EP3469196B1 - Method for producing a honeycomb structure - Google Patents

Description

The present invention relates to a method for producing a honeycomb structure. The honeycomb structure is in particular formed by at least one, at least partially structured metal foil which is stacked and / or wound and / or wound to produce the honeycomb structure. The honeycomb structure at least partially has flow channels through which a fluid can flow through the honeycomb structure from a first end face to a second end face. Partially structured means that the metal foil is partly smooth, partly with e.g. B. sinusoidal waves, with holes, with deflecting structures or the like. The honeycomb structure is preferably used to treat exhaust gas, in particular exhaust gas from an internal combustion engine in a motor vehicle, e.g. B. a car, a truck, a ship, an aircraft used.

The honeycomb structure has one or more air gaps which extend along an axial direction, in particular from one end face to the other end face, metal foils arranged adjacent to one another being arranged in an electrically insulated manner by the air gap. The air gap also extends through the honeycomb structure in a circumferential direction and / or a radial direction. The air gap serves z. B. the electrical insulation in an electrically heated honeycomb body. The course of a current path through the honeycomb body is at least partially predetermined by the air gap. Such electrically heated honeycomb bodies with an air gap are, for. B. from the WO 2013/150066 A1 known.

The DE 197 04 521 A1 discloses a method for producing a honeycomb body with a plurality of channels permeable to a fluid from a plurality of at least partially structured sheets, in which at least one stack is layered from a plurality of at least partially structured sheets. The stack is placed in a mold and held in it by a wrapping device in the central region of the stack. The stack is then subjected to a wrapping process until a predetermined degree of wrapping of the stack is reached. At least during the wrapping process, a structure formed in a central area with structures of the structured sheets of the stack lying relative to one another is retained.

The EP 0 218 062 A1 discloses a carrier matrix which is wound from a carrier tape profiled in its transverse direction. The carrier matrix has deflections of the carrier tape, the deflections being arranged in planes. The deflections are generated during the winding process by inserting deflection pins between the corresponding winding layers. The deflection pins are inserted depending on the desired cross section of the support matrix between the winding layers, so that after the winding process and after the removal of the deflection pins, the support matrix can be inserted into a jacket which has the cross section of the support matrix.

The WO 2013/150066 A1 discloses an electrical connection of a plurality of sheet metal layers of a honeycomb body to a connecting pin, the honeycomb body having a metal jacket with an inner circumference through which the connecting pin is passed in an electrically insulating manner in a bushing. The sheet layers are alternately arranged roughly structured and finely structured or smooth sheets.

The CN 105 464 766 A. discloses a method for producing an electrically heatable carrier body, the honeycomb body being formed from structured and smooth layers. The carrier has a heating core and an insulation body. Solder is placed on the heater core while none Solder material is placed on the insulation body before the layers are joined together. The insulator is removed after soldering, creating an electrically non-conductive area.

The JP H09 174179 A discloses a metallic honeycomb body which is optimized in that the winding tension can be increased when the honeycomb body is produced in order to obtain a stable body. For this purpose, a tension-generating tool and a tension-sensing tool are used in the manufacturing process.

To introduce an air gap into a honeycomb structure, previously oxidized smooth and corrugated foils (oxidized, at least partially structured metal foils) are used in the honeycomb structure with, which are then removed from the honeycomb structure after the soldering process.

Due to the elastic stacking of the metal foils, there may be an uneven stress distribution in the honeycomb structure, which can lead to a negative soldering quality (lack of connection of metal foils arranged adjacent to one another). Furthermore, when these metal foils producing the air gap are removed from the honeycomb structure after the soldering process, the honeycomb structure can be damaged, so that repair measures or new production of the honeycomb structure are necessary. In addition, the removal of these metal foils is very time-consuming and cannot be reproduced. Automation of the manufacturing process is therefore difficult. The removed metal foils cannot be used again and are disposed of as scrap.

It is therefore an object of the invention to at least partially solve the problems described with reference to the prior art and, in particular, to provide a method for producing a honeycomb structure with an air gap, in which a uniform prestressing in the honeycomb structure is ensured before and during a connection process Destruction of the means for generating the air gap is avoided, the process can be automated and reuse of the means used for generating the air gap is made possible.

These objects are achieved with a method according to the features of independent claim 1. Further advantageous configurations of the invention are specified in the dependent claims. It should be pointed out that the features listed individually in the dependent claims can be combined with one another in a technologically sensible manner and define further refinements of the invention. In addition, the features specified in the claims in the Description in more detail and explained, wherein further preferred embodiments of the invention are shown.

1. a. Bereitstellen der zumindest einen Metallfolie;
2. b. Bereitstellen eines Formtellers mit einer Auflagefläche und mindestens einer sich in einer axialen Richtung von der Auflagefläche erstreckenden ersten Stegstruktur, wobei sich die erste Stegstruktur zudem in einer Ebene parallel zu der Auflagefläche erstreckt und den in der Wabenstruktur zu erzeugenden Luftspalt abbildet;
3. c. Anordnen der zumindest einen Metallfolie auf der Auflagefläche zwischen der ersten Stegstruktur.

In this context, a method is proposed for producing a honeycomb structure comprising at least one at least partially structured metal foil, the metal foil being arranged in parts of the honeycomb structure so as to be electrically insulated from an adjacent metal foil by an air gap, at least comprising the following steps:

1. a. Providing the at least one metal foil;
2. b. Providing a molding plate with a support surface and at least one first web structure extending in an axial direction from the support surface, the first web structure also extending in a plane parallel to the support surface and representing the air gap to be generated in the honeycomb structure;
3. c. Arranging the at least one metal foil on the support surface between the first web structure.

With regard to the function and arrangement of an air gap for the insulation of metal foils and for guiding a current path through a honeycomb structure, reference is made to the above WO 2013/150066 A1 referenced, which is hereby incorporated by reference in its entirety.

A molding plate is therefore proposed here which has a first web structure. The shaping plate and in particular the first web structure are made of a temperature-resistant material, e.g. B. a steel alloy, a ceramic or the like. The web structure preferably forms the air gap to be generated in the finished honeycomb structure (that is, for example, also connected by a soldering process). For this purpose, the first web structure, starting from a support surface of the shaping plate, has a height in the axial direction, so that the metal foils to be arranged in the first web structure can plunge far enough into the first web structure a fixed air gap along the axial direction can be generated with a constant width. The first web structure extends in particular in the axial direction with a preferably constant height. Furthermore, the web structure extends in a plane parallel to the support surface, that is to say transversely to the axial direction, in particular in a spiral shape. A current path in the honeycomb structure can thus be predetermined by the web structure.

In step c. the at least one metal foil is arranged on the support surface and within the first web structure, that is to say between the walls of the first web structure.

It is also proposed that in a further step d. the shaping plate is fed together with the at least one metal foil to a connecting step in which the at least one metal foil is connected to one another for the permanent formation of the honeycomb structure, in a subsequent step e. the molding plate with the first web structure is removed from the honeycomb structure.

The connecting step comprises in particular a soldering process, preferably a soldering process, in which a solder material is melted at temperatures of 800 to 1200 ° C. [degrees Celsius] and the adjacent and touching metal foils are connected to one another at positions provided for this purpose. This soldering process is known for the production of the honeycomb bodies described here.

According to a preferred development, the molding plate has a plurality of first openings which extend through the molding plate in the axial direction, a support pin being able to be passed through at least one of the first openings for arrangement in the honeycomb structure after step c.

The support pin is used in particular for spacing one, and for fixing the honeycomb structure by a so-called Support honeycomb body, which can be arranged downstream or upstream of the honeycomb structure in a fluid (exhaust gas) line.

The support pin is used here in particular only for checking the position of the honeycomb structure produced. In this way, it can be ensured for later process steps that the honeycomb structure can be reproducibly connected to other supporting honeycomb structures.

In particular, in step c. the method additionally uses a winding spiral, which has a spiral-shaped second web structure which corresponds to the first web structure; wherein the second web structure is flush in the axial direction on a first end face facing the molding plate, wherein the second web structure has an incline on the second end side, the second end side continuously extending from the center of the second web structure along the spiral windings to the first end side approximates; and wherein the winding coil has at least two pins that extend further from the center along the axial direction; wherein the at least one metal foil is received between the two pins and is continuously taken up into the second web structure by rotation of the winding spiral and then transferred into the first web structure.

The winding spiral enables, in particular, an automated arrangement of the at least one metal foil in the first web structure. This process is explained in detail in the following description of the figures. Starting from a first end face of the winding spiral, which faces the shaping plate and the first web structure arranged thereon, a second web structure extends spirally, on the one hand along a circumferential direction and in a radial direction from the outside inwards and on the other hand with each turn also in the axial direction. The (complete) second web structure is flush with the first face, with the second web structure extends on the second face with a slope always further along the axial direction, so that a center on the second face of the second web structure is arranged at a greatest distance from the first face. The slope of the spiral second web structure enables the one metal foil (or the stack of metal foils) to be wound up successively spirally from the center as the winding spiral rotates and more and more turns (starting from an innermost turn in the center towards an outermost turn) in of the second web structure.

The second web structure also forms the predetermined air gaps in the honeycomb structure. The second web structure corresponds at least essentially to the shape of the first web structure (in a plane transverse to the axial direction). The at least one metal foil can thus be transferred from the winding spiral along the axial direction into the first web structure of the shaping plate and the winding spiral can be used further for the next winding process.

In particular, the winding spiral has driver pins which extend from the second web structure on the first end face and which extend into second openings in the first web structure and / or in the molding plate and / or into first openings in the molding plate.

These driver pins ensure in particular an aligned arrangement of the first web structure and the second web structure. Furthermore, the rotary movement of the shaping plate and winding spiral can be coupled to wind up the at least one metal foil.

It is also proposed in step c. also use a winding plate which has a spirally extending slot which corresponds to the second web structure; wherein during the rotation of the winding spiral, the winding spiral with the second web structure and beginning with the center dips into the slot and so the at least one metal foil arranged between the winding plate and the winding spiral is successively introduced along the axial direction into the winding spiral and finally transferred into the first web structure.

The winding plate is, in particular, flat, so that the at least one metal foil is preferably guided in its entire extent along the axial direction.

In particular, the movement along the axial direction is coupled and / or synchronized with the rotation of the winding plate and the shaping plate.

According to a preferred embodiment, the at least one at least partially structured metal foil forms a multilayer stack before being arranged in the first web structure. In particular, a metal foil is folded several times to form a stack. However, several, in particular differently structured (or at least partially not structured, ie essentially smooth) metal foils can also be arranged on top of one another to form a stack.

A winding device for carrying out a method according to the invention is also proposed, at least comprising a shaping plate with a first web structure.

In particular, the winding device further comprises at least one winding spiral with a second web structure and a winding plate.

Fig. 1:

einen Stapel Metallfolien in perspektivischer Ansicht;

Fig. 2:

einen Formteller in perspektivischer Ansicht;

Fig. 3:

eine Wabenstruktur und einen Formteller in perspektivischer Ansicht;

Fig. 4:

eine fertig hergestellte Wabenstruktur mit Luftspalt in perspektivischer Ansicht;

Fig. 5:

einen zweiten Formteller in perspektivischer Ansicht; und

Fig. 6:

eine Wickelvorrichtung in Explosionsdarstellung und in perspektivischer Ansicht.

The invention and the technical environment are explained in more detail below with reference to the figures. It should be pointed out that the figures show particularly preferred embodiment variants of the invention, but these are not restricted thereto is. The same components are provided with the same reference numerals in the figures. They show schematically:

Fig. 1:

a stack of metal foils in a perspective view;

Fig. 2:

a shaped plate in a perspective view;

Fig. 3:

a honeycomb structure and a mold plate in a perspective view;

Fig. 4:

a finished honeycomb structure with an air gap in a perspective view;

Fig. 5:

a second mold plate in a perspective view; and

Fig. 6:

a winding device in an exploded view and in a perspective view.

Fig. 1 shows a stack 24 of metal foils 2 in a perspective view and the method step a.

Fig. 2 shows a molding plate 5 in a perspective view and the method step b. The shaping plate 5 has a first web structure 8. The first web structure 8 forms the air gap 4 to be generated in the finished honeycomb structure 1 (see also, for example, connected by a soldering process) (see Fig. 4 ). For this purpose, the first web structure 8, starting from the support surface 6 of the shaping plate 5, has a height in the axial direction 7, so that the metal foils 2 to be arranged in the first web structure 8 can penetrate far enough into the first web structure 8, according to a defined air gap 4 can be generated along the axial direction 7 with a constant width (see Fig. 3 ). The first web structure 8 extends in a plane 9 parallel to the support surface 6, that is to say transversely to the axial direction 7 Web structure 8, a current path in the honeycomb structure 1 can be specified. Furthermore, the molding plate 5 has a plurality of first openings 10 which extend through the molding plate 5 in the axial direction 7, wherein a support pin 11 can be passed through at least one of the first openings 10 for arrangement in the honeycomb structure 1 after step c.

Fig. 3 shows a shaped plate 5 and a honeycomb structure 1 arranged thereon in a perspective view and method step c. The first web structure 8 extends here in the axial direction 7 with a constant height. The first honeycomb structure 1 here comprises a plurality of at least partially structured metal foils 2, individual metal foils 2 being arranged in partial regions 3 of the honeycomb structure 1 so as to be electrically insulated from an adjacent metal foil 2 by an air gap 4.

In a further step d. the molding plate 5, together with the at least one metal foil 2, is fed to a connecting step in which the at least one metal foil 2 is connected to one another for the permanent formation of the honeycomb structure 1.

Fig. 4 shows a finished honeycomb structure 1 with an air gap 4 in a perspective view. In step e. the molding plate 5 with the first web structure 8 has been removed from the honeycomb structure 1.

Fig. 5 shows a second mold plate 5 in a perspective view. The comments on Fig. 2 apply accordingly. Here, too, a plurality of first openings 10 are provided, which extend through the shaping plate 5 in the axial direction 7. The first web structure 8 comprises a plurality of windings 18 and also has second openings 21, into which driver pins 20 of the winding spiral 12 can extend (see Fig. 6 ).

Fig. 6 shows a winding device 25 in an exploded view and in a perspective view. The winding device 25 shown here is in step c. of the procedure used. The winding device 25 comprises a receptacle 26 which can be driven in at least one circumferential direction 27. The winding device 25 further comprises a shaping plate 5, a winding spiral 12 and a winding plate 22.

The winding spiral 12 has a spiral-shaped second web structure 13 which corresponds to the first web structure 8 on the shaping plate 5; the second web structure 13 ends flush on the first end face 14 facing the shaping plate 5 in the axial direction 7, the second web structure 13 having an incline 16 on the second end face 15. Starting from a center 17 of the second web structure 13, the second end face 15 continuously approaches the first end face 13 along the spiral windings 18; and wherein the winding spiral 12 has at least two pins 19 which extend further from the center 17 along the axial direction 7. The stack 24 of metal foils 2 is received between the two pins 19 and continuously taken up into the second web structure 13 by rotating the winding spiral 12 and then transferred into the first web structure 8.

The winding spiral 12 thus enables an automated arrangement of the at least one metal foil 2 in the first web structure 8. Starting from a first end face 14 of the winding spiral 12, which faces the shaping plate 5 and the first web structure 8 arranged thereon, a second web structure 13 extends in a spiral , on the one hand along a circumferential direction 27 and in a radial direction 28 from the outside inwards and on the other hand with each turn 18 also in the axial direction 7. The complete second web structure 13 is flush with the first end face 14, the second web structure 13 along the second end face 15 with an incline 16 the axial direction 7, so that a center 17 on the second end face 15 of the second web structure is arranged at a greatest distance from the first end face 14. The slope 16 of the spiral second web structure 13 enables the one metal foil 2 (or the stack 24 of metal foils 2) to be wound up successively from the center 17 when the winding spiral 12 rotates and more and more turns 18 (starting from an innermost turn 18 in the center 17 towards an outermost turn 18) in the second web structure 13.

The second web structure 13 likewise forms the predetermined air gaps 4 in the honeycomb structure 1. The second web structure 13 corresponds at least substantially to the shape of the first web structure 8 (in a plane 9 transverse to the axial direction 7). The at least one metal foil 2 can thus be transferred from the winding spiral 12 along the axial direction 7 into the first web structure 8 of the shaping plate 5 and the winding spiral 12 can be used further for the next winding process.

Here, the winding spiral 12 has driver pins 20 which extend from the second web structure 13 on the first end face 14 in the axial direction 7 and which extend into second openings 21 in the first web structure 8 and / or in the shaping plate 5 and / or in first openings 10 extend into the molding plate 5.

These driver pins 20 ensure an aligned arrangement of the first web structure 8 and the second web structure 13. Furthermore, the rotary movement of receptacle 26, shaping plate 5 and winding spiral 12 can be coupled in this way for winding up the at least one metal foil 2.

Here, a winding plate 22 is further shown, which has a spirally extending slot 23, which corresponds to the second web structure 13. The winding spiral 12 dips during the rotation of the winding spiral 12 with the second web structure 13 and starting with the center 17 into the slot 23 and thus transfers the at least one metal foil 2 arranged between the winding plate 22 and the winding spiral 12 successively along the axial direction 7 into the winding spiral 12 and finally into the first web structure 8.

The winding plate 22 is of flat design here, so that the at least one metal foil 2 is guided essentially in its entire extent along the axial direction 7.

Claims (10)

1. Method for producing a honeycomb structure (1) comprising at least one at least partially structured metal foil (2), wherein, in subregions (3) of the honeycomb structure (1), the metal foil (2) is arranged spaced apart from an adjacently arranged metal foil (2) so as to be electrically insulated by an air gap (4), at least comprising the following steps:

   a. providing the at least one metal foil (2);

   b. providing a forming plate (5) with a bearing surface (6) and with at least one first web structure (8) extending from the bearing surface (6) in an axial direction (7), wherein the first web structure (8) also extends in a plane (9) parallel to the bearing surface (6) and images the air gap (4) to be produced in the honeycomb structure (1);

   c. arranging the at least one metal foil (2) on the bearing surface (6) in the first web structure (8).
2. Method according to Claim 1, wherein, in a further step d., the forming plate (5) is sent, together with the at least one metal foil (2), to a connection step in which interconnection of the at least one metal foil (2) is realized for the permanent formation of the honeycomb structure (1), wherein, in a following step e., the forming plate (5) with the first web structure (8) is removed from the honeycomb structure (1).
3. Method according to Claim 2, wherein the connection step comprises a soldering process.
4. Method according to one of the preceding claims, wherein the forming plate (5) has a plurality of first openings (10) which extend through the forming plate (5) in the axial direction (7), wherein a support pin (11) is able to be passed through at least one of the first openings (10) for the purpose of arrangement in the honeycomb structure (1) according to step c.
5. Method according to one of the preceding claims, wherein, in step c. of the method, use is additionally made of a winding spiral (12) which has a spiral-shaped second web structure (13) which corresponds to the first web structure (8), wherein the second web structure (13) terminates in a flush manner in the axial direction (7) at a first end side (14) facing the forming plate (5), wherein the second web structure (13) has a pitch (16) at the second end side (15), wherein, proceeding from a center (17) of the second web structure (13), the second end side (15) continuously approaches the first end side (14) along the spiral-shaped windings (18), and wherein the winding spiral (12) has at least two pins (19), which extend further along the axial direction (7) proceeding from the center (17), wherein the at least one metal foil (2) is received between the at least two pins (19) and, by rotation of the winding spiral (12), continuously received into the second web structure (13) and then transferred into the first web structure (8).
6. Method according to Claim 5, wherein the winding spiral (12) has driving pins (20) which extend from the second web structure (13) at the first end side (14) and which extend into second openings (21) in the first web structure (8) and/or in the forming plate (5) and/or into first openings (10) in the forming plate (5).
7. Method according to Claim 5 or 6, wherein, in step c., use is also made of a winding plate (22) which has a slot (23) extending in a spiral-shaped manner and corresponding to the second web structure (13), wherein, during the rotation of the winding spiral (12), the winding spiral (12) sinks into the slot (23) with the second web structure (13) and starting with the center (17), and thus the at least one metal foil (2), arranged between the winding plate (22) and the winding spiral (12), is, along the axial direction (7), gradually introduced into the winding spiral (12) and, finally, transferred into the first web structure (8).
8. Method according to one of the preceding claims, wherein, prior to being arranged in the first web structure (8), the at least one at least partially structured metal foil (2) forms a multi-layered stack (24).
9. Winding device (25) for implementing a method according to one of Claims 1 to 8, at least comprising a forming plate (5) with a first web structure (8).
10. Winding device (25) according to Claim 9, wherein the winding device (25) furthermore comprises at least one winding spiral (12) with a second web structure (13), and a winding plate (22).

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