TECHNICAL FIELD
-
The present invention relates to a laminated heat exchanger
constituted by laminating numerous tube elements, which is utilized in a
freezing cycle or the like of an air-conditioning system for vehicles, and is
ideal in application in a laminated heat exchanger constituted by
laminating tube elements via fins to allow a heat exchanging medium to
pass through a plurality of times.
BACKGROUND ART
-
Heat exchangers in the known art include the heat exchanger
illustrated in FIGS. 1 and 2 and the single-side tank type heat exchanger
illustrated in FIGS. 15 and 16.
-
In the heat exchanger shown in FIGS. 1 and 2, a core main body is
formed by laminating tube elements via fins 2, a pair of tank portions 12
provided on one side of each tube elements are made to communicate with
each other through a turnaround passage portion 13, a heat exchanging
medium path with a plurality of passes is formed at the core main body by
communicating the tank portions 12 of adjacent tube elements as
appropriate, a heat exchanging medium intake portion 4 and a heat
exchanging medium outlet portion 5 are provided at one end of the core
main body along the laminating direction, the intake portion 4 is made to
communicate with a tank block 21 located on the upstream-most side via a
communicating pipe 30 and the outlet portion 5 is made to directly
communicate with a tank block 22 on the downstream-most side.
-
The heat exchanger shown in FIGS. 15 and 16, in which a core
main body is formed by laminating tube elements via fins 2, a pair of tank
portions 12 provided on one side (the lower side) of each tube element are
made to communicate with each other through a turnaround passage
portion 13 and a heat exchanging medium path with a plurality of passes is
formed at the core main body by communicating the tank portions 12 of
adjacent tube elements as appropriate, differs from the heat exchanger
described above in that a heat exchanging medium intake portion 4 and a
heat exchanging outlet portion 5 are provided at the front of the core main
body.
-
In the heat exchangers described above, the heat exchanging
medium having flowed in through the intake portion 4 enters the tank
block 21 on the upstream-most side in the heat exchanging medium path
either via the communicating pipe 30 or directly, reaches the tank block 22
on the downstream-most side in the heat exchanging medium path after
making a plurality of passes and flows out through the outlet portion 5
communicating with the tank block 22. In this context, the flow of the
heat exchanging medium along one direction, i.e., the heat exchanging
medium flowing from the tank portions into the turnaround passage
portions or flowing from the turnaround passage portions into the tank
portions, is counted as one pass and, for instance, a heat exchanger in
which the heat exchanging medium passes through the turnaround passage
portions 13 twice and a heat exchanger in which the heat exchanging
medium passes through the turnaround passage portions three times while
it travels from the tank block on the upstream-most side to the tank block
on the downstream-most side in the heat exchanging medium path are
respectively referred to as a four-pass a heat exchanger and a six-pass heat
exchanger.
-
However, in the four-pass heat exchanger described above, for
instance, in which the heat exchanging medium flows along the laminating
direction via the tank portions in communication with each other while
moving from the second pass into the third pass, as illustrated in FIG.
54(a), the heat exchanging medium concentrates further into the third pass
due to the inertial force of the heat exchanging medium and, as a result, the
flow rate of the heat exchanging medium becomes reduced at the tube
elements near a partitioning portion 18 in the third and the fourth passes.
Thus, the temperature of the air having passed through the space between
tube elements near the partitioning portion becomes higher than the
temperature at other positions, as indicated by the dotted lines in FIG. 55,
to result in a reduction in the heat exchanging efficiency when a coolant is
used as the heat exchanging medium.
-
It is to be noted that the term "tube number" (TUBE No.) in the
figure refers to the position of a given tube element counted from the right
side in FIG. 1. In addition, the passing air temperature (AIR TEMP.)
refers to the temperature of the air having passed through the space
between the tube elements and having undergone heat exchange with the
fins, which is measured at a position 1 ~ 2 cm away from the end surface
of the core main body on the downstream side.
-
The problem described above also occurs in the six-pass heat
exchanger and the uneven flow of the heat exchanging medium occurring
as shown in FIG. 54(b) results in a large deviation in the temperature of the
passing air in the area where the heat exchanging medium switches from
the third pass to the fourth pass and where it switches from the fifth pass to
the sixth pass at positions close to partitioning portions 18, relative to the
passing air temperature in other areas. In addition, in the six-pass heat
exchanger, too, the heat exchanging medium concentrates unevenly when
it switches from an even-numbered pass to an odd-numbered pass and, as a
result, the flow rate of the heat exchanging medium becomes reduced over
the areas close to the partitioning portions 18.
-
As a means for eliminating such uneven distribution of the heat
exchanging medium, the applicant of the present invention has previously
proposed a structure in which the heat exchanging medium is allowed to
flow in sufficient quantity to tube elements near partitioning portions by
providing a constriction which constricts the flow passage cross section
where an even-numbered pass shifts to an odd-numbered pass (see
Japanese Unexamined Patent Publication No. H 8-285407). However, this
structure proposed previously, which prevents uneven distribution of the
heat exchanging medium by constricting the flow passage cross section to
lower the speed of the flow or by causing the heat exchanging medium to
flow in a complex pattern, requires careful design, in order to ensure that
the passage resistance does not become excessive.
-
In addition, there is a structure in the known art achieved by
providing a rotational flow generating plate at the flow path between tanks
through which the heat exchanging medium is delivered from the upstream
side heat exchanging block to the downstream side heat exchanging block
to cause the heat exchanging medium to rotate around the center line of the
flow path as disclosed in Japanese Unexamined Patent Publication No. H
8-178581, proposed as a measure for eliminating uneven flow of the heat
exchanging medium.
-
However, while this structure, which achieves a consistent gas-liquid
mixed state by agitating the heat exchanging medium with the
rotational flow generating plate to prevent the heat exchanging medium
from entering a gas-liquid two phase state in the flow path between the
tanks to eliminate an uneven distribution of the heat exchanging medium
and achieves consistent heat exchanging performance at all the tanks
regardless of their locations, i.e., whether they are provided at upper
positions or lower positions, is effective in that coolant in a gas-liquid
mixed state is guided into the individual tube elements, it does not prevent
the heat exchanging medium from becoming concentrated further into the
third pass due to the inertial force of the heat exchanging medium itself as
illustrated in FIG. 54(a) in the case of a four-pass heat exchanger, for
instance, since it simply mixes gas and liquid by rotating the heat
exchanging medium. Rather, if the rotating heat exchanging medium
advances through the flow path between the tanks, it becomes a concern
that the heat exchanging medium may concentrate in even greater quantity
further into the third pass since it is more difficult for the heat exchanging
medium to flow into the individual passage portions due to the inertia of
the rotation and to change its direction while it advances along the center
line of the flow path between the tanks and, as a result, the problem of the
reduction in the flow rate of the heat exchanging medium at tube elements
close to the partitioning portion 18 is expected to become even more
pronounced at the third and fourth passes.
-
Accordingly, an object of the present invention is to provide a
laminated heat exchanger capable of achieving an improvement in the heat
exchanging efficiency by minimizing uneven flow of the heat exchanging
medium and achieving an almost completely uniform distribution of the
heat exchanging medium to all the tube elements along the laminating
direction. Another object of the present invention is to provide a laminated
heat exchanger capable of reducing inconsistent distribution of the heat
exchanging medium by dispersing the heat exchanging medium more
aggressively while minimizing the passage resistance.
DISCLOSURE OF THE INVENTION
-
Accordingly, the laminated heat exchanger according to the present
invention, assuming a structure in which tube elements each having a
plurality of tank portions and a passage portion communicating with the
tank portions are laminated over numerous levels by sequentially abutting
the tank portions, all the tank portions or a plurality of the tank portions
thus abutted are made communicate with each other via communicating
holes formed at the individual tank portions, a pass through which a heat
exchanging medium is allowed to flow from a plurality of contiguous tank
portions into passage portions communicating with the tank portions is
provided and the heat exchanging medium is caused to travel along the
laminating direction via the communicating holes over an area where
another pass shifts to this pass, a guide plate that causes the flow of the
heat exchanging medium traveling along the laminating direction to
advance straight toward the communicating point at which the tank
portions to which the heat exchanging medium is traveling and the passage
portions communicating with the tank portion communicate with each
other is provided at, at least, one position over the shifting area where the
other pass shifts into the pass or in the vicinity of the shifting area.
-
In this structure, in which the direction in which the heat
exchanging medium traveling along the laminating direction via the
communicating holes is actively changed by the guide plate to advance
straight toward the communicating point at which the tank portions to
which the heat exchanging medium is moving a and of the passage
portions communicating with the tank portions, the heat exchanging
medium is distributed in all the passage portions so as to avoid
concentration of the heat exchanging medium at the area near the ends
along the laminating direction.
-
In particular, when adopting the present invention in the single-side
tank type laminated heat exchanger, i.e., in a laminated heat exchanger
constituted by laminating tube elements each having a pair of tank portions
provided on one side and a turnaround passage portion communicating
between the pair of tank portions over numerous levels via fins,
sequentially abutting the tank portions of adjacent tube elements,
communicating the abutted tank portions via communicating holes in units
of individual blocks, setting as appropriate the number of tank portions
constituting each block to provide an odd-numbered pass through which
the heat exchanging medium flows from the tank portions of the tube
elements into the passage portions and an even-numbered pass in which
the heat exchanging medium flows from the passage portions of the tube
elements into the tank portions and allowing the heat exchanging medium
to move along the laminating direction via the communicating holes over
the shifting area in which the even-numbered pass shifts to the odd-numbered
pass, a guide plate that causes the flow of the heat exchanging
medium traveling along the laminating direction to advance straight
toward the communicating points at which the tank portions in the odd-numbered
pass communicate with the corresponding passage portions
should be provided at, at least, one location over the shifting area or in the
vicinity of the shifting area.
-
As a result, since the heat exchanging medium having flowed into
the block on the upstream-most side flows out through the block on the
downstream-most side after traveling over a plurality of passes and the
guide plate is provided at the shifting area where the even-numbered pass
shifts into the odd-numbered pass in this structure, the direction in which
the heat exchanging medium advances straight is actively changed by the
guide plate so that the heat exchanging medium advances straight to be
almost completely evenly distributed into the individual passage portions
constituting the odd-numbered pass. Thus, the heat exchanging medium is
supplied into all the tube elements in sufficient quantity and, consequently,
the passing air temperature does not greatly deviate at different positions
as indicated by the solid lines in FIG. 55, thereby achieving the objects
described above.
-
In this single-side tank type laminated heat exchanger, a heat
exchanging medium intake portion and a heat exchanging medium outlet
portion may be provided at one end along the direction in which the tube
elements are laminated with the intake portion made to communicate with
the block on the upstream-most side and the outlet portion made to
communicate with the block on the downstream-most side or an intake
portion and an outlet portion may be respectively provided at the block on
the upstream-most side and the block on the downstream-most side, both
at a right angle to the laminating direction.
-
In addition, in a heat exchanger having tube elements each
constituted by bonding two formed plates and having the boundary of a
pass in which the heat exchanging medium flows from the tank portions to
the corresponding passage portions defined by providing at a specific
position a formed plate having a partitioning portion for disallowing
communication between tank portions along the laminating direction, the
guide plate to be provided at the shifting area may be either located at a
formed plate adjacent to the formed plate having the partitioning portion or
at the formed plate having the partitioning portion itself. In addition, the
partitioning portion and the guide plate may be offset from each other to
the front and to the rear along the laminating direction within a range over
which an improvement is achieved in the flow rate of the heat exchanging
medium flowing near the partitioning portion, and the guide plate provided
in the vicinity of the shifting area may adopt such a structure.
-
If the angle of inclination of the guide plate relative to the
laminating direction is too small, a change that is effective enough to
eliminate the unbalanced flow of the heat exchanging medium cannot be
achieved, whereas if the angle of inclination is too large, the passage
resistance increases to lower the flow rate of the heat exchanging medium
and a reduction in the heat exchanging efficiency occurs. For this reason,
with the length of the guide plate over the inclined portion set within a
range of 1 ~ 15mm in consideration of the effectiveness for changing the
flow direction and due to the manufacturing restrictions, it is desirable to
select the angle of inclination within a range of 5 ~ 65°. In addition, while
the guide plate may be constituted as a member which is independent of
the tank portions, it may be formed as an integrated part of the member
constituting the tank portions in order to achieve a reduction in the number
of manufacturing steps and to facilitate the production process.
-
In specific application modes of the guide plate practical use, the
guide plate may be constituted of a bridge provided across the
communicating hole and an inclined portion which is bent from an end
edge of the bridge and extends at an angle, the guide plate may be
constituted of a portion bent from the circumferential edge of the
communicating hole and extending at an angle or it may be constituted by
twisting a portion extending across the communicating hole so as to cause
the entire portion to become inclined. Furthermore, numerous guide plates
may be formed at the shifting area or in its vicinity in order to ensure that
the direction along which the heat exchanging medium advances straight is
changed with a high degree of reliability.
-
In the laminated heat exchanger adopting the structure described
above having a pass in which the heat exchanging medium is allowed to
flow from a plurality of contiguous tank portions into the passage portions
communicating with the tank portions and a guide plate that changes the
direction of the flow of the heat exchanging medium traveling along the
laminating direction toward the communicating points at which the tank
portions to which the heat exchanging medium is moving and the passage
portions communicating with the tank portions communicate with each
other provided at, at least, one location at the area over which the heat
exchanging medium moves into the pass, e.g., at the shifting area over
which the second pass shifts into the third pass, or in the vicinity of the
shifting area, the guide plate, which is provided at a communicating hole
formed at a distended portion for tank formation at a formed plate
constituting a tube element, is manufactured by leaving on the cut section
that is created when punching the communicating hole and is disposed of
as waste in the prior art. However, since the coolant flows at a high speed
and in a great quantity through the communicating holes in the shifting
area, force is applied to the guide portion to cause vibration and such
vibration may be communicated to the outside as noise via the tube
elements or it may deform the guide portion to offset the guiding direction.
-
Accordingly, the strength of the guide plates used to reduce the
unbalanced flow of heat exchanging medium needs to be improved and
vibration at the guide plate must be prevented.
-
Thus, as a means for eliminating these problems, a guide plate
provided at a plurality of the tube elements in a laminated heat exchanger
constituted by laminating tube elements each having a plurality of tank
portions and a passage portion communicating between the tank portions
over numerous levels, which is located at a communicating hole formed at
a distended portion for tank formation at a formed plate constituting a tube
element, should be formed in a curved shape along the lateral direction of
the formed plate.
-
By forming the guide plate in such a curved shape, its strength is
improved to achieve greater durability. In addition, the curved shape of
the guide plate enables it to change the direction of the flow of the heat
exchanging medium effectively, and also achieves improvements in the
ease of forming and dimensional accuracy.
-
The guide portion may be formed in a curved shape by bending it at
a specific curvature, a curved shape may be formed at areas close to the
two ends along the lateral direction of the guide portion or a curved surface
may be formed as a reservoir. Furthermore, a straight portion may be
formed at the two ends along the lateral direction of the guide plate formed
in a curved shape, and these straight portions may be formed at the bridge
provided over the communicating hole.
-
Alternatively, in the laminated heat exchanger according to the
present invention constituted by laminating tube elements each having a
plurality of tank portions and a passage portion communicating between
the tank portions over numerous levels, a guide plate is provided at some
of the tube elements, which is located at a communicating hole formed in a
distended portion for tank formation at a formed plate constituting a tube
element and a bead may be provided at, at least, one location at the guide
plate along the direction in which it projects out from the formed plate.
-
The presence of the bead at the guide plate improves its strength to
achieve greater durability. In addition, improvements in the ease of
formation and the dimensional accuracy are achieved.
-
The length of the bead at the guide plate may be set equal to the
length over which the guide portion projects out or shorter than the length
over which the guide portion projects out. The bead may be formed in a
diamond shape as well.
-
Alternatively, in the laminated heat exchanger according to the
present invention constituted by laminating tube elements each having a
plurality of tank portions and a passage portion communicating between
the tank portions over numerous levels, a guide plate is provided at some
of the tube elements, which is located at a passage formed in a distended
portion for tank formation at a formed plate constituting a tube element
and the two shoulders of the guide plate at the front end along the direction
in which the guide plate projects out from the formed plate may be
rounded.
-
By forming the two shoulders of the guide portion in a rounded
shape, any angularity is eliminated and, as a result, vibration is prevented
from occurring at the guide portion when the heat exchanging medium
flows to suppress the occurrence of the vibration noise. In addition,
improvements in the ease of forming and the dimensional accuracy are
achieved.
-
Alternatively, in the laminated heat exchanger according to the
present invention constituted by laminating tube elements each having a
plurality of tank portions and a passage portion communicating between
the tank portions over numerous levels, a guide plate is provided at some
of the tube elements, which is located at a communicating hole formed in a
distended portion for tank formation at a formed plate constituting a tube
element and the guide plate may be formed in a curved shape along the
lateral direction of the formed plate with a bead provided at, at least, one
location along the direction in which the guide plate projects out.
-
In this example, the strength of the guide plate is improved by
forming it in a curved shape and providing the bead at the guide plate.
-
Alternatively, in the laminated heat exchangers according to the
present invention constituted by laminating tube elements each having a
plurality of tank portions and a passage portion communicating between
the tank portions over numerous levels, a guide plate is provided at some
of the tube elements, which is located at a passage formed in a distended
portion for tank formation at a formed plate constituting a tube element
and the guide plate may be formed in a curved shape along the lateral
direction of the formed plate with the two shoulders of the guide plate at
the front end along the direction in which the guide plate projects out from
the formed plate formed in a rounded shape. In this example, an
improvement in the strength of the guide plate is achieved and, at the same
time, vibration is prevented by forming the guide plate in a curved shape
and rounding the two shoulders.
-
Alternatively, in the laminated heat exchanger according to the
present invention constituted by laminating tube elements each having a
plurality of tank portions and a passage portion communicating between
the tank portions over numerous levels, a guide plate is provided at some
of the tube elements, which is located at a passage formed in a distended
portion for tank formation at a formed plate constituting a tube element
and a bead may be provided at, at least, one position at the guide plate
along the direction in which the guide plate projects out from the formed
plate with the two shoulders of the guide plate at the front end along the
direction in which it projects out from the formed plate formed in a
rounded shape.
-
In this example, an improvement in the strength is achieved and the
occurrence of the vibration is prevented by forming the bead at the guide
plate and rounding the two shoulders.
-
Alternatively, in the laminated heat exchanger according to the
present invention constituted by laminating tube elements each having a
plurality of tank portions and a passage portion communicating between
the tank portions over numerous levels, a guide plate is provided at some
of the tube elements, which is located at a passage formed in a distended
portion for tank formation at a formed plate constituting a tube element,
the guide plate may be formed in a curved shape along the lateral direction
of the formed plate and a bead may be provided at, at least, one position at
the guide plate along the direction in which the guide plate projects out
from the formed plate with the two shoulders of the guide plate at the front
end along the direction in which it projects out from the formed plate
formed in a rounded shape.
-
In this example, an improvement in the strength is achieved and the
occurrence of vibration is prevented by forming the bead at the guide plate,
forming the guide plate in a curved shape and rounding the two shoulders
of the guide plate.
BRIEF DESCRIPTION OF THE DRAWINGS
-
- FIG. 1 illustrates an end surface of the laminated heat exchangers in
a first embodiment of the present invention, which is set perpendicular to
the direction of air flow;
- FIG. 2(a) illustrates a side surface of the laminated heat exchanger
shown in FIG. 1, where the intake and outlet portions are provided, and
FIG. 2(b) illustrates the bottom surface of the laminated heat exchanger in
FIG. 1;
- FIG. 3 illustrates formed plates constituting the tube elements in the
laminated heat exchanger, with FIG. 3(a) showing a regular formed plate
6a, FIG. 3(b) showing a formed plate 6d having a partitioning portion and
FIG. 3(c) showing a formed plate 6e having a guide plate;
- FIG. 4 presents an example in which a guide plate is formed at an
approximate center of the communicating hole, with FIG. 4(a) presenting
an enlarged front view of a portion of a formed plate having a guide plate
formed therein and FIG. 4(b) showing the tube element having the guide
plate and tube elements laminated on the downstream side relative to the
tube element with the guide plate and illustrating the shape of the guide
plate and the flow of the heat exchanging medium;
- FIG. 5 is an enlargement of the tank portion of the tube element
having the guide plate;
- FIG. 6 is a front view of a formed plate in a structural example
achieved by forming a guide plate at a position lower than the center of the
communicating hole;
- FIG. 7 is a front view of a formed plate in a structural example
achieved by forming a guide plate at a position higher than the center of a
communicating hole;
- FIG. 8 is a front view of a formed plate in a structural example
achieved by forming a guide plate as an integrated part of the distended
portion for tank formation at the lower end of the distended portion for
tank formation;
- FIG. 9 presents another example in which a guide plate is formed
at an approximate center of the communicating hole, with FIG. 9(a)
presenting an enlarged front view of the portion of a formed plate having a
guide plate formed therein and FIG. 9(b) showing the tube element having
the guide plate and tube elements laminated on the downstream side
relative to the tube element with the guide plate and illustrating the shape
of the guide plate and the flow of the heat exchanging medium;
- FIG. 10 presents a structural example in which a guide plate is bent
toward the outside of the tank portion where the guide plate is located;
- FIG. 11 presents a structural example achieved by gradually
increasing the angle of inclination of the guide plate;
- FIG. 12 presents a structural example achieved by forming a
plurality of guide plates over the upper half of the communication hole,
with FIG. 12(a) presenting an enlarged front view of a portion of a formed
plate having guide plates formed therein and FIG. 12(b) showing the tube
elements having the guide plates and tube elements. laminated the
downstream side of the tube element with the guide plates and illustrating
the shape of the guide plates and the flow of the heat exchanging medium;
- FIG. 13 presents a structural example achieved by forming a
plurality of guide plates over the entire communication hole, with FIG.
13(a) presenting an enlarged front view of a portion of a formed plate
having guide plates formed therein and FIG. 13(b) showing the tube
elements having the guide plates and tube elements laminated on the
downstream side relative to the tube element with the guide plates and
illustrating the shape of the guide plates and the flow of the heat
exchanging medium;
- FIG. 14 presents a structural example achieved by forming the
guide plates horizontally over the lower half of the communication hole in
the structure shown in FIG. 13, with FIG. 14(a) presenting an enlarged
front view of the portion of a formed plate having guide plates formed
therein and FIG. 14(b) showing the tube elements having the guide plates
and tube elements laminated on the downstream side relative to the tube
element with the guide plates and illustrating the shape of the guide plates
and the flow of the heat exchanging medium;
- FIG. 15 illustrates an end surface of the laminated heat exchanger
in a second embodiment of the present invention, which is set
perpendicular to the direction of air flow;
- FIG. 16(a) illustrates a side surface of the laminated heat exchanger
shown in FIG. 15 and FIG. 16(b) illustrates the bottom surface of the
laminated heat exchanger in FIG. 15;
- FIG. 17 is an enlarged front view of a portion of a formed plate in
which a guide plate and a partitioning portion are formed as an integrated
part;
- FIG. 18 illustrates a structure achieved by providing a guide plate at
two locations in adjacent tube elements, with the guide plates placed in
contact with each other so as to allow their inclined portions to extend
continuously;
- FIG. 19 presents an example in which a guide plate is provided at
two locations, in adjacent tube elements, with the guide plates formed over
a distance from each other;
- FIGS. 20 ~ 52 present individual embodiments of the guide plate
19 according to the present invention, with FIG. 20 presenting an enlarged
front view of a portion of a formed plate having a guide plate formed in a
curved shape achieving a specific curvature;
- FIG. 21 is a lateral cross section of the guide plate in FIG. 20;
- FIG. 22 is a longitudinal cross section of the guide plate in FIG. 20;
- FIG. 23 shows the tube element having the guide plate in FIG. 20
and tube elements laminated on the downstream side relative to the tube
element with the guide plate and illustrates the shape of the guide plate and
the flow of the heat exchanging medium;
- FIG. 24 is an enlargement of a portion of a formed plate having a
guide plate assuming a curved shape in areas close to the two ends along
the lateral direction;
- FIG. 25 is a lateral cross section of the guide plate in FIG. 24;
- FIG. 26 is a longitudinal cross section of the guide plate in FIG. 24;
- FIG. 27 is an enlarged front view of a portion of a formed plate
having a guide plate with a reservoir formed at its curved surface;
- FIG. 28 is a lateral cross section of the guide plate in FIG. 27;
- FIG. 29 is a longitudinal cross section of the guide plate in FIG. 27;
- FIG. 30 is an enlarged front view of a portion of a formed plate
with a straight portion formed at the two ends along the lateral direction of
a guide plate formed in a curved shape;
- FIG. 31 is a lateral cross section of the guide plate in FIG. 30;
- FIG. 32 is a longitudinal cross section of the guide plate in FIG. 30;
- FIG. 33 is an enlarged front view of a portion of a formed plate
having a guide plate with two shoulders thereof formed in a rounded
shape;
- FIG. 34 is a lateral cross section of the guide plate in FIG. 33;
- FIG. 35 is a longitudinal cross section of the guide plate in FIG. 33;
- FIG. 36 is an enlarged front view of a portion of a formed plate
having a guide plate with a bead formed therein;
- FIG. 37 is a lateral cross section of the guide plate in FIG. 36;
- FIG. 38 is a longitudinal cross section of the guide plate in FIG. 36;
- FIG. 39 is an enlarged longitudinal sectional view of a portion of a
formed plate having a guide plate with a short bead formed therein;
- FIG. 40 is an enlarged front view of a formed plate having a guide
plate assuming a curved shape in the areas close to the two ends along the
lateral direction and with a bead formed therein;
- FIG. 41 is a lateral cross section of the guide plate in FIG. 40;
- FIG. 42 is a longitudinal cross section of the guide plate in FIG. 40;
- FIG. 43 is an enlarged front view of a portion of a formed plate
having a guide plate with a reservoir formed at its curved surface and a
bead formed therein;
- FIG. 44 is a lateral cross section of the guide plate in FIG. 43;
- FIG. 45 is a longitudinal cross section of the guide plate in FIG. 43;
- FIG. 46 is an enlarged front view of a portion of a formed plate
having a straight portion at the two ends along the lateral direction of the
guide plate with a reservoir formed at its curved surface and a bead formed
therein;
- FIG. 47 is a lateral cross section of the guide plate in FIG. 46;
- FIG. 48 is a longitudinal cross section of the guide plate in FIG. 46;
- FIG. 49 is an enlarged front view of a portion of a formed plate
having a guide plate with a diamond-shaped bead formed therein;
- FIG. 50 is an enlarged front view of a portion of a formed plate
having a guide plate constituted of an inclined portion formed by cutting
through the lower circumferential edge of the communicating hole;
- FIG. 51 is a lateral cross section of the guide plate in FIG. 50;
- FIG. 52 is a longitudinal cross section of the guide plate in FIG. 50;
- FIG. 53 is an enlarged front view of a portion of a formed plate
achieved by forming a guide portion and a partitioning portion as an
integrated part;
- FIG. 54(a) is a diagram illustrating the concept of the flow of the
heat exchanging medium in a four-pass laminated heat exchanger in the
prior art having the heat exchanging medium intake and outlet portions at
one end of the core main body along the laminating direction and FIG.
54(b) illustrates the concept of the flow of the heat exchanging medium in
a six-pass laminated heat exchanger in the prior art; and
- FIG. 55(a) is a characteristics diagram of the temperature of the air
having passed through the upper portion of the laminated heat exchanger
in the first embodiment (representative temperature of the air having
passed through the upper half of the tube elements) and FIG. 55(b) is a
characteristics diagram of the temperature of the air having passed through
the upper portion of the laminated heat exchangers in the first embodiment
(representative-temperature of the air having passed through the lower half
of the tube elements).
-
THE BEST MODE FOR CARRYING OUT THE INVENTION
-
The following is an explanation of the embodiments of the present
invention, given in reference to the drawings. In FIGS. 1 and 2, a
laminated heat exchanger 1 may be, for instance a four-pass evaporator
with its core main body formed by alternately laminating fins 2 and tube
elements 3 over a plurality of levels and an intake portion 4 and an outlet
portion 5 through which the heat exchanging medium flows provided at
one end along the direction in which the tube elements 3 are laminated.
The tube elements 3 are each constituted by bonding two formed plates 6a
shown in FIG. 3(a), except for tube elements 3a and 3b at the two ends
along the laminating direction, a tube element 3c having an enlarged tank
portion which is to be detailed later, a tube element 3d located at an
approximate center and a tube element 3e adjacent to the tube element 3b.
-
The formed plates 6a are each formed by press machining an
aluminum plate and are each provided with two bowl-like distended
portions for tank formation 7 and 7 formed at one end thereof, a distended
portion for passage formation 8 continuous to the distended portions for
tank formation 7 and 7, an indented portion 9 formed between the
distended portions for tank formation, at which a communicating pipe to
be detailed later is mounted and a projection 10 formed at the distended
portion for passage formation 8, which extends from the area between the
two distended portions for tank formation 7 and 7 to the area near the other
end of the formed plate 6a. In addition, a projected piece 11 (see FIG. 1)
for preventing fins 2 from falling out during the assembly work prior to the
brazing process is provided at the other end of the formed plate 6.
-
The distended portions for tank formation 7 are formed to distend
further than the distended portion for passage formation 8 and the
projection 10 projects out so as to be set on the same plane as the bonding
margin at the circumferential edge of the formed plate, so that when two
formed plates 6a are bonded at their circumferential edges, their
projections 10, too, become bonded with each other to form a pair of tank
portions 12 and 12 with the distended portions for tank formation 7 facing
opposite each other and a turnaround passage portion 13 to communicate
between the tank portions with the distended portions for passage
formation 8 facing opposite each other.
-
The tube element 3a at an end along the laminating direction is
constituted by bonding a flat plate 14 to a formed plate 6a shown in FIG.
3(a), whereas the tube element 3b at the other end is constituted by
bonding a formed plate 6a in FIG. 3(a) and a formed plate flattened by
eliminating the distended portions for tank formation at a front plate 6a. In
addition, in each of formed plates 6b and 6c constituting the tube element
3c, one of the distended portions for tank formation is enlarged so that the
enlarged distended portion for tank formation lies close to the other
distended portion for tank formation. As a result, at the tube element 3c, a
tank portion 12 identical to those formed at the regular tube elements 3 and
an enlarged tank portion 12a which is enlarged so as to fill the indented
portion are formed. Since the other structural features of the formed plates
6b and 6c, i.e., the distended portions for passage formation 8 formed
continuous to the distended portions for tank formation, the projections 10
extending from the areas between the distended portions for tank
formation 7 to the areas near the other ends of the formed plates and the
projected pieces 11 provided to prevent the fins 2 from falling out at the
other ends of the formed plates, are identical to those of the formed plate 6
in FIG. 3(a), their. explanation is omitted.
-
In addition, the tube element 3d is constituted by using a formed
plate 6a in FIG. 3(a) and a formed plate 6d shown in FIG. 3(b), whereas
the tube element 3e is constituted by using a formed plate 6a in FIG. 3(a)
and a formed plate 6e shown in FIG. 3(c).
-
At the formed plate 6d, no communicating hole is formed at one of
its distended portions for tank formation, i.e., a distended portion for tank
formation 7a, and this non-communicating area forms a partitioning
portion 18 which partitions one of the tank groups, i.e., a tank group 15.
The partitioning portion may also be constituted by forming a blind tank
with no communicating hole at the adjacent tube element 3e as well and
bonding the distended portions for tank formation without a
communicating hole with each other to provide greater strength or by
placing a thin plate between the tube element 3d and the tube element 3e to
block the communicating hole communicating between the tank portions
instead of using a blind tank. In addition, at the formed plate 6e adjacent
to the formed plate 6d, a guide plate 19 to be detailed later is provided at
one of its distended portions for tank formation.
-
As illustrated in FIGS. 1 and 2, adjacent tube elements are abutted
at their tank portions in the heat exchanger, thereby forming two tank
groups, i.e., a first tank group 15 and a second tank group 16, extending
along the laminating direction (perpendicular to the direction of air flow)
with the individual tank portions in communication with each other via
communicating holes 17 formed at the distended portions for tank
formation 7 except for the formed plate 6d located at an approximate
center along the laminating direction in one of the tank groups, i.e., the
tank group 15, which includes the enlarged tank portion 12a and all the
tank portions in the other tank group 16 in communication with each other
via communicating holes 17 with no partition.
-
As a result, the first tank group 15 is divided by the partitioning
portion 18 into a first tank block 21 containing the enlarged tank portion
12a and a second tank block 22 in communication with the outlet portion
5, whereas the second tank group 16 with no partition constitutes a third
tank block 23 having the guide plate 19. In this embodiment, the tube
elements are laminated over a total of 27 levels, and the tube element 3c,
the tube element 3d and the tube element 3e are respectively positioned at
the sixth level, the fourteenth level and the fifteenth level counting from
the left side of the figure.
-
The intake portion 4 and the outlet portion 5 provided at one end
along the laminating direction are constituted by bonding a plate for
intake/outlet passage formation 24 with the flat plate 14 constituting an
end plate. By bonding these plates 14 and 24, an intake passage 25 and an
outlet passage 26 extending along the lengthwise direction are formed,
with an inflow port 28 and an outflow port 29 provided at the upper
portion of the plate for intake/outlet passage formation 24 to respectively
connect with the intake passage 25 and the outlet passage 26 via an
expansion valve fixing joint 27. The intake passage 25 and the enlarged
tank portion 12a are made to communicate with each other by bonding the
communicating pipe 30 secured at the indented portions 9 to the holes
formed at the plate 14 and the formed plate 6b, and the tank block 22 and
the outlet passage 26 are made to communicate with each other via a hole
formed at the flat plate 14.
-
Thus, the coolant having flowed in through the intake portion 4
travels through the communicating pipe 30 to enter the enlarged tank
portion 12a, then becomes dispersed over the entire first tank block 21, and
travels upward along that projections 10 through the turnaround passage
portions 13 of the tube elements in the first tank block 21 (first pass).
Then, it makes a U-turn over the projections can and travels downward
(second pass) to enter the tank group (third tank block 23) on the opposite
side. Subsequently, it moves along the laminating direction toward the
remaining tube elements constituting the third tank block 23 via the
communicating holes 17, and travels upward along the projections 10
through the turnaround passage portions 13 of the tube elements (third
pass). Next, it makes a U-turn over the projections 10 and travels
downward (fourth pass), is guided to the tank portions constituting the
second tank block 22 and finally flows out through the outlet portion 5. As
a result, the coolant undergoes heat exchange with the air via the fins 2
while it flows through the turnaround passage portions 13 constituting the
first ~ fourth passes.
-
The guide plate 19 at the formed plate 6e is provided to promote a
more even flow of the coolant over the area where the second pass shifts
into the third pass and an unbalanced flow tends to occur as explained
earlier. As illustrated in FIGS. 4 and 5, the guide plate 19 is constituted of
a bridge 19a extending along the horizontal direction at an approximate
center of the communicating holes 17 formed at the distended portion for
tank formation 7 and an inclined portion 19b bent from the upper edge of
the bridge 19a toward the inside of the tank portion 12. The guide plate 19
is formed as an integrated part of the formed plate by leaving a portion of
the distended portion for tank formation 7, which would normally be
disposed of as waste when punching the distended portion for tank
formation 7 to form the communicating hole 17, and the angle of
inclination (q) of the inclined portion 19b relative to the laminating
direction is set within a range of 5 ~ 65° and, more desirably, it should be
set within the range of 5 ~ 30° in the case of the heat exchanger described
above. In addition, the length of the portion inclining inside the tank
portion (L: the length of the inclined portion 19b projecting out from the
bridge in this example) should be set within a range of 1 ~ 15mm, and in
the structural example described above, it is set at approximately 2 - 6mm.
-
If the angle of the inclined portion 19b was set too large, the
passage resistance would increase to result in a greater pressure loss and a
reduction in the quantity of discharged heat (the heat exchanging quantity)
due to the lower coolant flow rate, where as if the angle was set too small,
the direction of the coolant flow would not be changed to a full extent and,
therefore, the problem of the unbalanced flow of the coolant observed in
the prior art would not be eliminated. In addition, structural differences
among individual heat exchangers affect the flow of the coolant. By
taking into consideration these factors, it is determined that the angle of
inclination must be set within the range of 5 q 65°, in order to achieve
an improvement in the coolant flow. At the same time, the direction of the
coolant flow can be changed to a significant degree even when the length
L of the inclined portion is small as long as q is large enough within this
angle range, whereas it is necessary to set the coolant flow direction by
increasing L by an appropriate degree if q is small. In addition, the
inclined portion must be formed by cutting up the distended portion for
tank formation during the manufacturing process. Thus, L must be set
within a range of 1 L 15mm. Accordingly, the optimal guide plate 19
must be formed by combining q and L within these ranges, and the
numerical values mentioned above have been set for the four-pass heat
exchanger by considering various combinations.
-
As a result, the guide plate 19 changes the direction of the flow of
the coolant moving through the third tank block 23 via the communicating
holes 17 along the laminating direction during the process of shifting from
the second pass into the third pass, to allow the coolant to advance straight
toward the communicating point at which the tank portions 12 constituting
the third pass communicate with the corresponding passage portions 13.
Consequently, the coolant is allowed to flow in sufficient quantity even in
the area near the partitioning portion 18.
-
The improvement in the coolant flow achieved by providing such a
guide plate 19 allows the coolant to flow into the individual tube elements
in an even manner, to eliminate any significant inconsistency in the heat
exchanging quantities at various locations. The results of a test conducted
by measuring the passing air temperature, which are presented in FIG. 55,
confirm that the temperature of the air having passed through the upper
level tube elements (in particular TUBE Nos. 5 ~ 13) near the partitioning
portion is lower than the air temperature measured in an heat exchanger in
the prior art without the guide plate 19, as indicated by the solid line to
achieve a temperature distribution with overall consistency.
-
While only one guide plate 19, which is constituted of the bridge
19a and the inclined portion 19b bent away from the bridge 19e in the
example described above is formed at an approximate center of the
communicating hole 17, similar advantages may be achieved even when
such a guide plate is formed at a different location or in a different shape,
or two or more such guide plates are provided. The following is an
explanation of such variations, given in reference to FIGS. 6 ~ 14. In the
structure shown in FIG. 6, a guide plate 19 constituted of the bridge 19a
and the inclined portion 19b is formed at that position lower than the
center of the communicating holes 17, whereas in the structure shown in
FIG. 7, a guide plate 19 constituted of the bridge 19a and the inclined
portion 19b is formed at a position higher than the center of the
communicating holes 17. In the structural example shown in FIG. 8, an
inclined portion 19b bent toward the inside of the tank portion from the
lower circumferential edge of the communicating hole 17 formed at the
distended portion for tank formation 7 is constituted as an integrated part
of the lower circumferential edge.
-
In addition, the guide plate 19 may take on a shape achieved by
twisting the portion extending across the communicating hole 17 along the
horizontal direction with its two ends used as fulcrums to cause it to
incline in its entirety as illustrated in FIG. 9, may assume a structure
achieved by bending the upper edge of the bridge 19a at an acute angle
toward the outside of the tank portion 12 where the guide plate 19 is
located to form an inclined portion 19b as illustrated in FIG. 10 or may
assume a structure in which the angle of inclination of the inclined portion
19b is gradually increased to form the inclined portion 19b in a curved
shape as illustrated in FIG. 11.
-
By forming a plurality of guide plates 19, the direction in which the
coolant advances straight can be changed even more effectively, and, as
illustrated in FIG. 12, a plurality (three in this example) of guide plates 19
inclining upward from the upstream side to the downstream side may be
formed over the upper half of the communicating hole 17 with no guide
plate 19 formed over the lower half. These guide plates 19 should be
formed as an integrated part of the distended portion for tank formation 7,
parallel to each other by setting their angles of inclination equal to each
other.
-
In a heat exchanger adopting this structure, the coolant having
passed through the lower half of the communicating hole 17 advances
straight along the laminating direction to be delivered further into the third
tank block 23, whereas the coolant having passed through the upper half is
caused to change the direction in which it advances by the guide plates 19
to flow toward the inflow positions of the individual passage portions 13
of the tube elements constituting the third pass. As a result, the coolant
flows in sufficient quantity into the tube elements near the partitioning
portion to achieve advantages similar to those described earlier.
-
As an alternative, a plurality (five in this example) of guide plates
19 inclining upward on the downstream side may be formed as an
integrated part over the entire communicating hole by providing guide
plates 19 over the lower half of the communicating hole 17 as well, to
change the direction of the entire flow of the coolant shifting into the third
pass, as shown in FIG. 13. Or, as illustrated in FIG. 14, the guide plates 19
formed horizontally over the lower half may be extended to ensure that a
sufficient quantity of coolant flows along the laminating direction instead.
The former structure is particularly effective when the number of tube
elements constituting the third pass is small, whereas the latter structure is
particularly effective when the number of tube elements constituting the
third pass is large and the coolant needs to be distributed evenly to the area
further toward the front and also to the area further inward.
-
It is to be noted that the structures that may be assumed for the
guide plates are not limited to the examples described above and similar
advantages may be achieved in variations achieved by varying as
appropriate the number of guide plates and the positions at which they are
formed in the individual structures explained above.
-
FIGS. 15 and 16 illustrate the second embodiment of the laminated
heat exchanger, and the following explanation mainly focuses on the
differences from the first embodiment by assigning the same reference
numbers to identical members in the figures to preclude the necessity for a
repeated explanation thereof.
-
In this laminated heat exchanger, which may be, for instance, a
four-pass evaporator having a heat exchanging medium intake portion 4
and a heat exchanging medium outlet portion 5 provided at an end surface
(the front surface in FIG. 15) of the core main body, the tube elements 3
are each constituted by bonding two formed plates 6a shown in FIG. 3(a)
except for tube elements 3a and 3b located at the two ends along the
laminating direction, a tube element 3d located at an approximate center
and a tube element 3e adjacent to the tube element 3d and tube elements 3f
each having the intake portion 4 or at outlet portion 5 formed as an
integrated part thereof.
-
In this structure, the tube elements 3a and 3b at the two ends are
each formed by bonding a formed plate 6a in FIG. 3(a) and a formed plate
flattened by eliminating the distended portions for tank formation of the
formed plate 6a. In addition, at each of the tube elements 3f, the intake
portion 4 or the outlet portion 5 is formed by opening up the upstream side
distended portions for tank formation 7, so as to allow them to project out
along the direction of airflow placing these opened projecting portions to
face each other and bonding the opened portions with each other. Since
the other structural features of the tube elements 3f, i.e., the
communicating holes formed at the distended portions for tank formation,
the distended portions for passage formation formed continuous to the
distended portions for tank formation, the projections formed extending
from the areas between the distended portions for tank formation to the
areas near the other ends of the formed plates and the projected pieces
provided at the other ends of the formed plates to prevent the fins 2 from
falling out are similar to those of the formed plate 6 in FIG. 3(a) and the
other tube elements assume similar structures to those described above,
their explanation is omitted.
-
In addition, while the partitioning portion 18 and the guide plates
19 assume structures similar to those described earlier, the tube elements.
are laminated over 26 levels in this heat exchanger, with the intake portion
4 and the outlet portion respectively formed at of the seventh level and the
twentieth level counting from the left side in the figure and the partitioning
portion 18 and the constricting portion 19 formed between the thirteenth
level (tube element 3e) and the fourteenth level (tube element 3d) counting
from the left side. In this heat exchanger, the guide plate 19 may assume
any of the various structures illustrated in FIGS. 4 ~ 14 with or without
quantity and the forming position varied. The angle q relative to the
horizontal direction and the length L of the inclined portion are set within
the ranges of 5 q 65° and 1 L 15mm respectively as explained
earlier.
-
Thus, in the heat exchanger structured as described above, the
coolant having flowed in through the intake portion 4 is dispersed over the
entire first tank block 21 and then travels upward along the projections 10
through the turnaround passage portions 13 at the tube elements in the first
tank block 21 (first pass). The coolant then moves downward after making
a U-turn over the projections 10 (second pass) to reach the tank group
(third tank block 23) on the opposite side. Subsequently, it moves along
the laminating direction toward the remaining tube elements constituting
the third tank block 23, and travels upward along the projections 10
through the turnaround passage portion 13 of the tube elements (third
pass). Next, it travels downward after making a U-turn over the
projections 10 (fourth pass), is guided to the tank portions constituting the
second tank block 22 and finally flows out through the outlet portion 5. As
a result, while the coolant flows through the turnaround passage portions
13 constituting the first pass ~ fourth pass, it undergoes heat exchange with
the air via the fins 2. During this process, the coolant shifting from the
second pass into the third pass is caused to change the direction in which it
advances straight by the guide plate 19 formed at the shifting area as in the
structure described earlier so that it flows into the tube elements near the
partitioning portion in a sufficient quantity.
-
It is to be noted that while the formed plate at which the
partitioning portion 18 is provided and the formed plate at which the guide
plate 19 is provided are formed independently of each other, the
partitioning portion 18 and the guide plate 19 may be formed on a single
formed plate in order to reduce the number of different types of formed
plates required in assembling the heat exchanger. When adopting such a
structure, the formed plate 6e shown in FIG. 3(c) may be replaced with the
formed plate 6e' in FIG. 17 with a formed plate 6a shown in FIG. 3(a)
placed adjacent to the formed plate 6e'.
-
In addition, while the guide plate 19 provided at the shifting area
over which an even-numbered pass shifts into an odd-numbered pass is
provided at the formed plate adjacent to the partitioning portion 18 or at
the formed plate where the partitioning portion is provided in the structures
described above, the present invention is not limited to these examples,
and a guide plate may be provided in the vicinity of the shifting area where
the second pass shifts into the third pass (e.g., at a tube element distanced
from the tube element having the partitioning portion 18 by one or two
positions).
-
The guide plate 19 in the various modes described above is unique
in that it prevents an unbalanced flow of the heat exchanging medium by
aggressively changing the direction in which the heat exchanging medium
advances straight while minimizing the passage resistance, in that it
changes the direction in which the heat exchanging medium advances
straight with a high degree of reliability by suppressing the rotating flow of
the heat exchanging medium and in that it allows the heat exchanging
medium to flow into the turnaround passage portions 13 of the individual
tube elements with ease to prevent an uneven flow and, therefore, it
achieves specific advantages which cannot be obtained by providing the
constricting portion disclosed in Japanese Unexamined Patent Publication
No. H 8-285407 or the guide plate disclosed in Japanese Unexamined
Patent Publication No. H 8-178581. However, the guide plate 19 according
to the present invention may be employed in conjunction with the
constricting portion disclosed in Japanese Unexamined Patent Publication
No. H 8-285407, for instance. Since the constricting portion disclosed in
the publication is provided to achieve a similar advantage of minimizing
an uneven flow of the heat exchanging medium, the combined use of the
constricting portion and the guide plate 19 is expected to prevent an
uneven flow to the full extent.
-
Furthermore, the guide plate 19 may be constituted as a member
separate from the formed plate or a plurality of guide plates may be
provided offset from each other along the laminating direction it may be
provided in the vicinity of the formed plate having the partitioning portion
18 or at the formed plate having the partitioning portion 18 and in the
vicinity of the formed plate. The description "the guide plate is provided
at, at least, one location at the shifting area or in its vicinity" allows for a
variation in which a plurality of guide plates are provided offset from each
other along the laminating direction as well as the variations illustrated in
FIGS. 12 ~ 14.
-
A plurality of guide plates may be provided offset along the
laminating direction by assuming the structure illustrated in FIG. 18 or 19,
for instance. In these examples, guide plates are provided at the formed
plates 6e and 6f located on the upstream side relative to the flow of the
heat exchanging medium travelling through the third tank block 23 along
the laminating direction in the tube element 3e and a tube element 3g
adjacent to the tube element 3e, and these guide plates 19 are each
constituted by forming the inclined portion 19b bent toward the inside of
the tank portion from the lower circumferential edge of the communicating
hole 17 formed at the distended portion for tank formation 7 as an
integrated part.
-
In particular, in the example shown in FIG. 18, the guide plate 19
formed at the formed plate 6e is made to extend to the communicating hole
at the other formed plate, i.e., the formed plate 6a, constituting the tube
element 3e so that it comes in contact with the guide plate 19 formed at the
formed plate 6f to provide the two inclining guide plates continuously. As
a result, the length L of the inclined portion is a total length of the length
L1 of the guide plate 19 formed at the formed plate 6e and the length L2 of
the guide plate 19 formed at the formed plate 6f.
-
Thus, the range 1 L 15mm set for the length L of the inclined
portion is the range used to set the length of the inclined portion 19b of
each guide plate 19 and also the range used to set the total length of the
inclined portions of a plurality of guide plates provided continuously to
each other when a sufficient length cannot be achieved with a single
inclined portion.
-
By providing the inclined portions of a plurality of guide plates
continuously to each other in this manner, the flow of the heat exchanging
medium traveling along the laminating direction can be guided along the
intended direction with a high degree of reliability, and with the coolant
supplied to the tube elements near the partitioning portion 18 in a
sufficient quantity, an almost completely uniform temperature distribution
can be achieved with ease.
-
In addition, the example shown in FIG. 19 is achieved by reducing
the length L1 of the inclined portion 19b of the guide plate 19 formed at
the formed plate 6e in the structure shown in FIG. 18 to allow a distance to
be created from the guide plate 19 formed at the adjacent tube element. It
is similar to the example in FIG. 18 in that the guide plate 19 formed at the
formed plate 6f is provided on an extended line of the guide plate 19
formed at the formed plate 6e.
-
In this structure, too, the coolant having had the direction of its
flow changed by the frontward guide plate smoothly moves toward the
rearward guide plate due to the inertia, and is further guided by the guide
plate to which it has moved to become distributed to the individual tube
elements, thereby achieving a similar advantage.
-
It is to be noted that there are various other structures that may be
adopted when providing a plurality of guide plates offset along the
laminating direction in addition to the structures explained above, and the
positions at which they are formed may be varied within the scope of the
teaching of the present invention or any of them may be adopted in
combination with the various examples explained earlier.
-
The guide plate 19 may be formed in a curved shape along the
lateral direction of the formed plate 6e as shown in FIGS. 20 ~ 23. This
curved shape achieves a specific curvature. By assuming such a curved
shape for the guide plate 19, an improvement in the strength of the guide
plate 19 is achieved and, at the same time, the direction of the flow of the
heat exchanging medium (coolant) can be changed in a desirable manner.
In this example, the two shoulders of the guide plate 19 at the front end
along the direction in which it projects out from the formed plate (the
laminating direction) are formed in a rounded shape (an R shape). With
any angularity at the shoulders eliminated by forming them in a rounded
shape, the guide plate 19 is not caused to vibrate by the flow of the
coolant.
-
Alternatively, the guide plate 19 may be formed to have a curved
shape only over areas close to the two ends along the lateral direction of
the formed plate 6e, as illustrated in FIGS. 24 ~ 26, with the portion
between the rounded areas formed in a flat shape. In this example, too, the
two shoulders of the guide plate are curved.
-
In FIGS. 27 ~ 29, the guide plate 19 is formed in a curved shape
along the lateral direction of the formed plate 6e and the curved shape
forms a reservoir (a bowl) toward the projecting end. In this example, too,
the two shoulders of the guide plate 19 are rounded.
-
In FIGS. 30 ~ 32, the guide plate 19 is formed in a curved shape
along the lateral direction of the formed plate 6e and the curved shape
forms a reservoir (a bowl) toward the projecting end as in the previous
example. It differs from the previous example in that straight portions 33
and 33 located at the two sides of the guide plate are provided at the bridge
19a extending across the communicating hole 17. In this example, too, the
two shoulders of the guide plate 19 are rounded.
-
While the rounded shoulders are included in the curved shape of the
guide plate 19 in the examples presented above, they may be provided at a
flat surface instead, as illustrated in FIGS. 33 ~ 35.
-
In FIGS. 36 ~ 38, the inclined portion 19b is bent at a specific angle
relative to the bridge 19a with the guide surface constituted as a flat
surface at the guide plate 19, and a continually bent portion (referred to as
a bead) 35 projecting downward from the formed plate 6e along the
direction in which the guide plate projects out from the formed plate 6e is
formed extending from the bridge 9a through the inclined portion 9b. The
length of the bead 35 is set equal to the length of the guide plate 19
extending along the direction in which it projects out (the laminating
direction). By providing the bead 35, the strength of the guide plate 19 is
improved and, at the same time, the presence of the bead 35 contributes to
improvement in the ease of forming and the dimensional accuracy. In this
case, too, the two shoulders of the guide plate are rounded. While the
length of the bead 35 formed at the guide plate 19 may be set equal to the
length of the guide plate 19 extending along the projecting direction as
explained earlier, it may be set shorter than the length of the guide plate
extending along the projecting direction as shown in FIG. 39.
-
As shown in FIGS. 40 ~ 42, the bead may be formed at a guide
plate 19 formed in a curved shape over areas close to the two ends along
the lateral direction of the formed plate 6e. Through the combination of
the bead 35 and the curved shape, the strength of the guide plate is further
improved.
-
As illustrated in FIGS. 43 ~ 45, the bead 35 may be provided at a
guide plate 19 formed in a curved shape along the lateral direction of the
formed plate 6e and having a reservoir (bowl) formed toward the
projecting end. In this case, too, the two shoulders of the guide plate 19
are rounded. Likewise, as illustrated in FIGS. 46 ~ 48, the guide plate 19
may assume a structure similar to those adopted in the preceding
examples, but with straight portions 33 and 33 provided at the two sides of
the bridge 19a. In this example, too, the two shoulders of the guide plate
19 are rounded.
-
As shown in FIG. 49, the bead may be formed in a diamond shape
at the area where the inclined portion 19b becomes bent from the bridge
19a, to improve the strength of the guide plate 19. It is to be noted that
although only a single bead 35 is presented in the illustrated examples, a
plurality of beads 35 e.g., two beads, may be provided.
-
While the guide plate 19 is constituted of the bridge 19a extending
across the communicating hole 17 and the inclined portion 19b bent from a
side edge of the bridge and extends at an angle, an alternative structure
shown in FIGS. 50 ~ 52 in which the inclined portion 19b inclines from
the lower circumferential edge of the communicating hole, with the
communicating hole 17 present in the upper section of the figure may be
adopted instead. Any of the structures shown in FIG. 20 and subsequent
drawings may be assumed in the guide plate 19 and, in this example, it is
formed in rounded shape and a continuously bent portion (bead) 35 is
formed ranging from of the formed plate to the inclined portion 19b along
the projecting direction in which the guide plate projects out from the
formed plate 6d.
-
This structure improves the strength due to the presence of the bead
35, and prevents occurrence of vibration through rounding (R machining).
It is to be noted that straight portions 33 and 33 are formed at the two sides
of the guide plate 19. In addition, although not shown, the inclined portion
19b may be bent to give it a curved shape.
-
In the heat exchanger shown in FIGS. 15 and 16, too, a guide plate
19 similar to any of those described above may be provided. Namely, by
forming the guide plate 19 in a curved shape, forming a bead at the guide
plate 19 or rounding the two shoulders of the guide plate 19 as in any of
the embodiments illustrated in FIGS. 20 ~ 49, an improvement in the
strength is achieved and occurrence of vibration is prevented.
-
It is to be noted that while the formed plate having the partitioning
portion 18 and the formed plate having the guide plate 19 are formed
independently of each other in the structures described above, the
partitioning portion 18 and the guide plate 19 may be formed on a single
formed plate to reduce the number of different types of formed plates
required in assembling the heat exchanger. When adopting such a
structure, the formed plate 6e shown in FIG. 3(c) should be replaced with
the formed plate 6e' shown in FIG. 53 with a formed plate 6a shown in
FIG. 3(a) placed adjacent to the formed plate 6e'.
Industrial applicability
-
As explained above, according to the present invention provided
with a guide plate that causes the heat exchanging medium traveling along
the laminating direction to flow straight toward the communicating point
at which the tank portions to which the heat exchanging medium is
traveling and the corresponding passage portions communicate with each
other when the heat exchanging medium is flowing from the tank portions
into the passage portions in communication with the tank portions after the
heat exchanging medium travels along the laminating direction through the
tank portions which are in communication, the heat exchanging medium is
distributed into the individual tube elements in an almost completely
uniform manner, to avoid great deviations occurring in the passing air
temperature at different locations due to an uneven flow of the heat
exchanging medium. In addition, since the guide plate aggressively
changes the direction in which the heat exchanging medium advances
straight, an uneven distribution of the heat exchanging medium is
minimized without increasing the passage resistance and, at the same time,
occurrence of a rotating flow is also prevented, so that the heat exchanging
medium is guided to the passage portions near the shifting area with ease.
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In a single-side tank type heat exchanger, in particular, by
providing the guide plate at the shifting area where an even-numbered pass
shifts into an odd-numbered pass, the heat exchanging medium is guided
into the passage portions located immediately into the odd-numbered pass,
to achieve a consistent distribution of the heat exchanging medium.
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In addition, by providing the guide plate at a formed plate adjacent
to the formed plate having the partitioning portion which constitutes the
boundary of the pass in which the heat exchanging medium flows from the
tank portions to the passage portions among the formed plates constituting
the tube elements or by providing the guide plate at the formed plate
having the partitioning portion formed therein, the heat exchanging
medium can be guided into the passage portions in the vicinity of the
partitioning portion with ease. In particular, by providing the guide plate
and the partitioning portion on a single formed plate, the number of
different types of formed plates required in assembling the heat exchanger
can be reduced.
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While the degree to which the flow of the heat exchanging medium
can be improved by the guide plate depends upon how the angle of
inclination of the guide plate and the length of the inclined portion are
combined, by setting the angle of inclination within the range of 5 ~ 65°
and the length of the inclined portion within the range of 1 ~ 15mm
respectively, the unbalanced flow of heat exchanging medium can be
reduced to improve the heat exchanging efficiency. Furthermore, by
forming the guide plate as an integrated part of the member constituting
the tank portion, the number of manufacturing steps can be reduced and
the manufacturing process is facilitated.
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While the guide plate may assume any of various shapes, by
constituting the guide plate with a bridge provided across the
communicating hole and an inclined portion bent from the side edge of the
bridge and extending at an angle, by directly bending the circumferential
edge of the communicating hole to achieve an inclining shape or by
twisting the portion extending across the communicating hole to achieve
an inclining shape for the entire guide plate, a guide plate that can be
manufactured easily and can be put into practical use with ease is
provided. In addition, by forming numerous guide plates at the shifting
area or in its vicinity, the flow of the heat exchanging medium can be
changed with a high degree of reliability to effectively prevent an
unbalanced flow of heat exchanging medium.
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Moreover, in the structure described above and achieved by
providing the guide plate at the communicating hole of a tube element at a
specific position to change the direction of the flow of the heat exchanging
medium traveling along the laminating direction toward the
communicating point at which the tank portions to which the heat
exchanging medium is moving and the corresponding passage portions
communicate with each other when the heat exchanging medium flows
from the tank portions to the passage portions in communication with the
tank portions after the heat exchanging medium flows along the laminating
direction through the tank portions which are in communication with each
other, the guide plate may be formed in a curved shape or a bead may be
provided at the guide plate to improve the strength and the two shoulders
of the guide plate may be rounded to prevent occurrence of vibration.