U.S. patent application number 14/119445 was filed with the patent office on 2014-07-03 for heat transfer device.
This patent application is currently assigned to PIERBURG GMBH. The applicant listed for this patent is Peter Corbach, Hans-Ulrich Kuehnel. Invention is credited to Peter Corbach, Hans-Ulrich Kuehnel.
Application Number | 20140182825 14/119445 |
Document ID | / |
Family ID | 45937344 |
Filed Date | 2014-07-03 |
United States Patent
Application |
20140182825 |
Kind Code |
A1 |
Corbach; Peter ; et
al. |
July 3, 2014 |
HEAT TRANSFER DEVICE
Abstract
A heat transfer device for an internal combustion engine
includes an outer housing comprising an inner wall. An inner
housing comprises a partition wall which comprises an outer
surface. The inner housing separates an inner duct, which has a
fluid to be cooled flow therethrough, from an outer coolant duct,
which is formed between the inner housing and the outer housing.
Fins extend from the partition wall into the inner duct. Recesses
are formed on the outer surface. An inner wall is formed on a
surface of the outer housing facing the coolant duct. Projections
extend from the inner wall. The projections extend towards the
recess on the partition wall so that a cross section of the coolant
duct is substantially constant. The projections on the inner wall
of the outer housing are formed by beads on the outer housing.
Inventors: |
Corbach; Peter; (Bochum,
DE) ; Kuehnel; Hans-Ulrich; (Moenchengladbach,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Corbach; Peter
Kuehnel; Hans-Ulrich |
Bochum
Moenchengladbach |
|
DE
DE |
|
|
Assignee: |
PIERBURG GMBH
NEUSS
DE
|
Family ID: |
45937344 |
Appl. No.: |
14/119445 |
Filed: |
March 30, 2012 |
PCT Filed: |
March 30, 2012 |
PCT NO: |
PCT/EP2012/055759 |
371 Date: |
January 23, 2014 |
Current U.S.
Class: |
165/165 |
Current CPC
Class: |
F28F 9/00 20130101; F28D
9/0031 20130101; F28F 2225/02 20130101; Y02T 10/12 20130101; F01N
3/0205 20130101; F28D 7/103 20130101; Y02T 10/146 20130101; F02B
29/0462 20130101; F28F 1/426 20130101; F28F 3/048 20130101 |
Class at
Publication: |
165/165 |
International
Class: |
F01N 3/02 20060101
F01N003/02 |
Foreign Application Data
Date |
Code |
Application Number |
May 24, 2011 |
DE |
10 2011 050 596.2 |
Claims
1-7. (canceled)
8. A heat transfer device for an internal combustion engine, the
heat transfer unit comprising: an outer housing comprising an inner
wall; an inner housing comprising a partition wall which comprises
an outer surface, the inner housing being configured to separate an
inner duct, which is configured to have a fluid to be cooled flow
therethrough, from an outer coolant duct, which is formed between
the inner housing and the outer housing; fins extending from the
partition wall into the inner duct; recesses formed on the outer
surface; an inner wall formed on a surface of the outer housing
facing the coolant duct; and projections extending from the inner
wall, the projections being arranged to extend towards the recess
on the partition wall so that a cross section of the coolant duct
is substantially constant, the projections on the inner wall of the
outer housing being formed by beads on the outer housing.
9. The heat transfer device as recite in claim 8, wherein each of
the fins comprise a fin base, and each of the recesses are formed
between a respective fine base.
10. The heat transfer device as recited in claim 9, wherein each of
the recesses are formed at a respective fin base.
11. The heat transfer device as recited in claim 8, wherein the
fins are arranged in rows one behind the other in a flow direction
of the fluid to be cooled, the fins of successive rows being
arranged offset to each other, and the beads being formed to
correspond to the offset.
12. The heat transfer device as recited in claim 8, wherein the
outer surface of the inner housing facing the coolant duct, and the
inner wall of the outer housing facing the coolant duct, are each
formed so as to be continuous.
13. The heat transfer device as recited in claim 8, wherein the
inner housing is manufactured in a die-casting process.
14. The heat transfer device as recited in claim 8, wherein the
outer housing is manufactured in a sandcasting process.
Description
CROSS REFERENCE TO PRIOR APPLICATIONS
[0001] This application is a U.S. National Phase application under
35 U.S.C. .sctn.371 of International Application No.
PCT/EP2012/055759, filed on Mar. 30, 2012 and which claims benefit
to German Patent Application No. 10 2011 050 596.2, filed on May
24, 2011. The International Application was published in German on
Nov. 29, 2012 as WO 2012/159806 Al under PCT Article 21(2).
FIELD
[0002] The present invention relates to a heat transfer device for
an internal combustion engine, the heat transfer device having an
outer housing, an inner housing which has a partition wall by means
of which an inner duct through which a fluid to be cooled can flow
is separated from an outer coolant duct formed between the inner
housing and the outer housing, fins which extend from the partition
wall into the duct through which the fluid to be cooled can flow,
recesses which are formed on the outer surface of the partition
wall of the inner housing, and projections which extend from an
inner wall, which point toward the coolant duct, of the outer
housing in the direction of the recesses on the partition wall in
such a way that a cross section of the coolant duct is
substantially constant.
BACKGROUND
[0003] Such heat exchangers are used, for example, as coolers in
internal combustion engines. Applications for cooling exhaust gas,
as well as for cooling charge air, have previously been described.
In both cases, this cooling serves to enhance the combustion
process and thus to reduce the content of pollutants in the exhaust
gas.
[0004] The manufacture of heat exchangers, in particular heat
exchangers made from a die cast metal, from a plurality of nested
shells from which fins extend in particular into the duct through
which the fluid to be cooled can flow, have previously been
described. In these cases, the base plate from which the fins
extend typically serves as a partition wall between the coolant
duct and the duct usually carrying gas.
[0005] To increase efficiency, as well as to simplify the casting
process, it has previously been described to provide the partition
wall of the inner housing with a wave-shaped design to enhance the
flow of the molten metal during the casting process and to enlarge
the heat transfer surfaces.
[0006] With such heat exchangers having recesses in the partition
wall, DE 10 2007 008 865 A1 further describes casting the outer
housing so that a substantially constant coolant gap is formed by
simultaneously casting corresponding projections on the inner wall
of the outer housing. It is thereby prevented that different flow
resistances occur in the cross section of the main flow direction
of the coolant which would cause a non-uniform through-flow so that
colder and warmer zones would be formed in the heat exchanger.
[0007] This is, however, disadvantageous in that the weight of the
outer housing increases due to the material accumulations forming.
The housing parts are further often subjected to a high pressure
that has the effect that the necessary strength is not achieved
with lesser wall thicknesses.
SUMMARY
[0008] An aspect of the present invention is to provide a heat
exchanger which has a maximum strength while at the same time
maintaining a low weight of the outer housing. A uniform flow
resistance should also be maintained in the coolant jacket.
[0009] In an embodiment, the present invention provides a heat
transfer device for an internal combustion engine which includes an
outer housing comprising an inner wall. An inner housing comprises
a partition wall which comprises an outer surface. The inner
housing is configured to separate an inner duct, which is
configured to have a fluid to be cooled flow therethrough, from an
outer coolant duct, which is formed between the inner housing and
the outer housing. Fins extend from the partition wall into the
inner duct. Recesses are formed on the outer surface. An inner wall
is formed on a surface of the outer housing facing the coolant
duct. Projections extend from the inner wall. The projections are
arranged to extend towards the recess on the partition wall so that
a cross section of the coolant duct is substantially constant. The
projections on the inner wall of the outer housing are formed by
beads on the outer housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention is described in greater detail below
on the basis of embodiments and of the drawings in which:
[0011] FIG. 1 shows a three-dimensional illustration of a heat
transfer device of the present invention from diagonally above;
and
[0012] FIG. 2 shows a sectional front end view of the heat transfer
device of the present invention in FIG. 1.
DETAILED DESCRIPTION
[0013] The amount of material required is reduced due to the fact
that the projections on the inner wall of the outer housing are
formed by beads on the outer housing, while the strength is
increased due to the beads, and the weight is reduced. The
formation may be provided, for example, in a sandcasting process. A
coolant duct with uniform through-flow is formed at the same time
so that a high degree of efficiency of the cooler is achieved,
while the fuel consumption of the internal combustion engine is
reduced because of the lower weight.
[0014] In an embodiment of the present invention, the recesses can,
for example, respectively be formed between the fin bases. The
cooling surface is thereby enlarged so that the efficiency can be
further enhanced.
[0015] In an embodiment of the present invention, the recesses can,
for example, respectively be formed at the fin bases. This
simplifies manufacturing by improving the flow of the liquid metal
during the casting process. Cast parts with a uniform structure are
formed, whereby the strength is further enhanced.
[0016] In an embodiment of the present invention, the fins can, for
example, be arranged one after the other in rows in the flow
direction, the fins of respective successive rows being arranged
offset to one another and the beads being formed corresponding to
this offset. Boundary layers are dissolved in this manner so that a
good mixing of the fluid to be cooled is provided in the duct flown
through by the fluid to be cooled, whereby the efficiency is
enhanced. This embodiment can also include a corresponding design
of the beads which has the effect that the flow through the cross
section of the coolant duct is uniform, whereby dead spaces, in
which the coolant flow velocity is zero, are prevented in the
coolant duct and the efficiency is further enhanced.
[0017] In an embodiment of the present invention, the surface of
the inner housing facing the coolant duct and the inner wall of the
outer housing facing the coolant duct can, for example, be formed
in a continuous manner so that no sudden variations in cross
section occur in the duct flown through by the cooling fluid. The
pressure loss is thereby again reduced and dead water regions are
avoided. Low-power coolant pumps can be used in this manner.
[0018] In an embodiment of the present invention, the inner housing
is made in a die-casting process and the outer housing is made in a
sandcasting process. The heat exchanger can thus be built from a
small number of housing parts and can be manufactured in an
economic manner.
[0019] With the embodiments of the heat transfer device of the
present invention, the cooling efficiency can be maintained while
the strength is enhanced and the material effort is reduced. The
reduced weight makes it possible to save costs for raw materials
and to lower fuel consumption.
[0020] An embodiment of a heat transfer device of the present
invention is illustrated in the drawings as hereafter
described.
[0021] The heat transfer device illustrated in FIG. 1 comprises an
outer housing 2 in which a two-part inner housing 4 with an upper
shell 6 and a lower shell 8 is arranged, the shells being joined by
friction stir welding.
[0022] Both the upper shell 6 and the lower shell 8 of the inner
housing 4, which are each made in a die-casting process, for
example, have a partition wall 10 from which, seen in cross
section, fins 12 alternately extend from the upper shell 6 and the
lower shell 8 into a duct 14 inside the inner housing 4, which duct
14 is flown through by a fluid to be cooled. This fluid may, for
example, be the exhaust gas of an internal combustion engine.
[0023] The inner housing 4 is inserted into the outer housing 2 so
that a coolant duct 16 is formed between the inner housing 4 and
the outer housing 2, through which coolant can flow and which is
separated by the partition wall 10 from the duct 14 flown through
by the fluid to be cooled. Flange connections 18 provide for a
tight connection of the inner housing 4 with the outer housing 2 so
that the coolant duct 16 is configured as a close coolant
jacket.
[0024] The duct 14 flown through by the fluid to be cooled extends
from an inlet 20 at the front end side of the heat transfer device
to an outlet 22 at the opposite side of the heat transfer device.
An intermediate wall 24 divides the duct 14 into a first partial
duct 26 and a second partial duct 28, wherein the first partial
duct 26 is connected with an exhaust manifold of a first group of
cylinders and the second partial duct 28 is connected with an
exhaust manifold of a second group of cylinders of the internal
combustion engine. This separation prevents interferences between
the individual emitted exhaust gas pulses, whereby, given the use
of a non-return valve arranged downstream, the overall mass flow
can be increased.
[0025] The intermediate wall 24 extends continuously from the
partition wall 10 of the lower shell 8 into an opposite groove 30
formed in the partition wall 10 of the upper shell 6. The
intermediate wall 24 is fixed in the groove 30 by friction stir
welding through the partition wall 10 so that an overflow of the
intermediate wall 24 is prevented and, at the same time, the
stability of the inner housing 4 is significantly increased by
halving the existing projected areas.
[0026] It can further be seen that the partition wall 10 of both
the lower shell 8 and the upper shell 6 of the inner housing 4
comprises a corrugated outer surface 32. The corrugated outer
surface 32 is achieved by recesses 34 between fin bases 36 of the
successive fin rows 38. In the regions of the corrugated outer
surface 32 located between the fin rows 38 in the longitudinal
direction, the recesses 34 present an offset 40 extending only over
this region so that at the start of the next fin row 38, which is
similarly arranged offset to the previous row, the recesses 34 are
again arranged in the spaces between the fin bases 36.
[0027] The outer housing 2, manufactured, for example, in a
sandcasting process, comprises an inner wall 42 designed
corresponding to the recesses 34 of the inner housing 4. This means
that a projection 44 extends into each recess 34 between the fin
bases 36 so that the distance of the corrugated outer surface 32 of
the inner housing 4 to the inner wall 42 of the outer housing 2 is
substantially the same all over. As a consequence, the flow cross
section is substantially the same all over, both in the direction
of flow and perpendicular to the through-flow direction. Thereby
constant coolant flows with a uniform heat output, since dead water
zones can be largely excluded due to the constant flow resistance,
whereby a very high cooling efficiency is achieved.
[0028] According to the present invention, the projections 44 are
formed by beads 46, i.e., by groove-shaped recesses 48 in an outer
wall 50 of the outer housing 2, which are provided to increase
rigidity. Respectively opposite thereto, i.e., on the inner wall
42, a projection 44 is formed by the displacement of material if
the bead 46 is formed subsequently. This bead design can also be
formed directly in the casting process, whereby an increase in
rigidity is achieved without an increase in required material.
Thin-walled outer housings 2 can thus be formed with sufficient
strength. The beads here follow the course of the recesses 34 in
the outer surface 32 of the inner housing 4.
[0029] As shown in FIG. 1, the outer housing 2 is additionally
provided with a coolant inlet port 52 and a flange-shaped coolant
outlet 54.
[0030] A heat transfer device of such construction has a high
degree of efficiency due to the uniform through-flow of coolant
and, at the same time, can be manufactured with little material
effort. Because of the reduced weight, it is possible to save fuel
if the device is used in an internal combustion engine.
[0031] It should be clear that the scope of protection is not
limited to the embodiment described. The outer housing may, for
example, be made from sheet metal instead of sandcast material, and
the beads may be formed subsequently. It is also possible to form
the recesses in the inner housing at the fin bases, respectively,
whereby the castability is significantly enhanced. It is also
possible to divide the housing parts in a different manner and, in
particular, to shift the joint planes. Further design changes are
conceivable. Reference should also be had to the appended
claims.
* * * * *