U.S. patent application number 11/576649 was filed with the patent office on 2007-11-01 for evaporator.
Invention is credited to Naohisa Higashiyama, Yukihiro Tsurumi.
Application Number | 20070251681 11/576649 |
Document ID | / |
Family ID | 36148490 |
Filed Date | 2007-11-01 |
United States Patent
Application |
20070251681 |
Kind Code |
A1 |
Higashiyama; Naohisa ; et
al. |
November 1, 2007 |
Evaporator
Abstract
A corrugate fin of an evaporator includes wave crest portions,
wave trough portions, and flat connection portions connecting
together the wave crest portions and the wave trough portions.
Opposite end portions of a cutout extend to corresponding
connection portions located at opposite ends of the wave crest
portion and the wave trough portion. A projection projecting inward
is formed integrally with end portions of the connection portions,
the end portions of the connection portions corresponding to
opposite ends of the cutout. The projection extends between the end
portions of the connection portions located at the opposite ends of
the wave crest portion and the wave trough portion. The projection
projects inward in a shape resembling a lying letter V. The
evaporator exhibits excellent drainage of condensed water and
enables high work efficiency in manufacture thereof.
Inventors: |
Higashiyama; Naohisa;
(Oyama-shi, JP) ; Tsurumi; Yukihiro; (Oyama-shi,
JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Family ID: |
36148490 |
Appl. No.: |
11/576649 |
Filed: |
October 13, 2005 |
PCT Filed: |
October 13, 2005 |
PCT NO: |
PCT/JP05/19255 |
371 Date: |
April 4, 2007 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60619009 |
Oct 18, 2004 |
|
|
|
Current U.S.
Class: |
165/153 |
Current CPC
Class: |
F28D 2021/0085 20130101;
F28F 17/005 20130101; F25B 2500/01 20130101; F25B 39/022 20130101;
F28F 9/0214 20130101; F28D 1/05391 20130101; F28F 1/128
20130101 |
Class at
Publication: |
165/153 |
International
Class: |
F28D 3/02 20060101
F28D003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 13, 2004 |
JP |
2004-298284 |
Claims
1. An evaporator comprising a plurality of refrigerant flow members
arranged in parallel in a left-right direction, and corrugate fins
disposed in corresponding air-passing clearances between the
adjacent refrigerant flow members, the corrugate fins each
comprising wave crest portions, wave trough portions, and flat
connection portions connecting together the wave crest portions and
the wave trough portions, a cutout being for ed in each of the wave
crest portions and the wave trough portions.
2. An evaporator according to claim 1, wherein a plurality of
louver groups each consisting of a plurality of louvers juxtaposed
in a front-rear direction are arranged at predetermined intervals
in the front-rear direction at each connection portion of each
corrugate fin, whereby a plurality of louver-free portions are
provided at each connection portion at the predetermined intervals
in the front-rear direction; and the cutout is formed in each of
the wave crest portions and the wave trough portions at least at a
position corresponding to one of the louver-free portions of each
connection portion.
3. An evaporator according to claim 1, wherein opposite end
portions of each cutout of each corrugate fin extend to connection
portions located at opposite ends of the corresponding wave crest
portion or wave trough portion.
4. An evaporator according to claim 3, wherein a projection
projecting inward is for ed integrally with corresponding end
portions of each pair of connection portions of each corrugate fin,
the end portions of the connection portions corresponding to
opposite ends of one of the cutouts.
5. An evaporator according to claim 4, wherein each projection of
each corrugate fin is formed in such a manner as to extend between
the corresponding end portions of the connection portions located
at the opposite ends of the corresponding wave crest portion or
wave trough portion, the end portions of the connection portions
corresponding to the opposite ends of one of the cutouts.
6. An evaporator according to claim 5, wherein the projections of
the corrugate fins project inward in a shape resembling a lying
letter V.
7. An evaporator according to claim 5, wherein a pair of slits
spaced apart from each other in the front-rear direction is for ed
in each of the wave crest portions and the wave trough portions of
each corrugate fin in such a manner as to extend to the connection
portions located at the opposite ends of the corresponding wave
crest portion or wave trough portion; and a portion sandwiched
between the slits is bent inward to thereby form the cutout and the
projection.
8. An evaporator according to claim 1, wherein each of the wave
crest portions and the wave trough portions of each corrugate fin
comprises a flat portion and round portions located at
corresponding opposite ends of the flat portion and connected to
the corresponding connection portions; and the round portions have
a radius of curvature of 0.7 mm or less.
9. An evaporator according to claim 1, wherein a fin height of each
corrugate fin, which is a direct distance between the wave crest
portions and the wave trough portions, is 7.0 mm to 10.0 mm; and a
fin pitch, which is a pitch of the connection portions, is 1.3 mm
to 1.8 mm.
10. An evaporator according to claim 1, wherein tube groups are
arranged in a plurality of rows at predetermined internals in the
front-rear direction, each tube group consisting of a plurality of
flat tubes arranged in parallel at predetermined intervals in the
left-right direction; and a plurality of flat tubes arranged in
tandem in the front-rear direction constitute a single refrigerant
flow member.
11. An evaporator according to claim 10, wherein front end portions
of the corrugate fins project frontward beyond front ends of the
refrigerant flow members, and a cutout is formed in each of the
front projecting portions of the corrugate fins.
12. An evaporator according to claim 10, wherein the cutouts are
formed in each corrugate fin at positions corresponding to
clearances between adjacent front and rear flat tubes of the
refrigerant flow members.
13. An evaporator according to claim 12, wherein front end portions
of the corrugate fins project frontward beyond front ends of the
refrigerant flow members, and a cutout is formed in each of the
front projecting portions of the corrugate fins.
14. An evaporator according to claim 10, further comprising a
refrigerant inlet header section which is disposed on a side toward
the front and on a first-end side of the refrigerant flow members
and to which the flat tubes of at least a single tube group are
connected, a refrigerant outlet header section which is disposed on
the first-end side of the refrigerant flow members and rearward of
the refrigerant inlet header section and to which the flat tubes of
the remaining tube groups are connected; a first inter mediate
header section which is disposed on the side toward the front and
on a second-end side of the refrigerant flow members and to which
the flat tubes connected to the refrigerant inlet header section
are connected; and a second inter mediate header section which is
disposed on the second-end side of the refrigerant flow members and
rearward of the first inter mediate header section and to which the
flat tubes connected to the refrigerant outlet header section are
connected; wherein the first and second intermediate header
sections communicate with each other.
15. An evaporator according to claim 10 wherein a tube height,
which is a thickness of the individual flat tubes as measured in
the left-right direction, is 0.75 mm to 1.5 mm.
16. An evaporator according to claim 1, wherein each of the
refrigerant flow members is formed of two metal plates whose
peripheral edge portions are joined together; a bulging refrigerant
flow tube portion is for ed between the two metal plates, and a
bulging header formation portion is connectedly formed at each of
opposite ends of the bulging refrigerant flow tube portion; and a
plurality of the refrigerant flow members are laminated such that
their bulging header formation portions abut each other and such
that air-passing clearances are formed between the bulging
refrigerant flow tube portions.
17. An evaporator according to claim 16, wherein a drain groove for
draining condensed water downward is for ed on an outer surface of
the refrigerant flow members, and the cutouts are formed in the
corrugate fins at positions corresponding to the drain grooves.
18. An evaporator according to claim 16, wherein a tube portion
height, which is a thickness of the bulging refrigerant flow tube
portion as measured in the left-right direction, is 0.75 mm to 1.5
mm.
19. A refrigeration cycle comprising a compressor, a condenser, and
an evaporator, and using a chlorofluorocarbon-based refrigerant,
the evaporator being an evaporator according to claim 1.
20. A vehicle having installed therein a refrigeration cycle
according to claim 19 as a car air conditioner.
21. A supercritical refrigeration cycle which comprises a
compressor, a gas cooler, an evaporator, a pressure-reducing
device, and an intermediate heat exchanger for performing heat
exchange between a refrigerant from the gas cooler and a
refrigerant from the evaporator and in which a supercritical
refrigerant is used, the evaporator being an evaporator according
to claim 1.
22. A vehicle having installed therein a refrigeration cycle
according to claim 21 as a car air conditioner.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is an application filed under 35 U.S.C.
.sctn.111(a) claiming the benefit pursuant to 35 U.S.C.
.sctn.119(e)(1) of the filing date of Provisional Application No.
60/619,009 filed Oct. 18, 2004 pursuant to 35 U.S.C.
.sctn.111(b).
TECHNICAL FIELD
[0002] The present invention relates to an evaporator for use in a
car air conditioner, which is a refrigeration cycle to be mounted
on, for example, a vehicle.
[0003] Herein and in the appended claims, the upper, lower,
left-hand, and right-hand sides of FIGS. 1 and 2 will be referred
to as "upper," "lower," "left," and "right," respectively. The
downstream side of an air flow (a side represented by arrow X in
FIG. 1, and a right-hand side in FIG. 3) is referred to as the
"front," and the opposite side as the "rear."
BACKGROUND ART
[0004] A conventionally used evaporator for use in a car air
conditioner includes a plurality of refrigerant flow members
arranged in parallel, and corrugate fins each disposed between and
brazed to the adjacent refrigerant flow members. Each of the
corrugate fins includes wave crest portions, wave trough portions,
and horizontal connection portions connecting together the wave
crest portions and the wave trough portions. The wave crest
portions and the wave trough portions are brazed to the refrigerant
flow members. A plurality of louvers are formed in the connection
portions in such a manner as to be juxtaposed in the air flow
direction.
[0005] In the evaporator, a portion of condensed water on the
surface of the refrigerant flow members and on the surface of the
corrugate fins flows downward through openings between adjacent
louvers. The residual condensed water flows, by the effect of
surface tension, toward joint portions between the refrigerant flow
members and the wave crest portions of the corrugate fins and
toward joint portions between the refrigerant flow members and the
wave trough portions of the corrugate fins. Then, the residual
condensed water flows, by the effect of the flowing air, in the air
flow direction and flows downward along the front ends of the
refrigerant flow members. However, in the case where the quantity
of condensed water is large, drainage performance may become
insufficient.
[0006] An evaporator in which the above problem is solved has been
proposed. In the evaporator, a corrugate fin disposed between
adjacent refrigerant flow members is divided into a plurality of
separate fin members, which are arranged at predetermined intervals
in the air flow direction. A clearance is formed between the
adjacent separate fin members. Drain grooves for draining condensed
water are formed on the outer surface of the refrigerant flow
members at positions corresponding-to the clearances. (Such an
evaporator is proposed in, for example, Japanese Patent Application
Laid-Open (kokai) No. 10-141805.)
[0007] However, in the evaporator described in the above-mentioned
publication, each of the corrugate fins is divided into a plurality
of separate fin members, which are arranged at predetermined
intervals in the air flow direction, and a clearance is formed
between the adjacent separate fin members. This, in manufacture of
the evaporator, raises a problem that assembling together the
refrigerant flow members and the separate fin members is
troublesome. Also, as compared with an undivided corrugate fin, the
divided corrugate fin is smaller in the area of heat transfer with
air that flows through an air-passing clearance between adjacent
refrigerant flow members, thus raising a problem of an impairment
in heat-exchanging performance.
[0008] An object of the present invention is to solve the above
problem and to provide an evaporator which exhibits excellent
drainage of condensed water and enables high work efficiency in
manufacture thereof.
DISCLOSURE OF THE INVENTION
[0009] To achieve the above object, the present invention comprises
the following modes.
[0010] 1) An evaporator comprising a plurality of refrigerant flow
members arranged in parallel in a left-right direction, and
corrugate fins disposed in corresponding air-passing clearances
between the adjacent refrigerant flow members, the corrugate fins
each comprising wave crest portions, wave trough portions, and flat
connection portions connecting together the wave crest portions and
the wave trough portions, a cutout being formed in each of the wave
crest portions and the wave trough portions.
[0011] 2) An evaporator according to par. 1), wherein a plurality
of louver groups each consisting of a plurality of louvers
juxtaposed in a front-rear direction are arranged at predetermined
intervals in the front-rear direction at each connection portion of
each corrugate fin, whereby a plurality of louver-free portions are
provided at each connection portion at the predetermined intervals
in the front-rear direction; and the cutout is formed in each of
the wave crest portions and the wave trough portions at least at a
position corresponding to one of the louver-free portions of each
connection portion.
[0012] 3) An evaporator according to par. 1), wherein opposite end
portions of each cutout of each corrugate fin extend to connection
portions located at opposite ends of the corresponding wave crest
portion or wave trough portion.
[0013] 4) An evaporator according to par. 3), wherein a projection
projecting inward is formed integrally with corresponding end
portions of each pair of connection portions of each corrugate fin,
the end portions of the connection portions corresponding to
opposite ends of one of the cutouts.
[0014] 5) An evaporator according to par. 4), wherein each
projection of each corrugate fin is formed in such a manner as to
extend between the corresponding end portions of the connection
portions located at the opposite ends of the corresponding wave
crest portion or wave trough portion, the end portions of the
connection portions corresponding to the opposite ends of one of
the cutouts.
[0015] 6) An evaporator according to par. 5), wherein the
projections of the corrugate fins project inward in a shape
resembling a lying letter V.
[0016] 7) An evaporator according to par. 5), wherein a pair of
slits spaced apart from each other in the front-rear direction is
formed in each of the wave crest portions and the wave trough
portions of each corrugate fin in such a manner as to extend to the
connection portions located at the opposite ends of the
corresponding wave crest portion or wave trough portion; and a
portion sandwiched between the slits is bent inward to thereby form
the cutout and the projection.
[0017] 8) An evaporator according to par. 1), wherein each of the
wave crest portions and the wave trough portions of each corrugate
fin comprises a flat portion and round portions located at
corresponding opposite ends of the flat portion and connected to
the corresponding connection portions; and the round portions have
a radius of curvature of 0.7 mm or less.
[0018] 9) An evaporator according to par. 1), wherein a fin height
of each corrugate fin, which is a direct distance between the wave
crest portions and the wave trough portions, is 7.0 mm to 10.0 mm;
and a fin pitch, which is a pitch of the connection portions, is
1.3 mm to 1.8 mm.
[0019] 10) An evaporator according to par. 1), wherein tube groups
are arranged in a plurality of rows at predetermined intervals in
the front-rear direction, each tube group consisting of a plurality
of flat tubes arranged in parallel at predetermined intervals in
the left-right direction; and a plurality of flat tubes arranged in
tandem in the front-rear direction constitute a single refrigerant
flow member.
[0020] 11) An evaporator according to par. 10), wherein front end
portions of the corrugate fins project frontward beyond front ends
of the refrigerant flow members, and a cutout is formed in each of
the front projecting portions of the corrugate fins.
[0021] 12) An evaporator according to par. 10), wherein the cutouts
are formed in each corrugate fin at positions corresponding to
clearances between adjacent front and rear flat tubes of the
refrigerant flow members.
[0022] 13. An evaporator according to claim 12, wherein front end
portions of the corrugate fins project frontward beyond front ends
of the refrigerant flow members, and a cutout is formed in each of
the front projecting portions of the corrugate fins.
[0023] 13) An evaporator according to par. 12), wherein front end
portions of the corrugate fins project frontward beyond front ends
of the refrigerant flow members, and a cutout is formed in each of
the front projecting portions of the corrugate fins.
[0024] 14) An evaporator according to par. 10), further comprising
a refrigerant inlet header section which is disposed on a side
toward the front and on a first-end side of the refrigerant flow
members and to which the flat tubes of at least a single tube group
are connected; a refrigerant outlet header section which is
disposed on the first-end side of the refrigerant flow members and
rearward of the refrigerant inlet header section and to which the
flat tubes of the remaining tube groups are connected; a first
intermediate header section which is disposed on the side toward
the front and on a second-end side of the refrigerant flow members
and to which the flat tubes connected to the refrigerant inlet
header section are connected; and a second intermediate header
section which is disposed on the second-end side of the refrigerant
flow members and rearward of the first intermediate header section
and to which the flat tubes connected to the refrigerant outlet
header section are connected; wherein the first and second
intermediate header sections communicate with each other.
[0025] 15) An evaporator according to par. 10), wherein a thickness
of the individual flat tubes as measured in the left-right
direction; i.e., a tube height, is 0.75 mm to 1.5 mm.
[0026] 16) An evaporator according to par. 1), wherein each of the
refrigerant flow members is formed of two metal plates whose
peripheral edge portions are joined together; a bulging refrigerant
flow tube portion is formed between the two metal plates, and a
bulging header formation portion is connectedly formed at each of
opposite ends of the bulging refrigerant flow tube portion; and a
plurality of the refrigerant flow members are laminated such that
their bulging header formation portions abut each other and such
that air-passing clearances are formed between the bulging
refrigerant flow tube portions.
[0027] 17) An evaporator according to par. 16), wherein a drain
groove for draining condensed water downward is formed on an outer
surface of the refrigerant flow members, and the cutouts are formed
in the corrugate fins at positions corresponding to the drain
grooves.
[0028] 18) An evaporator according to par. 16), wherein a thickness
of the bulging refrigerant flow tube portion as measured in the
left-right direction; i.e., a tube portion height, is 0.75 mm to
1.5 mm.
[0029] 19) A refrigeration cycle comprising a compressor, a
condenser, and an evaporator, and using a chlorofluorocarbon-based
refrigerant, the evaporator being an evaporator according to any
one of pars. 1) to 18).
[0030] 20) A vehicle having installed therein a refrigeration cycle
according to par. 19) as a car air conditioner.
[0031] 21) A supercritical refrigeration cycle which comprises a
compressor, a gas cooler, an evaporator, a pressure-reducing
device, and an intermediate heat exchanger for performing heat
exchange between a refrigerant from the gas cooler and a
refrigerant from the evaporator and in which a supercritical
refrigerant is used, the evaporator being an evaporator according
to any one of pars. 1) to 18).
[0032] 22) A vehicle having installed therein a refrigeration cycle
according to par. 21) as a car air conditioner.
[0033] With the evaporator of any one of pars. 1) to 3), a portion
of condensed water on the surface of the refrigerant flow members
and on the surface of the corrugate fins flows downward through
openings between adjacent louvers. The residual condensed water
flows, by the effect of surface tension, toward joint portions
between the refrigerant flow members and the wave crest portions
and the wave trough portions of the corrugate fins, and is
collected on the joint portions. The condensed water collected on
the joint portions between the refrigerant flow members and the
wave crest portions and the wave trough portions of the corrugate
fins flows frontward by the effect of air passing through the
air-passing clearances. Accordingly, the condensed water remaining
rearward of the cutouts flows downward through the cutouts, and the
condensed water remaining frontward of the cutouts flows downward
along the front ends of the refrigerant flow members. Since the
quantity of condensed water collected on the joint portions located
frontward of the cutouts and the quantity of condensed water
collected on the joint portions located rearward of the cutouts
become relatively small, drainage of condensed water is enhanced.
This prevents splashing of condensed water from front end portions
of the refrigerant flow members at the time of an abrupt change in
air flow rate; a drop in cooling performance caused by an increase
in air flow resistance which, in turn, is caused by surface tension
causing condensed water to block openings between the louvers; and
freezing of condensed water. In contrast to the corrugate fins of
the evaporator described in the above-mentioned publication, each
of the corrugate fins is not divided into a plurality of separate
fin members in the air flow direction. This facilitates assembly of
the refrigerant flow members and the corrugate fins in manufacture
of the evaporator, and suppresses a reduction in the area of heat
transfer between the corrugate fins and the air flowing through
air-passing clearances between adjacent refrigerant flow members,
thereby suppressing a drop in cooling performance of the
evaporator.
[0034] The evaporator of any one of pars. 4) to 6) exhibits
further-enhanced drainage of condensed water.
[0035] In manufacture of the corrugate fin of the evaporator of
par. 7), through utilization of a release plate used to release a
fin from a fin-forming roll, the cutouts and the projections can be
formed simultaneously, thereby simplifying manufacturing work.
[0036] With the evaporator of par. 8), the quantity of condensed
water collected on the joint portions between the refrigerant flow
members and the wave crest portions and on the joint portions
between the refrigerant flow members and the wave trough portions
tends to increase. However, even in this case, employment of the
configuration of any one of pars. 1) to 6) enhances drainage of
condensed water.
[0037] With the evaporator of par. 9), while an increase of air
flow resistance is suppressed, heat exchange performance is
enhanced, thereby establishing good balance between air flow
resistance and heat exchange performance.
[0038] With the evaporator of par. 11), condensed water which is
collected, by the effect of surface tension, on the joint portions
between the refrigerant flow members and the wave crest portions
and the wave trough portions of the corrugate fins passes through
the cutouts of the front projecting portions of the corrugate fins
and flows while being attracted, by the effect of surface tension,
toward internal corner portions each defined by the front end
surface of the front-end flat, hollow member and the front
projecting portion of the corrugate fin. Subsequently, the
condensed water flows downward along the internal corner portions
and is then drained away. Accordingly, drainage of condensed water
is enhanced, thereby preventing splashing of condensed water from
front end portions of the refrigerant flow members at the time of
an abrupt change in air flow rate; a drop in cooling performance
caused by an increase in air flow resistance which, in turn, is
caused by surface tension causing condensed water to block openings
between the louvers; and freezing of condensed water.
[0039] With the evaporator of par. 12), condensed water which is
collected, by the effect of surface tension, on the joint portions
between the refrigerant flow members and the wave crest portions
and the wave trough portions of the corrugate fins passes through
the cutouts; flows downward along the portions of the refrigerant
flow members located between adjacent front and rear flat tubes of
the refrigerant members; and is drained away. Accordingly, drainage
of condensed water is enhanced, thereby preventing splashing of
condensed water from front end portions of the refrigerant flow
members at the time of an abrupt change in air flow rate; a drop in
cooling performance caused by an increase in air flow resistance
which, in turn, is caused by surface tension causing condensed
water to block openings between the louvers; and freezing of
condensed water.
[0040] With the evaporator of par. 13), condensed water collected
rearward of the cutouts formed at positions corresponding to the
portions located between adjacent front and rear flat tubes is
drained away as in the case of the evaporator of par. 12). Also,
condensed water collected rearward of the cutouts formed at the
front projecting portions is drained away as in the case of the
evaporator of par. 11). Accordingly, drainage of condensed water is
enhanced, thereby preventing splashing of condensed water from
front end portions of the refrigerant flow members at the time of
an abrupt change in air flow rate; a drop in cooling performance
caused by an increase in air flow resistance which, in turn, is
caused by surface tension causing condensed water-to block openings
between the louvers; and freezing of condensed water.
[0041] With the evaporator of par. 15), while an increase of air
flow resistance is suppressed, heat exchange performance is
enhanced, thereby establishing good balance between air flow
resistance and heat exchange performance.
[0042] With the evaporator of par. 17), condensed water which is
collected, by the effect of surface tension, on the joint portions
between the refrigerant flow members and the wave crest portions
and the wave trough portions of the corrugate fins enters the drain
grooves via the cutouts; flows downward in the drain grooves; and
is drained away. Accordingly, drainage of condensed water is
enhanced, thereby preventing splashing of condensed water from
front end portions of the refrigerant flow members at the time of
an abrupt change in air flow rate; a drop in cooling performance
caused by an increase in air flow resistance which, in turn, is
caused by surface tension causing condensed water to block openings
between the louvers; and freezing of condensed water.
[0043] With the evaporator of par. 18), while an increase of air
flow resistance is suppressed, heat exchange performance is
enhanced, thereby establishing good balance between air flow
resistance and heat exchange performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] FIG. 1 is a partially cut-away perspective view showing the
overall configuration of Embodiment 1 of an evaporator according to
the present invention; FIG. 2 is a fragmentary view in vertical
section showing the evaporator shown in FIG. 1 as it is seen from
the rear, with its intermediate portion omitted; FIG. 3 is an
enlarged fragmentary view in section taken along line A-A of FIG.
2; FIG. 4 is an exploded perspective view of a refrigerant
inlet/outlet tank of the evaporator shown in FIG. 1; FIG. 5 is an
exploded perspective view of a refrigerant turn tank of the
evaporator shown in FIG. 1; FIG. 6 is an enlarged fragmentary view
in section taken along line B-B of FIG. 2; FIG. 7 is an enlarged
fragmentary view in section taken along line C-C of FIG. 2; FIG. 8
is a sectional view taken along line D-D of FIG. 2; FIG. 9 is an
enlarged perspective view showing a refrigerant flow member and a
corrugate fin; FIG. 10 is a sectional view taken along line E-E of
FIG. 9; FIG. 11 is a diagram showing the flow of a refrigerant in
the evaporator shown in FIG. 1; FIG. 12 is a view equivalent to
FIG. 9, showing Embodiment 2 of an evaporator according to present
invention; FIG. 13 is a view equivalent to FIG. 9, showing
Embodiment 3 of an evaporator according to present invention; FIG.
14 is an enlarged perspective view showing a refrigerant flow
member and a corrugate fin in Embodiment 4 of an evaporator
according to the present invention; FIG. 15 is a sectional view
taken along line F-F of FIG. 14; FIG. 16 is an exploded perspective
view showing a refrigerant flow member used in the evaporator of
FIG. 14; FIG. 17 is an exploded perspective view showing a modified
embodiment of a refrigerant flow member used in the evaporator of
Embodiment 4; and FIG. 18 is a graph showing the test results of
Experimental Examples 1 and 2 and Comparative Experimental
Example.
BEST MODE FOR CARRYING OUT THE INVENTION
[0045] Embodiments of the present invention will next be described
in detail with reference to the drawings. The embodiments are of an
evaporator according to the present invention that is applied to a
car air conditioner using a chlorofluorocarbon-based
refrigerant.
[0046] In the drawings, like parts or like elements are denoted by
like reference numerals, and repeated descriptions thereof are
omitted.
Embodiment 1
[0047] The present embodiment is illustrated in FIGS. 1 to 10.
[0048] FIGS. 1 to 3 show the overall configuration of an
evaporator, and FIGS. 4 to 10 show the configuration of essential
portions of the evaporator. FIG. 11 shows how a refrigerant flows
in the evaporator.
[0049] In FIGS. 1 to 3, the evaporator (1), which is used in a car
air conditioner using a chlorofluorocarbon-based refrigerant,
includes a refrigerant inlet/outlet tank (2) made of aluminum and a
refrigerant turn tank (3) made of aluminum, the tanks (2) and (3)
being vertically spaced apart from each other, and further includes
a heat exchange core section (4) provided between the tanks (2) and
(3).
[0050] The refrigerant inlet/outlet tank (2) includes a refrigerant
inlet header section (5) located on a side toward the front
(downstream side with respect to the air flow direction) and a
refrigerant outlet header section (6) located on a side toward the
rear (upstream side with respect to the air flow direction). A
refrigerant inlet pipe (7) made of aluminum is connected to the
refrigerant inlet header section (5) of the refrigerant
inlet/outlet tank (2). A refrigerant outlet pipe (8) made of
aluminum is connected to the refrigerant outlet header section
(6).
[0051] The refrigerant turn tank (3) includes a refrigerant inflow
header section (9) located on the side toward the front and a
refrigerant outflow header section (11) located on the side toward
the rear. A connection section (10) connects the header sections
(9) and (11) together. The header sections (9) and (11) and the
connection section (10) define a drain gutter (20).
[0052] The heat exchange core section (4) includes a plurality of
refrigerant flow members (13) arranged in parallel at predetermined
intervals in the left-right direction; corrugate fins (14) made of
aluminum, disposed within air-passing clearances between the
adjacent refrigerant flow members (13) and on the outer sides of
the leftmost and rightmost refrigerant flow members (13), and
brazed to the refrigerant flow members (13); and side plates (15)
made of aluminum, disposed outer sides of the leftmost and
rightmost corrugate fins (14), and brazed to the corresponding
corrugate fins (14). Each of the refrigerant flow members (13)
includes a plurality of; herein, two, flat tubes (12) made from an
aluminum extrudate and disposed at predetermined intervals in the
front-rear direction such that their widths extend in the
front-rear direction. The upper and lower ends of the front flat
tube (12) are connected to the refrigerant inlet header section (5)
and the refrigerant inflow header section (9), respectively,
whereas the upper and lower ends of the rear flat tube (12) are
connected to the refrigerant outlet header section (6) and the
refrigerant outflow header section (11), respectively.
[0053] As shown in FIGS. 2 to 4, the refrigerant inlet/outlet tank
(2) is formed from an aluminum brazing sheet having a brazing
material layer on each of opposite sides thereof, and includes a
first member (16) having a plate-like shape and to which the flat
tubes (12) are connected; a second member (17) formed from a bare
aluminum extrudate and covering the upper side of the first member
(16); and caps (18) and (19) formed from an aluminum brazing sheet
having a brazing material layer on each of opposite sides thereof,
and joined to the opposite ends of the first and second members
(16) and (17) to thereby close the left and right end openings. A
joint plate (21) made of aluminum and elongated in the front-rear
direction is brazed to the outer surface of the right-hand cap (19)
while facing the respective ends of the refrigerant inlet header
section (5) and the refrigerant outlet header section (6). The
refrigerant inlet pipe (7) and the refrigerant outlet pipe (8) are
connected to the joint plate (21).
[0054] The first member (16) has front and rear curved portions
(22), whose central regions each have an arcuate cross section
projecting downward and having a small curvature. A plurality of
tube insertion holes (23), which are elongated in the front-rear
direction, are formed in the curved portions (22) at predetermined
intervals in the left-right direction. The tube insertion holes
(23) of the front curved portion (22) and those of the rear curved
portion (22) are identical in position in the left-right direction.
A rising wall (22a) is formed integrally with each of the front
edge of the front curved portion (22) and the rear edge of the rear
curved portion (22), over the entire length of the front and rear
edges. A plurality of through holes (25) are formed in a flat
portion (24) located between the curved portions (22) of the first
member (16), at predetermined intervals in the left-right
direction.
[0055] The second member (17) includes front and rear walls (26)
extending in the left-right direction and jointly forming a cross
section resembling the letter m, which opens downward; a partition
wall (27) provided at a central region thereof between the front
and rear walls (26), extending in the left-right direction, and
dividing the interior of the refrigerant inlet/outlet tank (2) into
a front space and a rear space; and two substantially arcuate
connection walls (28) projecting upward and integrally connecting
the upper end of the partition wall (27) and the upper ends of the
front and rear walls (26). A flow-dividing resistance plate (29)
integrally connects a lower end portion of the rear wall (26) of
the second member (17) and a lower end portion of the partition
wall (27) over the entire length thereof. A plurality of
refrigerant passage holes (31A) and (31B) in a through-hole form
and elongated in the left-right direction are formed in a rear
region, excluding left and right end portions thereof, of the
flow-dividing resistance plate (29) at predetermined intervals in
the left-right direction. The lower end of the partition wall (27)
projects downward beyond the lower ends of the front and rear walls
(26). A plurality of projections (27a) are integrally formed on the
lower end face of the partition wall (27) at predetermined
intervals in the left-right direction in such a manner as to
project downward, and are fitted into corresponding through holes
(25) of the first member (16). The projections (27a) are formed by
cutting off predetermined portions of the partition wall (27).
[0056] A leftward projecting portion (32) to be fitted into the
refrigerant inlet header section (5) is formed integrally with the
right-hand cap (19), on the side toward the front. An upper,
leftward projecting portion (33) and a lower, leftward projecting
portion (34) are formed integrally with the right-hand cap (19), on
the side toward the rear, and spaced apart from each other in the
vertical direction. The upper, leftward projecting portion (33) is
fitted into a space (6a) of the refrigerant outlet header section
(6), the space (6a) being located above the flow-dividing
resistance plate (29). The lower, leftward projecting portion (34)
is fitted into a space (6b) of the refrigerant outlet header
section (6), the space (6b) being located under the flow-dividing
resistance plate (29). An engagement finger (35) projecting
leftward is formed integrally with each of an arcuate portion
extending between the front side edge and the top edge of the
right-hand cap (19) and an arcuate portion extending between the
rear side edge and the top edge of the right-hand cap (19).
Further, an engagement finger (36) projecting leftward is formed
integrally with each of a front portion and a rear portion of the
lower end face of the right-hand cap (19). A refrigerant inlet (37)
is formed in the bottom wall of the leftward projecting portion
(32), located on the side toward the front, of the right-hand cap
(19). A refrigerant outlet (38) is formed in the bottom wall of the
upper, leftward projecting portion (33), located on the side toward
the rear, of the right-hand cap (19). The left-hand cap (18) is a
mirror image of the right-hand cap (19) and includes the following
integrally formed portions: a rightward projecting portion (39) to
be fitted into the refrigerant inlet header section (5); an upper,
rightward projecting portion (41) to be fitted into the space (6a)
of the refrigerant outlet header section (6), the space (6a) being
located above the flow-dividing resistance plate (29); a lower,
rightward projecting portion (42) to be fitted into the space (6b)
of the refrigerant outlet header section (6), the space (6b) being
located under the flow-dividing resistance plate (29); and upper
and lower engagement fingers (43) and (44) projecting rightward. No
opening is formed in the bottom walls of the rightward projecting
portion (39) and the upper, rightward projecting portion (41). The
upper edge of the cap (18) and the upper edge of the cap (19) each
assume a shape such that two substantially arcuate portions are
integrally connected together at a central position in the
front-rear direction, so as to coincide with the corresponding left
and right ends of the upper surface of the second member (17) of
the refrigerant inlet/outlet tank (2). The lower edge of the cap
(18) and the lower edge of the cap (19) each assume a shape such
that two substantially arcuate portions are integrally connected
together via a flat portion located centrally in the front-rear
direction, so as to coincide with the corresponding left and right
ends of the lower surface of the first member (16) of the
refrigerant inlet/outlet tank (2).
[0057] The joint plate (21) includes a short, cylindrical
refrigerant inflow port (45) communicating with the refrigerant
inlet (37) of the right-hand cap (19), and a short, cylindrical
refrigerant outflow port (46) communicating with the refrigerant
outlet (38) of the right-hand cap (19). A bent portion (47)
projecting leftward is formed at a portion of each of the upper and
lower edge portions of the joint plate (21) located between the
refrigerant inflow port (45) and the refrigerant outflow port (46).
The upper bent portion (47) is-fitted between two substantially
arcuate portions of the upper edge of the right-hand cap (19) and
between the two connection walls (28) of the second member (17).
The lower bent portion (47) is fitted to the above-mentioned flat
portion formed between two substantially arcuate portions of the
lower edge of the right-hand cap (19) and to the flat portion (24)
of the first member (16). An engagement finger (48) projecting
leftward is formed integrally with each of front and rear end
portions of the lower edge of the joint plate (21). The engagement
fingers (48) are fitted to the lower edge of the right-hand cap
(19). A-diameter-reduced portion formed at one end portion of the
refrigerant inlet pipe (7) is inserted into and brazed to the
refrigerant inflow port (45) of the joint plate (21). Similarly, a
diameter-reduced portion formed at one end portion of the
refrigerant outlet pipe (8) is inserted into and brazed to the
refrigerant outflow port (46) of the joint plate (21). Although
unillustrated, an expansion valve attachment member is joined to
the other end portions of the refrigerant inlet and outlet pipes
(7) and (8) while facing the ends of the pipes (7) and (8).
[0058] The first and second members (16) and (17) of the
refrigerant inlet/outlet tank (2), the caps (18) and (19), and the
joint plate (21) are brazed together as follows. In assembly of the
first and second members (16) and (17), the projections (27a) of
the second member (17) are inserted into the corresponding through
holes (25) of the first member (16), followed by crimping. As a
result, upper end portions of the front and rear rising walls (22a)
of the first member (16) are fitted to corresponding lower end
portions of the front and rear walls (26) of the second member
(17). In the thus-established condition, the first and second
members (16) and (17) are brazed together by utilization of the
brazing material layers of the first member (16). In attachment of
the caps (18) and (19), the front projecting portions (39) and (32)
are fitted into the space defined by the first and second members
(16) and (17) and located frontward of the partition wall (27); the
rear, upper projecting portions (41) and (33) are fitted into the
space defined by the first and second members (16) and (17) and
located rearward of the partition wall (27) and above the
flow-dividing resistance plate (29); the rear, lower projecting
portions (42) and (34) are fitted into the space defined by the
first and second members (16) and (17) and located rearward of the
partition wall (17) and under the flow-dividing resistance plate
(29); the upper engagement fingers (43) and (35) are fitted to the
connection walls (28) of the second member (17); and the lower
engagement fingers (44) and (36) are fitted to the curved portions
(22) of the first member (16). In the thus-established condition,
the caps (18) and (19) are brazed to the first and second members
(17) and (17) by utilization of the brazing material layers
thereof. In attachment of the joint plate (21), the bent portions
(47) are fitted to the right-hand cap (19) and the second member
(17), and the engagement fingers (48) are fitted to the right-hand
cap (19). In the thus-established condition, the joint plate (21)
is brazed to the right-hand cap (19) by utilization of the brazing
material layers of the right-hand cap (19).
[0059] The refrigerant inlet/outlet tank (2) is thus formed. A
portion of the refrigerant inlet/outlet tank (2) located frontward
of the partition wall (27) of the second member (17) serves as the
refrigerant inlet header section (5), and a portion of the
refrigerant inlet/outlet tank (2) located rearward of the partition
wall (27) serves as the refrigerant outlet header section (6). The
flow-dividing resistance plate (29) divides the interior of the
refrigerant outlet header section (6) into the upper and lower
spaces (6a) and (6b). The spaces (6a) and (6b) communicate with
each other through the refrigerant passage holes (31A) and (31B).
The refrigerant outlet (38) of the right-hand cap (19) communicates
with the upper space (6a) of the refrigerant outlet header section
(6). The refrigerant inflow port (45) of the joint plate (21)
communicates with the refrigerant inlet (37), and the refrigerant
outflow port (46) communicates with the refrigerant outlet
(38).
[0060] As shown in FIGS. 2, 3, and 5 to 8, the refrigerant turn
tank (3) is formed from an aluminum brazing sheet having a brazing
material layer on each of opposite sides thereof and includes a
first member (50) having a plate-like shape and to which the flat
tubes (12) are connected; a second member (51) formed from a bare
aluminum extrudate and covering the lower side of the first member
(50); caps (52) and (53) formed from an aluminum brazing sheet
having a brazing material layer on each of opposite sides thereof,
and closing the left and right end openings of the first and second
members (50) and (51); an auxiliary drain plate (54) formed from an
aluminum bare material, elongated in the left-right direction, and
joined to the connection section (10); and a communication member
(55) formed from an aluminum bare material, elongated in the
front-rear direction, and brazed to the outer surface of the
left-hand cap (52) in such a manner as to face the ends of the
refrigerant inflow header section (9) and the refrigerant outflow
header section (11). The refrigerant inflow header section (9) and
the refrigerant outflow header section (11) communicate with each
other at their left end portions via the communication member
(55).
[0061] Each of the refrigerant inflow header section (9) and the
refrigerant outflow header section (11) has a top face, a front
side face, a rear side face, and a bottom face. The top faces,
excluding their inside and outside portions with respect to the
front-rear direction, of the header sections (9) and (11) serve as
horizontal flat faces (9a) and (11a), respectively. The inside
portions with respect to the front-rear direction of the top faces
of the header sections (9) and (11) serve as first low portions
(9b) and (11b), respectively, which are of faces inclined linearly
downward and toward the inside with respect to the front-rear
direction. The first low portions (9b) and (11b) serve as front and
rear side surfaces of the drain gutter (20). The front and rear
side surfaces of the drain gutter (20) fan out upward and in the
front-rear direction. Preferably, the first low portions (9b) and
(11b) are inclined downward at an angle of 45 degrees or greater
with respect to a horizontal plane. The front and rear side
surfaces of the drain gutter (20); i.e., the first low portions
(9b) and (11b) of the header sections (9) and (11), are not
necessarily inclined linearly, but may be curved, so long as they
fan out upward and in the front-rear direction. Outside portions
with respect to the front-rear direction of the top faces of the
header sections (9) and (11) serve as second low portions (9c) and
(11c), respectively, which are of faces inclined linearly downward
and toward the outside with respect to the front-rear direction.
Preferably, the second low portions (9c) and (11c) are inclined
downward at an angle of 45 degrees or greater with respect to a
horizontal plane. The front and rear outside surfaces of the header
sections (9) and (11) are connected to the corresponding second low
portions (9c) and (11c) of the top faces.
[0062] The first member (50) includes a first header formation
portion (56), which forms an upper portion of the refrigerant
inflow header section (9); a second header formation portion (57),
which forms an upper portion of the refrigerant outflow header
section (11); and a connection wall (58), which connects the header
formation portions (56) and (57) and forms the connection section
(10). The first header formation portion (56) includes a horizontal
flat top wall (56a); a first inclined wall (56b), which is formed
integrally with the rear edge of the top wall (56a) over the entire
length thereof and inclined rearward and downward; a second
inclined wall (56c), which is formed integrally with the front edge
of the top wall (56a) over the entire length thereof and inclined
frontward and downward; and a vertical wall (56d), which is formed
integrally with the front edge of the second inclined wall (56c)
over the entire length thereof. The second header formation portion
(57) includes a horizontal flat top wall (57a); a first inclined
wall (57b), which is formed integrally with the front edge of the
top wall (57a) over the entire length thereof and inclined
frontward and downward; a second inclined wall (57c), which is
formed integrally with the rear edge of the top wall (57a) over the
entire length thereof and inclined rearward and downward; and a
vertical wall (57d), which is formed integrally with the rear edge
of the second inclined wall (57c) over the entire length thereof.
The connection wall (58) integrally connects the lower edge of the
first inclined wall (56b) of the first header formation portion
(56) and the lower edge of the first inclined wall (57b) of the
second header formation portion (57). The bottom end faces of the
vertical walls (56d) and (57d) of the header formation portions
(56) and (57), respectively, are inclined downward, and inward with
respect to the front-rear direction. An outside portion of each of
the bottom faces partially forms a stepped portion (69), which will
be described later. The upper surface of the top wall (56a) of the
first header formation portion (56) serves as the top face of the
refrigerant inflow header section (9); i.e., as the horizontal flat
face (9a); the upper surfaces of the inclined walls (56b) and (56c)
serve as the low portions (9b) and (9c); and the outer surface of
the vertical wall (56c) serves as an upper portion of the front
surface of refrigerant inflow header section (9). The upper surface
of the top wall (57a) of the second header formation portion (57)
serves as the top face of the refrigerant outflow header section
(11); i.e., as the horizontal flat face (11a); the upper surfaces
of the inclined walls (57b) and (57c) serve as the low portions
(11b) and (11c); and the outer surface of the vertical wall (57d)
serves as an upper portion of the rear surface of the refrigerant
outflow header section (11).
[0063] A plurality of tube insertion holes (59) elongated in the
front-rear direction are formed in the header formation portions
(56) and (57) of the first member (50) at predetermined intervals
in the left-right direction. The tube insertion holes (59) of the
header formation portion (56) and those of the header formation
portion (57) are identical in position in the left-right direction.
End portions, located on a side toward the connection section (10),
of the tube insertion holes (59); i.e., rear end portions of the
tube insertion holes (59) of the first header formation portion
(56) and front end portions of the tube insertion holes (59) of the
second header formation portion (57), are located in the first
inclined walls (56b) and (57b), respectively. Thus, the end
portions, located on the side toward the connection section (10),
of the tube insertion holes (59) are located in the side surfaces
of the drain gutter (20). Outer end portions, with respect to the
front-rear direction, of the tube insertion holes (59); i.e., front
end portions of the tube insertion holes (59) of the first header
formation portion (56) and rear end portions of the tube insertion
holes (59) of the second header formation portion (57), are located
in the second inclined walls (56c) and (57c), respectively. Thus,
the front and rear end portions of the tube insertion holes (59)
are located in the second low portions (9c) and (11c) of the top
faces of the header sections (9) and (11).
[0064] In the top walls (56a) and (57a) and the inclined walls
(56b), (56c), (57b), and (57c) of the header formation portions
(56) and (57) of the first member (50), their portions located on
the left and right sides of each tube insertion hole (59) serve as
inclined portions (61) that are inclined downward and toward the
tube insertion hole (59). The inclined portions (61) located on the
left and right sides of each tube insertion hole (59) define a
recess (62). Drain grooves (63) for draining condensed water
downward of the refrigerant turn tank (3) are formed, in connection
with the front and rear end portions of the corresponding tube
insertion holes (59), on the upper surfaces of the second inclined
walls (56c) and (57c) and the outer surfaces of the vertical walls
(56d) and (57d) of the header formation portions (56) and (57) of
the first member (50). The bottom of each drain groove (63) extends
downward as the distance from the corresponding tube insertion hole
(59) increases. The bottom of a portion of each drain groove (63)
located on the second inclined wall (56c) or (57c); i.e., on the
second low portion (9c) or (11c), is linearly inclined, with
respect to a horizontal plane, downward and toward the front or the
rear. Preferably, the bottom of the portion of each drain groove
(63) located on the second low portion (9c) or (11c) is inclined at
an angle of 45 degrees or greater with respect to the horizontal
plane. The lower end of a portion of each drain groove (63) located
on the vertical wall (56d) or (57d) opens at the bottom end face of
the vertical wall (56d) or (57d) (see FIG. 6).
[0065] A plurality of drain through-holes (64) elongated in the
left-right direction are formed in the connection wall (58) of the
first member (50) at predetermined intervals in the left-right
direction. Also, a plurality of fixation though-holes (65) are
formed in the connection wall (58) of the first member (50) at
predetermined intervals in the left-right direction while being
shifted from the drain through-holes (64).
[0066] The first member (50) is formed, by press work, from an
aluminum brazing sheet in such a manner as to form the header
formation portions (56) and (57); i.e., the top walls (56a) and
(57a), the inclined walls (56b), (56c), (57b), and-(57c), the
vertical walls (56d) and (57d), the connection wall (58), the tube
insertion holes (59), the inclined portions (61), and the drain
grooves (63), and to form the drain through-holes (64) and the
fixation through-holes (65) in the connection wall (58).
[0067] The second member (51).includes a first header formation
portion (66), which forms a lower portion of the refrigerant inflow
header section (9); a second header formation portion (67), which
forms a lower portion of the refrigerant outflow header section
(11); and a connection wall (68), which connects together the
header formation portions (66) and (67) and is brazed to the
connection wall (58) of the first member (50) to thereby form the
connection section (10). The first header formation portion (66)
includes vertical front and rear walls (66a), and a bottom wall
(66b) integrally connecting the bottom ends of the front and rear
walls (66a), projecting downward, and having a substantially
arcuate cross section. The second header formation portion (67)
includes vertical front and rear walls (67a); a bottom wall (67b)
integrally connecting the bottom ends of the front and rear walls
(67a), projecting downward, and having a substantially arcuate
cross section; and a horizontal flow-dividing control wall (67c)
integrally connecting upper end portions of the front and rear
walls (67a). The connection wall (68) integrally connects an upper
end portion of the rear wall (66a) of the first header formation
portion (66) and an upper end portion of the front wall (67a) of
the second header formation portion (67). The outer surface of the
front wall (66a) of the first header formation portion (66) and the
outer surface of the rear wall (67a) of the second header formation
portion (67) are located inward, with respect to the front-rear
direction, of the outer surface of the vertical wall (56d) of the
first header formation portion (56) and the outer surface of the
vertical wall (57d) of the second header formation portion (57),
respectively, of the first member (50). Thus, the stepped portion
(69) is provided at each of joint portions between the vertical
walls (56d) and (57d) of the first member (50) and the front and
rear walls (66a) and (67a) of the second member (51); the outer
surfaces of the vertical walls (56d) and (57d) are located outward,
with respect to the front-rear direction, of the outer surfaces of
the front and rear walls (66a) and (67a), respectively, via the
corresponding stepped portions (69); and the entire bottom end of
each drain groove (63) opens at the corresponding stepped portion
(69) (see FIGS. 6 and 7). The outer surface of an upper edge
portion of the front wall (66a) of the first header formation
portion (66) is flush with the bottom surface of a portion of the
drain groove (63) located on the vertical wall (56d), and the outer
surface of an upper edge portion of the rear wall (67a) of the
second header formation portion (67) is flush with the bottom
surface of a portion of the drain groove (63) located on the
vertical wall (57d). The outer surface of the front wall (66a)
of-the first header formation portion (66) serves as a lower
portion of the front surface of the refrigerant inflow header
section (9). The outer surface of the rear wall (67a) of the second
header formation portion (67) serves as a lower portion of the rear
surface of the refrigerant outflow header section (11).
[0068] A plurality of circular refrigerant passage holes (71) in a
through-hole form are formed in a rear region of the flow-dividing
control wall (67c) of the second header formation portion (67) of
the second member (51) at predetermined intervals in the left-right
direction. The distance between the two adjacent circular
refrigerant passage holes (71) increases gradually as the distance
from the left end of the flow-dividing control wall (67c)
increases. Thus, the number of circular refrigerant passage holes
(71) per unit length of the flow-dividing control wall (67c)
reduces toward the right. Notably, the distance between the two
adjacent circular refrigerant passage holes (71) may be constant. A
plurality of through holes (72) elongated in the left-right
direction are formed in the connection wall (68) of the second
member (51), in alignment with the corresponding drain
through-holes (64) of the first member (50). Also, a plurality of
fixation through-holes (73) are formed in the connection wall (68),
in alignment with the corresponding fixation through-holes (65) of
the first member (50).
[0069] The second member (51) is formed as follows. First, the
front and rear walls (66a) and (67a) and the bottom walls (66b) and
(67b) of the header formation portions (66) and (67), the
flow-dividing control wall (67c) of the second header formation
portion (67), and the connection wall (68) are integrally formed by
extrusion. Subsequently, the resultant extrudate is subjected to
press work so as to form the refrigerant passage holes (71) in the
flow-dividing control wall (67c), and the drain through-holes (72)
and the fixation through-holes (73) in the connection wall
(68).
[0070] Cutouts (74) are formed in the auxiliary drain plate (54) in
such a manner as to extend from its upper edge and to correspond to
the drain through-holes (64) and (72) of the first and second
members (50) and (51). The width of an open portion of the cutout
(74) as measured in the left-right direction is equal to the length
of the drain through-holes (64) and (72) as measured in the
left-right direction. Auxiliary drain grooves (75) are formed on
the front and rear surfaces of the auxiliary drain plate (54) as
follows: the auxiliary drain grooves (75) extend vertically and are
connected to the corresponding lower end portions of the cutouts
(74); and their lower end portions are open at the bottom face of
the auxiliary drain plate (54). Projections (76) are formed at the
top edge of the auxiliary drain plate (54) in such a manner as to
align with the corresponding fixation through-holes (65) and (73)
of the first and second members (50) and (51) and to project upward
so as to be inserted into the corresponding fixation through-holes
(65) and (73). The auxiliary drain plate (54) is formed, by press
work, from an aluminum bare material in such a manner as to form
the cutouts (74), the auxiliary drain grooves (75), and the
projections (76).
[0071] The caps (52) and (53) assume a plate-like form and are
formed, by press work, from an aluminum brazing sheet having a
brazing material layer on each of opposite sides thereof. A
rightward projecting portion (77) to be fitted into the refrigerant
inflow header section (9) is formed integrally with the left-hand
cap (52), on the side toward the front. An upper, rightward
projecting portion (78) and a lower, rightward projecting portion
(79) are formed integrally with the left-hand cap (52), on the side
toward the rear, and spaced apart from each other in the vertical
direction. The upper, rightward projecting portion (78) is fitted
into a space (11A) of the refrigerant outflow header section (11),
the space (11A) being located above the flow-dividing control wall
(67c). The lower, rightward projecting portion (79) is fitted into
a space (11B) of the refrigerant outflow header section (11), the
space (11B) being located under the flow-dividing control wall
(67c). In the left-hand cap (52), an engagement finger (81)
projecting rightward is formed integrally with each of an arcuate
portion extending between the front side edge and the bottom edge
and an arcuate portion extending between the rear side edge and the
bottom edge, and is also formed integrally with the top edge at
front and rear positions; and further, an engagement finger (82)
projecting leftward is formed on each of the upper and lower edges
at a central position with respect to the front-rear direction.
Through holes (83) and (84) are formed in the bottom wall of the
front, rightward projecting portion (77) and the bottom wall of the
rear, lower, rightward projecting portion (79), respectively, of
the left-hand cap (52). The front through hole (83) establishes
communication between the interior and the exterior of the
refrigerant inflow header section (9). The rear through hole (84)
establishes communication between the interior and the exterior of
the space (11B), located under the flow-dividing control wall
(67c), of the refrigerant outflow header section (11).
[0072] A leftward projecting portion (85) to be fitted into the
refrigerant inflow header section (9) is formed integrally with the
right-hand cap (53), on the side toward the front. An upper,
leftward projecting portion (86) and a lower, leftward projecting
portion (87) are formed integrally with the right-hand cap (53), on
the side toward the rear, and spaced apart from each other in the
vertical direction. The upper, leftward projecting portion (86) is
fitted into the space (11A) of the refrigerant outflow header
section (11), the space (11A) being located above the flow-dividing
control wall (67c). The lower, leftward projecting portion (87) is
fitted into the space (11B) of the refrigerant outflow header
section (11), the space (11B) being located under the flow-dividing
control wall (67c). In the right-hand cap (53), an engagement
finger (88) projecting leftward is formed integrally with each of
an arcuate portion extending between the front side edge and the
bottom edge, and an arcuate portion extending between the rear side
edge and the bottom edge, and is also formed integrally with the
top edge at front and rear positions. No through hole is formed in
the bottom walls of the leftward projecting portion (85) and the
lower, leftward projecting portion (87).
[0073] The communication member (55) is formed, by press work, from
an aluminum bear material and assumes, as viewed from the left, a
plate-like form identical with that of the left-hand cap (52). A
peripheral edge portion of the communication member (55) is brazed
to the outer surface of the left-hand cap (52). An outward bulging
portion (89) is formed on the communication member (55) so as to
establish communication between the two through holes (83) and (84)
of the left-hand cap (52). The interior of the outward bulging
portion (89) serves as a communication channel (91) for
establishing communication between the through holes (83) and. (84)
of the left-hand cap (52). A cutout (92) is formed on each of the
upper and lower edges of the communication member (55) at a central
position with respect to the front-rear direction. The engagement
fingers of the left-hand cap (52) are fitted into the corresponding
cutouts (92).
[0074] In assembly of the refrigerant turn tank (3), the first and
second members (50) and (51), the auxiliary drain plate (54), the
caps (52) and (53), and the communication member (55)- are brazed
together as follows. In assembly of the first member (50) and the
second member (51), the connection walls (58) and (68) are brought
in contact with each other such that the drain through-holes (64)
and (72) are aligned with each other and such that the fixation
through-holes (65) and (73) are aligned with each other; the bottom
ends of the vertical walls (56d) and (57d) of the header formation
portions (56) and (57) are engaged with the corresponding top ends
of the front wall (66a) of the first header formation portion (66)
and the rear wall (67a) of the second header formation portion
(67); and the projections (76) of the auxiliary drain plate (54)
are inserted from underneath into the fixation through-holes (73)
and (65) of the members (50) and (51) and then crimped, thereby
tacking the members (56) and (57) together. In the thus-established
condition, these members are brazed together by utilization of the
brazing material layers of the first member (50). The auxiliary
drain plate (54) is brazed to the connection walls (58) and (68) of
the members (50) and (51) by utilization of the brazing material
layers of the first member (50). In attachment of the caps (52) and
(53), the front projecting portions (77) and (85) are fitted into
the space defined by the first header formation portions (56) and
(66) of the members (50) and (51); the rear, upper projecting
portions (78) and (86) are fitted into the upper space defined by
the second header formation portions (57) and (67) of the members
(50) and (51) and located above the flow-dividing control wall
(67c); the rear, lower projecting portions (79) and (87) are fitted
into the lower space defined by the second header formation
portions (57) and (67) of the members (50) and (51) and located
under the flow-dividing control wall (67c); the upper engagement
fingers (81) are fitted to the first member (50); and the lower
engagement fingers (81) and (88) are fitted to the second member
(51). In the thus-established condition, the caps (52) and (53) are
brazed to the first and second members (50) and (51) by utilization
of the brazing material layers thereof. In attachment of the
communication member (55)., the communication member (55) is
engaged with the left-hand cap (52) such that the engagement
fingers (82) are fitted into the corresponding cutouts (92). In the
thus-established condition, the communication member (55) is brazed
to the left-hand cap (52) by utilization of the brazing material
layers of the left-hand cap (52).
[0075] The refrigerant turn tank (3) is thus formed. The first
header formation portions (56) and (66) of the members (50) and
(51) define the refrigerant inflow header section (9). The second
header formation portions (57) and (67) define the refrigerant
outflow header section (11). The flow-dividing control wall (67c)
divides the interior of the refrigerant outflow header section (11)
into the upper and lower spaces (11A) and (11B). The spaces (11A)
and (11B) communicate with each other through the circular
refrigerant passage holes (71). The rear through hole (84) of
left-hand cap (52) communicates with the lower space (11B) of the
refrigerant outflow header section (11). The interior of the
refrigerant inflow header section (9) and the lower space (11B) of
the refrigerant outflow header section (11) communicate with each
other via the through holes (83) and (84) of the left-hand cap (52)
and the communication channel (91) in the outward bulging portion
(89) of the communication member (55). The connection walls (58)
and (68) of the members (50) and (51) define the connection section
(10). The first low portion (9b) of the refrigerant inflow header
section (9), the first low portion (11b) of the refrigerant outflow
header section (11), and the connection section (10) define the
drain gutter (20). The drain through-holes (64) and (72) of the
connection walls (58) and (68) of the members (50) and (51) define
the drain holes (93) of the connection section (10).
[0076] Each of the flat tubes (12) is formed from a bare aluminum
extrudate and assumes a flat form having a wide width in the
front-rear direction. In the flat tube (12), a plurality of
refrigerant channels (12a) extending in the longitudinal direction
thereof are formed in parallel therein. The front flat tubes (12)
and the rear flat tubes (12) are arranged in such a manner as to be
identical in position in the left-right direction. Upper end
portions of the flat tubes (12) are inserted into the corresponding
tube insertion holes (23) of the first member (16) of the
refrigerant input/output tank (2) and brazed to the first member
(16) by utilization of the brazing material layers of the first
member (16). Lower end portions of the flat tubes (12) are inserted
into the corresponding tube insertion holes (59) of the first
member (50) of the refrigerant turn tank (3) and brazed to the
first member (50) by utilization of the brazing material layers of
the first member (50). The front flat tubes (12) communicate with
the refrigerant inlet header section (5) and the refrigerant inflow
header section (9). The rear flat tubes (12) communicate with the
refrigerant outlet header section (6) and the refrigerant outflow
header section (11).
[0077] Preferably, the thickness of the flat tube (12) as measured
in the left-right direction; i.e., a tube height (h), is 0.75 mm to
1.5 mm (see FIG. 10); the width of the flat tube (12) as measured
in the front-rear direction is 12 mm to 18 mm; the wall thickness
of the flat tube (12) is 0.175 mm to 0.275 mm; the thickness of a
partition wall separating the refrigerant channels (12a) from each
other is 0.175 mm to 0.275 mm; the pitch of the partition walls is
0.5 mm to 3.0 mm; and the front and rear end walls each have a
radius of curvature of 0.35 mm to 0.75 mm as measured on the outer
surface thereof.
[0078] In place of use of the flat tube (12) formed from an
aluminum extrudate, a flat tube to be used may be formed such that
an inner fin is inserted into a seam welded pipe of aluminum so as
to form a plurality of refrigerant channels therein. Alternatively,
a flat tube to be used may be formed as follows. An aluminum
brazing sheet having a brazing material layer on each of opposite
sides thereof is subjected to a rolling process so as to form a
plate that includes two flat-wall-forming portions connected
together via a connection portion; side-wall-forming portions,
which are formed, in a bulging condition, integrally with the
corresponding flat-wall-forming portions at their side edges
located in opposition to the connection portion; and a plurality of
partition-wall-forming portions, which are formed integrally with
the flat-wall-forming portions in such a manner as to project from
the flat-wall-forming portions, and to be arranged at predetermined
intervals in the width direction of the flat-wall-forming portions.
The thus-prepared plate is bent at the connection portion into a
hairpin form such that the side-wall-forming portions abut each
other, followed by brazing. The partition-wall-forming portions
become partition walls. In this case, corrugate fins formed from a
bare material are used.
[0079] As shown in FIGS. 9 and 10, each of the corrugated fins (14)
is made in a wavy form from an aluminum brazing sheet having a
brazing material layer over opposite surfaces thereof. The
corrugate fin (14) includes wave crest portions (14a), wave trough
portions (14b), and horizontal flat connection portions each
connecting together the wave crest portion (14a) and the wave
trough portion (14b). A plurality of louvers (94) are formed at the
connection portions (14c) in such a manner as to be juxtaposed in
the front-rear direction. The front and rear flat tubes (12) that
constitute the refrigerant flow member (13) share the corrugate fin
(14). The width of the corrugate fin (14) as measured in the
front-rear direction is slightly greater than the span between the
front end of the front flat tube (12) and the rear end of the rear
flat tube (12) and a front end portion of the corrugate fin (14)
projects frontward beyond the front end of the front flat tube
(12). The wave crest portions (14a) and the wave trough portions
(14b) of the corrugate fin (14) are brazed to the front and rear
flat tubes (12) that constitute the refrigerant flow member (13).
Preferably, a fin height (H) of the corrugate fin (14); i.e., a
direct distance between the wave crest portion (14a) and the wave
trough portion (14b), is 7.0 mm to 10.0 mm; and a fin pitch (P);
i.e., the pitch of the connection portions (14c), is 1.3 mm to 1.8
mm. Each of the wave crest portion (14a) and the wave trough
portion (14b) of the corrugate fin (14) includes a flat portion,
which is brazed in a surface contact condition to the flat tubes
(12), and round portions, which are located at corresponding
opposite ends of the flat portion and connected to the
corresponding connection portions (14c). Preferably, the round
portions have a radius (R) of curvature of 0.7 mm or less.
[0080] The louver (94) is not formed on the connection portions
(14c) of the corrugate fin (14) at positions corresponding to the
clearance between the adjacent front and rear flat tubes (12). A
vertically extending cutout (95) is formed at each of the wave
crest portions (14a) and the wave trough portions (14b) at
positions corresponding to the clearance between the adjacent front
and rear flat tubes (12). Opposite end portions of each cutout (95)
extend to the corresponding connection portions (14c) located at
vertically opposite ends of each of the wave crest portions (14a)
and the wave trough portions (14b). An inward projection (96)
having a shape resembling a lying letter V as viewed from the front
is formed integrally with respective end portions of the connection
portions (14c) located at vertically opposite ends of each of the
wave crest portions (14a) and the wave trough portions (14b),.the
respective end portions of the connection portions. (14c)
corresponding to the opposite ends of the cutout (95). Each of the
inward projections (96) is formed as follows: a pair of slits is
formed at each of the wave crest portions (14a) and the wave trough
portions (14b) in such a manner as to extend to the connection
portions (14c) located at the opposite ends of each of the wave
crest portions (14a) and the wave trough portions (14b); and a
portion sandwiched between the paired slits is bent inward. For
example, in manufacture of the corrugate fin (14) for use in an
evaporator, through utilization of a release plate used to release
the fin (14) from a fin-forming roll, the cutouts (95) and the
inward projections (96) can be formed simultaneously.
[0081] In manufacture of the evaporator (1), component members
thereof excluding the refrigerant inlet pipe (7) and the
refrigerant outlet pipe (8) are assembled and tacked together, and
the resultant assembly is subjected to batch brazing.
[0082] The evaporator (1), together with a compressor, a condenser,
and a pressure-reducing device, constitutes a refrigeration cycle
that uses a chlorofluorocarbon-based refrigerant. The refrigeration
cycle is installed in a vehicle, for example, an automobile, as a
car air conditioner.
[0083] In the evaporator (1) described above, as shown in FIG. 11,
two-phase refrigerant of vapor-liquid phase having passed through a
compressor, a condenser, and an expansion valve enters the
refrigerant inlet header section (5) of the refrigerant
inlet/outlet tank (2) from the refrigerant inlet pipe (7) through
the refrigerant inflow port (45) of the joint plate (21) and the
refrigerant inlet (37) of the right-hand cap (19). Then, the
refrigerant dividedly flows into the refrigerant channels (12a) of
all of the front flat tubes (12).
[0084] The refrigerant having entered the refrigerant channels
(12a) of all the front flat tubes (12) flows downward through the
refrigerant channels (12a) and enters the refrigerant inflow header
section (9) of the refrigerant turn tank (3). The refrigerant
having entered the refrigerant inflow header section (9) flows
leftward and then flows through the front through hole (83) of the
left-hand cap (52), the communication channel (91) in the outward
bulging portion (89) of the communication member (55), and the rear
through hole (84) of the left-hand cap (52), thereby turning its
flow direction and entering the lower space (11B) of the
refrigerant outflow header (11).
[0085] Even when the distribution of temperature (dryness of
refrigerant) of the refrigerant flowing through the front flat
tubes (12) becomes nonuniform due to a failure in the refrigerant
flowing from the refrigerant inlet header section (5) to the front
flat tubes (12) in a uniformly divided condition, the refrigerant
is mixed up when the refrigerant outflowing from the refrigerant
inflow header section (9) turns its flow direction and flows into
the lower space (11B) of the refrigerant outflow header section
(11), so that its temperature becomes uniform.
[0086] The refrigerant having entered the lower space (11B) of the
refrigerant outflow header section (11) flows rightward; enters the
upper space (11A) through the circular refrigerant passage holes
(71) of the flow-dividing control wall (67c); and dividedly flows
into the refrigerant channels (12a) of all of the rear flat tubes
(12).
[0087] The refrigerant having flown into the refrigerant channels
(12) of the flat tubes (12) flows upward, in opposition to the
previous flow direction; enters the lower space (6b) of the
refrigerant outlet header section (6); and enters the upper space
(6a) through the elongated refrigerant passage holes (31A) and
(31B) of the flow-dividing resistance plate (29). Since the
flow-dividing control walls (67c) and (29) impart resistance to the
flow of the refrigerant, the divided flow from the upper space
(11A) of the refrigerant outflow header section (11) to the rear
flat tubes (12) becomes uniform, and the divided flow from the
refrigerant inlet header section (5) to the front flat tubes (12)
becomes uniform to a greater extent. As a result, the refrigerant
flow rate becomes uniform among all the flat tubes (12), so that
the temperature distribution throughout the heat exchange core
section (4) becomes uniform.
[0088] Next, the refrigerant having entered the upper space (6a) of
the refrigerant outlet header section (6) flows out to the
refrigerant outlet pipe (8) through the refrigerant outlet (38) of
the right-hand cap (19) and the refrigerant outflow port (46) of
the joint plate (21). While flowing through the refrigerant
channels (12a) of the front flat tubes (12) and through the
refrigerant channels (12a) of the rear flat tubes (12), the
refrigerant is subjected to heat exchange with the air flowing
through the air-passing clearances in the direction of arrow X
shown in FIGS. 1 and 11 and flows out from the evaporator (1) in a
vapor phase.
[0089] During the heat exchange, condensed water is generated on
the surface of the corrugate fins (14). A portion of the condensed
water flows downward through openings between the louvers (94).
Also, the condensed water flows, by the effect of surface tension,
toward joint portions between the flat tubes (12) and the wave
crest portions (14a) and the wave trough portions (14b) of the
corrugate fins (14), and is collected on the joint portions. The
condensed water collected on the joint portions between the flat
tubes (12) and the wave crest portions (14a) and the wave trough
portions (14b) of the corrugate fins (14) flows frontward by the
effect of air passing through the air-passing clearances.
Accordingly, the condensed water remaining rearward of the cutouts
(95) flows downward, through the cutouts (95), along the clearances
between the front and rear flat tubes (12) of the refrigerant flow
members (13), and the condensed water remaining frontward of the
cutouts (95) flows downward along the front end faces of the front
flat tubes (12). When condensed water flows downward through the
cutouts (95), the inward projections (96) function to suppress
remaining of condensed water on the corrugate fins (14). In the
regions between the wave crest portions (14a) and the wave trough
portions (14b), condensed water flows downward through the openings
between the louvers (94).
[0090] Accordingly, drainage of condensed water is enhanced,
thereby preventing splashing of condensed water from end portions
located downward with respect to the air flow direction at the time
of an abrupt change in air flow rate; a drop in cooling performance
caused by an increase in air flow resistance which, in turn, is
caused by surface tension causing condensed water to block openings
between the louvers; and freezing of condensed water.
[0091] Condensed water drained from the corrugate fins (14) flows
down onto the refrigerant inflow header section (9) and the
refrigerant outflow header section (11) of the refrigerant turn
tank (3). A portion of the condensed water having flown down onto
the refrigerant turn tank (3) enters the drain gutter (20). When
the condensed water collected in the drain gutter (20) reaches a
certain amount, the condensed water flows down the connection
section (10) through the drain holes (93); flows along side edge
portions of the cutouts (74) of the auxiliary drain plate (54);
enters the auxiliary drain grooves (75); flows down in the
auxiliary drain grooves (75); and drops downward below the
refrigerant turn tank (3) from the bottom end openings of the
auxiliary drain grooves (75). The remaining condensed water enters
the drain grooves (63); flows in the drain grooves (63); and drops
downward below the refrigerant turn tank (3) from the bottom end
openings of the drain grooves (63); i.e., from the openings of the
stepped portions (69).
[0092] The above mechanism prevents freezing of condensed water
which could otherwise result from stagnation of condensed water in
a large amount in the regions between the bottom ends of the
corrugate fins (14) and the horizontal flat faces (9a) and (11a) of
the header sections (9) and (11) of the refrigerant turn tank (3).
As a result, a drop in performance of the evaporator (1) is
prevented.
Embodiment 2
[0093] The present embodiment is illustrated in FIG. 12.
[0094] In the corrugate fins (14) of the evaporator of Embodiment
2, in addition to the cutouts (95) and the inward projections (96)
provided at positions corresponding to clearances between the
adjacent front and rear flat tubes (12), the cutouts (95) and the
inward projections (96) are formed at front projecting portions
(140) of the corrugate fins (14) projecting frontward beyond the
front ends of the front flat tubes (12).
[0095] Other configurational features are similar to those of the
evaporator (1) of Embodiment 1.
[0096] In the evaporator of Embodiment 2, when condensed water is
generated on the surface of the corrugate fins (14), a portion of
the condensed water flows downward through openings between the
louvers (94). Also, the condensed water flows, by the effect of
surface tension, toward joint portions between the flat tubes (12)
and the wave crest portions (14a) and the wave trough portions
(14b) of the corrugate fins (14), and is collected on the joint
portions. The condensed water collected on the joint portions
between the flat tubes (12) and the wave crest portions (14a) and
the wave trough portions (14b) of the corrugate fins (14) flows
frontward by the effect of air passing through the air-passing
clearances. Accordingly, the condensed water remaining rearward of
the cutouts (95) located at the position corresponding to the
clearance between the adjacent front and rear flat tubes (12) flows
downward, through the cutouts (95), along the clearances between
the front and rear flat tubes (12) of the refrigerant flow members
(13). The condensed water remaining rearward of the cutouts (95) of
the front projection portions (140) passes through the cutouts (95)
of the front projecting portions (140) and flows while being
attracted, by the effect of surface tension, toward internal corner
portions each defined by the front end surface of the front flat
tube (12) and the front projecting portion (140) of the corrugate
fin (14). Subsequently, the condensed water flows downward along
the internal corner portions.
Embodiment 3
[0097] The present embodiment is illustrated in FIG. 13.
[0098] In the corrugate fins (14) of the evaporator of Embodiment
3, in place to the cutouts (95) and the inward projections (96)
provided at positions corresponding to clearances between the
adjacent front and rear flat tubes (12), the cutouts (95) and the
inward projections (96) are formed at the front projecting portions
(140) of the corrugate fins (14) projecting frontward beyond the
front ends of the front flat tubes (12).
[0099] Other configurational features are similar to those of the
evaporator (1) of Embodiment 1.
[0100] In the evaporator of Embodiment 3, when condensed water is
generated on the surface of the corrugate fins (14), a portion of
the condensed water flows downward through openings between the
louvers (94). Also, the condensed water flows, by the effect of
surface tension, toward joint portions between the flat tubes (12)
and the wave crest portions (14a) and the wave trough portions
(14b) of the corrugate fins (14), and is collected on the joint
portions. The condensed water collected on the joint portions
between the flat tubes (12) and the wave crest portions (14a) and
the wave trough portions (14b) of the corrugate fins (14) flows
frontward by the effect of air passing through the air-passing
clearances. Then, the condensed water passes through the cutouts
(95) and flows while being attracted, by the effect of surface
tension, toward internal corner portions each defined by the front
end surface of the front flat tube (12) and the front projecting
portion (140) of the corrugate fin (14).. Subsequently, the
condensed water flows downward along the internal corner
portions.
Embodiment 4
[0101] The present embodiment is illustrated in FIGS. 14 to 16.
[0102] In the present embodiment, the evaporator is configured such
that a plurality of refrigerant flow members (100) each having a
vertically elongated rectangular shape are arranged in a laminated
condition in the left-right direction and joined together while
their widths extend in the front-rear direction (air flow
direction).
[0103] Each of the refrigerant flow members (100) includes two
vertically extending rectangular aluminum plates (101) whose
peripheral edge portions are brazed together. Each of the aluminum
plates (101) is formed from an aluminum brazing sheet having a
brazing material layer on each of opposite sides thereof. Two
(front and rear) vertically extending, bulging refrigerant flow
tube portions (102) and (103), and bulging header formation
portions (104) and (105) are provided between the two aluminum
plates (101), which partially constitute the refrigerant flow
member (100). The bulging header formation portions (104) and (105)
are connected to corresponding upper and lower end portions of the
refrigerant flow tube portions (102) and (103). An aluminum
corrugate inner fin (106) is disposed in each of the refrigerant
flow members (100) in such a manner as to extend across the front
and rear refrigerant flow tube portions (102) and (103). The
corrugate inner fin (106) is brazed to the aluminum plates (101).
Notably, two aluminum corrugate inner fins may be disposed
separately in the corresponding refrigerant flow tube portions
(102) and (103). A drain groove (107) extending vertically and
adapted to drain condensed water is formed in a portion of the
outer surface of the refrigerant flow member (100), the portion
being sandwiched between the front and rear refrigerant flow tube
portions (102) and (103).
[0104] The right-hand aluminum plate (101) used to partially
constitute the refrigerant flow member (100) includes two (front
and rear) vertically extending, rightward bulging,
tube-portion-forming bulging portions (108) and four rightward
bulging, header-forming bulging portions (109) connected to the
corresponding upper and lower ends of the tube-portion-forming
bulging portions (108) and having a bulging height greater than
that of the tube-portion-forming bulging portions (108). A portion
of the right-hand side surface of the right-hand aluminum plate
(101) sandwiched between the two tube-portion-forming bulging
portions (108) serves as the drain groove (107). The top wall of
each of the header-forming bulging portions (109) is punched out to
thereby form a through-hole (111). The left-hand aluminum plate
(101) used to partially constitute the refrigerant flow member
(100) is a mirror image of the right-hand aluminum plate (101). The
header formation portions (104) and (105) of the two refrigerant
flow members (100) are respectively joined together in a
communicating condition such that slightly size-reduced end
portions of the header-forming bulging portions (109) of one
refrigerant flow member (100) are press-fitted into and brazed to
the corresponding through-holes (111) of the header-forming bulging
portions (109) of the other refrigerant flow member (100).
[0105] In the refrigerant flow members (100), the height of the
header formation portions (104) and (105) in the left-right
direction is greater than that of the refrigerant flow tube
portions (102) and (103). Clearances between the refrigerant flow
tube portions (102) and clearances between the refrigerant flow
tube portions (103) of the adjacent refrigerant flow members (100)
serve as air-passing clearances. The corrugate fins (14) similar to
those of Embodiment 1 are disposed in the corresponding air-passing
clearances in such a manner as to be shared between the refrigerant
flow tube portions (102) and (103). The wave crest portions (14a)
and the wave trough portions (14b) of each corrugate fin (14) are
brazed to the outer surfaces of the refrigerant flow tube portions
(102) and (103). The cutouts (95) of the corrugate fins (14) are
located at positions corresponding to the drain grooves (107) of
the refrigerant flow members (100).
[0106] Preferably, the thickness of the refrigerant flow tube
portions (102) and (103) of the refrigerant flow member (100) as
measured in the left-right direction; i.e., a tube height (h1), is
0.75 mm to 1.5 mm (see FIG. 15); the width of the refrigerant flow
member (100) as measured in the front-rear direction is 12 mm to 18
mm; and the wall thickness of the aluminum plate (101) is 0.175 mm
to 0.275 mm.
[0107] In manufacture of the evaporator, component members thereof
are assembled and tacked together, and the resultant assembly is
subjected to batch brazing.
[0108] In the evaporator of the present embodiment, the flow of
refrigerant is optimized by means of blocking communication via the
through-hole (111) between two predetermined adjacent refrigerant
flow members (100).
[0109] In the evaporator of the present embodiment, when condensed
water is generated on the surface of the corrugate fins (14), the
condensed water is drained as in the case of the evaporator of
Embodiment 1. However, the condensed water remaining rearward of
the cutouts (95) enters the drain grooves (107) via the cutouts
(95) and flows downward in the drain grooves (107), thereby
enhancing drainage of condensed water.
[0110] In the evaporator of Embodiment 4, in addition to or in
place of the cutouts (95) and the inward projections (96) provided
in a central region in the front-rear direction, the cutouts (95)
and the inward projections (96) may be formed at front end portions
of the corrugate fins (14).
[0111] FIG. 17 shows a modified embodiment of the refrigerant flow
member used in the evaporator of Embodiment 4. In FIG. 17, a
hairpin refrigerant flow tube portion (116) and two bulging header
formation portions (119) and (120) are provided between the two
aluminum plates (130), which partially constitute a refrigerant
flow member (115). The hairpin refrigerant flow tube portion (116)
includes two (front and rear) vertically extending, bulging linear
portions (117) and a bulging communication portion (118) for
establishing communication between the two bulging linear portions
(117) at upper end portions thereof. The two bulging header
formation portions (119) and (120) are connected to corresponding
lower end portions of the two bulging linear portions (117) of the
refrigerant flow tube portion (116). Each of the two aluminum
plates (130) is formed from an aluminum brazing sheet having a
brazing material layer on each of opposite sides thereof. An
aluminum corrugate inner fin (106) is disposed in each of the
refrigerant flow members (115) in such a manner as to extend across
the two bulging linear portions (117) of the refrigerant flow tube
portion (116). The corrugate inner fin (106) is brazed to the two
aluminum plates (130). A drain groove (121) extending vertically
and adapted to drain condensed water is formed in a portion of the
outer surface of the refrigerant flow member (115), the portion
being sandwiched between the front and rear bulging linear portions
(117) of the refrigerant flow tube portion (116).
[0112] The right-hand aluminum plate (130) used to partially
constitute the refrigerant flow member (115) includes two (front
and rear) vertically extending, rightward bulging,
linear-portion-forming bulging portions (122); a rightward bulging,
communication-portion-forming bulging portion (123) adapted to
establish communication between upper end portions of the
linear-portion-forming bulging portions (122) and having a bulging
height equal to that of the linear-portion-forming bulging portions
(122); and two (front and rear) rightward bulging, header-forming
bulging portions (124) connected to the corresponding lower ends of
the linear-portion-forming bulging portions (122) and having a
bulging height greater than that of the linear-portion-forming and
communication-portion-forming bulging portions (122) and (123). A
plurality of inward projecting arcuate ribs (125) are formed at
certain intervals on the top wall of the
communication-portion-forming bulging portion (123) by means of
concaving the corresponding portions of the top wall. The ribs
(125) have a bulging height equal to that of the
linear-portion-forming bulging portions (122). The top wall of each
of the header-forming bulging portions (124) is punched out to
thereby form a through-hole (126). The left-hand aluminum plate
(130) used to partially constitute the refrigerant flow member
(115) is a mirror image of the right-hand aluminum plate (130).
[0113] In the refrigerant flow members (115), the height of the
header formation portions (119) and (120) in the left-right
direction is greater than that of the refrigerant flow tube
portions (116). Clearances between the refrigerant flow tube
portions (116) of the adjacent refrigerant flow members (115) serve
as air-passing clearances. The corrugate fins (14) similar to those
of Embodiment 1 are disposed in the corresponding air-passing
clearances in such a manner as to be shared between the bulging
linear portions (117). The wave crest portions (14a) and the wave
trough portions (14b) of each corrugate fin (14) are brazed to the
outer surfaces of the bulging linear portions (117). The cutouts
(95) of the corrugate fin (14) are located at positions
corresponding to the drain grooves (121) of the refrigerant flow
members (115).
[0114] In the evaporator using the refrigerant flow members (115)
shown in FIG. 17, the flow of refrigerant is optimized by means of
blocking communication via the through-hole (126) between two
predetermined adjacent refrigerant flow members (115).
[0115] The above four embodiments are described while mentioning
the evaporator applied to an evaporator of a car air conditioner
that uses a chlorofluorocarbon-based refrigerant. However, the
present invention is not limited thereto. The evaporator of the
present invention may be used as an evaporator of a car air
conditioner used in a vehicle, for example, an automobile, the car
air conditioner including a compressor, a gas cooler, an
evaporator, a pressure-reducing device, and an intermediate heat
exchanger for performing heat exchange between a refrigerant from
the gas cooler and a refrigerant from the evaporator, and using a
supercritical refrigerant such as a CO.sub.2 refrigerant.
[0116] Next will be described Experimental Examples regarding tests
that were conducted for evaluating drainage of condensed water of
corrugate fins.
EXPERIMENTAL EXAMPLE 1
[0117] An evaporator having the configuration of Embodiment 1 and
in a condition before connection of a refrigerant inlet pipe and a
-refrigerant outlet pipe thereto was prepared. The tube height (h)
of the flat tube was 1.4 mm; the fin height (H) of the corrugate
fin (14) was am; the fin pitch (P) was 1.5 mm; and the radius (R)
of curvature of round portions of the wave crest portion (14a) and
the wave trough portion (14b) connected to the connection portion
(14c) was 0.6 mm. The refrigerant inflow port and the refrigerant
outflow port of the joint plate were closed. The evaporator was
immersed in water contained in a water tank so as to remove
remaining air from spaces between the flat tubes and spaces around
the corrugate fins and then allowed to stand for 30 minutes. Then,
the evaporator was lifted out of water in a vertical condition and
measured for weight for 1,800 seconds so as to evaluate drainage
performance.
EXPERIMENTAL EXAMPLE 2
[0118] An evaporator prepared had a configuration similar to that
of Experimental Example 1 except that the corrugate fins had
cutouts formed therein, but had-no inward projections formed
therein. The evaporator was evaluated for drainage performance in a
manner similar to that of Experimental Example 1.
COMPARATIVE EXPERIMENTAL EXAMPLE 1
[0119] An evaporator prepared had a configuration similar to that
of Experimental Example 1 except that the corrugate fins had no
cutouts and inward projections formed therein. The evaporator was
evaluated for drainage performance in a manner similar to that of
Experimental Example 1.
[0120] FIG. 18 shows the test results of Experimental Examples 1
and 2 and Comparative Experimental Example 1. In FIG. 18, the term
"water-retained weight" represents the percentage of evaporator
weight to an evaporator weight that is measured immediately after
the evaporator is lifted out of water in a vertical condition and
taken as 100%. A reduction in water-retained weight means an
increase in the amount of drained water, indicating an enhancement
in drainage performance.
[0121] The test results shown in FIG. 18 reveal that, even when
only cutouts are formed in the corrugate fins, drainage performance
is enhanced in contrast to the case where no cutouts and inward
projections are formed. The test results also reveal that, when
cutouts and inward projections are formed in the corrugate fins,
drainage performance is further enhanced as compared with the case
where only cutouts are formed in the corrugate fins.
INDUSTRIAL APPLICABILITY
[0122] The evaporator of the present invention is favorably used as
an evaporator for use in a car air conditioner, which is a
refrigeration cycle of, for example, an automobile.
* * * * *