WO2002038320A1 - Method for producing a soldered honeycomb body arrangement - Google Patents

Abstract

The invention relates to a method for producing a soldered honeycomb body arrangement, whereby, a honeycomb body (1) is initially constructed in the form of piles and/or rolls of metal sheets which are at least partially structured, so that the honeycomb body (1) comprises channels which allows fluid to flow through; the honeycomb body (1) is subsequently placed inside a tool (3), which outlines the outer form of the honeycomb body (1). The outer form of the honeycomb body (1) is essentially the defined, inner form of the outer jacket or the housing (2). The honeycomb body (1) is then soldered with solder powder according to a known soldering method for honeycomb bodies (1) arranged in an outer jacket; the honeycomb body (1) is then subsequently transferred by a tool (3) and arranged in an outer jacket or housing (2), whereby only a minor relative movement of the metal sheets occurs during the transfer, and finally a soldering process is carried out. The invention is characterised in that it enables front-faced soldered honeycomb bodies to be produced in outer jackets or housing which are unsuitable for front-faced soldering methods. Relative movements of the sheets in the honeycomb bodies (1) is reduced so that solder powder does not become detached and the production of a soldered honeycomb body arrangement is carried out with homogeneous application of solder in a rational manner.

Description

 Method of making a soldered honeycomb assembly

The present invention relates to a method for producing a soldered honeycomb structure.

Honeycomb bodies which are formed by stacking and / or winding sheet metal layers, the sheet metal layers being at least partially structured, so that the honeycomb body has channels for a fluid to flow through, are known in many forms. Such honeycomb bodies are provided, for example, with catalytic coatings and are used in the automotive industry as catalyst carrier bodies in exhaust gas purification. Different configurations of honeycomb body arrangements as catalyst carrier bodies are described, for example, in EP-AI-0245 738.

The stacked and / or wound sheet metal layers are at least partially soldered to one another, so that a monolithic honeycomb body is formed. It is also known to at least partially solder the honeycomb body to the jacket tube in which it is arranged. For this purpose, solder is introduced into the soldering areas of the sheet metal layers and on the inside of the casing tube.

Methods for applying an adhesive for soldering a metallic honeycomb structure are known, for example, from WO 89/11938, WO 94/06594, WO 93/25339 and DE-Al-2924 592.

In particular, soldering techniques are known from the prior art which apply the solder to the front of the honeycomb body. Here, the unsoldered honeycomb body is at least partially pushed into a tubular casing or a housing and the end face of the honeycomb body is provided with adhesive or solder powder. With certain geometries of casing tubes, however, the problem arises that soldering on the end face is not possible at least on one end face, since the direct access to this end face of the honeycomb body necessary for the soldering is pers is blocked. For example, in the case of tapered or curved casing pipes, such as those which occur in applications where value is placed on a small space requirement (for example in the case of motorcycles), soldering on the end face is difficult. Failure to solder the end face will result in premature damage to the fine honeycomb structures. In manufacturing processes in which a honeycomb body is first soldered, then inserted into a jacket tube using conventional methods and finally subjected to a soldering process, the honeycomb body would change its shape due to its still lacking mechanical stability. Because of the relative movements of the sheet metal layers to one another, at least some of the solder powder would fall off the surface of the sheet metal layers, and on the other hand areas with too much solder and areas with too little solder would be formed. This would result in an uneven soldering. Such a consequence of procedural steps has therefore not previously been considered.

Proceeding from this, the present invention is based on the object of specifying a method for producing a soldered honeycomb body arrangement which avoids the mentioned disadvantages of the prior art and enables rational and high-quality production of the soldered honeycomb body arrangement. In particular, honeycomb bodies soldered on the end face should be able to be produced inside a housing that is not easily accessible from one end face.

To solve these problems, a method according to the invention is proposed with the features of claim 1. Advantageous refinements and developments of the method are the subject of the dependent claims.

According to the invention for producing a soldered honeycomb body arrangement it is proposed to first form a honeycomb body by stacking and / winding sheet metal layers which are at least partially structured, so that the honeycomb body has channels for a fluid to flow through. Then the ^' Honeycomb body introduced into a tool which specifies the outer shape of the honeycomb body, the outer shape of the honeycomb body being essentially the final, inner shape of the casing tube or the housing. Thereupon, the honeycomb body is soldered with solder powder according to a soldering process, as is known for honeycomb bodies arranged in a jacket tube. Then the honeycomb body is transferred from the tool into a housing or casing tube arranged in alignment with it, with only a slight relative movement of the sheet metal layers with one another taking place during the transfer. Finally a soldering process is carried out. The advantage of this method is that due to the slight relative movement of the sheet metal layers to one another, no solder powder is pushed aside by the sheet metal layers in contact with one another, so that areas with an undesirable excess or lack of solder powder are avoided. Uniform soldering is achieved and the solder powder does not fall off the sheet layers. The tool specifies the outer shape of the honeycomb body, as it will later appear in the casing tube or in the housing. By final is meant that during the manufacturing process of the soldered honeycomb body arrangement, the shape of the casing tube or the housing can change, for example by reducing the cross-sectional shape of the casing tube or housing, but the goal after the honeycomb body has been soldered to the honeycomb body in to change its shape only insignificantly. Relative movements of the sheet metal layers with one another are hereby avoided. The tool can be designed like a jacket tube, ie the inner shape of the tool corresponds to the inside shape of the jacket tube or the housing, but can also be pliers-like, which only holds the honeycomb body at certain points. It is crucial here that the tool brings the honeycomb body into its final shape and essentially holds it.

In a development of the method according to the invention, the honeycomb body is introduced into a tool which, compared to the casing tube or housing, has a cross-sectional shape which is reduced by 0.1 to 2 mm, preferably 0.5 to 1 mm, in particular a reduced diameter , This is is sufficient that the honeycomb body can be inserted in a simple manner by the tool, for example by pushing with a punch into the casing tube or the housing, without the friction of the sheet metal layers on the inside of the casing tube or the housing causing the honeycomb body to deform.

According to a further development of the method according to the invention, before the transfer of the honeycomb body, the jacket tube or the housing is provided on the inside with at least one circumferential strip of solder material. This ensures that the honeycomb body is also soldered to the inside of the housing or the casing tube and a mechanically stable connection is created.

In a further embodiment of the method according to the invention, the inner shape of the casing tube or the housing is reduced to the outer shape of the honeycomb body during the transfer. In this way, the casing tube or the housing can be calibrated and / or brought to its final shape.

In a still further embodiment of the method according to the invention, the outer shape of the honeycomb body is detected by means of a sensor in order to thereby reduce the inner shape of the casing tube or the housing exactly to that of the honeycomb body. In this way, a particularly good fit of the honeycomb body in the casing tube or the housing is achieved without relative movement of the sheet metal layers.

According to a still further development of the method according to the invention, the honeycomb body is formed in such a way that the ends of the sheet metal layers each abut the casing tube or the housing and can be soldered there.

In a special embodiment of the method according to the invention, the sheet metal layers of the honeycomb body are formed in an involute or S shape. Further details and advantages of the invention are explained with reference to the process section shown in the drawing.

The drawing shows schematically the transfer of the honeycomb body, which is important for the invention, after the soldering from the tool into a housing or jacket tube.

Here, a honeycomb body 1 is surrounded by a tool 3, the outer shape of the honeycomb body 1 being predetermined by the inner shape of the tool 3. A curved section 6 of a casing tube or a housing 2 does not permit face soldering from one side. In this embodiment, the tool 3 consists of two opposite half-shells, each of which is connected to a gripping device 5, which can move the tool 3. Alternatively, instead of half-shells, bolts, circular segments or other force-exerting elements which are able to specify the external shape of the honeycomb body can also be used. A plunger 4 presses the honeycomb body 1 out of the tool 3 into a housing or casing tube 2 aligned with the honeycomb body 1. What is important here is that the tool 3 does not open after the honeycomb body 1 has been soldered before the honeycomb body 1 at least partially is introduced into the casing tube or housing. In this way, relative movements of the sheet layers with one another are avoided, which would otherwise deteriorate the quality of the brazing. It is advantageous to provide the outer shape of the honeycomb body 1 somewhat smaller than the inner shape of the housing or jacket tube, so that the honeycomb body 1 can be introduced into the jacket tube or housing 2 without greater friction of the sheet metal layers of the honeycomb body 1 on the inside of the casing tube or housing. Alternatively, the honeycomb body 1 can be at least partially inserted into the casing tube or housing 2, the internal shape of the housing or casing tube 2 being larger than its final shape, whereupon the housing or casing tube 2 by the action of another tool (not shown). is reduced. It is important here to avoid relative movements of the sheets of the honeycomb body 1. The invention relates to a method for producing a soldered honeycomb body arrangement, which enables the manufacture of the honeycomb body soldered on the end face in jacket tubes or housings that are not suitable for soldering processes on the end face. Relative movements of the sheet metal layers after the brazing of their surfaces are avoided. The process is characterized in that soldered honeycomb body arrangements can be produced particularly quickly, economically and efficiently, with a uniform solder application.

LIST OF REFERENCE NUMBERS

honeycombs

Jacket tube or housing

Tool

stamp

gripping device

section

Claims

claims 1. A method for producing a soldered honeycomb body arrangement with the following steps: forming a honeycomb body (1) by stacking and / or winding Sheet metal layers which are at least partially structured so that the honeycomb body (1) has channels for a fluid to flow through; Introducing the honeycomb body (1) into a tool (3) which specifies the outer shape of the honeycomb body (1), the outer shape of the honeycomb body (1) essentially the final, inner shape of the casing tube or the housing (2 ) is; Soldering the honeycomb body (1) with solder powder according to a soldering process, as is known for honeycomb bodies (1) arranged in a jacket tube; Transferring the honeycomb body (1) from the tool (3) into a casing tube or housing (2) aligned with it, with only a slight relative movement of the sheet metal layers with one another taking place during the transfer; and carrying out a soldering process. 2. The method according to claim 1, characterized in that the honeycomb body (1) is introduced into the tool (3), which in comparison to the casing tube or housing (2) by 0.1 - 2 mm, preferably 0.5 - 1 mm, has a reduced cross-sectional shape. 3. The method according to any one of claims 1 or 2, characterized in that the jacket tube or housing (2) is provided on the inside with at least one circumferential circumferential strip of solder material before transfer. 4. The method according to any one of the preceding claims, characterized in that the inner shape of the casing tube or the housing (2) is reduced to the outer shape of the honeycomb body (1) during the transfer. 5. The method according to claim 4, characterized in that the outer shape of the honeycomb body (1) is detected by a sensor and the inner shape of the casing tube or the housing (2) is reduced to that of the honeycomb body (1). 6. The method according to any one of the preceding claims, characterized in that the honeycomb body (1) is designed such that the sheet metal layers are each fastened at their ends to the casing tube or to the housing (2). 7. The method according to any one of the preceding claims, characterized in that the sheet metal layers of the honeycomb body (1) are formed in an involute or S shape.