Title of Invention

PROCESS FOR PRODUCING A METALLIC HONEYCOMB BODY WITH RECEPTACLE FOR A SENSOR

Abstract The invention relates to a method of producing a metal honeycomb body (1), comprising at least partially structured (2) pieces of sheet metal (3), with channels (4) that are especially adapted for an exhaust gas of an internal combustion engine to pass through. Said honeycomb body further has at least one receiver (6) for a sensor (7) extending into the interior (5) of the honeycomb body. The inventive method comprises the following steps: producing recesses (8) on at least one piece of sheet metal (3); stacking and/or coiling up the pieces of sheet metal (3) to form a honeycomb structure (9), the at least one piece of sheet metal (3) being disposed in such a manner as to form a receiver (6) that extends into the interior (5); inserting the pieces of sheet metal (3) into a sheathing tube (10) with an opening (11), said opening (11) extending at least partially across the receiver (6); producing, by joining techniques, a link between the pieces of sheet metal (3) and/or with the sheathing tube (10). The inventive method prevents the channels (4) from being damaged during manufacture when receivers (6) for sensors (7) are subsequently produced and allows, for example, an especially effective conversion of exhaust gases.
Full Text FIELD OF INVENTION
The present relates to a process for producing a metallic honeycomb body which
comprises at least partially structured metal foils, with passages being formed
through which in particularly an exhaust gas from an internal combustion engine
can flow. The metallic honeycomb body has at least one receptacle, which
extends into the interior of the honeycomb body, for a sensor.
BACKGROUND OF INVENTION
Honey comb bodies with sensors of this type are used in particular for onboard
diagnosis (OBD), the objective of which is the functional monitoring of catalytic
converters for example in an exhaust system of an automobile. In this
application, catalytic converters are used to convert pollutants (such as for
example nitrogen oxides, unsaturated hydrocarbons, carbon monoxide)
contained in the exhaust gas into constitutes which can be released into the
environment in accordance with the current statutory provisions. On account of
the fact that direct measurement of, for example, harmful hydrocarbons by
means of a sensor does not currently appear possible, there are currently two
methods which are used to monitor the functionality of catalytic converters.
The objective of the first method is to determine the level of oxygen stored in
the catalytic converter. For this purpose, an oxygen sensor is arranged both
upstream and downstream of the catalytic converter, these sensors determining
the oxygen content in the exhaust gas. Form this information, it is possible to
draw conclusions as to the storage capacity of the catalytic converter and/or as
to the progress of aging. The second method uses two thermal sensors, which
are arranged directly upstream and downstream of the catalytic converter, to
record the change in temperature of the exhaust gas. This is caused by thermal
processes inside the catalytic converter, in particular exothermic reactions
between the catalytic converter and the exhaust gas.
In addition to arrangements of two sensors upstream and downstream of a
catalytic converter of this type, German Utility Model DE 881 6154U has
described a support body for a catalytic reactor for exhaust gas purification, the
honeycomb body of which is composed of a single piece comprising corrugated
metal strips. In this case, a sensor is arranged at the support body in such a
manner that it extends into the interior of the metal honeycomb body.
Furthermore, it is proposed for the opening required for this installation to be
produced by means of electron-beam or leaser cutting, cavity sinking or high-
speed milling and grinding. Producing an opening of this type after the metallic
honeycomb body has been formed has proven to be difficult in terms of the
manufacturing technology required.
OBJECTS OF INVENTION
Working on this basis, it is an object of the present invention to provide a
process for producing a metallic honeycomb body which ensures a reliable
production process which is suitable for series production.
SUMMARY OF THE INVENTION
According to the invention, the process for producing a metallic honeycomb body
comprising at least partially structured metal foils, with passages being formed,
through which in particular an exhaust gas from an internal combustion engine
can flow, and which has at least one receptacle, which extends into the interior
of the honeycomb body, for a sensor, includes the following steps:
- producing recesses at at least one metal foil;
- stacking and/or winding the metal foils in order to form a honeycomb
structure, the at least one metal foil being arranged in such a manner that
at least one receptacle which extends into the interior is formed;
- introducing the metal foils into a tubular casing having an opening, the
opening extending at least partially over the at at least one receptacle;
- producing a connection, by joining technology, between the individual
metal foils and/or between the metal foils and the tubular casing.
The proposed process is distinguished in particular by the fact that essential
production processes for forming the receptacle are performed even before the
metal foils are stacked and/or wound to form a honeycomb structure. The result
of this is that producing recesses of this type affects only the immediately
adjoining areas of the at least one metal foil. By contrast, producing a
corresponding receptacle using the conventional processes led to the
deformation of a large number of adjacent metal foils, since these were already
arranged close together. Deformation of this nature led in particular to passages
becoming blocked, which in turn caused, for example, the efficiency of a catalytic
converter or the pressure loss to be adversely affected. These drawbacks are
avoided by the proposed process according to the invention, in which in
particular the machining of each individual foil separately is preferred.
According to a further configuration, it is proposed to produce a receptacle in the
form of a blind bore. Accordingly, the recesses at the at least one metal foil are
to be designed in such a way that after the stacking and/or winding operation
they generate a receptacle which extends from the periphery of the honeycomb
structure into inner regions. The dimensions of the blind bore are to be selected
such that the blind bore is only slightly larger than the sensor which extends into
the interior of the honeycomb body. This ensures that, despite a sensor being
arranged in the interior of the honeycomb body, a sufficiently large number of
passage have a completely continuous wall, providing the surface area required
for catalytic conversion of pollutants in the exhaust gas.
According to a further configuration, the metallic honeycomb body has metal
foils with a thickness which is less than 0.03 mm. When using thin foils,
subsequent machining (in the stacked and/or wound state) is particularly
difficult, meaning that the proposed process is especially suitable for metal foils
of this type.
According to yet another configuration of the process, the recesses are produced
even before the structure of the metal foils has been generated. It is customary
to build up metallic honeycomb bodies using smooth and corrugated metal foils.
The corrugated metal foils are introduced into the metal foils using a rolling
process. With regard to the production of the recesses, it is advantageous for
them to be produced in advance, since it is possible to use relatively simple
manufacturing processes. For example, it is possible in particular for the recesses
to be stamped or trimmed out of the metal foils. This prevents damage to the
structure of the metal foils.
Furthermore, it is proposed for the metal foils to be initially at least partially
structured and then for at least the metal foils which are intended to produced
the receptacle to be stacked, the recesses then being produced with the aid of a
high-energy beam or jet. This means in particular laser cutting processes, plasma
cutting processes and water/abrasive jet cutting processes. In this case, the
number of metal foils which are to be stacked and are machined simultaneously
should preferably be restricted to 20, in particular 10 or 5 metal foils.
According to yet another configuration of the process, the metal foils are initially
stacked and are then wound in and S shape or are arranged in such a way that
the metal foils run in an involute form from the inside outwards towards the
tubular casing. In this case, the recesses are preferably produced prior to the
stacking operation. The S-shaped or involute-shaped arrangement of the metal
foils means that they each extend as far as the edge of the honeycomb body or
as far as the tubular casing. This has the advantage that it is particularly simple
to produce a corresponding recess. To do this, it is sufficiently to provide a
predeterminable number of adjacent metal foils, as a function of the dimensions
of the sensor, with recesses. The recesses directly form the desired receptacle.
By contrast, if the metal foils are arranged helically, it is always necessary,
during production of the recesses, to take account of the change in
circumference, so that the recess of the wound metal layer is arranged over the
recess of the previous metal layer.
The recesses are in this case preferably U-shaped, with in particular adjacent
metal foils having different depths. The U-shaped configuration of the recesses in
particular allows the use of sensors in rod form. The slightly curved arrangement
of the metal foils in the vicinity of the tubular casing is taken into account with
the aid of preferably slight variations in the depth of the recesses in adjacent
metal foils, this also, for example, ensuring the integration of sensors in rod form
without the sensors making contact with the metal foils.
According to an advantageous configuration of the process, the receptacle is
designed in such a way that at least in sections it follows a profile of the metal
foils. The result of this is that only a relatively small amount of adjacent metal
foils have to be provided with recesses. In this case, the sensor to be used is
preferably designed to match the profile of the metal foils. This prevents damage
to the metal foils, while having only a very influence on the functionality of the
honeycomb structure.
Further advantageous configurations and particularly preferred embodiments are
explained in more detail on the basis of the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1 shows a diagrammatic and perspective view of a metallic honeycomb body
having a sensor,
Fig. 2 shows a diagrammatic and perspective view of an arrangement of metal
foils with recesses,
Fig. 3 shows a diagrammatic and perspective view of the sequence of one
configuration of the process according to the invention,
Fig. 4 diagrammatically depicts a cross section through an embodiment of a
metallic honeycomb body with metal foils running in involute form, and
Fig. 5 diagrammatically depicts a detailed view of a coated honeycomb structure.
DETAILED DESCRIPTION OF PREFERRED EMBODIEMENTS OF
INVENTION
Fig. 1 shows a metallic honeycomb body 1 which has metal foils which at least
in part are designed with structures 2 forming passages 4. A metallic honeycomb
body 1 of this type is used in particular to purify exhaust gasses from an internal
combustion engine, with the exhaust gas which is to be purified flowing through
the passages 4 in the honeycomb body 1. The honeycomb body 1 has a
receptacle 6 which extends into the interior 5 of the honeycomb body 1 and in
which a sensor 7 is arranged. The receptacle 6 is formed by a number of
recesses 8 which have been formed into a suitable number of metal foils 3. The
metal foils 3 are in this case wound in an S shape and surrounded by tubular
casing 10.
Fig. 2 shows a stack of smooth and corrugated metal foils which together form a
honeycomb structure 9. The metal foils 3 have a thickness 12 of preferably less
than 0.03 mm. A stack of this type is then wound, for example, in an S shape. In
order, in the process, by way of example, to produce a receptacle 6 as shown in
Fig. 1, some metal sheets have recesses 8 which have a predeterminable depth
14 starting from the edge of the metal foils which subsequently bears against the
tubular casing 10. The depth 14 of the recesses 8 in adjacent metal foils 3 is in
this case preferably to be designed to differ. In this context, it is advantageous
for the metal foils to be machined individually using a cutting process.
Fig. 3 diagrammatically depicts the sequence involved in producing the metallic
honeycomb body 1, the metal foils 3 of which are wound helically. In this case, a
smooth metal foil 3 and a structured metal foil 3 are placed on top of one
another and the recesses 8 are produced with the aid of a high-energy beam or
jet 13. In the process, by way of example, a nozzle is moved over the metal foils
3 (as indicated by an arrow) in accordance with the desired shape of the recess
8, in order to produce, for example, round recesses 8 with the aid of the water
jet/abrasive jet cutting process. The metal foils 3 which have been treated in this
way are wound up to form a honeycomb structure, with the distances between
the adjacent recesses 8 being designed in such a manner that they always
overlap one another during the winding operation. When the honeycomb
structure has reached a predetermined diameter, the metal foils 3 supplied are
served and the honeycomb structured is introduced into a tubular casing 10. The
tabular casing 10 has an opening 11 which is oriented in such a way that it is
arranged at least partially above the openings 8. In this way, a receptacle 6 (not
shown) is formed, in which a sensor 7 can subsequently be arranged.
Fig. 4 diagrammatically depicts a cross section through an embodiment of a
metallic honeycomb body 1 with metal foils 3, with the structure 2 (not shown)
in this case having been disregarded. The metal foils 3 are in this case arranged
in a tubular casing 10, forming an involute-like profile 19. The receptacle 6
formed by the metal metal foils 3 in this case, in a section 18, follows the profile
19, as does a sensor 7 which has been arranged in the receptacle 6 and is
shaped suitably. The sensor 7 is in this case fixed in the original 11 in the tubular
casing 10 by means of a holder 15. The sensor 7 is of at least partially elastic or
deformable design, in order to facilitate the introduction of the sensor 7 into the
receptacle 6. The number of the metal foils 3 with recesses 8 (not shown) is in
this way limited to less than 20, in particular less than 10.
Fig. 5 diagrammatically depicts a detailed view of a coated honeycomb
structured 9. The passages 4 of the honeycomb structure 9 are delimited by the
metal foils 3, with a metal foil 3 with a structure 2 and a smooth metal foil 3
being wound alternately. The metal foils in this case have a thickness 12 of less
than 0.03 mm. In view of the preferred use of honeycomb bodies of this type as
catalyst support bodies for exhaust gas purification, the honeycomb structure 9
illustrated has a catalytically active coating 16. During the purification process,
the coating 16 comes into contact with the exhaust gas flowing through the
passages 4, the precious metal 17 including the coating 16 allowing the
pollutants to be converted.
The process according to the invention prevents manufacturing damage to
passages during the retrospective production of receptacles for sensors and
thereby ensures, for example, particularly effective conversion of exhaust gases.
LIST OF REFERENCE SYMBOLS
WE CLAIM
1. A process for producing a metallic honeycomb body (1), comprising at
least partially structured (2) metal foils (3), with channels (4) being
formed, adaptable in particular for an exhaust gas from an internal
combustion engine to flow, the metallic honeycomb body (1) having at
least one receptacle (6) for a sensor (7), extension into an interior (5) of
the honeycomb body (1), characterized by comprising the following steps:
- producing recesses (8) at at least one metal foil (3), the recesses
(8) being produced even before the structure (2) of the sheet
metal (3) has been formed;
- stacking and/or the metal foils (3) to form a honeycomb structure
(9), the at least one metal foil (3) being arranged in such a manner
so as to form at least one receptacle (6) which extends into the
interior (5);
- inserting the metal foils (3) into a tubular casing (10) having an
opening (11), the opening (11) extending at least partially across
the at least one receptacle (6);
- producing a connection, by joining techniques between the
individual metal foils (3) and between the metal foils (3) and the
tubular casing (10) or between the metal foils (3) and the tubular
casing (10).
2. The process as claimed in claim 1, wherein a receptacle (6) is produced in
the form of a blind bore.
3. The process as claimed in claim 1 or 2, wherein the metal foils (3) have a
thickness (12) of less than 0.03 mm.
4. The process as claimed in one of claims 1 to 3, wherein the recesses (8)
are stamped.
5. The process as claimed in one of claims 1 to 4, wherein the metal foils (3)
are initially stacked and are then wound in an S shape or are arranged so
as to run in an involute form from the inside (5) outwards the tubular
casing (10).
6. The process as claimed in claim 5, wherein the recesses (8) are of U-
shaped design.
7. The process as claimed in claim 5 or 6, wherein the recesses (8) cf
adjacent metal foils (3) have different depths (14).
8. The process as claimed in one of claims 5 to 7, wherein the receptacle (6)
is configured in such a way that, at least in sections (18), the receptacle
(6) corresponds a profile (19) of the metal foils (3), to enable insertion of
a correspondingly shaped sensor (7).
This invention relates to a method of producing a metal honeycomb body (1),
comprising at least partially structured (2) pieces of sheet metal (3), with
channels (4) that are especially adapted for an exhaust gas of an internal
combustion engine to pass through. Said honeycomb body further has atleast
one receiver (6) for a sensor (7) extending into the interior (5) of the honeycomb
body. The inventive method comprises the following steps: producing recesses
(8) on at least one piece of sheet metal (3); stacking and/or coiling up the pieces
of sheet metal (3) to form a honeycomb structure (9), that at least one piece of
sheet metal (3) being disposed in such a manner as to form a receiver (6) that
extends into the interior (5); inserting the pieces of sheet metal (3) into a
sheathing tube (10) with an opening (11), said opening (11) extending at least
partially across the receiver (6); producing by joining techniques, a link between
the pieces of sheet metal (3) and/or with the sheathing tube (10). The inventive
method prevents the channels (4) from being damaged during manufacture
when receivers (6) for sensors (7), are subsequently produced and allows for
example, an especially effective conversion of exhaust gases.

Documents:

1118-kolnp-2003-granted-abstract.pdf

1118-kolnp-2003-granted-claims.pdf

1118-kolnp-2003-granted-correspondence.pdf

1118-kolnp-2003-granted-description (complete).pdf

1118-kolnp-2003-granted-drawings.pdf

1118-kolnp-2003-granted-examination report.pdf

1118-kolnp-2003-granted-form 1.pdf

1118-kolnp-2003-granted-form 18.pdf

1118-kolnp-2003-granted-form 2.pdf

1118-kolnp-2003-granted-form 3.pdf

1118-kolnp-2003-granted-form 5.pdf

1118-kolnp-2003-granted-gpa.pdf

1118-kolnp-2003-granted-letter patent.pdf

1118-kolnp-2003-granted-reply to examination report.pdf

1118-kolnp-2003-granted-specification.pdf


Patent Number 214993
Indian Patent Application Number 01118/KOLNP/2003
PG Journal Number 08/2008
Publication Date 22-Feb-2008
Grant Date 20-Feb-2008
Date of Filing 03-Sep-2003
Name of Patentee EMITEC GESELLSCHAFT FUR EMISSIONSTECHNOLOGIE MBH
Applicant Address HAUPTSTRASSE 150, 53797 LOHMAR
Inventors:
# Inventor's Name Inventor's Address
1 BRUCK ROLF FROBELSTRASSE 12, 51429 BERGISCH GLADBACH
PCT International Classification Number B 01 D 53/06
PCT International Application Number PCT/EP0202123
PCT International Filing date 2002-02-28
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 101 12 678.6 2001-03-16 Germany