Information
-
Patent Grant
-
6832648
-
Patent Number
6,832,648
-
Date Filed
Tuesday, September 30, 200320 years ago
-
Date Issued
Tuesday, December 21, 200419 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Harness, Dickey & Pierce, PLC
-
CPC
-
US Classifications
Field of Search
-
International Classifications
-
Abstract
In a resinous heat exchanger, a core portion includes a plurality of heat exchanging plate portions forming inside fluid passages therein and holding portions. The heat exchanging plate portions are layered with predetermined spaces between them so that outside fluid passages are formed between the adjacent heat exchanging plate portions. The heat exchanging plate portions are held by holding portions. The heat exchanging plate portions and the holding portions are integrally formed by extrusion of a resin material. Thus, the heat exchanger is light in weight and is capable of improving productivity.
Description
CROSS REFERENCE TO RELATED APPLICATION
This application is based on Japanese Patent Application No. 2002-289794 filed on Oct. 2, 2002, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a resinous heat exchanger constructed of a plurality of plate members defining inside fluid passages therein and a method of manufacturing the same. The heat exchanger is for example suitable in use as an evaporator for a vehicle air conditioner.
BACKGROUND OF THE INVENTION
JP-A-2001-41678 (U.S. Pat. No. 6,401,804 B1) discloses a heat exchanger constructed of a plurality of flat tubes without interposing fins between them. Each of the flat tubes is formed by joining a pair of aluminum plates such that inside fluid passages are formed therein. The flat tubes are layered such that outside fluid passages are formed between the adjacent tubes. Thus, the heat exchanger performs heat exchange between an inside fluid, such as refrigerant, flowing inside the flat tubes and an outside fluid, such as air, passing through the outside fluid passages. Since the heat exchanger is constructed of the layered aluminum plates, it is generally heavy in weight.
JP-B2-2749586 (U.S. Pat. No. 4,955,435)discloses a panel heat exchanger without having fins. A panel is formed by opposing two resinous sheets and bonding the two resinous sheets at necessary positions, so that header portions and fluid passages are formed in the panel. Since the heat exchanger is made of the resin material, it is generally light in weight. However, the panel requires a large heat exchanging surface area for maintaining efficiency of heat exchange. Therefore, it is likely to be difficult to maintain spaces for outside fluid passages when in use.
SUMMARY OF THE INVENTION
The present invention is made in view of the foregoing matter and it is an object of the present invention to provide a heat exchanger, which is made of resin and capable of improving productivity.
It is another abject of the present invention to provide a method of manufacturing a resinous heat exchanger, which is simple and capable of improving productivity.
According to the present invention, a heat exchanger includes a core portion made of resin and tank portions connected to ends of the core portions. The core portion includes a plurality of heat exchanging plate portions each forming inside fluid passages therein and a holding portion. The heat exchanging plate portions are layered with predetermined spaces between them and held by the holding portion. The heat exchanging plate portions and the holding portion are integrally formed into a single piece.
Accordingly, since the core portion is made of resin, it is light in weight. Also, it improves productivity. Preferably, the core portion is formed by removing predetermined portions from a resinous extrusion body. Accordingly, the core portion is easily produced, thereby improving the productivity of the heat exchanger.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which like parts are designated by like reference numbers and in which:
FIG. 1
is a perspective view of an extrusion body according to the embodiment of the present invention;
FIG. 2
is an exploded perspective view of a heat exchanger according to the embodiment of the present invention;
FIG. 3
is a partly enlarged perspective view of an end of a core portion of the heat exchanger denoted by a circle II in
FIG. 2
;
FIG. 4
is a partly enlarged perspective view of a tank portion of the heat exchanger denoted by a circle IV in
FIG. 2
; and
FIG. 5
is a schematic cross-sectional view of heat exchanging plates of the heat exchanger for showing air passages formed between the heat exchanging plates according to the embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENT
An embodiment of the present invention will be described hereinafter with reference to the drawings.
A heat exchanger
10
of the present invention is for example used for an evaporator of a vehicle air conditioner. As shown in
FIG. 2
, the evaporator
10
has a core portion
11
for performing heat exchange between an inside fluid such as a refrigerant and an outside fluid such conditioning air. The core portion
11
includes a plurality of heat exchanging plate portions
12
each forming inside fluid passages (refrigerant passages)
19
therein through which the inside fluid flows. The heat exchanging plate portions
12
are layered with predetermined spaces between them so that outside fluid passages are formed between the adjacent heat exchanging plate portions
12
. Here, a flow direction A of the outside fluid is substantially perpendicular to a flow direction B of the inside fluid.
The layered heat exchanging plate portions
12
are integrally provided by extrusion of a resin material such as nylon.
FIG. 1
shows an extrusion body
35
having substantially a rectangular parallelepiped shape right after the extrusion of the resin material. The extrusion body
35
forms peripheral end portions (end walls)
37
,
38
opposing each other and the plurality of heat exchanging plate portions
12
between the peripheral end portions
37
,
38
. The heat exchanging plate portions
12
and the peripheral end portions
37
,
38
are substantially perpendicular. Further, the heat exchanging plates
12
forms projection ribs
14
protruding from sides of the heat exchanging plates
12
in a direction that the plates
12
are layered. The projection ribs
14
have substantially trapezoidal-shaped cross-sections or substantially rectangular-shaped cross-sections. Furthermore, the refrigerant passages (inside fluid passages)
19
, which have substantially circular-shaped cross-sections are formed in the heat exchanging plates
12
. Spaces
36
for constructing air passages (outside fluid passages) are formed between the heat exchanging plates
12
.
Right after the extrusion, the spaces
36
are closed at ends in the air flow direction A by the peripheral end portions
37
,
38
, as shown in FIG.
2
. In this condition, the spaces
36
do not function as the air passages. Then, the peripheral end portions
37
,
38
, which are located on the ends of the spaces
36
, are partly removed so that the ends of the spaces
36
are open in the air flow direction A. Specifically, portions
39
,
39
a
,
40
,
40
a
, which correspond to shaded portions in
FIG. 1
, are removed by such as cutting.
FIG. 2
shows the extrusion body
35
after the portions
39
,
39
a
,
40
,
40
a
are removed. The ends of the spaces
36
are open in the air flow direction A. The portions
39
,
39
a
,
40
,
40
a
are divided in a longitudinal direction of the rectangular parallelepiped shape, and portions
41
,
42
are not removed from the extrusion
35
. Therefore, the heat exchanging plates
12
are integrally held by the portions (holding portions)
41
,
42
. For example, the portions
41
,
42
are narrow and extend perpendicular to the longitudinal directions of the heat exchanging plates
12
.
As shown in
FIG. 2
, tank portions
44
,
45
are connected to the longitudinal ends of the extrusion body
35
(core portion
11
) from which the portions
39
a
,
40
a
are removed. As shown in
FIGS. 2 and 4
, the tank portions
44
,
45
are formed with slits
43
into which the longitudinal ends of the heat exchanging plates
12
are inserted. The tank portions
44
,
45
forms communication passages
46
in the insides so that the slits
43
are communicated through the communication passages
46
in the inside of the tank portions
44
,
45
. Further, as shown in
FIG. 4
, the tank portions
44
,
45
have slanting surfaces(chamfer surfaces)
43
a
at the end of the slits
43
into which the ends of the heat exchanging plates
12
are inserted. The slanting surfaces
43
a
incline with respect to the longitudinal directions of the heat exchanging plates
12
.
The tank portions
44
,
45
are formed by injection molding of a resin material such as nylon. The tank portions
44
,
45
has connecting portions
23
,
24
into which refrigerant pipes (not shown) are connected, respectively. The connecting portions
23
,
24
have substantially pipe shape, for example. The refrigerant flows in and out the tank portions
44
,
45
through the connecting portions
23
,
24
. In an example shown in
FIG. 2
, the connecting portion
23
of the upper tank
44
forms a refrigerant inlet and the connecting portion
24
of the lower tank
44
forms a refrigerant outlet.
The refrigerant flowing into the upper tank
44
from the refrigerant inlet
23
is divided into the refrigerant passages
19
formed in the heat exchanging plates
12
. After passing through the refrigerant passages
19
, the refrigerant collects in the lower tank
45
and flows out from the refrigerant outlet
24
. In assembling the evaporator
10
the core portions
11
and the tank portions
44
,
45
are bonded by using an adhesive agent such as epoxy resin.
For example, the refrigerant inlet
23
communicates with a pressure reducing device such as an expansion valve of a refrigerant cycle through the refrigerant pipe. The refrigerant outlet
24
communicates with an inlet of a compressor (not shown) through the refrigerant pipe. Thus, the gas and liquid refrigerant decompressed in the pressure reducing device is introduced into the evaporator
10
. After the refrigerant is evaporated in the evaporator
10
, the refrigerant in a phase of gas is introduced to the compressor.
As shown in
FIG. 5
, each of the heat exchanging plates
12
has projection ribs
14
that protrude from both surfaces of a base plate portion
13
, which is substantially in a form of substantially plate. The projection ribs
14
have substantially trapezoidal-shaped cross-sections or rectangular-shaped cross-sections, as shown in
FIGS. 3 and 5
. The projection ribs
14
form the refrigerant passages
19
that have substantially circular-shaped cross-sections therein. The projection ribs
14
continuously extend in the longitudinal direction of the heat exchanging plates
12
, that is, substantially perpendicular to the air flow direction A. The longitudinal axes of the refrigerant passages
19
are parallel to each other. For example, each of the heat exchanging plates
12
has six projection ribs
14
and six refrigerant passages
19
therein, as shown in FIG.
3
. Minimum thickness of the wall defining the refrigerant passage
19
is approximately between 0.1 mm and 0.4 mm.
The projection ribs
14
project from the base plate portion
13
alternately in opposite directions. Thus, the projection ribs
14
of one heat exchanging plate
12
and the projection ribs
14
of the adjacent heat exchanging plate
12
project to the space
36
alternately with respect to the air flow direction A. More specifically, the projection ribs
14
of one heat exchanging plate
12
oppose to recessions between the projection ribs
14
of the adjacent heat exchanging plate
12
.
Further, the adjacent heat exchanging plates
12
are spaced from each other by a predetermined distance such that predetermined clearance is defined between the end surfaces of the projection ribs
14
and the opposing surface of the base plate portion
13
of the adjacent heat exchanging plate
12
. Thus, continuous air passage
36
is formed in form of wave between the adjacent heat exchanging plates
12
as denoted by a waved arrow Al in FIG.
5
. Accordingly, the conditioning air supplied to the core portion
11
in the direction A passes between the heat exchanging plates
12
while meandering as in form of wave as shown by the arrow A
1
.
The evaporator
10
is housed in an air conditioning unit case (not shown) for example in up and down direction shown in FIG.
2
. The conditioning air is supplied to the evaporator
10
by a blower unit in the direction shown by the arrow A. When the compressor is driven, the gas and liquid refrigerant, which is decompressed by the pressure reducing device, is supplied into the evaporator
10
.
In the core portion
11
, the air passes through the air passages
36
formed between the heat exchanging plates
12
. While the conditioning air passes through the air passages
36
, the refrigerant flowing in the refrigerant passages
19
absorbs heat from the conditioning air. Therefore, the conditioning air is cooled.
The air flow direction A is perpendicular to the longitudinal direction B of the projection ribs
14
. The projection ribs
14
have surfaces (heat exchanging surfaces) that are substantially perpendicular to the air flow direction A. Thus, the straight flow of the air is blocked by the surfaces of the projection ribs
14
.
Because the flow of the air is disturbed between the heat exchanging plates
12
, the disturbed air flow improves efficiency of the heat exchange of the air flow. Here, since the core portion
11
is only constructed of the heat exchanging plates
12
, that is, the core portions
11
does not have fins, the heat exchanging area of the core portion
11
is smaller than that of a heat exchanger having fins between heat exchanging plates. The decrease of the heat exchanging area is compensated by the improvement of the heat exchanging efficiency of the disturbed air flow. Accordingly, heat exchanging capacity is maintained.
Next, effects of the embodiment will be described. First, the core portion
11
is constructed of the layered heat exchanging plates
12
defining the refrigerant passages
19
therein. The air passages
36
are formed between the adjacent heat exchanging plates
12
. Further, the heat exchanging plates
12
are spaced from each other by predetermined distance and held by the holding portions
41
,
42
. The heat exchanging plates
12
and the holding portions
41
,
42
are integrally formed into a single article. Accordingly, the evaporator
10
is reduced in weight. Further, productivity of the evaporator
10
improves.
The core portion
11
is integrally formed by extrusion of the resin material. After the extrusion, the peripheral end portions
37
,
38
are partly removed by such as cutting and the holding portions
41
,
42
are remained without removing. Since the core portion
11
are formed by removing necessary portions from the extrusion body
35
, it is simply and easily produced. Thus, this improves productivity of the evaporator
10
.
The projection ribs
14
protrude from the base plate portions
13
and forming the circular shaped refrigerant passages
19
therein. Further, the projection ribs
14
have substantially trapezoidal-shaped cross-sections or rectangular-shaped cross-sections. The heat exchanging plates
12
having this configuration are integrally formed by extrusion of the resin material. Further, the shape the projection ribs
14
increases the heat exchanging surface area. Also, the refrigerant passages
19
are formed to have substantially circular-shaped cross-sections for maintaining pressure withstanding. Accordingly, the heat exchanging plates
12
are formed with the suitable shapes.
The tank portions
44
,
45
are formed by molding of the resin material. The tank portions
44
,
45
includes the refrigerant inlet portion
23
, the refrigerant outlet portion
24
, the communication passages and the slits
43
for receiving the longitudinal ends of the heat exchanging plates
12
. By this configuration, the weight of the evaporator
10
is reduced. Also, this improves productivity of the evaporator
10
. Further, since the evaporator
10
is only formed of the resin material, it is easily recycled after the use.
Further, the slits
43
have slanting surfaces
43
a
at the ends through which the longitudinal ends of the heat exchanging plates
12
are inserted. Therefore, the core portion
11
is easily fitted into the tank portions
44
,
45
. Further, the core portion
11
and the tank portions
44
,
45
are bonded by the adhesive agent. Because the step of heating such as for brazing is not required, it is easily assembled by a simple assembly, thereby reducing power for the assembly.
In the above embodiment, the heat exchanger
10
made of the resin material is used for the evaporator for performing heat exchange between the low-pressure side refrigerant of the refrigerant cycle and the conditioning air. However,the heat exchanger of the present invention can be used for another heat exchanger that performs heat exchange between fluids for other purposes.
In the above embodiment, the air flow direction A is perpendicular to the longitudinal directions B of the refrigerant passages
19
. However, it is possible to incline the air flow direction A at a predetermined angle from the longitudinal directions B of the refrigerant passages
19
as long as the air flow direction A intersects the longitudinal directions B of the refrigerant passages
19
.
The present invention should not be limited to the disclosed embodiments, but may be implemented in other ways without departing from the spirit of the invention.
Claims
- 1. A heat exchanger comprising:a core portion for performing heat exchange between an inside fluid and an outside fluid; and tank portions connected to ends of the core portion, wherein the core portion is made of resin and includes a plurality of heat exchanging plate portions, each of which forms inside fluid passages therein through which the inside fluid flows, and a holding portion, and the plurality of heat exchanging plate portions are layered with predetermined spaces therebetween and held by the holding portion, the heat exchanging plate portions and the holding portion are integrally formed; and the core portion is provided by a resinous extrusion.
- 2. The heat exchanger according to claim 1,wherein each of the heat exchanging plate portions includes a base portion substantially in a form of plate and projection ribs projecting from the base portion, wherein each of the projection ribs has one of a substantially trapezoidal-shaped cross-section and a substantially rectangular-shaped cross-section and forms the inside fluid passage therein.
- 3. The heat exchanger according to claim 2,wherein the inside fluid passage has substantially a circular-shaped cross-section.
- 4. The heat exchanger according to claim 2,wherein the projection ribs project from the base portion alternately in opposite directions, thereby forming waved outside fluid passages through which the outside fluid flows between the adjacent heat exchanging plates.
- 5. The heat exchanger according to claim 1,wherein the tank portions are made of resin, wherein each of the tank portions forms slits in which ends of the heat exchanging plate portions are received and a communication passage for allowing the slits to communicate in the tank portion.
- 6. The heat exchanger according to claim 5,wherein the tank portions form communication ports through which the inside fluid is introduced into and discharged from the communication passages of the tank portions.
- 7. The heat exchanger according to claim 5,wherein the tank portions have slanting surfaces at ends of the slits through which the ends of the heat exchanging plate portions are inserted.
- 8. The heat exchanger according to claim 1,wherein the core portion and the tank portions are bonded.
- 9. The heat exchanger according to claim 1,wherein the holding portion extends substantially perpendicular to longitudinal directions of the heat exchanging plate portions for holding the layered heat exchanging plate portions.
- 10. A method of manufacturing the heat exchanger of claim 1 comprising:forming an extrusion body by extrusion of a resin material so that the extrusion body has end walls opposing each other and a plurality of heat exchanging plate portions perpendicular to the end walls between the end walls and the plurality of heat exchanging plate portions are layered with predetermined spaces therebetween; and removing predetermined portions of the end walls so that the spaces defined between the adjacent heat exchanging plate portions are open in directions parallel to the heat exchanging plate portion and the heat exchanging plate portions are held by remaining portions of the end walls.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2002-289794 |
Oct 2002 |
JP |
|
US Referenced Citations (9)
Foreign Referenced Citations (2)
Number |
Date |
Country |
55-35812 |
Mar 1980 |
JP |
58-22896 |
Feb 1983 |
JP |