg material P takes place via the pressure hose 8th , which when pressurized the prepreg material P against the inner wall of the lower part of the tool 2 or upper part of the tool 3 presses or presses.

An impact on the outside of the mandrel 4th adjacent prepreg material P takes place in that the pressure piece 5 , 6th thermally expanded and so, supported in the radially expanded segments 10 the prepreg material P against the outer surface of the mandrel 4th presses.

After curing is complete, the pipe, in particular the pipe body, can be removed from the tool arrangement. Due to the fact that the prepreg material P in a first ring segment 11 with an inside against the smooth outside of the metal-made mandrel 4th is pressed with a defined surface, in particular surface roughness, has the first ring segment 11 a defined, in particular comparatively smooth, inner surface.

The same applies to the tubular body at least in one of the first ring segment 11 axially facing away from the second ring segment 12 , whereby here by pressing the prepreg material P to a defined inner surface of the lower tool part 2 and tool head 3 the second ring segment 12 has a defined, in particular comparatively smooth, outer surface.

The thorn 4th as well as the lower part of the tool 2 and the upper part of the tool 3 are at least in the area of the first and second ring segment 11 and 12 formed with appropriately defined, in particular smooth surfaces. The smooth inner surface of the first ring segment created on the pipe body 11 and the smooth outer surface of the second ring segment 12 enable the implementation of a pipeline plug-in system.

In particular, the second ring segment can with appropriately designed diameters 12 into a first ring segment 11 a subsequent pipe body or pipe can be inserted. As a result of the comparatively smooth inner and outer surfaces, a connection between two pipes that is tight against air or air currents, for example, can be established. If necessary, first and second ring segments connected to one another can also be glued to one another. For example, adhesive bonding of the contact surfaces between the first and second ring segment should be mentioned here.

It should be noted that the thorn 4th at one axial end, in the illustration of 1 on the left, a flange extending radially outward 16 may have. This flange 16 is preferably provided to the mandrel 4th , if necessary together with the pressure piece properly relative to the lower part of the tool 2 and tool head 3 to position and align. The mandrel can also be used to attach to the first pipe segment 11 to form radially protruding flanges or tabs.

As in 1 is at least indicated, the tubular body in the area of the first ring segment 11 be designed as an, in particular radially expanded, outer sleeve, the inner diameter of which corresponds to the outer diameter of the tubular body in the region of the second ring segment 12 is adapted.

2 shows a cross-section of a pipe produced according to the method described above using the corresponding tool arrangement 13 or a tubular body. How out 2 can be seen, points the pipe 13 on one, in the representation of the 2 the left, axial end one in the area of the first ring segment 11 formed outer sleeve on 14. The outer sleeve, which is expanded radially in relation to the rest of the pipe body 14th has because of the system on the mandrel 4th a defined and comparatively smooth inner surface during hardening.

At the opposite end of the tube 13 has this one in the area of the second ring segment 12 trained inner sleeve 15th on. Due to the contact with the inner surface of the lower part of the tool 2 and tool head 3 during the hardening process, the inner sleeve 15th a defined and comparatively smooth outer surface.

When using two pipes manufactured with corresponding diameters 13 can the inner sleeve 15th in the outer sleeve 14th of a subsequent pipe, in particular being inserted, with a tight, in particular airtight, connection of the two pipes, in particular because of the comparatively smooth outer and inner surfaces 13 can be achieved. This significantly facilitates the construction or assembly of a ventilation and / or air conditioning system, in particular in aircraft cabins.

In particular in connection with the exemplary embodiment described in relation to the figures, it becomes clear that the manufacturing method proposed herein, pipe and the proposed tool arrangement, an easy-to-use and comparatively easy-to-install pipeline system, in particular for ventilation and / or air conditioning applications in aircraft or for supplies the aircraft sector.

List of reference symbols

1

Tool arrangement

2

Tool base

3

Tool head

4th

mandrel

5

first half-shell

6th

second half-shell

7th

Connection plate

7a

End plate

8th

pressure hose

9

Forming surface

10

expanded segment

11

first ring segment

12

second ring segment

13

pipe

14th

Outer sleeve

15th

Inner sleeve

16

flange

Claims (13)

Production method for a pipe (13), in particular a ventilation or air conditioning pipe, wherein a pipe body at least partially forming the pipe (13) is produced from a curable fiber composite material (P), with an inner surface of a first one during the curing of the fiber composite material (P) of the pipe body Ring segment (11) of the tubular body, pressurized from the outside, is pressed against an outer surface of a mandrel (4) inserted into the first ring segment (11), and a second ring segment (12) of the tubular body, in particular adjoining the first ring segment (11) pressurized from the inside against an inner surface of a tool (2, 3) that encircles at least the second ring segment (12), with a radially encircling pressure piece (5, 6) overlapping with the mandrel (4) on the outside of the first ring segment (11) ) is attached, and wherein the first ring segment (11) is pressed against the mandrel (4) by thermal expansion of the pressure piece (5, 6) approx. Manufacturing process according to Claim 1 , wherein the tubular body from a fiber composite material (P) in the form of a fiber-plastic composite material, in particular a fiber-resin composite material, in particular a prepreg material (P) is produced. Manufacturing process according to Claim 1 , wherein the pressure piece (5, 6) is composed of several elements, preferably two half-shells (5, 6). Manufacturing process according to Claim 1 , wherein the pressure piece (5, 6) is supported against an inner wall of the tool (2, 3). Manufacturing process according to one of the Claims 1 to 4th , the second ring segment (12) being pressurized from the inside by a flexible pressure hose (8), the pressure hose (8) preferably being arranged through the second segment (12) and the mandrel (4). Manufacturing process according to one of the Claims 1 to 5 , wherein the mandrel (4) and inside mold surfaces (9), in particular two pressure half-shells (2, 3), of the tool are separately covered with the fiber composite material (P), the occupied mandrel (4), in particular together with the pressure piece (5 , 6), is inserted into a radially widened segment (10) of the tool (2, 3) directly adjoining the occupied mold surfaces (9). Manufacturing process according to Claim 6 wherein the mandrel (4) with pressure piece (5, 6) is clamped between two tool halves (2, 3) of the tool by inserting the mandrel (4) with pressure piece (5, 6) into a first tool half (2), and then a second tool half (3) encompassing the mandrel (4) and the pressure piece (5, 6) is connected to the first tool half (2). Manufacturing process according to Claim 7 , wherein, in particular before the connection of the tool halves (2, 3), the pressure hose (8) axially into a tool (2, 3) coated on the inside with fiber composite material (P) and the mandrel (4) coated on the outside with fiber composite material (P) centrally penetrating pipe cavity is introduced or is. Manufacturing process according to one of the Claims 1 to 8th , wherein the tube (13) is produced with a first ring segment (11) at the end and a, in particular adjoining, second ring segment (12), the first ring segment (11) as a, in particular radially widened, sleeve (14), in particular socket, is formed. Manufacturing process according to Claim 9 The second ring segment (12), in particular an outer side of the second ring segment (12), on a side of the tube (13) facing away from the first ring segment (11) is designed as an inner sleeve (15), optionally with a reduced diameter. Arrangement (1) for producing a pipe (13), in particular by a production method according to one of the Claims 1 to 10 , comprising a tool with a first half-shell (2) and a second half-shell (3), a mandrel (4) and a thermally expandable pressure piece (5, 6), wherein the first (2) and second half-shell (3) to form a cylindrical cavity can be connected to one another, wherein an inner surface of the tool composed of the first and second half-shell preferably comprises a radially widened segment (10) extending in the axial direction over a certain length, into which the mandrel (4) and the pressure piece ( 5, 6) can be used at least in part, so that a ring segment (11) of the pipe (13) to be produced located between the mandrel (4) and pressure piece (5, 6) is acted upon by thermal expansion of the pressure piece (5, 6) during manufacture with pressure. Arrangement (1) according to Claim 11 , wherein the pressure piece (5, 6) is formed from at least two half-shells (5, 6), and wherein the assembled half-shells (5, 6) have an inner diameter that essentially corresponds to an outer diameter of an outer shaped surface of the mandrel (4) corresponds. Arrangement (1) according to one of the Claims 11 or 12 , wherein the mandrel (4) is designed like a hollow cylinder and preferably has a radially outwardly extending, in particular circumferential, flange (16) at one axial end.

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