Title of Invention	"METHOD AND DEVICE FOR APPLYING HARD SOLDER"
Abstract	The invention relates to a device and a method for applying hard solder (1) to an at least partially structured metal foil (2), comprising at least the following steps: (a) providing at least one flat metal foil (2), (b) shaping the at least one metal foil (2) such that a structure (3) is generated, (c) applying hard solder (1) to at least one metal foil (2), with steps (b) and (c) being carried out discontinuously and at least partially together. The invention is preferably used in the production of metallic honeycomb bodies for the treatment of exhaust gases in vehicles.

Title of Invention

"METHOD AND DEVICE FOR APPLYING HARD SOLDER"

Abstract

The invention relates to a device and a method for applying hard solder (1) to an at least partially structured metal foil (2), comprising at least the following steps: (a) providing at least one flat metal foil (2), (b) shaping the at least one metal foil (2) such that a structure (3) is generated, (c) applying hard solder (1) to at least one metal foil (2), with steps (b) and (c) being carried out discontinuously and at least partially together. The invention is preferably used in the production of metallic honeycomb bodies for the treatment of exhaust gases in vehicles.

Full Text	Method and device for hard solder application The present invention relates to a method for applying hard solder to an at least partially structured metal foil. Also described here are methods for producing a honeycomb body, a device for applying hard solder and exhaust-gas treatment units and vehicles. The invention is used in particular in the field of production of metallic exhaust-gas treatment units which are constructed with a plurality of at least partially structured metal foils. In order to produce exhaust-gas treatment units of said type, the smooth and/or structured metal foils are stacked one on top of the other and are twisted or wound with one another and inserted into a housing. For a long service life in an exhaust system of a vehicle, it is necessary for joining connections between the metal foils themselves or between the metal foils and the housing to be of stable design. Hard-soldered and/or welded connections have been proven to be fundamentally suitable for this purpose. In connection with the hard-soldering of ever further developed honeycomb bodies, technical problems always occur during the application of the hard solder. For example, it must firstly be ensured that the hard solder is positioned precisely at the points at which a joining connection is ultimately to be formed. However, it is also to be ensured that an excess accumulation of hard solder is avoided, since during the subsequent thermal treatment, undesired diffusion processes between the hard solder and the metallic components of the honeycomb body can occur, which can adversely affect the service life of the metal foil. The supply of hard solder to the metal foils can take place already before the twisting or winding to form a honeycomb structure, for example by virtue of hard solder strips and/or hard solder pastes being applied. It is additionally known to provide the finished honeycomb structure with (hi particular powdered) hard solder at the end side. Finally, it is also known to place hard solder on predetermined partial regions of the surface of the metal foils by means of a so-called imprinting ("inkjet") process. Proceeding from this, it is an object of the present invention to at least partially solve the technical problems highlighted with regard to the prior art. It is intended in particular to specify a method for applying hard solder in which hard solder can be positioned on partial regions of the metal foils hi a precise manner which is also suitable for series production. It is also intended to specify suitable means and devices for applying hard solder. Said objects are achieved by means of a method according to the features of patent claim 1 and a device according to the features of patent claim 9. Further advantageous embodiments of the invention are described hi each of the dependent patent claims. It is to be pointed out that the features listed individually in said claims can be combined with one another in any desired technologically expedient manner and highlight further embodiments of the invention. The method for applying hard solder to an at least partially structured metal foil accordingly comprises at least the following steps: (a) providing at least one flat metal foil, (b) shaping the at least one metal foil such that a structure is generated, (c) applying hard solder to at least one metal foil, with steps (b) and (c) being carried out discontinuously and at least partially together. Here, it is often the case that a flat metal foil is unrolled from a type of coil and said flat, smooth metal foil is subsequently provided with a structure. Here, it is preferable for the metal foil to be shaped in such a way that it is provided entirely with a structure, with the structure preferably being formed as a corrugated, sinusoidal, rectangular, sawtooth-shaped or similar structure. The hard solder is placed during the shaping of the metal foil or shortly after the shaping of the metal foil has taken place. Here, steps (b) and (c) are carried out discontinuously, so that for example the feed of the metal foil is not constant but slows its feed significantly or comes to rest intermittently. During said rest period, the shaping and the application of the hard solder are carried out. Here, the two steps are carried out at least partially together, in particular simultaneously. It is also possible for at least a part of the application of the hard solder to take place during the transport or during the supply, positioning, etc. of the metal foil with respect to the tool. In any case, steps (b) and (c) are performed spatially very close to one another, for example with a spacing in the direction of the metal foil of less than 100 structures, in particular less than 10 structures, such as for example between 1 and 5 structures. It is thereby possible under some circumstances to dispense with sensor monitoring of the position of the "applied hard solder, as is necessary if the metal foil is unguided over a relatively great distance. The combination of the two steps (b) and (c) results in a synchronization of these working steps. It is thereby possible for the first time to dispense with an application of hard solder with a separate working step, as has hitherto been conventional. At the same time, it is possible by means of a very precise application of hard solder to precisely predetermine the type of connections and to therefore also ensure a minimum consumption of hard solder. According to one advantageous refinement of the method, step (b) comprises shaping by means of reciprocating punching with a clock frequency, with step (c) being carried out with the same clock frequency. During reciprocating punching, the flat metal foil is passed through between a die and a stamp, with the structure being formed in the metal foil as the stamp penetrates into the die. For this purpose, a reciprocating movement which predefines a clock frequency is often necessary. Here the clock frequency is for example 100 to 800 Hertz (Hz, 1/s), in particular in a range from 400 to 600 Hz, for metal foils with a thickness of less than 0.15 millimeters (mm). The synchronization of steps (b) and (c) takes place here by means of the clock frequency; accordingly, during the production of a certain number of structure elements (for example corrugation sections), an equal number of partial regions (for example corrugation sections) of the metal foil are therefore advantageously provided with hard solder. Since the time for producing the structure is required in any case and the application of hard solder takes place simultaneously, the production process of honeycomb bodies is for example also shortened in relation to known methods. It is also advantageous for step (b) and step (c) to be carried out in a manner mechanically coupled to one another. For this purpose, mechanically coupled tools are preferably used, in particular in the manner of a so-called follow-on tool. Even if this has been selected here as a preferred variant with regard to costs, the two steps can also be performed in a combined manner by means of electronic circuits, software and the like. It is particularly advantageous for step (c) to comprise the provision of hard solder foil, and the step of separating hard solder labels from a hard solder foil is in particular also included, in order to generate a plurality. In this way, it is possible to provide precisely apportioned hard solder labels which comprise the quantity of hard solder precisely predetermined for the partial region. Hard solder labels of said type are easy to handle, and in addition, the hard solder foil can be particularly well utilized for the provision of hard solder labels of said type. In one preferred application, such as in the production of catalytic converter support bodies, hard solder labels are used which have dimensions in the range from 1 mm width and up to 5 mm length, wherein, per hard solder label, often at most approximately 1 gram (g) of hard solder is applied so as to be aligned positionally accurately with respect to the structure. It is also advantageous for step (c) to follow the application of hard solder foil by means of at least one of the processes adhesive bonding and welding. A type of pre-fixing of the hard solder foil or of the hard solder label is therefore given, hi the case of adhesive bonding, the adhesive can be provided on one side of the hard solder foil or of the hard solder label and/or on the metal foil. In the case of welding, a laser is preferably used. With said pre-fixing, it is ensured that the hard solder foil does not move from the desired position during the formation of the honeycomb body, in which the metal foils slide on one another. According to one refinement of the method, the at least one metal foil is generated with a corrugated structure with elevations and depressions, with the hard solder being applied from at least one side of the at least one metal foil to a plurality of partial regions of the elevations or depressions. Here, the elevations and depressions are formed preferably over the entire width of the metal foil, hi addition, the elevations can be provided with pockets, vanes, turned-out portions, etc., with it also for example being possible for the pockets to serve as a reservoir for applied hard solder. The metal foil is preferably provided with hard solder from both sides, in particular simultaneously. The partial regions are preferably position close to an edge or the later end side of the honeycomb body. In addition, it is also possible for hard solder to be applied to other, inner partial regions of the metal foil. In addition, a method for producing a honeycomb body is also proposed, which method comprises at least the following steps: a method variant for applying hard solder as described here according to the invention, - placing the hard solder in contact with sections of the at least one metal foil, with at least one honeycomb structure being formed, fixing the at least one honeycomb structure, hard-soldering of at least one honeycomb structure. With regard to the working steps which follow the hard solder application, it is to be noted that the hard solder can be placed in contact with for example unsoldered partial sections of the same metal foil or of another, if appropriate smooth metal foil. Here, contact of the metal foil sections against one another with a certain preload is desirable. The fixing and if appropriate preloading of the honeycomb structure formed when contact is made can take place by means of separate tools and/or by means of a housing arranged around the honeycomb structure. It is thereby ensured that, for subsequent transport of the honeycomb structure to an oven in which the hard-soldering is carried out, the position of the hard solder with respect to the adjacent metal foil remains unchanged. According to a further aspect of the present invention, a device for applying hard solder to an at least partially structured metal foil is proposed, which device has at least the following elements: at least one foil supply for at least one flat metal foil, at least one shaping unit for the discontinuous generation of a structure in the at least one metal foil, at least one positioning unit for the discontinuous application of hard solder to the at least one metal foil, with synchronizing means for coordinating the movements of the at least one shaping unit and of the at least one positioning unit being provided. The device is suitable in particular for carrying out a method for applying hard solder as described above according to the invention. The foil supply can for example comprise conveyer belts, gearwheels or toothed racks, guide rails and the like, but need not strictly be an integral component of the shaping unit and/or of the positioning unit The shaping unit preferably means a bending or punching system in which certain partial sections of the flat metal foil are intermittently provided with a structure. This means in particular not continuously operating rolling systems with rolling wheels which engage into one another. The positioning unit advantageously applies the hard solder with the same clock frequency as the shaping unit forms the structure into the at least one metal foil. The synchronizing means can also comprise parts of a controller, software, a regulating circuit or a data processing system. Here, it is however preferable for the synchronizing means to comprise a mechanical coupling device. The mechanical coupling device acts both on the shaping unit and also on the positioning unit, so that a synchronized movement of the two units is ensured. This has the result that the application of hard solder is, with relatively little technical expenditure, carried out during the production of the structure, which leads to a precise application of hard solder in a shortened time. It is also preferable that at least one adhesive bonding device or one welding device for applying the hard solder is provided in the device. The embodiment of the device alternatively with an adhesive bonding device or a welding device will often be sufficient; under some circumstances, however, a combination of both devices is also expedient. By means of the adhesive bonding device or the welding device, the hard solder is pre-fixed to the metal foil, so that the hard solder no longer changes its position with respect to the metal foil during subsequent transport. According to a further embodiment of the device, the at least one shaping unit is a reciprocating punching system and the synchronizing means bring about a common movement of the reciprocating punching system and positioning unit. Here, it is preferable for the reciprocating punching system and the positioning unit to perform a translator^ movement, in particular a reciprocating movement, towards the metal foil, with said movement being performed simultaneously. Also proposed is an exhaust-gas treatment unit which comprises at least one honeycomb body which has been produced according to the method according to the invention or by means of the device according to the invention. Also proposed, as a preferred field of use, is a vehicle having at least one exhaust-gas treatment unit of said type. Considerable time and cost advantages are therefore obtained in the field of series production of mobile exhaust systems. The invention and the technical field are explained in more detail below on the basis of the appended figures. It is to be noted that the figures schematically show particularly preferred exemplary embodiments of the invention, to which the invention is however not restricted. In the figures, in each case schematically: figure 1 shows the construction of a device for applying hard solder, figure 2 shows a detail of the device for applying hard solder, figure 3 shows a structured metal foil provided with hard solder, figure 4 shows a method for carrying out in order to produce a honeycomb body, and figure 5 shows a vehicle comprising an exhaust-gas treatment unit. The device 13 for applying hard solder schematically illustrated in figure 1 comprises a foil supply 14 which is embodied as a conveyer belt and by means of which a smooth metal foil 2 is moved towards the shaping unit 15. By means of the shaping unit 15, which is embodied here as a reciprocating punching system 21, a structure 3 is formed in the metal foil 2. For this purpose, the reciprocating punching system 21 performs a reciprocating movement as indicated by the dashed starting position and the arrow. Here, the reciprocating punching system 21 is formed with a plurality of stamps 43 which operate regularly offset in terms of time during one shaping step. It is for example preferable for the stamp 43 which adjoins the last structure 3 to begin, and for the stamps 43 which bear against it to subsequently perform shaping individually. It is thereby ensured that sufficient material of the metal foil 2 can be pulled into the reciprocating punching system 21 for the shaping process. Directly thereafter, the metal foil 2 which is provided with the structure 3 passes to the positioning unit 16. As has been indicated by dashed lines and an arrow, the positioning unit 16 performs the same reciprocating movement, which is effected with the aid of synchronizing means 17. In the embodiment variant illustrated here, the synchronizing means 17 comprise a coupling device 18. At the same time as the application of the hard solder 1 to the metal foil 2, pre-fixing of the hard solder 1 is carried out by means of an adhesive bonding device 19. The metal foil 2 which is provided with hard solder can subsequently be transported for further processing. Figure 2 shows how the hard solder is prepared and supplied to the metal foil 2. Here, the hard solder is provided as a hard solder foil 4 which is unrolled from a coil 24. Said hard solder foil 4 is subsequently supplied to a separating tool 25 which generates a plurality of hard solder labels 5 from the hard solder foil 4. The hard solder labels 5 correspond for example precisely to the hard solder quantity which is required for connecting individual elevations 6 or depressions 7 of the metal foil 2. Said hard solder labels 5 are thus supplied to the elevations 6 from one side 8 of the metal foil 2 and are subsequently pre-fixed to the depressions 7 by means of a welding device 20. The hard solder labels 5 are subsequently matched by means of a pressing tool 26 to the structure of the corrugated foil 2, so that said hard solder labels 5 substantially nestle against the elevations 6 or depressions 7. It is to be pointed out that the steps of attaching, pre-fixing and pressing can under some circumstances be carried out partially simultaneously using one tool. Figure 3 now shows, in a perspective illustration, a metal foil 2 with a structure 3, with hard solder labels 5 having been positioned in predetermined partial regions 9. Here, the first partial regions 9 are positioned close to the edge 42 of the metal foil 2. In addition, hard solder 1 is likewise applied in inner partial regions which are formed here with recesses 27 (or pockets). The provision of recesses 27 of said type ensures that the hard solder 1 (for example also in the event of contact of said structured metal foil 2 against a metal foil which slides on the latter) remains in the desired partial regions, with it being possible here if appropriate to dispense with pre-fixing. Figure 4 now shows the production of a honeycomb body 10 which is constructed in the manner of a spiral with a smooth metal foil 2 and a structured metal foil 2. It is fundamentally to be noted that other types of honeycomb body 10 can be produced in this way, for example in which the metal foils 2 are firstly stacked and are subsequently twisted in an involute shape or S-shape. In the embodiment variant shown here, the smooth metal foil 2 is thus placed onto the structured metal foil 2 so that hard solder 1 which is positioned at the elevations and depressions comes into contact with sections 11 of the smooth metal strip 2. Said layer is subsequently wound in a spiral shape, so that, as illustrated here, a cylindrical honeycomb structure 12 is formed. The honeycomb structure 12, which is viewed here from an end side 29, now forms substantially axially running parallel ducts 28 with the smooth and the structured metal foil 2. Said honeycomb structure 12 is now inserted into a housing 30 which serves for fixing. In addition, the housing 30 can likewise be provided with hard solder, so that during a subsequent thermal treatment in an oven 31 (for example at over 1000°C and under a vacuum), joining connections are formed between the metal foils 2 and the housing 30 and between the metal foils 2 themselves. Figure 5 now shows a particularly preferred field of use of honeycomb bodies 10 of said type as an exhaust-gas treatment unit 22. A vehicle 23 is shown which comprises an internal combustion engine 33 which is operated by means of an engine controller 32. The engine controller 32 can for example influence the operating mode of the internal combustion engine 33 taking into consideration measuring sensors 35 which are installed in the exhaust system 40. The exhaust gas generated by the internal combustion engine 33 is supplied via an exhaust line 34 to a plurality of exhaust-gas treatment units 22 which all have a corresponding metallic honeycomb body 10. hi the flow direction of the exhaust gas, the exhaust gas flows firstly through an oxidation catalytic converter 36, then a particle trap 37, an adsorber 38 and a further catalytic converter 39. Said exhaust gas finally flows through a silencer 41 before it is discharged, purified, to the environment. With the invention proposed here, it is possible for the hard solder to be applied without a separate working step, with targeted application for a precisely predetermined brazing pattern and a minimal use of hard solder being obtained at the same time. This leads to a considerable time and cost benefit within the context of series production of metallic exhaust-gas treatment units for motor vehicles. List of reference symbols 1 Hard solder 2 Metal foil 3 Structure 4 Hard solder foil 5 Hard solder label 6 Elevation 7 Depression 8 Side 9 Partial region 10 Honeycomb body 11 Section 12 Honeycomb structure 13 Device 14 Foil supply 15 Shaping unit 16 Positioning unit 17 Synchronization means 18 Coupling device 19 Adhesive bonding device 20 Welding device 21 Reciprocating punching system 22 Exhaust-gas treatment unit 23 Vehicle 24 Coil 25 Separating tool 26 Pressing tool 27 Recess 28 Duct 29 End side 30 Housing 31 Oven 32 Engine controller 33 Internal combustion engine 34 Exhaust line 35 Measuring sensor 36 Oxidation catalytic converter 37 Particle trap 38 Adsorber 39 Converter 40 Exhaust system 41 Silencer 42 Edge 43 Stamp Patent claims 1. A method for applying hard solder (1) to an at least partially structured metal foil (2), comprising at least the following steps: (a) providing at least one flat metal foil (2), (b) shaping the at least one metal foil (2) such that a structure (3) is generated, (c) applying hard solder (1) to at least one metal foil (2), with steps (h) and (c) being carried out discontinuously and at least partially together. 2. The method as claimed in claim 1, in which step (b) comprises shaping by means of reciprocating punching with a clock frequency, with step (c) being carried out with the same clock frequency. 3. The method as claimed in claim 1 or 2, in which step (b) and step (c) are carried out in a manner mechanically coupled to one another. 4. The method as claimed in one of the preceding claims, in which step (c) comprises the provision of hard solder foil (4). 5. The method as claimed in one of the preceding claims, in which step (c) comprises the separation of hard solder foil (4) in order to generate a plurality of hard solder labels (5). 6. The method as claimed in one of the preceding claims, in which step (c) the application of hard solder foil (4) takes place by means of at least one of the processes adhesive bonding and welding. 7. The method as claimed in one of the preceding claims, in which the at least one metal foil (2) is generated with a corrugated structure (3) with elevations (6) and depressions (7) (if appropriate reservoir pockets), with the hard solder (1) being applied from at least one side of the at least one metal foil (2) (simultaneously) to a plurality of (end-side) partial regions (9) of the elevations (6) or depressions (7). 8. A method for producing a honeycomb body (10) comprising at least the following steps: - a method for applying hard solder (1) as claimed in one of the preceding claims, - placing the hard solder (1) in contact with sections (11) of the at least one metal foil (2), with at least one honeycomb structure (12) being formed, fixing the at least one honeycomb structure (12), - hard-soldering of at least one honeycomb structure (12). 9. A device (13) for applying hard solder (1J to an at least partially structured metal foil (2) at least having: - at least one foil supply (14) for at least one flat metal foil (2), - at least one shaping unit (15) for the discontinuous generation of a structure (3) in the at least one metal foil (2), - at least one positioning unit (16) for the discontinuous application of hard solder (1) to the at least one metal foil (2), with synchronizing means (17) for coordinating the movements of the at least one shaping unit (15) and of the at least one positioning unit (16) being provided. 10. The device (13) as claimed in claim 9, in which the synchronizing means (17) comprise a mechanical coupling device (18). 11. The device (13) as claimed in claim 9 or 10, in which at least one adhesive bonding device (19) or one welding device (20) for applying the hard solder (1) is provided. 12. The device (13) as claimed in one of claims 9 to 11, in which the at least one shaping unit (15) is a reciprocating punching system (21) and the synchronizing means (17) bring about a common movement of the reciprocating punching system (17) and positioning unit (16). 13. An exhaust-gas treatment unit (22) comprising at least one honeycomb body (10) produced by means of a method as claimed in one of claims 1 to 8 or produced by means of a device as claimed in one of claims 9 to 12. 14. A vehicle (23) having at least one exhaust-gas treatment unit (22) as claimed in claim 13.

Full Text

Method and device for hard solder application
The present invention relates to a method for applying hard solder to an at least partially structured metal foil. Also described here are methods for producing a honeycomb body, a device for applying hard solder and exhaust-gas treatment units and vehicles. The invention is used in particular in the field of production of metallic exhaust-gas treatment units which are constructed with a plurality of at least partially structured metal foils.
In order to produce exhaust-gas treatment units of said type, the smooth and/or structured metal foils are stacked one on top of the other and are twisted or wound with one another and inserted into a housing. For a long service life in an exhaust system of a vehicle, it is necessary for joining connections between the metal foils themselves or between the metal foils and the housing to be of stable design. Hard-soldered and/or welded connections have been proven to be fundamentally suitable for this purpose.
In connection with the hard-soldering of ever further developed honeycomb bodies, technical problems always occur during the application of the hard solder. For example, it must firstly be ensured that the hard solder is positioned precisely at the points at which a joining connection is ultimately to be formed. However, it is also to be ensured that an excess accumulation of hard solder is avoided, since during the subsequent thermal treatment, undesired diffusion processes between the hard solder and the metallic components of the honeycomb body can occur, which can adversely affect the service life of the metal foil.
The supply of hard solder to the metal foils can take place already before the twisting or winding to form a honeycomb structure, for example by virtue of hard
solder strips and/or hard solder pastes being applied. It is additionally known to provide the finished honeycomb structure with (hi particular powdered) hard solder at the end side. Finally, it is also known to place hard solder on predetermined partial regions of the surface of the metal foils by means of a so-called imprinting ("inkjet") process.
Proceeding from this, it is an object of the present invention to at least partially solve the technical problems highlighted with regard to the prior art. It is intended in particular to specify a method for applying hard solder in which hard solder can be positioned on partial regions of the metal foils hi a precise manner which is also suitable for series production. It is also intended to specify suitable means and devices for applying hard solder.
Said objects are achieved by means of a method according to the features of patent claim 1 and a device according to the features of patent claim 9. Further advantageous embodiments of the invention are described hi each of the dependent patent claims. It is to be pointed out that the features listed individually in said claims can be combined with one another in any desired technologically expedient manner and highlight further embodiments of the invention.
The method for applying hard solder to an at least partially structured metal foil accordingly comprises at least the following steps:
(a) providing at least one flat metal foil,
(b) shaping the at least one metal foil such that a structure is generated,
(c) applying hard solder to at least one metal foil,
with steps (b) and (c) being carried out discontinuously and at least partially together.
Here, it is often the case that a flat metal foil is unrolled from a type of coil and said flat, smooth metal foil is subsequently provided with a structure. Here, it is
preferable for the metal foil to be shaped in such a way that it is provided entirely with a structure, with the structure preferably being formed as a corrugated, sinusoidal, rectangular, sawtooth-shaped or similar structure.
The hard solder is placed during the shaping of the metal foil or shortly after the shaping of the metal foil has taken place. Here, steps (b) and (c) are carried out discontinuously, so that for example the feed of the metal foil is not constant but slows its feed significantly or comes to rest intermittently. During said rest period, the shaping and the application of the hard solder are carried out. Here, the two steps are carried out at least partially together, in particular simultaneously. It is also possible for at least a part of the application of the hard solder to take place during the transport or during the supply, positioning, etc. of the metal foil with respect to the tool. In any case, steps (b) and (c) are performed spatially very close to one another, for example with a spacing in the direction of the metal foil of less than 100 structures, in particular less than 10 structures, such as for example between 1 and 5 structures. It is thereby possible under some circumstances to dispense with sensor monitoring of the position of the "applied hard solder, as is necessary if the metal foil is unguided over a relatively great distance.
The combination of the two steps (b) and (c) results in a synchronization of these working steps. It is thereby possible for the first time to dispense with an application of hard solder with a separate working step, as has hitherto been conventional. At the same time, it is possible by means of a very precise application of hard solder to precisely predetermine the type of connections and to therefore also ensure a minimum consumption of hard solder.
According to one advantageous refinement of the method, step (b) comprises shaping by means of reciprocating punching with a clock frequency, with step (c) being carried out with the same clock frequency. During reciprocating punching, the flat metal foil is passed through between a die and a stamp, with the structure
being formed in the metal foil as the stamp penetrates into the die. For this purpose, a reciprocating movement which predefines a clock frequency is often necessary. Here the clock frequency is for example 100 to 800 Hertz (Hz, 1/s), in particular in a range from 400 to 600 Hz, for metal foils with a thickness of less than 0.15 millimeters (mm).
The synchronization of steps (b) and (c) takes place here by means of the clock frequency; accordingly, during the production of a certain number of structure elements (for example corrugation sections), an equal number of partial regions (for example corrugation sections) of the metal foil are therefore advantageously provided with hard solder. Since the time for producing the structure is required in any case and the application of hard solder takes place simultaneously, the production process of honeycomb bodies is for example also shortened in relation to known methods.
It is also advantageous for step (b) and step (c) to be carried out in a manner mechanically coupled to one another. For this purpose, mechanically coupled tools are preferably used, in particular in the manner of a so-called follow-on tool. Even if this has been selected here as a preferred variant with regard to costs, the two steps can also be performed in a combined manner by means of electronic circuits, software and the like.
It is particularly advantageous for step (c) to comprise the provision of hard solder foil, and the step of separating hard solder labels from a hard solder foil is in particular also included, in order to generate a plurality. In this way, it is possible to provide precisely apportioned hard solder labels which comprise the quantity of hard solder precisely predetermined for the partial region. Hard solder labels of said type are easy to handle, and in addition, the hard solder foil can be particularly well utilized for the provision of hard solder labels of said type. In one preferred application, such as in the production of catalytic converter support
bodies, hard solder labels are used which have dimensions in the range from 1 mm width and up to 5 mm length, wherein, per hard solder label, often at most approximately 1 gram (g) of hard solder is applied so as to be aligned positionally accurately with respect to the structure.
It is also advantageous for step (c) to follow the application of hard solder foil by means of at least one of the processes adhesive bonding and welding. A type of pre-fixing of the hard solder foil or of the hard solder label is therefore given, hi the case of adhesive bonding, the adhesive can be provided on one side of the hard solder foil or of the hard solder label and/or on the metal foil. In the case of welding, a laser is preferably used. With said pre-fixing, it is ensured that the hard solder foil does not move from the desired position during the formation of the honeycomb body, in which the metal foils slide on one another.
According to one refinement of the method, the at least one metal foil is generated with a corrugated structure with elevations and depressions, with the hard solder being applied from at least one side of the at least one metal foil to a plurality of partial regions of the elevations or depressions. Here, the elevations and depressions are formed preferably over the entire width of the metal foil, hi addition, the elevations can be provided with pockets, vanes, turned-out portions, etc., with it also for example being possible for the pockets to serve as a reservoir for applied hard solder. The metal foil is preferably provided with hard solder from both sides, in particular simultaneously. The partial regions are preferably position close to an edge or the later end side of the honeycomb body. In addition, it is also possible for hard solder to be applied to other, inner partial regions of the metal foil.
In addition, a method for producing a honeycomb body is also proposed, which method comprises at least the following steps:
a method variant for applying hard solder as described here according to
the invention,
- placing the hard solder in contact with sections of the at least one metal foil, with at least one honeycomb structure being formed, fixing the at least one honeycomb structure, hard-soldering of at least one honeycomb structure.
With regard to the working steps which follow the hard solder application, it is to be noted that the hard solder can be placed in contact with for example unsoldered partial sections of the same metal foil or of another, if appropriate smooth metal foil. Here, contact of the metal foil sections against one another with a certain preload is desirable. The fixing and if appropriate preloading of the honeycomb structure formed when contact is made can take place by means of separate tools and/or by means of a housing arranged around the honeycomb structure. It is thereby ensured that, for subsequent transport of the honeycomb structure to an oven in which the hard-soldering is carried out, the position of the hard solder with respect to the adjacent metal foil remains unchanged.
According to a further aspect of the present invention, a device for applying hard solder to an at least partially structured metal foil is proposed, which device has at least the following elements:
at least one foil supply for at least one flat metal foil,
at least one shaping unit for the discontinuous generation of a structure in
the at least one metal foil,
at least one positioning unit for the discontinuous application of hard
solder to the at least one metal foil,
with synchronizing means for coordinating the movements of the at least one shaping unit and of the at least one positioning unit being provided. The device is suitable in particular for carrying out a method for applying hard solder as described above according to the invention.
The foil supply can for example comprise conveyer belts, gearwheels or toothed racks, guide rails and the like, but need not strictly be an integral component of the shaping unit and/or of the positioning unit The shaping unit preferably means a bending or punching system in which certain partial sections of the flat metal foil are intermittently provided with a structure. This means in particular not continuously operating rolling systems with rolling wheels which engage into one another.
The positioning unit advantageously applies the hard solder with the same clock frequency as the shaping unit forms the structure into the at least one metal foil. The synchronizing means can also comprise parts of a controller, software, a regulating circuit or a data processing system.
Here, it is however preferable for the synchronizing means to comprise a mechanical coupling device. The mechanical coupling device acts both on the shaping unit and also on the positioning unit, so that a synchronized movement of the two units is ensured. This has the result that the application of hard solder is, with relatively little technical expenditure, carried out during the production of the structure, which leads to a precise application of hard solder in a shortened time.
It is also preferable that at least one adhesive bonding device or one welding device for applying the hard solder is provided in the device. The embodiment of the device alternatively with an adhesive bonding device or a welding device will often be sufficient; under some circumstances, however, a combination of both devices is also expedient. By means of the adhesive bonding device or the welding device, the hard solder is pre-fixed to the metal foil, so that the hard solder no longer changes its position with respect to the metal foil during subsequent transport.
According to a further embodiment of the device, the at least one shaping unit is a
reciprocating punching system and the synchronizing means bring about a common movement of the reciprocating punching system and positioning unit. Here, it is preferable for the reciprocating punching system and the positioning unit to perform a translator^ movement, in particular a reciprocating movement, towards the metal foil, with said movement being performed simultaneously.
Also proposed is an exhaust-gas treatment unit which comprises at least one honeycomb body which has been produced according to the method according to the invention or by means of the device according to the invention. Also proposed, as a preferred field of use, is a vehicle having at least one exhaust-gas treatment unit of said type. Considerable time and cost advantages are therefore obtained in the field of series production of mobile exhaust systems.
The invention and the technical field are explained in more detail below on the basis of the appended figures. It is to be noted that the figures schematically show particularly preferred exemplary embodiments of the invention, to which the invention is however not restricted. In the figures, in each case schematically:
figure 1 shows the construction of a device for applying hard solder,
figure 2 shows a detail of the device for applying hard solder,
figure 3 shows a structured metal foil provided with hard solder,
figure 4 shows a method for carrying out in order to produce a honeycomb
body, and
figure 5 shows a vehicle comprising an exhaust-gas treatment unit.
The device 13 for applying hard solder schematically illustrated in figure 1
comprises a foil supply 14 which is embodied as a conveyer belt and by means of which a smooth metal foil 2 is moved towards the shaping unit 15. By means of the shaping unit 15, which is embodied here as a reciprocating punching system 21, a structure 3 is formed in the metal foil 2. For this purpose, the reciprocating punching system 21 performs a reciprocating movement as indicated by the dashed starting position and the arrow. Here, the reciprocating punching system 21 is formed with a plurality of stamps 43 which operate regularly offset in terms of time during one shaping step. It is for example preferable for the stamp 43 which adjoins the last structure 3 to begin, and for the stamps 43 which bear against it to subsequently perform shaping individually. It is thereby ensured that sufficient material of the metal foil 2 can be pulled into the reciprocating punching system 21 for the shaping process.
Directly thereafter, the metal foil 2 which is provided with the structure 3 passes to the positioning unit 16. As has been indicated by dashed lines and an arrow, the positioning unit 16 performs the same reciprocating movement, which is effected with the aid of synchronizing means 17. In the embodiment variant illustrated here, the synchronizing means 17 comprise a coupling device 18. At the same time as the application of the hard solder 1 to the metal foil 2, pre-fixing of the hard solder 1 is carried out by means of an adhesive bonding device 19. The metal foil 2 which is provided with hard solder can subsequently be transported for further processing.
Figure 2 shows how the hard solder is prepared and supplied to the metal foil 2. Here, the hard solder is provided as a hard solder foil 4 which is unrolled from a coil 24. Said hard solder foil 4 is subsequently supplied to a separating tool 25 which generates a plurality of hard solder labels 5 from the hard solder foil 4. The hard solder labels 5 correspond for example precisely to the hard solder quantity which is required for connecting individual elevations 6 or depressions 7 of the metal foil 2. Said hard solder labels 5 are thus supplied to the elevations 6 from
one side 8 of the metal foil 2 and are subsequently pre-fixed to the depressions 7 by means of a welding device 20. The hard solder labels 5 are subsequently matched by means of a pressing tool 26 to the structure of the corrugated foil 2, so that said hard solder labels 5 substantially nestle against the elevations 6 or depressions 7. It is to be pointed out that the steps of attaching, pre-fixing and pressing can under some circumstances be carried out partially simultaneously using one tool.
Figure 3 now shows, in a perspective illustration, a metal foil 2 with a structure 3, with hard solder labels 5 having been positioned in predetermined partial regions 9. Here, the first partial regions 9 are positioned close to the edge 42 of the metal foil 2. In addition, hard solder 1 is likewise applied in inner partial regions which are formed here with recesses 27 (or pockets). The provision of recesses 27 of said type ensures that the hard solder 1 (for example also in the event of contact of said structured metal foil 2 against a metal foil which slides on the latter) remains in the desired partial regions, with it being possible here if appropriate to dispense with pre-fixing.
Figure 4 now shows the production of a honeycomb body 10 which is constructed in the manner of a spiral with a smooth metal foil 2 and a structured metal foil 2. It is fundamentally to be noted that other types of honeycomb body 10 can be produced in this way, for example in which the metal foils 2 are firstly stacked and are subsequently twisted in an involute shape or S-shape. In the embodiment variant shown here, the smooth metal foil 2 is thus placed onto the structured metal foil 2 so that hard solder 1 which is positioned at the elevations and depressions comes into contact with sections 11 of the smooth metal strip 2. Said layer is subsequently wound in a spiral shape, so that, as illustrated here, a cylindrical honeycomb structure 12 is formed. The honeycomb structure 12, which is viewed here from an end side 29, now forms substantially axially running parallel ducts 28 with the smooth and the structured metal foil 2. Said
honeycomb structure 12 is now inserted into a housing 30 which serves for fixing. In addition, the housing 30 can likewise be provided with hard solder, so that during a subsequent thermal treatment in an oven 31 (for example at over 1000°C and under a vacuum), joining connections are formed between the metal foils 2 and the housing 30 and between the metal foils 2 themselves.
Figure 5 now shows a particularly preferred field of use of honeycomb bodies 10 of said type as an exhaust-gas treatment unit 22. A vehicle 23 is shown which comprises an internal combustion engine 33 which is operated by means of an engine controller 32. The engine controller 32 can for example influence the operating mode of the internal combustion engine 33 taking into consideration measuring sensors 35 which are installed in the exhaust system 40. The exhaust gas generated by the internal combustion engine 33 is supplied via an exhaust line 34 to a plurality of exhaust-gas treatment units 22 which all have a corresponding metallic honeycomb body 10. hi the flow direction of the exhaust gas, the exhaust gas flows firstly through an oxidation catalytic converter 36, then a particle trap 37, an adsorber 38 and a further catalytic converter 39. Said exhaust gas finally flows through a silencer 41 before it is discharged, purified, to the environment.
With the invention proposed here, it is possible for the hard solder to be applied without a separate working step, with targeted application for a precisely predetermined brazing pattern and a minimal use of hard solder being obtained at the same time. This leads to a considerable time and cost benefit within the context of series production of metallic exhaust-gas treatment units for motor vehicles.

List of reference symbols
1 Hard solder
2 Metal foil
3 Structure
4 Hard solder foil
5 Hard solder label
6 Elevation
7 Depression
8 Side
9 Partial region
10 Honeycomb body
11 Section
12 Honeycomb structure
13 Device
14 Foil supply
15 Shaping unit
16 Positioning unit
17 Synchronization means
18 Coupling device
19 Adhesive bonding device
20 Welding device
21 Reciprocating punching system
22 Exhaust-gas treatment unit
23 Vehicle
24 Coil
25 Separating tool
26 Pressing tool
27 Recess
28 Duct
29 End side
30 Housing
31 Oven
32 Engine controller
33 Internal combustion engine
34 Exhaust line
35 Measuring sensor
36 Oxidation catalytic converter
37 Particle trap
38 Adsorber
39 Converter
40 Exhaust system
41 Silencer
42 Edge
43 Stamp

Patent claims
1. A method for applying hard solder (1) to an at least partially structured metal
foil (2), comprising at least the following steps:
(a) providing at least one flat metal foil (2),
(b) shaping the at least one metal foil (2) such that a structure (3) is
generated,
(c) applying hard solder (1) to at least one metal foil (2),
with steps (h) and (c) being carried out discontinuously and at least partially together.
2. The method as claimed in claim 1, in which step (b) comprises shaping by
means of reciprocating punching with a clock frequency, with step (c) being
carried out with the same clock frequency.
3. The method as claimed in claim 1 or 2, in which step (b) and step (c) are
carried out in a manner mechanically coupled to one another.
4. The method as claimed in one of the preceding claims, in which step (c)
comprises the provision of hard solder foil (4).
5. The method as claimed in one of the preceding claims, in which step (c)
comprises the separation of hard solder foil (4) in order to generate a plurality
of hard solder labels (5).
6. The method as claimed in one of the preceding claims, in which step (c) the
application of hard solder foil (4) takes place by means of at least one of the
processes adhesive bonding and welding.
7. The method as claimed in one of the preceding claims, in which the at least
one metal foil (2) is generated with a corrugated structure (3) with elevations
(6) and depressions (7) (if appropriate reservoir pockets), with the hard solder
(1) being applied from at least one side of the at least one metal foil (2)
(simultaneously) to a plurality of (end-side) partial regions (9) of the
elevations (6) or depressions (7).
8. A method for producing a honeycomb body (10) comprising at least the
following steps:

- a method for applying hard solder (1) as claimed in one of the preceding
claims,
- placing the hard solder (1) in contact with sections (11) of the at least one
metal foil (2), with at least one honeycomb structure (12) being formed,
fixing the at least one honeycomb structure (12),
- hard-soldering of at least one honeycomb structure (12).
9. A device (13) for applying hard solder (1J to an at least partially structured
metal foil (2) at least having:
- at least one foil supply (14) for at least one flat metal foil (2),
- at least one shaping unit (15) for the discontinuous generation of a
structure (3) in the at least one metal foil (2),
- at least one positioning unit (16) for the discontinuous application of hard
solder (1) to the at least one metal foil (2),
with synchronizing means (17) for coordinating the movements of the at least one shaping unit (15) and of the at least one positioning unit (16) being provided.
10. The device (13) as claimed in claim 9, in which the synchronizing means (17)
comprise a mechanical coupling device (18).
11. The device (13) as claimed in claim 9 or 10, in which at least one adhesive
bonding device (19) or one welding device (20) for applying the hard solder
(1) is provided.
12. The device (13) as claimed in one of claims 9 to 11, in which the at least one
shaping unit (15) is a reciprocating punching system (21) and the
synchronizing means (17) bring about a common movement of the
reciprocating punching system (17) and positioning unit (16).
13. An exhaust-gas treatment unit (22) comprising at least one honeycomb body
(10) produced by means of a method as claimed in one of claims 1 to 8 or
produced by means of a device as claimed in one of claims 9 to 12.
14. A vehicle (23) having at least one exhaust-gas treatment unit (22) as claimed
in claim 13.

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Patent Number

259488

Indian Patent Application Number

1909/DELNP/2008

PG Journal Number

12/2014

Publication Date

21-Mar-2014

Grant Date

13-Mar-2014

Date of Filing

04-Mar-2008

Name of Patentee

EMITEC GESELLSCHAFT FUR EMISSIONSTECHNOLOGIE MBH.,

Applicant Address

HAUPTSTRASSE 128, 53797 LOHMAR DENMARK.

Inventors:

#	Inventor's Name	Inventor's Address
1	WIERES LUDWIG,	OPPELNER STRASSE 2, 51491 OVERATH DENMARK.

PCT International Classification Number

B23K 1/00

PCT International Application Number

PCT/EP2006/009007

PCT International Filing date

2006-09-15

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	10 2005 044 499.7	2005-09-16	Denmark