U.S. patent application number 13/274321 was filed with the patent office on 2012-04-26 for exhaust manifold.
Invention is credited to Armin Buchsteiner, Matthias Kroll.
Application Number | 20120096842 13/274321 |
Document ID | / |
Family ID | 44582014 |
Filed Date | 2012-04-26 |
United States Patent
Application |
20120096842 |
Kind Code |
A1 |
Kroll; Matthias ; et
al. |
April 26, 2012 |
EXHAUST MANIFOLD
Abstract
An exhaust manifold for an internal combustion engine with an
exhaust gas conducting inner tube and an outer jacket which is
insulated particularly effectively and inexpensively is described.
To this end, it is suggested to embody the insulation as an
insulating molded part pressed into shape and to arrange it between
the jacket and the interior, the insulating molded part containing
an insulating fibrous tissue and a binder.
Inventors: |
Kroll; Matthias;
(Dackenheim, DE) ; Buchsteiner; Armin; (Sinsheim,
DE) |
Family ID: |
44582014 |
Appl. No.: |
13/274321 |
Filed: |
October 15, 2011 |
Current U.S.
Class: |
60/323 |
Current CPC
Class: |
F01N 13/102 20130101;
F01N 2310/02 20130101; F01N 13/16 20130101; F01N 13/141
20130101 |
Class at
Publication: |
60/323 |
International
Class: |
F01N 13/10 20100101
F01N013/10 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 2010 |
DE |
10 2010 048 973.5 |
Claims
1. Exhaust manifold (1) for an internal combustion engine, having
an exhaust gas conducting inner tube (2), an outer jacket (3), and
an insulation (4), characterized in that the insulation is embodied
as an insulating molded part (4) pressed into shape and arranged
between the jacket (3) and the inner tube, and that it contains an
insulating fibrous tissue and a binder.
2. Exhaust manifold according to claim 1, wherein: the insulating
fibrous tissue contains a fiber mat of mineral fibers, such as a
woven glass and/or silicate and/or ceramic fiber mat.
3. Exhaust manifold according to claim 1, wherein: the binder is
alumina, in particular bentonite.
4. Exhaust manifold according to claim 1, wherein: the insulating
molded part (4) is separated from the inner tube (2) by an air gap
(5).
5. Exhaust manifold according to claim 4, wherein: the insulating
fibrous tissue of the insulating molded part (4) is arranged
adjacent to the air gap (5).
6. Exhaust manifold according to claim 1, wherein: the insulating
molded part (4) contains heat absorbing and/or heat reflecting
pigments.
7. An exhaust manifold for an internal combustion engine
comprising: an exhaust gas conducting inner tube; a jacket spaced a
distance from said exhaust gas conducting inner tube; and an
insulating molded part pressed into a shape and placed between said
exhaust gas conducting inner tube and said jacket, said insulating
molded part comprising an insulating fibrous tissue and a binder,
whereby a mechanical cohesion is obtained and fibers are prevented
from being blown out.
8. An exhaust manifold for an internal combustion engine as in
claim 7 wherein: said insulating molded part is placed adjacent
said jacket so that an air gap is formed between said insulating
molded part and said exhaust gas conducting inner tube.
9. An exhaust manifold for an internal combustion engine as in
claim 7 wherein: the insulating fibrous tissue comprises a woven
cloth of insulating fibers.
Description
FIELD OF THE INVENTION
[0001] The invention relates to an exhaust manifold for an internal
combustion engine of the type having an exhaust gas inner tube and
an outer jacket.
BACKGROUND OF THE INVENTION
[0002] Exhaust manifolds are often insulated, in particular if the
exhaust gas temperature is to reach a high level as soon as
possible for downstream units, for example a catalyst or a
turbocharger or the like, so that the downstream units can work
correctly, or the construction can be built from low-quality
materials, or so that these work at all.
SUMMARY OF THE INVENTION
[0003] The object underlying the invention is to provide a
particularly effective kind of insulation for an exhaust
manifold.
[0004] The object is achieved by the features of an insulation
embodied as an insulating molded part pressed into shape and
arranged between the jacket and the inner tube and that contains an
insulating fibrous tissue and a binder.
BRIEF DESCRIPTION OF THE DRAWING
[0005] The FIGURE shows a schematic representation of a section
through an exhaust manifold.
BACKGROUND OF THE INVENTION
[0006] The inventive design as an insulating molded part on the
basis of an insulating fibrous tissue permits arranging the
insulation inside, i.e. between the exhaust gas conducting inner
tube and the outer jacket of the exhaust manifold. By this, the
outer jacket is also protected from increased temperatures, or an
increase in the temperature level in the exhaust gas for the
downstream units is reached earlier, and some sound protection is
simultaneously achieved. By the design as a molded part on the
basis of a woven cloth of insulating fibers, a mechanical cohesion
of the insulation is furthermore achieved without any additional
provisions, for example without any additional foil coating or the
like. By this, the air gap between the jacket and the inner tube
provided in the installation is maintained even under rough
operational conditions, and fibers are simply and safely prevented
from being blown out.
[0007] Advantageous further developments of the invention can be
taken or appreciated from the claims.
[0008] The insulating fibrous tissue preferably consists of
silicate fibers, but it can also consist of glass fibers or the
like.
[0009] The binder used for compression molding the insulating
molded part is alumina, in particular bentonite.
[0010] P-2869
[0011] The insulating molded part is preferably installed such that
the insulating fibrous tissue, or the side of the insulating molded
part containing the largest proportion of insulating fibrous
tissue, is adjacent to an air gap.
[0012] It is furthermore possible to mix the insulating molded part
with pigments which have a heat absorbing or heat reflecting
effect.
[0013] One embodiment of the invention will be illustrated below
with reference to the single figure which shows a section through a
schematically represented inventive exhaust manifold.
[0014] The FIGURE shows, in a schematic representation, a section
through an exhaust manifold 1 for an internal combustion engine,
preferably for motor vehicles.
[0015] The exhaust manifold 1 contains the usual exhaust gas
conducting inner tubes 2 which are surrounded by a jacket 3 at a
distance A. The exhaust tubes 2 and the jacket 3 can consist of the
usual materials, such as cast parts or steel plate.
[0016] An inner insulation 4 is accommodated within the distance A.
The inner insulation 4 preferably covers the complete inner surface
of the jacket 3, however, it is thinner than the distance A, so
that, despite the installation of the insulation 4, an insulating
air gap 5 to the inner tube 2 remains.
[0017] The insulation 4 is between 1 mm and 3 mm, preferably
between 1.5 mm to 2 mm thick, so that the air gap 5 is reduced by
this amount with respect to the distance A.
[0018] The insulation 4 is embodied as an insulating molded part.
The insulating molded part contains a carrier mat in the form of a
woven cloth of insulating fibers, in particular silicate fibers,
but also glass fibers or the like. The insulating fibrous tissues
are commercially available and consist of transverse and
longitudinal threads which are interlaced with most diverse kinds
of weave known from the field of textiles. A particularly preferred
embodiment of an insulating fibrous tissue is on the market under
the trade mark Hakoterm.RTM. 1200 HG 1305. This material consists
of twisted silicate fibers that have been woven to form a woven
mat.
[0019] Instead of woven mats of silicate fibers, however, woven
glass fibers or woven cloths of similar fibers suited for
insulation, e.g. mineral fibers, can also be employed.
[0020] For the manufacture of the insulating molded part, an
adequate blank of the insulating fibrous tissue is provided with a
conventional binder, for example alumina in the form of bentonite,
suspended in water, and then finally shaped by hot pressing.
[0021] Color pigments can also be added to the binder and influence
heat absorption and/or heat reflection such that, on the one hand,
the surrounding components are protected from thermal overload, and
on the other hand, care is taken that, when the internal combustion
engine is started, an increase in the exhaust energy is achieved
very quickly, resulting in a quick increase in the temperature in
the exhaust pipe during the warm-up time, and thereby in a
reduction of NO.sub.x values and CO.sub.2 emission.
[0022] A particularly suited color pigment is a copper chromite
black spinell, as it is available, for example, as Black 30C965
from the Company "The Shepherd Color Company". This color pigment
mainly acts in an absorbing manner. A preferably reflecting color
pigment is a yellow color pigment (buff rutile on the basis of
chrome, antimony and titanium), preferably YELLOW 193 of the same
company.
[0023] The color pigments are preferably admixed to the binder, but
they can also get onto or into the insulating molded body in any
other way.
[0024] The installation of the insulating molded part 4 is effected
such that the woven side of the insulating molded part, i.e. the
side which consists of the woven mat or comprises the higher
proportion of the woven mat, abuts the air gap 5, and the opposite
side abuts the jacket 3. This ensures that maximum protection
against the blowing out and detachment of components of the
insulation due to vibrations or the like is provided, so that the
risk of malfunctions due to blown away or otherwise displaced
particles in the exhaust system is not given. The insulating molded
part 4 manufactured in this manner is self-supporting, so that no
additional protective layer, for example a metal foil or the like,
is required as a delimitation or for mechanical stabilization. The
insulating molded part 4 can be simply fixed at the outer jacket 3,
and the jacket 3 can be fixed, together with the insulation 4,
around the inner tubes 2 with the required air gap 5.
* * * * *