Title of Invention

HONEYCOMB BODY WITH AT LEAST PARTIALLY CERAMIC HONEYCOMB STRUCTURE AND RECEPTACLE FOR MEASUREMENT SENSOR, AND PROCESS FOR PRODUCING A HONEYCOMB BODY OF THIS TYPE

Abstract The honeycomb body (1) according to the invention, in particular for use in the exhaust system of a motor vehicle, comprising an at least partially ceramic honeycomb structure (2) , through which a fluid can flow, in a tubular casing (3) , the honeycomb structure (2) having cavities (4) , is distinguished by the fact that the honeycomb body (1) , in a longitudinal direction (10), has at least two axial subregions (11, 12, 13), the honeycomb structure (2) being connected to the tubular casing (3) in an axial securing region (11) , and an axial measurement sensor region (12) being designed with a recess (14) for accommodating a measurement sensor (8) in the honeycomb structure (2). On account of its preferably force-fitting and/or form-fitting connection between tubular casing (3) and honeycomb structure (2) in the securing region (11), the honeycomb body (1) according to the invention has a permanent connection between tubular casing (3) and ceramic honeycomb structure (2) ; despite the formation of the recess (14), further damage to the honeycomb structure (2) in the measurement sensor region (12) is advantageously avoided.
Full Text - 1 -
Honeycomb body with at least partially ceramic
honeycomb structure and receptacle for measurement
sensor, and process for producing a honeycomb body of
this type
The subject matter of the present invention is a
honeycomb body having an at least partially ceramic
honeycomb structure through which a fluid can flow,
which has cavities and which is formed in a tubular
casing. A honeycomb body of this type is preferably
used in the exhaust system of a motor vehicle, in
particular as a catalyst support body or filter body.
Furthermore, the invention also comprises a process for
producing a corresponding honeycomb body.
Honeycomb bodies are often designed with a metallic or
ceramic honeycomb structure. These honeycomb bodies are
used in exhaust systems of motor vehicles, such as for
example automobiles, in particular also as catalyst
support bodies or filter bodies. There are numerous
countries throughout the world which have set limits on
certain components in the exhaust gas from automobiles.
These limits can generally only be complied with by
catalytically treating the exhaust gas from the
internal combustion engines. The very high conversion
rates which are increasingly required for certain
components of the exhaust gas can only be achieved by
making an increased reaction surface area available to
the exhaust gas. To ensure that it is not necessary to
install excessively large honeycomb bodies, therefore,
there is a trend toward honeycomb bodies with a very
high cell density, i.e. a very large number of cavities
or cavities per unit cross-sectional area. However,
this means that the walls which delimit the cavities
have to be made considerably thinner compared to
honeycomb bodies with a lower cell density. At the same
time, to comply with the statutory limits, many exhaust

- 2 -
systems require regulation from the engine control,
which makes it imperative to measure the composition of
the exhaust gas by means of a measurement sensor in the
exhaust system. By way of example, lambda sensors are
often used in the exhaust system to obtain information
about the air/fuel ratio.
However, particularly in the case of ceramic honeycomb
structures, the introduction of a lambda sensor or in
general terms of a measurement sensor into the
honeycomb structure weakens the honeycomb structure,
since it has to be provided in a subregion with a
recess in which the measurement sensor engages. This
type of initial weakening of the honeycomb structure,
however, generally leads, in particular in the case of
a force-fitting and/or form-fitting connection of the
tubular casing to the honeycomb structure, to this
being damaged further by the existing weakening of the
honeycomb structure. Since constant heating and cooling
processes occur in the exhaust system when the
honeycomb body is operating, leading to strong thermal
gradients and/or transients in the honeycomb body, this
leads to slowly advancing damage to the honeycomb
structure on account of the altered force acting from
the outside from the tubular casing as a result.
It is an object of the present invention to at least
reduce the problems which have been described in
connection with the prior art, and in particular to
propose a honeycomb body and a process for producing a
honeycomb body in which the tubular casing is connected
to the honeycomb structure in such a way that, despite
a recess for a measurement sensor being formed in the
honeycomb structure, the honeycomb structure is
reliably held in the tubular casing, and on the other
hand progressive damage to the honeycomb structure is
avoided.

- 3 -
According to the invention, these objects are achieved
by a honeycomb body and a process having the features
of the independent claims. Advantageous refinements
form the subject matter of the respective dependent
claims.
The honeycomb body according to the invention is to be
used in particular in the exhaust system of a motor
vehicle. The honeycomb body according to the invention
comprises an at least partially ceramic honeycomb
structure, through which a fluid can flow, in a tubular
casing, the honeycomb structure having cavities. The
honeycomb body, in a longitudinal direction, has at
least two axial subregions, the honeycomb structure
being connected to the tubular casing in at least one
axial securing region, and at least one axial
measurement sensor region being designed with a recess
for accommodating at least one measurement sensor in
the honeycomb structure.
In particular, in a honeycomb body according to the
invention, the honeycomb structure is connected to the
tubular casing only in the securing region.
Furthermore, it is preferable for there to be no direct
connection between tubular casing and honeycomb
structure in the measurement sensor region. In the
present context, a motor vehicle is to be understood as
meaning in particular an automobile, such as a
passenger automobile or a truck, a motorized two-
wheeler, a quad bike, a boat and/or an aircraft. An at
least partially ceramic honeycomb structure in the
context of the present invention may also have metallic
parts, for example metallic reinforcing or guiding
elements, which are incorporated in the ceramic walls.
Preference is given to honeycomb structures which are
produced by extrusion. The honeycomb structure may have

- 4 -
Walls which are impermeable to a fluid, such as for
example exhaust gas, so that in this case a fluid can
flow through the cavities, for example passages.
However, it is also possible for at least part of the
walls to be formed from a porous material, in
particular a porous ceramic. At least some of the
cavities of the honeycomb structure may also be closed.
The honeycomb body according to the invention is
suitable in particular for use as a catalyst support
body or as a filter body, and particularly preferably
also as a diesel particulate filter.
It is preferable for the tubular casing to have a hole
through which the measurement sensor can pass. The
dimensions of this hole are preferably substantially
identical to the dimensions of the recess in the
honeycomb structure. Furthermore, it is advantageously
possible for means for connecting, in particular in a
gastight manner, the measurement sensor to the
honeycomb body to be formed, in particular a screw
thread which interacts with a screw thread on the
measurement sensor.
In the honeycomb body according to the invention, a
measurement sensor can be introduced into the recess in
the honeycomb structure; although this recess weakens
the honeycomb structure, it cannot lead to progressive
damage to the honeycomb structure, since a
corresponding securing is formed in the securing
region. In particular, a force-fitting, form-fitting
and/or materially cohesive connection between tubular
casing and honeycomb structure can be formed in the
securing region. Furthermore, according to the
invention it is possible for an intermediate element,
which can in particular also produce the connection, to
be formed between the tubular casing and honeycomb
structure. This may, for example, be a swellable mat. A

- 5 -
swellable mat consists in particular of a mixture of
various ceramic fibers and minerals, which if
appropriate are bonded by paper fibers to improve their
handling properties. Vermiculite particles, for
example, are introduced into the swellable mat as
mineral fractions. Vermiculite is a sheet silicate
which at high temperatures expands by means of
reversible release of water in order to change the
thickness of the swellable mat. This can be used in
particular to actively clamp the honeycomb structure in
the tubular casing when the operating temperature
rises. Therefore, in the case of a force-fitting and/or
form-fitting connection between tubular casing and
honeycomb structure, this connection is retained even
at relatively high temperatures, such as the operating
temperature of the catalyst support body. The honeycomb
body according to the invention allows a high degree of
operational reliability without damage to the honeycomb
body even for prolonged periods of time, since the
holding forces used to produce a connection between
tubular casing and honeycomb structure are preferably
introduced only in the securing region.
According to an advantageous configuration of the
honeycomb body according to the invention, the
honeycomb body comprises an axial sealing region in
which a sealing means is formed between honeycomb
structure and tubular casing.
This sealing means advantageously prevents a bypass
flow of the exhaust gas around the honeycomb structure.
A design of the sealing means which produces a seal
over the entire circumferential region is particularly
preferred. In such a case, the sealing means is
preferably formed over the entire circumference. A
suitable sealing means is in particular a ceramic fiber
mat, a swellable mat and/or mica. It is particularly

- 6 -
advantageous for the sealing means to be designed in
such a way that in the sealing region there is
substantially no force-fitting and/or form-fitting
connection between tubular casing and honeycomb
structure. However, it is also possible and in
accordance with the invention to provide just a very
weak attachment in this region, so that the forces
which occur on heating of a swellable mat designed as a
sealing means are so low that there is no damage to the
honeycomb structure in the sealing region and/or in the
measurement sensor region.
According to a further advantageous configuration of
the honeycomb body according to the invention, the
measurement sensor region is formed between sealing
region and securing region in the longitudinal
direction. In particular, the sealing region is formed
in the region of an end side of the honeycomb body.
The sealing region then particularly advantageously
prevents the exhaust gas from flowing around the
honeycomb structure, which would lead to a lower
conversion rate being achieved in the front end region
of the honeycomb body than in the rear region. It is in
this context advantageous for the sealing region to
comprise a blow-out protector in the direction of the
end side of the honeycomb body. A blow-out protector
serves to prevent the sealing region from blowing out.
The sealing region may blow out, for example, as a
result of the strongly pulsating exhaust gas striking
the end side of the sealing region. The blow-out
protector may comprise, for example, a thin metal foil
which is laid around the end-face region of the sealing
region and is preferably connected to it by joining
techniques. A force-fitting and/or form-fitting
connection between blow-out protector and sealing
region is also possible in accordance with the

- 7 -
invention. By way of example, it is possible to produce
a flanged or other mechanical form of clamping between
blow-out protector and sealing regions. It is
particularly preferable for a blow-out protector to be
formed in the region of a gas-inlet end side of the
honeycomb body.
According to another advantageous configuration of the
honeycomb body according to the invention, the
connection between honeycomb structure and tubular
casing is designed in at least one of the following
ways:
a) force-fitting;
b) form-fitting; or
c) materially cohesive.
In this context, it is preferable to form a force-
fitting or form-fitting connection between the tubular
casing and honeycomb structure in the securing region
by means of a press fit. Preference is given in this
context to forming a swellable mat between honeycomb
structure and tubular casing at least in the securing
region.
It has proven particularly advantageous for the
connection between tubular casing and honeycomb
structure to be configured in such a way that the
holding forces introduced in the securing region are
greater, preferably considerably greater, than the
holding forces which may be introduced into the
honeycomb structure in the sealing region and/or the
measurement sensor region. This also applies in
particular to the mean holding force taken over the
possible range of temperatures to which a honeycomb
body is exposed. In particular, the connection is
configured in such a way that there is no temperature

- 8 -
within this temperature range, preferably up to a
temperature of 900°C, at which the holding force in the
securing region is less than or equal to the holding
force in the sealing region and/or the measurement
sensor region. A design of the connection between
tubular casing and honeycomb structure in which the
quotient of a holding force in the securing region to a
holding force in the sealing region and/or the
measurement sensor region is greater than or equal to
1.5, preferably greater than or equal to 2,
particularly preferably greater than or equal to 3 or
even four, is also preferred. It is also preferable for
these relationships also to apply to mean holding
forces, in which case this mean may be taken in the
axial, radial and/or circumferential direction or also
over a temperature range, preferably the range of
temperatures to which the honeycomb body is exposed in
operation in the exhaust system of a motor vehicle.
According to a further advantageous configuration of
the honeycomb body according to the invention, in the
securing region a connection between tubular casing and
honeycomb structure is formed in axial and/or
circumferential subregions.
Consequently, the tubular casing does not have to be
connected to the honeycomb structure throughout the
entire securing region. It is possible to form both
circumferential and axial subregions in which the
connection is produced. This can be done in particular
by corresponding subregions of the tubular casing
having a smaller internal diameter than other
subregions or by a mat positioned between tubular
casing and honeycomb structure having subregions with
different intumescent properties or also subregions of
different thicknesses. As an alternative and/or in
addition, it is also preferable for corresponding

- 9 -
regions of larger external diameter to be formed on the
honeycomb structure.
According to a further advantageous configuration of
the honeycomb body according to the invention, at least
in a subregion a flexible and/or elastic mat is formed
between honeycomb structure and tubular casing.
This may preferably be a swellable mat, a fiber mat, in
particular a ceramic fiber mat, and/or a mat containing
mica.
According to another advantageous configuration of the
honeycomb body according to the invention, at least in
a subregion a swellable mat, a ceramic fiber mat and/or
an intermediate layer of mica is formed between
honeycomb structure and tubular casing.
In particular, in this case the entire honeycomb
structure may be surrounded by a mat, which accordingly
has a subregion corresponding to the securing region.
Corresponding intumescent subregions could be formed in
this subregion, leading to the production of a force-
fitting and/or form-fitting lock between tubular casing
and honeycomb structure even when the honeycomb
structure and/or tubular casing heats up. A mat of this
type may have a further subregion which corresponds to
the measurement sensor region. No intumescent regions
are formed in this subregion, and furthermore, this
region has a hole for the measurement sensor to pass
through. If appropriate, a region which is intumescent
may be formed in a further subregion, corresponding for
example to a sealing region.
According to another advantageous configuration of the
honeycomb body according to the invention, the tubular
casing, in the measurement sensor region, has a second

- 10 -
internal diameter which is larger than a first internal
diameter of the securing region.
This constitutes a further means according to the
invention of restricting a force-fitting lock between
tubular casing and honeycomb structure substantially to
the securing region. If, in such a case, a swellable
mat is formed between tubular casing and honeycomb
structure, the enlarged second internal diameter in the
measurement sensor region, given a suitable
configuration of the swellable mat with regard to its
intumescent properties, leads to a force-fitting lock
being produced, in the cold state, only in the securing
region, whereas in the measurement sensor region there
is no force-fitting connection between tubular casing
and honeycomb structure. Even when the honeycomb body
is heated, this does not lead to the exertion of forces
in the measurement sensor region if the difference
between the thickness of the swellable mat in the
heated state and the thickness in the cold state is
suitably matched to the difference between the second
internal diameter and the first internal diameter.
According to a further advantageous configuration of
the honeycomb body according to the invention, the
tubular casing, at least in the measurement sensor
region, curves convexly outward at least in
circumferential and/or axial subregions. It is in this
context particularly preferred if in the region of the
recess for the measurement sensor there is a
circumferential subregion which is curved convexly
outward. In this way, introduction of forces as a
result of the different thermal expansion properties of
tubular casing and honeycomb structure is even more
reliably avoided in this sensitive subregion.
According to a further advantageous configuration of

-l1-
the honeycomb body according to the invention, the
recess is formed at a distance of between 20 and 60 mm,
preferably between 30 and 50 mm, particularly
preferably between 35 and 45 mm, behind an end side of
the honeycomb body.
The distance can in this case be calculated to a
central point of the recess for the measurement sensor;
however, it is equally possible for one of the edge
points of this recess to be used as a reference point.
In particular in the case of long honeycomb bodies, it
is therefore advantageous for a measurement sensor to
be formed in the region of the front third of the
honeycomb body.
A further aspect of the present invention proposes a
process for producing a honeycomb body which comprises
the following steps:
a) providing an at least partially ceramic honeycomb
structure through which a fluid can flow and which
has at least one recess for accommodating a
measurement sensor;
b) providing a tubular casing having at least one
hole for the measurement sensor to pass through;
c) introducing the honeycomb structure into the
tubular casing and joining the honeycomb structure
to the tubular casing in at least one axial
securing region,
in which process, before or during step c) , the
honeycomb structure and the tubular casing are aligned
relative to one another, so that the hole in the
tubular casing and the recess in the honeycomb
structure at least partially overlap one another after
step c).
Before or during step c) , the honeycomb structure and
the tubular casing are aligned relative to one another,

- 12 -
ensuring that the hole in the tubular casing, following
step c) , lies above the recess in the honeycomb
structure, in such a way that the measurement sensor
can be introduced through the hole into the recess,
i.e. the hole and recess in particular at least
partially overlap one another. Therefore, in particular
before the honeycomb structure is introduced into the
tubular casing, it is possible first of all to align
the longitudinal axes of the honeycomb structure and
the tubular casing parallel, after which the honeycomb
structure and/or the tubular casing can be rotated
until the orientation of the hole and the recess
coincide in such a way that hole and recess overlap one
another after the honeycomb structure has been
introduced into the tubular casing. The honeycomb
structure is then introduced into the tubular casing.
In particular, before and/or during step c) an
intermediate layer can be introduced between the
honeycomb structure and the tubular casing. It is
preferable for the intermediate layer to comprise at
least one of the following materials:
- a swellable mat,
- a ceramic fiber mat,
- an intermediate layer of mica,
- a porous metallic mat,
- an elastic mat, and
- a flexible mat.
It is preferable for the intermediate layer to be
inhomogeneous. In particular, the compressibility, the
thickness of the intermediate layer and/or the
temperature-dependent nature of the expansion
properties may vary over the intermediate layer, so
that an intermediate layer of this type can be used to
form a spatially selective connection between tubular
casing and honeycomb structure, in particular

- 13 -
exclusively in at least one securing region. In
principle, the connection between tubular casing and
honeycomb structure is preferably force-fitting. That
part of the intermediate layer which corresponds to the
securing region is designed in such a way that the
connection between tubular casing and honeycomb
structure is retained even in the event of heating of
the tubular casing and/or the honeycomb structure. A
porous metallic mat is to be understood in particular
as meaning a knitted wire mat.
According to a further advantageous configuration of
the process according to the invention, step c)
comprises joining together at least two tubular casing
parts around the honeycomb structure. This is a process
known as multi-shell canning, which is used in
particular as two-shell canning. In this case, the
tubular casing is composed of two halves which are
joined together. The connection between the tubular
casing parts is in this case preferably materially
cohesive, in particular formed by welding. Joining the
tubular casing parts together preferably compresses an
intermediate layer, for example a swellable mat,
located between tubular casing part and honeycomb
structure, at least in subregions, in such a way that a
force-fitting connection is produced between tubular
casing and honeycomb structure by the intermediate
layer.
According to a further advantageous configuration of
the process according to the invention, in step c)
- the honeycomb structure is surrounded with a
compressible mat, and
- the honeycomb structure surrounded by the mat is
pressed into the tubular casing, compressing the
mat.

- 14 -
This is a process known as plug canning. The
compression of the mat produces a force-fitting
connection between the tubular casing and honeycomb
structure.
According to a further advantageous configuration of
the process according to the invention, in step c) the
tubular casing is wound in at least one layer around
the honeycomb structure.
The details and advantages which have been disclosed
for the honeycomb body according to the invention can
also be applied and transferred to the process
according to the invention. In the same way, the
details and advantages which have been disclosed for
the process according to the invention can also be
applied and transferred to the honeycomb body according
to the invention. Further advantages and exemplary
embodiments of the present invention are explained
below with reference to the drawing. The invention is
not restricted to the exemplary embodiments, advantages
and details shown in the figures. In the drawing:
Figure 1 diagrammatically depicts a perspective view
of an exemplary embodiment of a honeycomb
body according to the invention;
Figure 2 diagrammatically depicts a longitudinal
section through a further exemplary
embodiment of a honeycomb body according to
the invention;
Figure 3 diagrammatically depicts a longitudinal
section through a further exemplary
embodiment of a honeycomb body according to
the invention;

- 15 -
Figure 4 diagrairanatically depicts a cross section
through a further exemplary embodiment of a
honeycomb body according to the invention;
and
Figure 5 shows a mat, in particular for producing a
connection between tubular casing and
honeycomb structure of a honeycomb body
according to the invention.
Figure 1 shows a honeycomb body 1 according to the
invention, comprising a ceramic honeycomb structure 2
in a tubular casing 3. The honeycomb structure 2 has a
plurality of cavities 4 through which a fluid can flow.
In the present exemplary embodiment, the cavities 4
extend continuously from a first end side 5 to a second
end side 6 of the honeycomb body 1. However, it is also
possible for at least some of the cavities 4 to be at
least partially closed. In particular, it is also
possible for the walls 7 which form the cavities 4 to
be at least partially permeable to a fluid, in
particular to be porous. It is thus also possible to
form honeycomb bodies 1 according to the invention
which in addition to a function, for example, as a
catalyst support body also perform a function of a
particulate filter. A coating, in particular a
catalytically active coating, preferably based on
washcoat, can be formed on the walls 7.
Furthermore, the honeycomb body 1 has a measurement
sensor 8. The measurement sensor 8 is preferably a
lambda sensor, although the measurement sensor 8 may as
an alternative or in addition also perform further
functions, for example the function of a temperature
sensor, of a gas concentration sensor, etc. A sealing
means 9 is formed in the region of the first end wall 5.

- 16 -
Figure 2 diagrammatlcally depicts a longitudinal
section through a further exemplary embodiment of the
honeycomb body 1 according to the invention. In a
longitudinal direction 10, the honeycomb body 1 of the
present exemplary embodiment has three axial subregions
11, 12, 13. In an axial securing region 11, the tubular
casing 3 is connected to the honeycomb structure 2.
Furthermore, the honeycomb body 1 has an axial
measurement sensor region 12, in which there is formed
a recess 14 for accommodating a measurement sensor 8 in
the honeycomb structure 2. Furthermore, in the present
exemplary embodiment, there is an axial sealing region
13, in which a sealing means 9 is formed between
tubular casing 3 and honeycomb structure 2.
In the present exemplary embodiment, a supporting mat
15 is formed between tubular casing 3 and honeycomb
structure 2 in the securing region 11. A supporting mat
15 may, for example, be a swellable mat, a fiber mat,
in particular a ceramic fiber mat, and/or a layer of
mica. It is preferable for the supporting mat to have
the property of expanding as the temperature rises.
This can be achieved, for example, by incorporating
vermiculite in the mat. Vermiculite expands at high
temperatures, in particular in the range from 3 00°C to
700°C. These thermal expansion properties of the
supporting mat 15 can be exploited to counteract the
different thermal expansion of tubular casing 3 and
honeycomb structure 2. If the honeycomb structure 2 is
connected in a force-fitting and/or form-fitting manner
to the tubular casing 3, an intumescent supporting mat
15 of this type can be used to produce the force-fit
and/or form-fit even in the heated state of the
honeycomb body.
Supporting mats 15, in particular if they are
intumescent, i.e. expand thermally, lead to a

- 17 -
temperature-dependent force acting on the honeycomb
structure 2. The honeycomb structure 2, in particular
the walls 7 of the honeycomb structure 2, are designed
in such a way that they can substantially absorb at
least the highest forces which the supporting mat 15
exerts on the honeycomb structure 2 during heating.
The recess 14 having the recess edges 16 is formed in
the measurement sensor region 12. The recess 14 is used
to accommodate a measurement sensor 8 in the honeycomb
structure 2. The recess 14 also weakens the honeycomb
structure 2 in the measurement sensor region 12, and
consequently in this region the forces which can be
absorbed by the honeycomb structure 2 are lower than in
the securing region 11. To avoid damage to the
honeycomb structure 2 in the measurement sensor region
12, the invention proposes that the introduction of
force into the honeycomb structure 2 be reduced in the
measurement sensor region 12 compared to the securing
region 11, or that no corresponding force be introduced
in the measurement sensor region 12. According to the
invention, this can be achieved, for example, by no
supporting mat 15, or alternatively a mat which is not
intumescent, being formed in the measurement sensor
region 12, at least in the circumferential region of
the recess 14, and if appropriate in adjacent regions
to be selected in a suitable size. This can be
implemented, for example, by a corresponding supporting
mat 15 being provided with a hole in the region of the
recess or by a multi-part supporting mat 15 being used.
As an alternative or in addition, according to the
invention it is possible for the tubular casing 2 to be
curved convexly outward in the measurement sensor
region 12, at least in subregions 17. In particular,
the subregion 17 may be a circumferential and/or axial
subregion 17 of the measurement sensor region 12. This

- 18 -
measure likewise advantageously reduces and/or avoids
the introduction of force into the honeycomb structure
2 in the measurement sensor region 12.
Furthermore, in the present exemplary embodiment there
is a sealing region 13. A sealing means 9 is formed
between tubular casing 3 and honeycomb structure 2 in
the sealing region 13. This sealing means may
preferably be a swellable mat, a fiber mat and/or mica.
In particular, the supporting mat 15 and the sealing
means 9 may be a correspondingly designed single-piece
mat with appropriate cutouts in the measurement sensor
region 12. The sealing means 9 serves in particular to
prevent or reduce a bypass flow of the exhaust gas past
the honeycomb structure 2. If appropriate, the sealing
means 9 may be intumescent at least in subregions.
Here, it is recommended in particular for the subregion
which is formed at an end side 5, 6 of the honeycomb
body 1 to be designed to be intumescent. This achieves
a particularly good sealing action in this region. In
such a case, the sealing means 9 is to be designed in
such a way that the introduction of force based on
intumescence in this region does not lead to damage to
the honeycomb structure 2. It is in this context
particularly advantageous for a corresponding region of
the sealing means to be selected to be as small as
possible.
Furthermore, the sealing means 9 preferably comprises a
blow-out protector 18 in the direction of an end side
5, 6 of the honeycomb body 1. This blow-out protector
18 may be formed, for example, by a preferably thin
metal sheet which is suitably connected in a force-
fitting, form-fitting and/or materially cohesive manner
in this region of the sealing means 9.
Figure 3 shows a longitudinal section through a further

- 19 -
exemplary embodiment of a honeycomb body 1 according to
the invention. The honeycomb body 1 comprises a
honeycomb structure 2 which is held in a tubular casing
3. In the longitudinal direction 10, the honeycomb body
1 comprises a securing region 11 and a measurement
sensor region 12. In the securing region 11, a
supporting map 15 which expands under the action of
heat in order to compensate for different thermal
expansion properties of the tubular casing 3 and the
honeycomb structure 2 is formed between the tubular
casing 3 and the honeycomb structure 2. In the
measurement sensor region 12, there is a recess 14 with
recess edges 16 for accommodating a measurement sensor
8. To further reduce the introduction of force onto the
honeycomb structure 2, the tubular casing 3, in
accordance with the invention, has two internal
diameters 19, 20. The first internal diameter 19 is
present in the securing region 11, while the second
internal diameter 20 is present in the measurement
sensor region 12. The first internal diameter 19 is
smaller than the second internal diameter 20, which
means that forces can only act on the honeycomb
structure 2 from the tubular casing 3 in the securing
region 11. In the present exemplary embodiment, the
edge of the supporting mat 15 does not coincide with
the region of the tubular casing 3 in which the
internal diameter changes from the first internal
diameter 19 to the second internal diameter 20.
However, these two points may also coincide. Fig. 3
also shows, by way of example, a hole 28 with hole edge
29 in the tubular casing 3. Hole 28 and recess 14 at
least partially overlap with one another, so that a
measurement sensor can be introduced into the recess 14
through the hole 28. For further details, reference may
be made to Figure 2.
Figure 4 shows a cross section through a further

- 20 -
exemplary embodiment of a honeycomb body according to
the invention. The cross section is taken in the
securing region 11. The honeycomb body 1 comprises a
tubular casing 3 and a honeycomb structure 2 with
cavities 4 which are delimited by walls 7 and are only
indicated in a subregion of the drawing for the sake of
clarity. A supporting mat 15 is formed between tubular
casing 3 and honeycomb structure 2. In the securing
region 11, the tubular casing 3 has first subregions 21
and second subregions 22. The first subregions 21 in
this case have a smaller internal diameter than the
second subregions 22. As a result, holding forces are
only introduced into the honeycomb structure 2 in
certain circumferential subregions 21 of the honeycomb
body 1. The spatial formation of the subregions 21, 22
may in this case be either symmetric or asymmetric in
both the axial direction and the circumferential
direction. In the context of the present invention, a
subregion in the circumferential direction is to be
understood as meaning a subregion which is not formed
over the entire circumference of the cross section of
the honeycomb structure 2, but rather only part of it.
The spatial extent, in particular in the
circumferential direction of the subregions 21, 22, may
also vary from subregion 21, 22 to subregion 21, 22.
Figure 5 shows a mat 23 which can be used in particular
to form a honeycomb body 1 according to the invention.
The mat 23 is preferably a swellable mat and/or a
ceramic fiber mat. It is also preferable, as an
alternative or in addition, to form a layer which at
least partially comprises mica. In the honeycomb body 1
according to the invention, the mat 23 is located
between tubular casing 3 and honeycomb structure 2. The
subregions 11, 12, 13 of the honeycomb body 1 lying in
the longitudinal direction can already be recognized
from the mat 23. In principle, the mat 23 is not

- 21 -
intumescent, but intumescent regions 24 are formed
therein. These intumescent regions 24 contain, for
example, vermiculite which expands on heating.
Therefore, an in particular force-fitting and/or form-
fitting connection can be produced between tubular
casing 3 and honeycomb structure 2 in the securing
region 11. On heating, the intumescent regions 24 lead
to the different thermal expansion properties of
tubular casing 3 and honeycomb structure 2 being
compensated for, so that even in the heated state the
force-fitting and/or form-fitting connection between
tubular casing 3 and honeycomb structure 2 is retained.
In what is subsequently the measurement sensor region
12, the mat 23 includes a hole 25 which is delimited by
a hole edge 26. When constructing the honeycomb body 1,
this hole 25 is positioned in such a way that the hole
25 is located above the recess 14 in the honeycomb
structure 2, so that when the measurement sensor 8 is
being installed in the honeycomb body 1 it enters the
recess 14 through the hole 25. In addition to allowing
the measurement sensor 8 to pass through, the hole 25
also reduces the forces which are introduced into the
honeycomb structure 2 in the region of the recess 14.
Therefore, the hole 25, in particular in combination
with the non-intumescent property of the mat 23 in the
measurement sensor region 12, prevents damage to the
honeycomb structure 2 in operation.
In what will subsequently be the sealing region 13, the
mat 23 has a sealing property. For this purpose, it
may, for example, have a greater thickness in the
sealing region 13 that in the measurement sensor region
12. Furthermore, it is also possible for an intumescent
region 24 to be formed at the edge of the sealing
region 13, which on heating results in the formation of
a gap between tubular casing 3 and honeycomb structure
2, allowing the exhaust gas to bypass the honeycomb

- 22 -
structure 2. It is preferable for the extent of this
intumescent region 24 in the longitudinal direction 10
to be short compared to the total extent of the sealing
region 13 in the longitudinal direction 10.
Furthermore, as an alternative or in addition, a blow-
out protector 18 may be formed in this end-side region
of the mat 23 as described above, in order to prevent
the mat 23 from being blown out, for example on account
of the highly pulsating exhaust gas stream.
On account of its preferably force-fitting and/or form-
fitting connection between tubular casing 3 and
honeycomb structure 2 in the securing region 11, the
honeycomb body 1 according to the invention has a more
durable connection between tubular casing 3 and ceramic
honeycomb structure 2; further damage to the honeycomb
structure 2 in the measurement sensor region 12 is
advantageously avoided despite the formation of the
recess 14.

- 23 -
List of designations

1 Honeycomb body
2 Honeycomb structure
3 Tubular casing
4 Cavity
5 First end side
6 Second end side
7 Wall
8 Measurement sensor
9 Sealing means
10 Longitudinal direction
11 Securing region
12 Measurement sensor region
13 Sealing region
14 Recess
15 Supporting mat
16 Recess edge
17 Subregion
18 Blow-out protector
19 First internal diameter
20 Second internal diameter
21 First subregion
22 Second subregion
23 Mat
24 Intumescent region
25 Hole
26 Hole edge
27 Distance
28 Hole
29 Hole edge

- 24 –
CLAIMS
1. A honeycomb body (1), in particular for use in the
exhaust system of a motor vehicle, comprising an at
least partially ceramic honeycomb structure (2) ,
through which a fluid can flow, in a tubular casing
(3), the honeycomb structure (2) having cavities (4) ,
characterized in that the honeycomb body (1) , in a
longitudinal direction (10), has at least two axial
subregions (11, 12, 13) , the honeycomb structure (2)
being connected to the tubular casing (3) in at least
one axial securing region (11), and at least one axial
measurement sensor region (12) being designed with a
recess (14) for accommodating at least one measurement
sensor (8) in the honeycomb structure (2).
2. The honeycomb body (1) as claimed in claim 1,
characterized in that the honeycomb body (1) comprises
an axial sealing region (13), in which a sealing means
(9) is formed between honeycomb structure (2) and
tubular casing (3).
3. The honeycomb body (1) as claimed in claim 2,
characterized in that the measurement sensor region
(12) is formed between sealing region (13) and securing
region (11) in the longitudinal direction (10).
4. The honeycomb body (1) as claimed in claim 2 or 3,
characterized in that the sealing region (13) is formed
in the region of an end side (5, 6) of the honeycomb
body (1).
5. The honeycomb body (1) as claimed in claim 4,
characterized in that the sealing region (13) comprises
a blow-out protector (18) in the direction of the end
side (5, 6) of the honeycomb body (1).

- 25 -
6. The honeycomb body (1) as claimed in one of the
preceding claims, characterized in that the connection
between honeycomb structure (2) and tubular casing (3)
is designed in at least one of the following ways:
a) force-fitting;
b) form-fitting; or
c) materially cohesive
7. The honeycomb body (1) as claimed in one of the
preceding claims, characterized in that in the securing
region (11) a connection between tubular casing (3) and
honeycomb structure (2) is formed in axial and/or
circumferential subregions (21, 22) .
8. The honeycomb body (1) as claimed in one of the
preceding claims, characterized in that at least in a
subregion a flexible and/or elastic mat (9, 15, 23) is
formed between honeycomb structure (2) and tubular
casing (3).
9. The honeycomb body (1) as claimed in one of the
preceding claims, characterized in that at least in a
subregion (11, 12, 13) a swellable mat, a ceramic fiber
mat and/or an intermediate layer of mica is formed
between honeycomb structure (2) and tubular casing (3) .
10. The honeycomb body (1) as claimed in one of the
preceding claims, characterized in that the tubular
casing (3) , in the measurement sensor region (12) , has
a second internal diameter (20) which is larger than a
first internal diameter (19) of the securing region
(11).
11. The honeycomb body (1) as claimed in claim 10,
characterized in that the tubular casing (3) , at least
in the measurement sensor region (12), curves convexly
outward at least in circumferential and/or axial

- 26 –
subregions (17).
12. The honeycomb body (1) as claimed in one of the
preceding claims, characterized in that the measurement
sensor region (12) is formed at a distance (27) of
between 20 and 60 mm, preferably between 3 0 and 50 mm,
particularly preferably between 35 and 45 mm, behind an
end side (5) of the honeycomb body (1).
13. A process for producing a honeycomb body,
comprising the following steps:

a) providing an at least partially ceramic honeycomb
structure (2) through which a fluid can flow and
which has at least one recess (14) for
accommodating a measurement sensor (8) ;
b) providing a tubular casing (3) having at least one
hole (28) for the measurement sensor (8) to pass
through;
c) introducing the honeycomb structure (2) into the
tubular casing (3) and joining the honeycomb
structure (2) to the tubular casing (3) in at
least one axial securing region (11),
in which process, before or during step c), the
honeycomb structure (2) and the tubular casing (3) are
aligned relative to one another, so that the hole (28)
in the tubular casing (3) and the recess (14) in the
honeycomb structure (2) at least partially overlap one
another after step c).
14. The process as claimed in claim 13, in which an
intermediate layer comprising at least one of the
following materials:
- a swellable mat,
- a ceramic fiber mat,
- an intermediate layer of mica,
- a porous metallic mat;
- an elastic mat, and

- 27 -
- a flexible mat
is formed between honeycomb structure (2) and tubular
casing (3).
15. The process as claimed in claim 14, in which the
intermediate layer is spatially inhomogenous in form.
16. The process as claimed in one of claims 13 to 15,
in which step c) comprises joining together at least
two tubular casing parts around the honeycomb structure
(2).
17. The process as claimed in one of claims 13 to 15,
in which in step c)
- the honeycomb structure (2) is surrounded with a
compressible mat, and
- the honeycomb structure (2) surrounded by the mat
is pressed into the tubular casing (3),
compressing the mat.
18. The process as claimed in one of claims 13 to 15,
in which in step c) the tubular casing (3) is wound in
at least one layer around the honeycomb structure (2).

The honeycomb body (1) according to the invention, in particular for use in the exhaust system of a motor vehicle, comprising an at least partially ceramic honeycomb structure (2) , through which a fluid can flow, in a tubular casing (3) , the honeycomb structure (2) having cavities (4) , is distinguished by the fact that the honeycomb body (1) , in a longitudinal direction (10), has at least two axial subregions (11, 12, 13), the honeycomb structure (2) being connected to the tubular casing (3) in an axial securing region (11) , and an axial measurement sensor region (12) being designed with a recess (14) for accommodating a measurement sensor (8) in the honeycomb structure (2).
On account of its preferably force-fitting and/or form-fitting connection between tubular casing (3) and honeycomb structure (2) in the securing region (11), the honeycomb body (1) according to the invention has a permanent connection between tubular casing (3) and ceramic honeycomb structure (2) ; despite the formation of the recess (14), further damage to the honeycomb structure (2) in the measurement sensor region (12) is advantageously avoided.


Documents:

01832-kolnp-2007-abstract.pdf

01832-kolnp-2007-claims.pdf

01832-kolnp-2007-correspondence others 1.1.pdf

01832-kolnp-2007-correspondence others 1.2.pdf

01832-kolnp-2007-correspondence others.pdf

01832-kolnp-2007-description complete.pdf

01832-kolnp-2007-drawings.pdf

01832-kolnp-2007-form 1.pdf

01832-kolnp-2007-form 18.pdf

01832-kolnp-2007-form 2.pdf

01832-kolnp-2007-form 3.pdf

01832-kolnp-2007-form 5.pdf

01832-kolnp-2007-gpa.pdf

01832-kolnp-2007-international publication.pdf

01832-kolnp-2007-international search report.pdf

01832-kolnp-2007-pct request form.pdf

01832-kolnp-2007-priority document 1.1.pdf

01832-kolnp-2007-priority document.pdf

1832-KOLNP-2007-ABSTRACT.1.1.pdf

1832-KOLNP-2007-AMANDED CLAIMS.pdf

1832-KOLNP-2007-CANCELLED PAGES.pdf

1832-KOLNP-2007-CORRESPONDENCE.1.3.pdf

1832-KOLNP-2007-DESCRIPTION (COMPLETE).1.1.pdf

1832-KOLNP-2007-DRAWINGS.1.1.pdf

1832-KOLNP-2007-EXAMINATION REPORT.1.3.pdf

1832-KOLNP-2007-FORM 1.1.1.pdf

1832-KOLNP-2007-FORM 18.1.3.pdf

1832-KOLNP-2007-FORM 2.1.1.pdf

1832-KOLNP-2007-FORM 3.1.1.pdf

1832-KOLNP-2007-FORM 3.1.3.pdf

1832-KOLNP-2007-FORM 5.1.1.pdf

1832-KOLNP-2007-FORM 5.1.3.pdf

1832-KOLNP-2007-FORM-27.pdf

1832-KOLNP-2007-GPA.1.3.pdf

1832-KOLNP-2007-GRANTED-ABSTRACT.pdf

1832-KOLNP-2007-GRANTED-CLAIMS.pdf

1832-KOLNP-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

1832-KOLNP-2007-GRANTED-DRAWINGS.pdf

1832-KOLNP-2007-GRANTED-FORM 1.pdf

1832-KOLNP-2007-GRANTED-FORM 2.pdf

1832-KOLNP-2007-GRANTED-LETTER PATENT.pdf

1832-KOLNP-2007-GRANTED-SPECIFICATION.pdf

1832-KOLNP-2007-OTHERS.1.3.pdf

1832-KOLNP-2007-OTHERS.pdf

1832-KOLNP-2007-PETETION UNDER RULE 137.1.1.pdf

1832-KOLNP-2007-PETETION UNDER RULE 137.pdf

1832-KOLNP-2007-REPLY TO EXAMINATION REPORT.1.3.pdf

1832-KOLNP-2007-REPLY TO EXAMINATION REPORT.pdf

abstract-01832-kolnp-2007.jpg


Patent Number 247689
Indian Patent Application Number 1832/KOLNP/2007
PG Journal Number 18/2011
Publication Date 06-May-2011
Grant Date 02-May-2011
Date of Filing 23-May-2007
Name of Patentee EMITEC GESELLSCAHFT FUR EMISSIONSTECHNOLOGIE MBH
Applicant Address HAUPTSTRASSE 128, 53797 LOHMAR
Inventors:
# Inventor's Name Inventor's Address
1 BRUCK, ROLF FROBELSTRASSE 12, 51429 BERGISCH GLADBACH
PCT International Classification Number F01N 3/28
PCT International Application Number PCT/EP05/013965
PCT International Filing date 2005-12-23
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10 2004 063 546.3 2004-12-30 Germany