EP2165778A1 - Production method, extrusion press and die for an extruded hollow profile and extruded hollow profile and heat exchanger with an extruded hollow profile - Google Patents

Abstract

The manufacturing method involves providing a mantle with a cavity facing an inner layer, where the inner layer is formed during extrusion of an extruded hollow profile. A blank is extruded by a die-plate (10) of an extrusion press to form the mantle of the extruded hollow profile. Independent claims are included for the following: (1) an extrusion press for an extruded hollow profile, particularly for an extruded pipe; and (2) a heat exchanger.

Description

The invention relates to a production method for an extruded hollow profile on an extruder, which extruded hollow profile comprises: a jacket and a cavity and wherein the jacket is provided with at least one inner layer facing the cavity. The invention further relates to an extruder for such an extruded hollow section, wherein the extruder comprises: a die, a receptacle for a blank and a discharge area for the shell of the extruded hollow section. The invention also relates to a die for an extrusion press for such an extruded hollow profile, wherein the die comprises: a receptacle for a blank and a take-off region for the shell of the extruded hollow profile. Furthermore, the invention relates to an extruded hollow profile, in particular an extruded tube, comprising: a jacket and a cavity and wherein the jacket is provided with at least one inner layer facing the cavity. The invention also leads to a heat exchanger with the extruded hollow profile.

An extruded hollow profile, in particular an extruded tube, of the type mentioned, may be provided in particular for use in a heat exchanger of the type mentioned. To increase the durability of extruded hollow profiles, especially when used in heat exchangers, it is known after the forming Extrusion process to subject the hollow section to another - separate - coating process to attach to the inside of the shell at least one cavity facing the inner layer. The inner layer provided in this way can have a wide variety of functions, for example against abrasion or corrosion.

Basically, for example EP 0 473 103 B1 or DE 694 02 800 T2 or US 4,262,627 A method is known for mounting, on the inside of a jacket of a pipe of a general type, an inner layer facing the cavity, as a so-called "liner" material EP 0473103 B1 a method for treating water pipes and gas pipes, in which a sponge is introduced for a multi-branch piping system after the coating step for forming the coating surface in the pipeline under compressed air. Out US 4,262,627 It is known to provide two probes for the production of tubes with a large cross-section, wherein an abrasion probe is to prime an inner surface and a coating probe is provided for coating the inner surface. Out DE 794 02 800 T2 a method for coating the inner surface of hydrothermal plumbing tubes is known in which, after coating the inside of the pipe with resinous liquid, a gasketed head is inserted into the pipe and is moved by means of compressed air within the pipe, the inside of the Tube is scraped off.

Processes of this type are not suitable for the production of extruded hollow profiles, which regularly have a comparatively small opening cross-section, in particular not for the production of extruded hollow profiles, which are designed for use in a heat exchanger. In addition, the introduction of processing probes in a hollow profile associated with high costs, which should be avoided.

In principle, extrusion processes for hollow sections such as extruded tubes or the like. for example DE 102 32 608 B4 known. A device in the form of an extruder and a suitable die for representing an extruded profile, for example, in EP 0 329 567 B1 disclosed.

A manufacturing method for a component, in particular intended for use in a heat exchanger, of a general type, which is suitable for adding an inner layer to a cavity-facing side, is known, for example, from the application DE 10 2007 035 221 A1 the applicant known. In principle, such a method is also suitable for the coating of comparatively complicated three-dimensional internal structures such as inner tube side with flow guide elements or the like .. Basically, such a method also proves to be advantageous to attach a uniform layer on the inside of a hollow profile. When used for heat exchangers, this has the advantage that heat transfer can be realized comparatively well, ie with high efficiency. The aforementioned method based on a CVD process of the applicant is in the context of a manufacturing process for an extruded hollow section on an extruder still in need of improvement.

At this point, the invention is whose task is to provide a method and an apparatus of the type mentioned above and an extruded profile and a heat exchanger, by means of which a cavity of an extruded hollow profile facing inner layer is particularly reliable and at the same time easy to apply ,

The object is achieved in terms of the manufacturing process by a manufacturing method of the type mentioned, in which according to the invention it is provided that the inner layer is formed during extrusion of the extruded hollow profile.

In principle, with regard to the application of the inner layer, the in DE 10 2007 035 221 A1 said process parameters are advantageously used to achieve a relatively uniform and continuous inner layer, which to allow a particularly advantageous heat transfer in an extruded hollow section, in particular in an extrusion tube, which is designed for a heat exchanger. The disclosure of the DE 10 2007 035 221 A1 is hereby incorporated in the disclosure of the present application, in particular with regard to the process parameters for the attachment of the inner layer

The invention is further based on the consideration that in the production of extruded hollow sections special conditions are present, which make it possible to apply a cavity facing inner layer in a particularly advantageous manner. The invention has recognized that an advantageous application of an inner layer is possible if this is formed during the extrusion of the extruded hollow profile. The essential finding of the invention lies in the fact that process conditions during extrusion can be used advantageously for a coating process.

• Strangpressen eines Rohlings durch eine Matrize der Strangpresse unter Bildung des Mantels des Strangpress-Hohlprofils, und
• Einbringen eines Fluids in den Hohlraum des Mantels unter Bildung der Innenschicht, wobei die Bildung der Innenschicht unmittelbar nach der Bildung des Mantels erfolgt.

Within the scope of a particularly preferred development of the concept of the invention, it is provided that the production method has in particular the steps:

• Extruding a blank through a die of the extruder to form the shell of the extruded hollow profile, and
• Introducing a fluid into the cavity of the shell to form the inner layer, wherein the formation of the inner layer takes place immediately after the formation of the shell.

A particularly preferred embodiment provides that the fluid is a gas. In particular, the formation of the inner layer can take place by means of a CVD process. This is done in detail on the advantageous parameters of a CVD process, as in DE 10 2007 035 221 A1 is referenced.

Accordingly, the concept of the invention also leads to an extrusion press for an extruded hollow section according to the aforementioned type, wherein according to the invention a fluid feed opening into the draw-off region is provided for a fluid suitable for forming the inner layer. Accordingly, the concept of the invention also leads to a die for an extruder according to the aforementioned type, according to the invention a fluid inlet opening into the extraction area is provided for a fluid suitable for forming the inner layer.

The invention has recognized that by establishing a fluid feed in the draw-off region of an extruder or die, a fluid, in particular a gas, preferably a reactive gas, e.g. in the context of a CVD process, can be introduced into the cavity of the extruded profile, so that an inner coating by introducing the fluid can take place immediately after the extrusion of the blank, in particular directly on the extruder. Thus, in a particularly preferred development, the production method provides for extruding a blank from a receptacle through a die into a draw-off region for a shell of the extruded hollow profile and introducing the fluid into the cavity in the draw-off region. Advantageously, in the context of the concept of the invention, the introduction of the fluid takes place immediately after, in particular through, the die.

This eliminates the need for elaborate additional separate process steps, which are necessary in the prior art; Rather, all the requirements for an inner coating in the context of the manufacturing process during extrusion can be provided or be provided in an extruder in the exhaust area or in a die in the fume hood.

It has been shown to be advantageous that, according to the concept of the invention, an extruded hollow profile, in particular an extruded tube, comprises: a shell and a cavity, the shell being provided with at least one inner layer facing the cavity, and wherein the inner layer during extrusion of the extruded hollow profile is formed.

Such an inner layer is advantageously formed continuously and uniformly. Above all, a CVD inner layer proves to be advantageous in the context of the concept of the invention.

The invention also leads to a heat exchanger with an extruded hollow profile of the aforementioned type.

Further advantageous developments of the invention can be found in the subclaims and specify in detail advantageous possibilities to realize the above-described concept within the scope of the problem as well as with regard to further advantages.

In the context of a particularly preferred development, the die has a die axial part and a die peripheral part. It has been found that the introduction of the fluid can preferably take place through the die axial part. In particular, provision is made for the die axial part to be surrounded by the die peripheral part.

In particular, to form an extruded hollow profile, preferably an extruded tube, a gap is provided between the female axial part and the female part peripheral part. An interruption of the gap can serve to guide the fluid supply according to the concept of the development of the female part-peripheral part to the female axial part.

Advantageously, at least two brackets are provided on the die axial part, which hold the die axial part on the female part peripheral part. In a particularly preferred embodiment, provision is made for at least one of the holders to be used for arranging the fluid supply from the female-peripheral part to the female axial part.

A fluid feed opening into the draw-off area advantageously opens into the draw-off area in the axial direction. It has also been found that a number of mouths can be advantageous. Thus, one, two or more mouths may be provided. For example, in that a fluid supply branches off in the die axial part in a suitable manner in order to allow a suitable number of openings to the edge of the die axial part.

In particular, to form an extruded tube, the die, preferably the die axial part and the die peripheral part, constructed substantially centrosymmetric.

Embodiments of the invention will now be described below with reference to the drawing. This is not necessarily to scale the embodiments, but the drawing, where appropriate for explanation, executed in a schematized and / or slightly distorted form. With regard to additions to the teachings directly recognizable from the drawing reference is made to the relevant prior art. It should be noted that various modifications and changes may be made in the form and detail of an embodiment without departing from the general idea of the invention. The disclosed in the description, in the drawing and in the claims features of the invention may be essential both individually and in any combination for the development of the invention. In addition, all combinations of at least two of the features disclosed in the description, the drawings and / or the claims fall within the scope of the invention. The general idea of the invention is not limited to the exact form or detail of the preferred embodiment shown and described below or limited to an article which would be limited in comparison to the subject matter claimed in the claims. For the given design ranges, values within the stated limits should also be disclosed as limit values and be arbitrarily usable and claimable.

Fig. 1:

eine besonders bevorzugte Ausführungsform einer Matrize für eine Strangpresse, zur Herstellung eines Strangpress-Hohlprofils in einer Draufsicht (B), einer Seitenansicht (A) und einer Stirnansicht (C) - dies zur Erläuterung einer besonders bevorzugten Ausführungsform eines Herstellungsverfahrens und einer Matrize und Strangpresse gemäß dem Konzept der Erfindung;

Fig. 2:

eine bevorzugte Ausführungsform eines Strangpress-Hohlprofils gemäß dem Konzept der Erfindung in Form eines Strangpress-Rohres.

In detail, the drawing shows in:

Fig. 1:

a particularly preferred embodiment of a die for an extruder, for producing an extruded hollow profile in a plan view (B), a side view (A) and an end view (C) - this for explaining a particularly preferred embodiment of a manufacturing method and a die and extruder according to the concept of the invention;

Fig. 2:

a preferred embodiment of an extruded hollow profile according to the concept of the invention in the form of an extruded tube.

Fig. 1 shows a die 10 for use in an extruder not shown for producing an in Fig. 2 Extruded hollow sections 1 shown in detail in the form of an extruded tube. The extruded tube 1 has for this purpose: a jacket 3 and a cavity 5, the jacket 3 facing on its inner side 7 with a cavity 5. Inner layer 9 is provided. In the present case, the inner layer 9 is formed as a CVD inner layer, which is formed in the context of a CVD process, which is implemented in an extrusion production process. In particular, the in DE 10 2007 035 221 A1 disclosed process parameters are used.

The die 10 is in Fig. 1 schematically shown and in the present case has a female axial part 11 and a female peripheral part 12. For this purpose, the die axial part 11 is arranged essentially on an extrusion axis 13, while the die peripheral part 12 surrounds the die axial part 11 in a circumferential manner. To produce the shell 3, a blank, not shown, is pressed by a receptacle 15 through the die 10 into a withdrawal region 17 to form the shell 3 of the extruded tube 1. For this purpose, a non-illustrated press die of the extruder can be used, for example, to move the blank or the die 10 or to cause in other analogous manner, the deformation of the blank on the die 10. The tempered to a suitable extrusion temperature blank to meet in the receptacle 15 on the head of the female axial part 11, deforms on this and is pressed into mantle-shaped extrusion openings 19 between female axial part 11 and female peripheral part 12 to then in a flowing motion to form the extruded shell 3 in the vent area 17. The take-off area 17 expands to this directly behind the female axial part 11 tapered to account for a slight expansion behavior of the still highly tempered shell 3.

Following the concept of the invention, the die 10, in the present case the die axial part 11, is provided with a number of - in the present case symbolically two - gas feeds 21. In the present case, the gas supply lines 21 have openings 23 in the cavity 5 of the jacket 3 and thus bring the reactive gas 25 in the cavity 5 of the shell 3 a. Following the concept of the invention, therefore, the introduction of the reactive gas 25 takes place immediately after the die 10.

In general, the concept of the invention provides that the die 10 has openings of fluid feeds everywhere, which lead into a cavity of the extruded profile 1. As a result, a, for example, from a arranged outside the extruder reactive gas generator, discharged reactive gas 25 via the gas supply lines 21 and the mouths 23 at desired locations in the extruded hollow section 1.

Due to the tempering of the jacket 3 which continues in the draw-off region 17, a heat energy advantageous for the CVD process is available as activation energy for the reaction of the reactive gas 25. For this reason, the reactive gas 25 reacts on the inner side 7 of the jacket 3 to form the inner layer 9. This regularly leads, as was recognized by the concept of the invention, to a particularly uniform and continuous inner layer 9.

The concept of the invention has thus surprisingly synergistically combined and advantageously utilized the process conditions of an extrusion process and a CVD process. Advantageously, subsequent process steps which would have been necessary according to the prior art are eliminated. On the other hand, the achieved inner layer 9 of particularly good quality in the method proposed here. The resulting from the hot forming of the blank to the shell 3 heat is advantageously used not only as activation energy in the CVD process, but also degraded and leads to a total of a suitable microstructure in the resulting extrusion tube. 1

While the invention has been described herein with reference to a particular symbolically illustrated die 10, it is to be understood that this embodiment is not intended to be limiting. Rather, the concept of the invention can also be applied to any extrusion dies which provide corresponding fluid feeds for reactive fluids to introduce them into a cavity of an extruded hollow section and there form an inner layer within the framework of e.g. To generate CVD process.

In summary, the invention relates to a manufacturing method for an extruded hollow section 1 on an extruder, in particular for an extruded tube on an extruder, which extruded hollow section 1 comprises: a shell 3 and a cavity 5 and wherein the shell 3 with at least one of the cavity 5 facing inner layer 9 is provided, wherein the inner layer 9 is formed during extrusion of the extruded hollow section 1.

LIST OF REFERENCE NUMBERS

1

Extruded hollow section

3

coat

5

cavity

7

inside

9

inner layer

10

die

11

Template-axial part

12

Template peripheral part

13

Extrusion axis

15

admission

17

removal area

19

Extruded openings

21

gas supplies

23

mouths

25

reactive gas

Claims (15)

Production method for an extruded hollow profile (1) on an extruder, in particular for an extruded tube on an extruder,
which extruded hollow profile (1) has a jacket (3) and a cavity (5) and wherein the jacket (3) is provided with at least one inner layer (9) facing the cavity (5),
wherein the inner layer (9) during extrusion of the extruded hollow profile (1) is formed. Manufacturing method according to claim 1, characterized by the steps: - Extruding a blank through a die (10) of the extruder to form the jacket (3) of the extruded hollow profile (1), and - Introducing a fluid in the cavity (5) of the jacket (3) to form the inner layer (9), wherein the formation of the inner layer (9) takes place immediately after the formation of the jacket (3). Manufacturing method according to claim 1 or 2, characterized in that the introduction of the fluid immediately after the extrusion of the blank, in particular on the extruder, takes place. Manufacturing method according to one of claims 1 to 3, characterized in that the extrusion of a blank from a receptacle (15) by a die (10) in a take-off region (17) for a jacket (3) of the extruded hollow profile (1) takes place and the introduction of the fluid into the cavity (5) takes place in the draw-off region (17). Manufacturing method according to one of claims 1 to 4, characterized in that the introduction of the fluid takes place immediately after, in particular by, the die (10). Manufacturing method according to one of claims 1 to 5, characterized in that the die (10) has a die Axiaiteil (11) and a die-peripheral portion (12) and the introduction of the fluid through the die axial part (11). Manufacturing method according to one of claims 1 to 6, characterized in that the fluid in the form of a gas (21) is formed, in particular the formation of the inner layer (9) by means of a CVD process (Chemical Vapor Deposition) takes place. Manufacturing method according to one of claims 1 to 7, characterized in that the jacket (3) of the extruded hollow profile (1) is tempered in the extrusion of the blank and the inner layer (9) is formed on the still tempered jacket (3). Manufacturing method according to one of claims 1 to 8, characterized in that the inner layer (9) is formed by reaction of the fluid at an inner side (7) of the jacket (3) facing the cavity (5). Extruder for an extruded hollow profile (1), in particular for an extruded tube, which extruded hollow profile (1) comprises a shell (3) and a cavity (5) and wherein the shell (3) with at least one of the cavity ( 5) facing the inner layer (9), and wherein the extruder comprises: a die (10), a receptacle (15) for a blank and a take-off area (17) for the jacket (3) of the extruded hollow profile (1), further characterized by a fluid inlet leading into the draw-off region (17) for a fluid suitable for forming the inner layer (9). Die (10) for an extruder, for an extruded hollow profile (1), in particular for an extruded tube, which extruded hollow profile (1) comprises: a jacket (3) and a cavity (5) and wherein the jacket (3 ), wherein the die (10) has a receptacle (15) for a blank and a take-off region (17) for the jacket (3) of the extruded hollow profile ( 1), further characterized by a in the draw-off region (17) opening fluid supply for a for forming the inner layer (9) suitable fluid. Die (10) according to claim 10, characterized in that a die-axial part (11) and a die-peripheral part (12) is provided and the fluid supply in the die-axial part (11) is arranged. Extruded hollow profile (1), in particular extruded tube (1), preferably made of metal, such as aluminum or an aluminum alloy,
comprising: a jacket (3) and a cavity (5) and wherein the jacket (3) is provided with at least one inner layer (9) facing the cavity (5),
wherein the inner layer (9) is formed during the extrusion of the extruded hollow profile (1),
in particular according to a production method according to one of claims 1 to 9. Extruded hollow profile (1) according to claim 13, characterized in that the inner layer (9) is continuous and uniform, in particular a CVD inner layer (9). Heat exchanger with an extruded hollow profile (1) according to claim 13 or 14.

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