U.S. patent application number 11/703868 was filed with the patent office on 2007-08-16 for heat exchanger.
This patent application is currently assigned to DENSO Corporation. Invention is credited to Masaki Harada, Sumio Susa, Haruhiko Watanabe.
Application Number | 20070187081 11/703868 |
Document ID | / |
Family ID | 38289003 |
Filed Date | 2007-08-16 |
United States Patent
Application |
20070187081 |
Kind Code |
A1 |
Watanabe; Haruhiko ; et
al. |
August 16, 2007 |
Heat exchanger
Abstract
A heat exchanger comprising: a plurality of tubes inside of
which a fluid passes; fins which are joined to the outer surfaces
of the tubes and promote heat exchange between a fluid passing
around the tubes and the fluid passing through inside the tube; and
tank sections comprising core plates having insertion holes formed
for the tubes to be inserted therein and tank bodies having the
core plates joined thereto for distributing or collecting the fluid
to be passed through the tubes; the tube comprises a first and a
second tube plates joined in opposition to each other and inner
fins disposed between the first and second tube plates, and that
the portion of the tube to be inserted into the insertion hole of
the core plate has generally the same outer shape as the periphery
of the insertion hole, and that the portions of the first and
second tube plates not to be inserted into the insertion hole of
the core plate have overlapping sections which overlap each other
in laminating direction of the tubes.
Inventors: |
Watanabe; Haruhiko;
(Obu-city, JP) ; Susa; Sumio; (Anjo-city, JP)
; Harada; Masaki; (Kariya-city, JP) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Assignee: |
DENSO Corporation
Kariya-city
JP
|
Family ID: |
38289003 |
Appl. No.: |
11/703868 |
Filed: |
February 8, 2007 |
Current U.S.
Class: |
165/175 |
Current CPC
Class: |
F28F 9/0263 20130101;
F02B 29/0456 20130101; F28F 1/04 20130101; F28D 2021/0082 20130101;
F28F 1/126 20130101; Y02T 10/146 20130101; F28D 1/0391 20130101;
Y02T 10/12 20130101; F28F 9/18 20130101; F28D 1/0316 20130101; F28F
3/025 20130101 |
Class at
Publication: |
165/175 |
International
Class: |
F28F 9/02 20060101
F28F009/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 10, 2006 |
JP |
2006-033763 |
Claims
1. A heat exchanger comprising: a plurality of tubes inside of
which a fluid passes; fins which are joined to the outer surfaces
of said tubes and promote heat exchange between a-fluid passing
around said tubes and the fluid passing through inside said tube;
and tank sections comprising core plates having insertion holes
formed for said tubes to be inserted therein and tank bodies having
said core plates joined thereto for distributing or collecting the
fluid to be passed through said tubes; characterized in that said
tube comprises a first and a second tube plates joined in
opposition to each other and inner fins disposed between said first
and second tube plates, and that the portion of said tube to be
inserted into said insertion hole of said core plate has generally
the same outer shape as the periphery of said insertion hole, and
that the portions of said first and second tube plates not to be
inserted into said insertion hole of said core plate have
overlapping sections which overlap each other in laminating
direction of said tubes.
2. A heat exchanger as claimed in claim 1, wherein said overlapping
sections are formed by attaching inner surfaces of said first tube
plate and said second tube plate to each other.
3. A heat exchanger as claimed in claim 2, wherein said overlapping
sections are fixed in calking by bending one of said first tube
plate and said second tube plate.
4. A heat exchanger as claimed in claim 1, wherein said overlapping
sections are formed outside said tube, and the end portion of said
overlapping section in the tube longitudinal direction is abutted
to said core plate.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a heat exchanger and, more
particularly, to a heat exchanger for a supercharger in an internal
combustion engine.
[0003] 2. Description of Related Art
[0004] Conventionally, a heat exchanger for a supercharger in an
internal combustion engine used for cooling thermally-expanded
intake air in order to increase charging efficiency of the intake
air has been known, for example from Japanese Patent Publication
No. 2002-286394, which discloses a heat exchanger having a pair of
tanks, a plurality of tubes through which super-charged air passes,
and fins for increasing heat discharge, brazed together in one
unit. In such a heat exchanger, the tank comprises a tank body and
a core plate, and the tubes are inserted through insertion holes
formed in the core plate.
[0005] In such a heat exchanger, in order to further increase heat
exchange efficiency, inner fins are provided inside the tubes. In
mounting the inner fins inside the tubes, in one method, the inner
fins are slid and inserted into the tubes, so that mutual contact
may peel off brazing material and cause a defect in a brazed
portion, leading to leakage of cooling water. Therefore, in a known
structure, as shown in FIG. 14, a tube 201 is formed by fitting one
tube plate 201a having inner fins 201c placed thereon onto the
other tube plate 201b, and this tube 201 is inserted through a tube
insertion hole 202 of the core plate.
[0006] In such a structure, however, as shown in FIG. 15, the tube
plates 201a, 201b fitted together may be opened in the bent
portion, called "tati" in Japanese, bent in the U-shaped cross
section, which has squared corners at the bottom side thereof, due
to a draft angle at the time of press shaping or spring-back of the
material. As a result, there is a problem that a gap may be formed
at the fitting section 201f and may cause a brazing failure in the
brazed portion.
[0007] Also, there is a problem that, as shown in FIG. 16, a step
201g is produced as a result of forming the fitting section 201f,
and this step increases the clearance between the tube 201 and the
opening edge of the tube insertion hole 202 through which the tube
201 is inserted, leading to brazing failure.
[0008] Further, when a heat exchanger of larger size is used, it is
very difficult to achieve sufficient positioning accuracy of
individual components, and therefore, it is required to use a jig
or the like for adjustment, leading to another problem of
increasing the number of processing steps.
SUMMARY OF THE INVENTION
[0009] In view of above problems, it is an object of the present
invention to provide a heat exchanger that is capable of being
manufactured in small number of processing steps and exhibiting a
good brazing performance.
[0010] In order to accomplish the above object, according to a
first aspect of the present invention, there is provided a heat
exchanger comprising: a plurality of tubes (104) inside of which a
fluid passes; fins (105) which are joined to the outer surfaces of
the tubes (104) and promote heat exchange between a fluid passing
around the tubes (104) and the fluid passing through inside the
tube (104); and tank sections (101, 102) comprising core plates
(101b, 102b) having insertion holes (101c, 102c) formed for the
tubes (104 ) to be inserted therein and tank bodies (101a, 102a)
having the core plates joined thereto for distributing or
collecting the fluid to be passed through the tubes; the tube (104)
comprises a first and a second tube plates (104a, 104b) joined in
opposition to each other and inner fins (109) disposed between the
first and second tube plates (104a, 104b), and that the portion of
the tube (104) to be inserted into the insertion hole of the core
plate has generally the same outer shape as the periphery of the
insertion hole, and that the portions of the first and second tube
plates (104a, 104b) not to be inserted into the insertion hole of
the core plate have overlapping sections (104a, 104b) which overlap
each other in laminating direction of the tubes.
[0011] In accordance with the first aspect, the portion of a tube
to be inserted into an insertion hole of the core plate may be
formed to have generally the same shape as the periphery of the
insertion hole so that brazing performance of the core plate and
the tube can be improved. Also, in accordance with the first
aspect, the portions of the first and the second tube plates to be
inserted into the insertion hole of the core plate have overlapping
sections that overlap each other in the tube laminating direction.
Therefore, by using a jig or the like to compress the overlapping
sections in the tube laminating direction, the overlapping sections
can be securely abutted to each other and brazing performance can
be thereby improved.
[0012] In accordance with the second aspect, the overlapping
sections (104c, 104d) are formed by attaching inner surfaces of the
first tube plate (104a) and the second tube plate (104b) to each
other. Therefore, in accordance with the second aspect, the tube
plates can be formed in a shape that permits easy molding.
[0013] In accordance with the third aspect, the overlapping
sections (104c, 104d) are fixed in calking by bending one of the
first tube plate (104a) and the second tube plate (104b). By fixing
the overlapping sections in the shape of joined hands in calking,
the overlapping sections can be more securely fixed and brazing
performance can be further improved.
[0014] In accordance with the fourth aspect, said overlapping
sections are formed outside of said tube, with the end section of
the tube in the longitudinal direction of said overlapping section
abutted to said core plate. In accordance with the fourth aspect,
as the end section of the tube in the longitudinal direction of the
overlapping section is abutted to the core plate, positioning in
the longitudinal direction of the tube relative to the core plate
can be accomplished without requiring any jig.
[0015] Incidentally, the reference numerals in parentheses, to
denote the above means, are intended to show the relationship of
the specific means which will be described later in an embodiment
of the invention.
[0016] The present invention may be more fully understood from the
description of preferred embodiments of the invention set forth
below, together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a front view showing a heat exchanger 100
according to the present invention;
[0018] FIG. 2 is a sectional view showing a tube 104 according to a
first embodiment of the present invention;
[0019] FIG. 3 is a perspective view showing the tube 104 according
to the first embodiment of the present invention;
[0020] FIG. 4 is a sectional view showing the tube 104 according to
the first embodiment of the present invention as fitted to the core
plate 101b;
[0021] FIG. 5 is a perspective view showing the tube 104 according
to the first embodiment of the present invention as fitted to the
core plate 101b;
[0022] FIG. 6 is an enlarged sectional view showing the tube 104
according to the first embodiment of the present invention as
fitted to the core plate 101b;
[0023] FIG. 7 is a sectional view showing a variant of the tube 104
according to the first embodiment of the present invention;
[0024] FIG. 8 is a sectional view showing a variant of the tube 104
according to the first embodiment of the present invention;
[0025] FIG. 9 is a sectional view showing a variant of the tube 104
according to the first embodiment of the present invention;
[0026] FIG. 10 is a sectional view showing a tube 104 according to
a second embodiment of the present invention;
[0027] FIG. 11 is a sectional view showing a variant of the tube
104 according to the second embodiment of the present
invention;
[0028] FIG. 12 is a sectional view showing a variant of the tube
104 according to the present invention;
[0029] FIG. 13 is a partial sectional view showing a variant of the
tube 104 according to the present invention;
[0030] FIG. 14 is a sectional view showing a tube 201 according to
a prior art;
[0031] FIG. 15 is a sectional view showing a tube 201 according to
a prior art in opened state; and
[0032] FIG. 16 is a sectional view showing a tube 201 according to
a prior art as fitted to a tube insertion hole 203a of the core
plate 203.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] Now, the present invention will be described in detail with
reference to appended drawings showing embodiments thereof. A heat
exchanger according to the present invention is suitable to be
applied to an apparatus for cooling intake air used in a
supercharger of an internal combustion engine. FIG. 1 is a front
view showing a heat exchanger 100 according to the present
invention. The heat exchanger 100 comprises a pair of tanks 101,
102 and a heat exchanging core section 103 for heat exchange
between the supercharged air and external air, brazed in one
unit.
[0034] The tanks 101, 102 are composed of tank bodies 101a, 102a
and core plates 101b, 102b, respectively. The core plates 101b,
102b have tube insertion holes 101c, 102c formed therein for
inserting tubes 104. An inlet pipe 107 is connected to the upper
end portion of the tank 101 as an inlet for supercharged air. An
outlet pipe 108 is connected to the upper end portion of the tank
102 as an outlet for supercharged air.
[0035] The heat exchanging core section 103 has the tanks 101, 102
connected thereto, and comprises a plurality of tubes 104, fins 105
that are joined to outer surface of these tubes 104 and thereby
thermally connected to tubes 104 for promoting heat discharge of
the supercharged air, and side plates 106 disposed outside in
laminating direction of the tubes 104. Material of the tubes is red
brass containing 15% zinc and 0.8% iron.
[0036] The tube 104 comprises a first and second tube plates 104a,
104b each generally in the U-shaped cross section, which has
squared corners at bottom side thereof, and fitted together so as
to be opposed to each other, and inner fins 109 disposed inside the
tubes 104 for promoting heat exchange between the supercharged air
and external air. Brazing paste (specifically, brazing paste
consisting of 75% copper, 15% tin, 5% nickel and 5% phosphor) is
applied to inner surfaces of the tube plates 104a, 104b for brazing
the inner fins.
[0037] In the first and the second tube plates 104a, 104b, end
edges bent in horizontal direction extend over the distance between
the core plate 101b and the core plate 102b in the direction of the
longitudinal axis. With such construction, when these tube plates
104a, 104b are fitted together, as shown in FIG. 3, overlapping
sections 104c, 104d are formed with both inner surfaces of the tube
plates 104a, 104b abutted to each other. When the tube 104 is
fitted to the core plate 101b and the core plate 102b, both ends of
these side edges in the direction of longitudinal axis of these
side edges are abutted to the core plates 101b, 102b so that tube
104 can be reliably sealed.
[0038] At both ends of the tube plates 104a, 104b, the side edge is
not bent in the horizontal direction, and the cross-section of
these ends has generally the same shape as the periphery of the
tube insertion holes 101c, 102c. With such construction, by
inserting the first and the second tube plates 104a, 104b into the
tube insertion holes 101c, 102c, the first and the second tube
plates 104a, 104b can be positioned securely relative to each
other.
[0039] Next, the method of manufacturing the heat exchanger of the
present invention will be described. The tube is provisionally
assembled with the first and the second tube plates disposed in
opposition to each other such that the inner fins are sandwiched
therebetween and respective overlapping sections overlap each
other. The provisionally assembled tubes and fins are laminated
alternately, and each end of the tube is inserted into the tube
insertion hole of the core plate, and the heat exchanging core
section is provisionally assembled. The provisionally assembled
heat exchanging core section is compressed in the tube laminating
direction by winding wire around it, and is heated in a furnace to
be integrally brazed in one unit. Then, the tank bodies 101a, 102a
having the inlet pipe 107 and the outlet pipe 108 assembled to the
core plates 101b, 102b, is joined by welding or the like. The first
tube plate 104a and the 30 second tube plate 104b form two
overlapping sections 104c, 104d with surfaces overlapping each
other in the portion where they are not inserted into the tube
insertion holes 101c, 102c of the core plates 101b, 102b. Since
surfaces of the first tube plate 104a and the second tube plate
104b are abutted to each other in this manner, the first tube plate
104a and the second tube plate 104b can be stably positioned
relative to each other so that good brazing performance can be
achieved. Also, as the overlapping sections are formed so as to
overlap in the tube laminating direction, when the tubes are brazed
while being compressed in the tube laminating direction, the
overlapping sections can be securely abutted to each other and
brazing performance can be thereby improved.
[0040] On the one hand, as shown in FIG. 4, the first and the
second tube plates 104a, 104b have the outer surface of the tube
104 abutted to the periphery of the tube insertion holes 101c, 102c
at both ends inserted into the tube insertion holes 101c, 102c of
the core plates 101b, 102b. Thus, the first and the second tube
plates 104a, 104b can be positioned by the tube insertion holes
101c, 102c at both ends inserted into the tube insertion holes
101c, 102c of the core plates 101b, 102b, so that a good brazing
performance can be obtained.
[0041] On the other hand, the first and the second tube plates
104a, 104b may be abutted to the core plates 101b, 102b at both
ends of the overlapping sections 104c, 104d in the direction of
longitudinal axis so that the first and the second tube plates
104a, 104b can be securely positioned without need for adjustment
using a jig relative to the core plates 101b, 102b, and good
brazing performance can be thereby obtained. As has been described
above, a heat exchanger exhibiting good brazing performance can be
manufactured with a small number of processing steps.
[0042] The present embodiment adopts the construction in which two
overlapping sections 104c, 104d are formed by attaching inner
surfaces of the first tube plate 104a and the second tube plate
104b, so that abutting state of the overlapping sections 104c, 104d
is further enhanced by the weight of the laminated first and the
second tube plates 104a, 104b and brazing performance can be
thereby further improved.
[0043] As for the form of overlapping sections 104c, 104d in the
shape of joined hands, the construction as shown in FIG. 8 may be
adopted in which only one of the two tube plates 104a, 104b has a
bent edge and the other has a flat edge. This construction has the
advantage that only one of the tube plates needs to be subjected to
edge bending processing.
[0044] Besides the above-described shape, of joined hands, in which
inner surfaces of the first and the second tube plates 104a, 104b
are abutted to each other, the overlapping sections 104c, 104d can
also be constructed such that, as shown in FIG. 9, the inner
surface of the first tube plate 104a is attached to the outer
surface of the second tube plate 104b. In this construction, the
end edge of the first tube plate 104a is bent so as to situated
outward by an amount corresponding to the thickness of the tube
plate 104a such that it can cover the second tube plate 104b having
a U-shaped cross section, which has squared corners at bottom side
thereof. Needless to say, the first tube plate 104a and the second
tube plate 104b can be constructed conversely.
[0045] As a variant of the overlapping sections 104c, 104d, the two
overlapping sections 104c, 104d may be formed by bending one end
edge of the first and the second tube plates 104a, 104b,
respectively, and by calking these tube plates 104a, 104b. With
such construction, the overlapping sections 104c, 104d can be more
securely fixed and the brazing performance can be further
improved.
[0046] Next, a second embodiment of the present invention will be
described. This embodiment differs from the above-described
embodiment only in that, as shown in FIG. 10, the tube 104 is
composed of one tube plate and one overlapping section 104c is
formed by attaching the inner surface of the tube plate 104a to
itself. Therefore, explanation of same constituents as in the
above-described embodiment is omitted.
[0047] In this embodiment, the tube 104 comprises a tube plate 104a
that is bent and folded so as to form a passage for gas and has two
longitudinal end edges, and inner fins 109 that are disposed inside
the tube 104 for promoting heat exchange between the gas and fluid.
In the portion of the tube 104 that is not inserted into tube
insertion holes 101c, 102c, the tube plate 104a forms an
overlapping section 104c with its surface attached to itself, and
both ends of the overlapping section 104c in the direction of
longitudinal axis are abutted to the surfaces of the core plates
101b, 102b. It is preferred that, as shown in FIG. 11, the
overlapping section 104c be fixed by calking in the same manner as
in the above-described embodiment.
[0048] With respect to manufacturing method, this embodiment
differs from the first embodiment in that, unlike the first
embodiment in which the first and the second tube plates 104a, 104b
are fitted to each other, in the present embodiment, after the
inner fins 109 are placed on the tube plate 104a, the tube plate
104b is bent so as to form the tube 104 in tubular shape. With such
construction, same operative effect as in the previous embodiment
can be obtained, that is, a heat exchanger capable of being
manufactured in small number of processing steps and exhibiting
good brazing performance can be provided.
[0049] Finally, variants of both ends of the tube 104 which are
inserted into the tube insertion holes 101c, 102c of the core
plates 101b, 102b will be described. In a first variant, as shown
in FIG. 12, the first tube plate 104a is constructed such that the
end edges 104c', 104d' are fitted inside the end edges 104c'',
104d'' of the second tube plate 104b. In a second variant, as shown
in FIG. 13, the firsthand the second tube plates 104a, 104b are
constructed such that the end edges 104c', 104c'' are bent inward
and the outer surfaces are abutted to each other. As, in these
variants, the first and the second tube plates 104a, 104b are
abutted to the whole periphery of the tube insertion holes 101c,
102c of the core plates 101b, 102b, the first and the second tube
plates 104a, 104b can be securely positioned and brazing
performance can be thereby improved.
[0050] While the invention has been described by reference to
specific embodiments chosen for purposes of illustration, it should
be apparent that numerous modifications could be made thereto, by
those skilled in the art, without departing from the basic concept
and scope of the invention.
* * * * *