Technical field
The present invention relates to a heat exchanger member, such as a heat absorber or
heat rejector, provided in a Stirling cycle refrigerator, to a heat exchanger element for use in
such a heat exchanger member, and to a method of manufacturing such a heat exchanger
member.
Background art
First, a typical configuration of a free-piston-type Stirling cycle refrigerator exploiting
a Stirling cycle will be described. Fig. 29 is a diagram schematically showing a section, as
seen from the side, of a free-piston-type Stirling cycle refrigerator. Inside a cylinder 1, a
heat absorber 2 acting as a low-temperature portion, a regenerator 3, and a heat rejector 4
acting as a high-temperature portion are arranged in this order. The heat absorber 2 and the
heat rejector 4 are each built as a heat exchanger member composed of a tubular body 21 or
41 having a heat exchanger element 22 or 42 fitted on the inner surface thereof at one end.
Inside the cylinder 1, the heat exchanger elements 22 and 42 are each contiguous to the
regenerator 3.
Inside the cylinder 1 are also arranged a displacer 6 firmly fitted to one end of a
displacer rod 5, and a piston 7 through which the displacer rod 5 is placed. The other end of
the displacer rod 5 is connected to a spring 8. Inside the cylinder 1, the displacer 6 and the
piston 7 create an expansion space 9 in the heat absorber 2 and a compression space 10 in the
heat rejector 4. The expansion space 9 and the compression space 10 communicate with
each other through the regenerator 3, and thereby form a closed circuit.
Now, how this free-piston-type Stirling cycle refrigerator operates will be described.
The piston 7 is made to reciprocate along the axis of the cylinder 1 with a predetermined
period by an external power source, such as a linear motor (not shown). The compression
space 10 is filled with working gas, such as helium, beforehand.
As the piston 7 moves, the working gas in the compression space 10 is compressed.
This causes the working gas to flow through the heat exchanger element 42 then through the
regenerator 3 into the expansion space 9 (as indicated by broken-line arrows A in the figure).
Meanwhile, the working gas first releases heat in the heat rejector 4, by exchanging the heat
produced therein as a result of compression with the air outside, and is then precooled as it
passes through the regenerator 3, by receiving the cold accumulated in the regenerator 3
beforehand.
When the working gas flows into the expansion space 9, it presses the displacer 6
rightward against the spring 8. Thus, the working gas expands, and produces cold therein.
When the working gas expands to a certain degree, the resilience of the spring 8 presses the
displacer 6 back in the opposite direction.
As a result, the working gas in the expansion space 9 flows through the heat exchanger
element 22 of the heat absorber 2 and then through the regenerator 3 back to the compression
space 10 (as indicated by solid-line arrows A'). Meanwhile, the working gas first absorbs
heat in the heat exchanger element 22, by exchanging heat with the air outside, and is then
preheated as it passes through the regenerator 3, by receiving the heat accumulated in the
regenerator 3 beforehand. The working gas back in the compression space 10 is then
compressed again by the piston 7.
Through the repetition of this cycle of events, cryogenic cold is obtained in the heat
absorber 2. Here, the larger the amount of heat absorbed in the heat exchanger element 22 of
the heat absorber 2 and the amount of heat released in the heat exchanger element 42 of the
heat rejector 4, the better. This helps increase the efficiency with which the regenerator 3
precools and preheats the working gas, and thus helps reduce the burden on the regenerator 3,
leading to better chilling performance of the Stirling cycle refrigerator.
Next, the heat rejector 4 acting as the high-temperature-side heat exchanger member
of the Stirling cycle refrigerator described above will be described with reference to Fig. 30.
It is to be understood that, although the following description deals only with the heat rejector
4 and its heat exchanger element 42, the heat absorber 2 acting as the low-temperature-side
heat exchanger member and its heat exchanger element 22 are configured in the same manner.
As Fig. 30 shows, this heat exchanger element 42 is built as an annular corrugate fin
421 produced by forming a corrugated sheet material into a cylindrical shape. Thus, the heat
exchanger element 42 has a rugged surface, with a large number of axially-extending straight
V-shaped grooves 421a formed at regular intervals.
Here, the portions of the heat exchanger element 42 which protrude toward the center
of the body 41 of the heat rejector 4 are referred to as the bottoms 421b of the individual
grooves 421a, and the portions of the heat exchanger element 42 which protrude toward the
inner surface of the body 41 are referred to as the tops 421c between every two adjacent
grooves 421a. The diameter of the circle formed by smoothly connecting all the tops 421c
together (i.e. the external diameter of the annular corrugate fin 421) is substantially equal to
the internal diameter of the body 41. The body 41 and the annular corrugate fin 421 are
arranged so as to be coaxial with each other.
The inner surface of the body 41 and the tops 421c of the annular corrugate fin 421 are
firmly fixed together with adhesive or solder. Fig. 31 is an enlarged view of a portion of the
annular corrugate fin 421 as seen axially, and shows how it is fixed with adhesive. In this
case, first, adhesive 11 is applied thinly to the inner surface of the body 41, and then the
annular corrugate fin 421 is inserted into the body 41. Then, with the annular corrugate fin
421 held in the desired position for a while, the adhesive 11 is dried.
On the other hand, Fig. 32 shows how the annular corrugate fin 421 is fixed with
solder. In this case, first, the annular corrugate fin 421 is inserted into the body 41. Then,
with the annular corrugate fin 421 held in the desired position, solder 12 is applied to where
the inner surface of the body 41 makes contact with or comes close to the tops 421c of the
annular corrugate fin 421.
However, with this conventional heat exchanger member described above, the fixing
together of its components with adhesive or solder is performed by hand. Thus, this process
takes too much trouble and time, hindering the improvement of productivity and the reduction
of manufacturing costs. Moreover, the heat exchanger member thus manufactured is prone
to variations in quality, specifically in heat exchange performance, and thus tends to lack in
stability and reliability.
Furthermore, as the Stirling cycle refrigerator is used for an extended period, if the
annular corrugate fin 421 is damaged, it is impossible to simply remove and replace it. This
adds to the economic burden on the user in the event of repair, and is contrary to the general
trend toward recycling of resources in view of the global environment. An example of
a conventional heat exchanger member is shown in JP8-86526 A.
Disclosure of the invention
Attached fixing the annular corrugate fin and the inner ring-shaped
member helps increase the area of contact between them and thereby enhance
heat conductivity. Moreover, their integration makes the handling of the heat
exchanger element easy, and makes the repair, by replacement, of the heat
exchanger element possible. This makes the heat exchanger element very
economical and recycable. The integration is achieved by a bonding means,
such as brazing or soldering.
A heat exchanger member according to the present invention is
produced by inserting a heat exchanger element for a Stirling cycle
refrigerator into a hollow portion of a tubular body. In this case, the internal
diameter of the body may be made slightly smaller than the external diameter
of the heat exchanger element. This makes it possible to fit the heat
exchanger element into the body by press fitting, i.e. without bonding or
welding. Moreover, at least one end of the body may be tapered so that the
wall thickness of the body becomes smaller toward that end along the axis.
This permits easy insertion of the heat exchanger element into the body.
Moreover, around the annular corrugate fin, wave-shaped projections
may be formed so as to be in close contact with one another and at regular
intervals overall, with wave-shaped depressions formed in the inner surface of
the body so as to extend axially and correspond to the wave-shaped
projections, so that, when the heat exchanger element is inserted into the
body, the wave-shaped projections fit into the wave-shaped depressions. This
prevents the heat exchanger element from rotating out of position inside the
body.
Alternatively, the annular corrugate fin may be produced by forming a
linear corrugate fin, of which the endmost sides of the inverted-V-shaped
grooves at both ends are longer than the slant sides of the V-shaped grooves
in between, into a cylindrical shape, then holding the endmost sides together
so that the surfaces of those endmost sides are kept in contact with each other,
and then fitting the resulting protruding portion that is formed at the tip of the
endmost sides so as to protrude radially out of the outer periphery of the
annular corrugate fin into a groove that is formed in the inner surface of the
body so as to extend axially. This also prevents the heat exchanger element
from rotating out of position inside the body.
This heat exchanger member can be manufactured, for example, by
removably putting to the body one end of a tubular guide member tapered so
that the internal diameter thereof at one end is substantially equal to the
internal diameter of the body and that the wall thickness thereof becomes
smaller toward another end, and then inserting the heat exchanger element for
a Stirling cycle refrigerator into the body by guiding it through the guide
member axially from the other end thereof. In the heat exchanger member
manufactured in this way, when the annular corrugate fin is guided through
the guide member, its peripheral shape changes, increasing the area of contact
with the inner surface of the body. This enhances the heat conduction
efficiency of the annular corrugate fin, and thus makes it possible to realize a
heat exchanger member excellent in heat exchange performance.
A heat exchanger member according to the present invention is
produced by inserting the above-described heat exchanger element for a
Stirling cycle refrigerator into a hollow portion of a tubular body. In this
case, the internal diameter of the body is made slightly smaller than the
external diameter of the heat exchanger element. This makes it possible to fit
the heat exchanger element into the body by press fitting, i.e. without bonding
or welding. Moreover, at least one end of the body may be tapered so that the
wall thickness of the body becomes smaller toward that end along the axis.
This permits easy insertion of the heat exchanger element into the body.
The aforementioned annular corrugate fin is produced easily by forming
a linear corrugate fin, having contiguous V-shaped grooves, into a cylindrical
shape, and then engaging the endmost side of the V-shaped groove at one end
of the linear corrugate fin with the endmost side of the inverted V-shaped
groove at the other end thereof.
Alternatively, the annular corrugate fin is produced by forming a linear
corrugate fin, having contiguous V-shaped grooves, into a cylindrical shape,
and then coupling together the
endmost side of the V-shaped groove at one end of the linear corrugate fin and the endmost
side of the inverted-V-shaped groove at the other end thereof by performing spot welding on
the surfaces of those endmost sides.
Alternatively, the annular corrugate fin is produced by forming a linear corrugate fin,
having contiguous V-shaped grooves, into a cylindrical shape, and then coupling together the
endmost side of the V-shaped groove at one end of the linear corrugate fin and the endmost
side of the inverted-V-shaped groove at the other end thereof by bonding the surfaces of those
endmost sides together.
Alternatively, the annular corrugate fin is produced by forming a linear corrugate fin,
having contiguous V-shaped grooves, into a cylindrical shape, and then coupling together the
endmost side of the V-shaped groove at one end of the linear corrugate fin and the endmost
side of the inverted-V-shaped groove at the other end thereof by brazing the surfaces of those
endmost sides together.
Alternatively, the annular corrugate fin is produced by forming a linear corrugate fin,
having contiguous V-shaped grooves, into a cylindrical shape, then holding the endmost sides
of the inverted-V-shaped grooves at both ends of the linear corrugate fin together so that the
surfaces of those endmost sides are kept in contact with each other, and then fitting a coupling
member having a C-shaped section on the tip ofthose endmost sides of which the surfaces are
kept in contact with each other.
Alternatively, the annular corrugate fin is produced by forming a linear corrugate fin,
having contiguous V-shaped grooves, into a cylindrical shape, and then coupling together the
endmost sides of the inverted-V-shaped grooves at both ends of the linear corrugate fin by
engaging together a slit that is formed in the endmost side at one end of the linear corrugate
fin so as to extend from one flank halfway inward and a slit that is formed in the endmost side
at the other end of the linear corrugate fin so as to extend from another flank halfway inward.
Brief description of drawings
Fig. 1 is an external perspective view of the heat rejector of a first embedment of the
invention.
Fig. 2A is an external perspective view of the heat exchanger element of the heat
rejector.
Fig. 2B is an exploded perspective view of the heat exchanger element.
Fig. 3 is an enlarged plan view of a portion of the heat exchanger element, as seen
axially.
Fig. 4 is a vertical sectional outline of the body and the heat exchanger element of the
heat rejector.
Fig. 5 is an enlarged plan view of a portion of the heat rejector, as seen axially.
Fig. 6A is a plan view of the linear corrugate fin.
Fig. 6B is an enlarged plan view of the linear corrugate fin in a rounded state with
both ends brought close together.
Fig. 6C is an enlarged plan view of a portion of the annular corrugate fin in its finished
state.
Fig. 7 is an enlarged plan view of a portion of the heat rejector of a second
embodiment of the invention, as seen axially.
Fig. 8A is a plan view of the linear corrugate fin.
Fig. 8B is an enlarged plan view of the linear corrugate fin in a rounded state with
both ends brought close together.
Fig. 8C is an enlarged plan view of a portion of the annular corrugate fin in its finished
state.
Fig. 9 is an enlarged plan view of a portion of the heat rejector of a third embodiment
of the invention, as seen axially.
Fig. 10A is a plan view of the linear corrugate fin.
Fig. 10B is an enlarged plan view of the linear corrugate fin in a rounded state with
both ends brought close together.
Fig. 10C is an enlarged plan view of a portion of the annular corrugate fin in its
finished state.
Fig. 11 is an enlarged plan view of the heat rejector of a fourth embodiment of the
invention, as seen axially.
Fig. 12A is a plan view of the linear corrugate fin.
Fig. 12B is an enlarged plan view of the linear corrugate fin in a rounded state with
both ends brought close together.
Fig. 12C is an enlarged plan view of a portion of the annular corrugate fin in its
finished state.
Fig. 13 is an enlarged plan view of a portion of the heat rejector of a fifth embodiment
of the invention, as seen axially.
Fig. 14A is a plan view of the linear corrugate fin.
Fig. 14B is an enlarged plan view of the linear corrugate fin in a rounded state with
both ends brought close together.
Fig. 14C is an enlarged plan view of a portion of the annular corrugate fin in its
finished state.
Fig. 15 is an enlarged plan view of a portion of the heat rejector of a sixth embodiment
of the invention, as seen axially.
Fig. 16A is a plan view of the linear corrugate fin.
Fig. 16B is an enlarged plan view of the linear corrugate fin in a rounded state with
both ends brought close together.
Fig. 16C is an enlarged plan view of a portion of the annular corrugate fin in its
finished state.
Fig. 17 is an enlarged perspective view of a principal portion of Fig. 16B.
Fig. 18 is an enlarged plan view of the heat rejector of a seventh embodiment of the
invention, as seen axially.
Fig. 19A is a plan view of the linear corrugate fin.
Fig. 19B is a plan view of the annular corrugate fin formed by rounding the linear
corrugate fin and putting both ends thereof together.
Fig. 19C is a top view of the cylindrical body.
Fig. 20 is an external perspective view of a portion of the heat rejector of an eighth
embedment of the invention.
Fig. 21A is an external perspective view of the heat exchanger element of the heat
rejector.
Fig. 21B is an exploded perspective view of the heat exchanger element.
Fig. 22 is an enlarged plan view of a portion of the heat exchanger element, as seen
axially.
Fig. 23 is a vertical sectional outline of the body and the heat exchanger element of the
heat rejector.
Fig. 24 is an enlarged plan view of a portion of the heat rejector of a ninth
embodiment of the invention, as seen axially.
Fig. 25A is a sectional view of the heat rejector before the heat exchanger element is
inserted into it from the guide member side thereof
Fig. 25B is a sectional view of the heat rejector after the heat exchanger
element is inserted into it.
Fig. 26 is a plan view of the heat rejector of a tenth embodiment of the
invention.
Fig. 27 is a plan view of the heat exchanger element of the heat rejector.
Fig. 28 is a plan view of the cylindrical body.
Fig. 29 is a sectional outline of a conventional free-piston-type Stirling
cycle refrigerator.
Fig. 30 is an external perspective view of a heat rejector as a
conventional example of a heat exchanger member.
Fig. 31 is an enlarged plan view of a portion of an example of a
conventional heat exchanger element, as seen axially.
Fig. 32 is an enlarged plan view of a portion of an example of another
conventional heat exchanger element, as seen axially.
Hereinafter, embodiments of the present invention will be described
with reference to the drawings. In the following descriptions, such members
that have the same names as in the conventional examples shown in Figs. 29 to
32 are identified with the same reference numerals. Moreover, in the
following descriptions, although only the heat rejector 4 and its heat
exchanger element 42 are dealt with, the explanations given as to their
configurations, selection of materials for the members consulting them,
possible design changes in them, and other aspects of them apply also to the
heat absorber 2 and its heat exchanger element 22. Therefore, unless
otherwise stated, in the following descriptions, the heat rejector 4 and its
heat exchanger element 42 are used interchangeably with the heat absorber 2 and its heat
exchanger element 22.
A first embodiment of the invention will be described below. Fig. 1 is an external
perspective view of the heat rejector 4 serving as a heat exchanger member in this
embodiment. Figs. 2A and 2B are an external perspective view and an exploded perspective
view, respectively, of the heat exchanger element 42 of the heat rejector 4. Fig. 3 is an
enlarged plan view of a portion of the heat rejector, as seen axially.
This heat exchanger element 42 is composed of an annular corrugate fin 421 and an
inner ring-shaped member 422. The annular corrugate fin 421 is produced by forming a
corrugated sheet material into a cylindrical shape with the individual grooves 421a thereof
parallel to the axis of the cylindrical shape. The inner ring-shaped member 422 is a
cylindrical member made of a material having good thermal conductivity.
First, the manufacturing method of the annular corrugate fin 421 used in this
embodiment will be described. Figs. 6A to 6C show the manufacturing procedure of the
annular corrugate fin 421. Fig. 6A is a plan view of a linear corrugate fin 420, Fig. 6B is an
enlarged plan view of the linear corrugate fin 420 in a rounded state with both ends thereof
brought close together, and Fig. 6C is an enlarged plan view of the annular corrugate fin 421
in its finished state.
As Fig. 6A shows, the linear corrugate fin 420 has contiguous grooves 420e each
having a V-shaped section. At one end of the linear corrugate fin 420 is a V-shaped groove
420a, and at the other end thereof is an inverted-V-shaped groove 420b. The endmost side
420c of the groove 420a and the endmost side 420d of the groove 420b are so formed that
their length L1 is shorter than the length L of the slant sides between the tops and bottoms
420f and 420f of the grooves 420e in between.
The linear corrugate fin 420 is bent in the directions indicated by arrows F1 and F2 in
Fig. 6A so as to be formed into a cylindrical shape. With the endmost sides 420c and 420d
brought close together as shown in Fig. 6B, those endmost sides 420c and 420d are hooked on
each other as shown in Fig. 6C, and thereby the annular corrugate fin 421 is formed. Thus,
as the annular corrugate fin 421 tends to return to its original linear state, the endmost sides
420c and 420d so hooked on each other pull against each other, and thereby the annular shape
of the annular corrugate fin 421 is maintained. Reference numeral 421d represents the
coupled portion.
As Figs. 2A and 5 show, the inner ring-shaped member 422 is placed in contact with
the inner periphery of the annular corrugate fin 421 so that they are coaxial with each other
(i.e. so that their axes coincide with each other). Here, the diameter of the circle formed by
smoothly connecting all the bottoms 421b of the annular corrugate fin 421 (i.e. the internal
diameter of the annular corrugate fin 421) is made substantially equal to the external diameter
of the inner ring-shaped member 422.
The annular corrugate fin 421 and the inner ring-shaped member 422 are joined
together with a ring-shaped brazing metal 13. Specifically, as Fig. 2B shows, the brazing
metal 13 is placed where the annular corrugate fin 421 and the inner ring-shaped member 422
make contact with each other and is heated so that the molten brazing metal 13 flows down
along the bottoms 421b of the annular corrugate fin 421.
As a result, as Fig. 3 shows, the brazing metal 13 is applied substantially evenly to
where the annular corrugate fin 421 and the inner ring-shaped member 422 make contact with
each other. When the brazing metal 13 hardens, the annular corrugate fin 421 and the inner
ring-shaped member 422 are joined together and thereby integrated together. Instead of
brazing specifically mentioned above, soldering or the like may be used.
The heat exchanger element 42 described above is inserted into a body 41 shown in
Fig. 1 so that they are coaxial with each other, and thereby the heat rejector 4 is produced.
The heat exchanger element 42 is inserted into the body 41 by the following mechanism. As
shown in Fig. 4, which is a sectional outline of the body 41 and the heat exchanger element 42,
both ends of the body 41 are tapered so that the wall thickness thereof becomes smaller
towards the ends along the axis thereof (these portions are referred to as the tapered portions
41a).
Moreover, the external diameter of the heat exchanger element 42 (i.e. the external
diameter of the annular corrugate fin 421) R1 (= B) is made slightly smaller than the
maximum internal diameter R2 (= B + α1) of the body 41 at both ends thereof, and slightly
greater than the internal diameter R3 (= B - α2) of the body 41 in the portion thereof
between the tapered portions 41a.
Thus, when the heat exchanger element 42 is inserted into the heat exchanger element
42 from one end thereof, the insertion requires a small force at first. Since the internal
diameter of the body 41 gradually becomes smaller until it eventually becomes smaller than
the external diameter R1 of the heat exchanger element 42, as the heat exchanger element 42
is inserted, the force required to do so gradually increases. In this way, the heat exchanger
element 42 can be inserted into the body 41 easily.
Here, since the bottoms 421b of the annular corrugate fin 421 are fixed to the inner
ring-shaped member 422, the annular corrugate fin 421 thus fitted into the body 41, of which
the internal diameter R3 is smaller than the external diameter R1 of the annular corrugate fin
421, is brought into a state in which the grooves 421a are so pressed as to be wider open, and
this produces a resilient force acting radially outward.
Moreover, since the external diameter R1 of the annular corrugate fin 421 and the
depth of the grooves 421a are constant along the axis, the aforementioned resilient force
presses the heat exchanger element 42 onto the inner surface of the body 41 with a uniform
force all around and thereby keeps it in position. Here, the annular corrugate fin 421 and the
inner ring-shaped member 422 are firmly fixed together, and thus are not deformed.
As described above, in this embodiment, the inner ring-shaped member 422 can be
fixed in the desired position inside the body 41 without the use of adhesive or solder. This
helps simplify the manufacturing procedure and reduce the manufacturing cost, and also
stabilize the heat exchange performance of the heat exchanger member.
Moreover, when the annular corrugate fin 421 is damaged, the heat exchanger element
42 can be taken out of and removed from the body 41. This permits easy replacement as
required, and thus helps alleviate the economic burden on the user in the event of repair and
solve recycling problems.
Furthermore, in the heat exchanger element 42 used in this embodiment, the annular
corrugate fin 421 and the inner ring-shaped member 422 are integrated together by brazing,
soldering, or the like, and thus exhibit better thermal conductivity than where they are left
unintegrated. This helps increase heat exchange efficiency.
Next, a second embodiment of the invention will be described. Fig. 7 is an enlarged
plan view of the heat rejector 4 of this embodiment, as seen axially. The heat rejector 4 of
this embodiment, like that of the first embodiment described above, is composed of a heat
exchanger element 42, consisting of an annular corrugate fin 421 and an inner ring-shaped
member 422 brazed inside it, and a body 41 into which the heat exchanger element 42 is fitted.
First, the manufacturing method of the annular corrugate fin 421 used in this
embodiment will be described. Figs. 8A to 8C show the manufacturing procedure of the
annular corrugate fin 421. Fig. 8A is a plan view of the linear corrugate fin 420, Fig. 8B is
an enlarged plan view of the linear corrugate fin 420 in a rounded state with both ends thereof
brought close together, and Fig. 8C is an enlarged plan view of a portion of the annular
corrugate fin 421 in its finished state.
As Fig. 8A shows, the linear corrugate fin 420 has contiguous grooves 420e each
having a V-shaped section. At one end of the linear corrugate fin 420 is a V-shaped groove
420a, and at the other end thereof is an inverted-V-shaped groove 420b. The endmost side
420c of the groove 420a and the endmost side 420d of the groove 420b are so formed that
their length L2 is shorter than the length L of the slant sides between the tops and bottoms
420f and 420f of the grooves 420e in between.
The linear corrugate fin 420 is bent in the directions indicated by arrows F1 and F2 in
Fig. 8A so as to be formed into a cylindrical shape. With the endmost sides 420c and 420d
brought close together as shown in Fig. 8B, spot welding is performed on parts of the surfaces
of those endmost sides 420c and 420d so that these surfaces are joined together while they are
kept in contact with each other. In this way, the annular corrugate fin 421 as shown in Fig.
8C is produced. Reference numeral 421e represents the brazed or welded portion.
As Figs. 2A and 7 show, the inner ring-shaped member 422 is placed in contact with
the inner periphery of the annular corrugate fin 421 so that they are coaxial with each other.
Here, the diameter of the circle formed by smoothly connecting all the bottoms 421b of the
annular corrugate fin 421 (i.e. the internal diameter of the annular corrugate fin 421) is made
substantially equal to the external diameter of the inner ring-shaped member 422.
The annular corrugate fin 421 and the inner ring-shaped member 422 are joined
together with a ring-shaped brazing metal 13. Specifically, as Fig. 2B shows, the brazing
metal 13 is placed where the annular corrugate fin 421 and the inner ring-shaped member 422
make contact with each other and is heated so that the molten brazing metal 13 flows down
along the bottoms 421b of the annular corrugate fin 421.
As a result, as Fig. 3 shows, the brazing metal 13 is applied substantially evenly to
where the annular corrugate fin 421 and the inner ring-shaped member 422 make contact with
each other. When the brazing metal 13 hardens, the annular corrugate fin 421 and the inner
ring-shaped member 422 are joined together and thereby integrated together. Instead of
brazing specifically mentioned above, soldering or the like may be used.
The heat exchanger element 42 described above is inserted into a body 41 shown in
Fig. 1 so that they are coaxial with each other, and thereby the heat rejector 4 is produced.
The heat exchanger element 42 is inserted into the body 41 by the following mechanism. As
shown in Fig. 4, which is a sectional outline of the body 41 and the heat exchanger element 42,
both ends of the body 41 are tapered so that the wall thickness thereof becomes smaller
towards the ends along the axis thereof (these portions are referred to as the tapered portions
41a).
Moreover, the external diameter of the heat exchanger element 42 (i.e. the external
diameter of the annular corrugate fin 421) R1 (= B) is made slightly smaller than the
maximum internal diameter R2 (= B + α1) of the body 41 at both ends thereof, and slightly
greater than the internal diameter R3 (= B - α2) of the body 41 in the portion thereof
between the tapered portions 41a.
Thus, when the heat exchanger element 42 is inserted into the heat exchanger element
42 from one end thereof, the insertion requires a small force at first. Since the internal
diameter of the body 41 gradually becomes smaller until it eventually becomes smaller than
the external diameter R1 of the heat exchanger element 42, as the heat exchanger element 42
is inserted, the force required to do so gradually increases. In this way, the heat exchanger
element 42 can be inserted into the body 41 easily.
Here, since the bottoms 421b of the annular corrugate fin 421 are fixed to the inner
ring-shaped member 422, the annular corrugate fin 421 thus fitted into the body 41, of which
the internal diameter R3 is smaller than the external diameter R1 of the annular corrugate fin
421, is brought into a state in which the grooves 421a are so pressed as to be wider open, and
this produces a resilient force acting radially outward.
Moreover, since the external diameter R1 of the annular corrugate fin 421 and the
depth of the grooves 421a are constant along the axis, the aforementioned resilient force
presses the heat exchanger element 42 onto the inner surface of the body 41 with a uniform
force all around and thereby keeps it in position. Here, the annular corrugate fin 421 and the
inner ring-shaped member 422 are firmly fixed together, and thus are not deformed.
As described above, in this embodiment, the inner ring-shaped member 422 can be
fixed in the desired position inside the body 41 without the use of adhesive or solder. This
helps simplify the manufacturing procedure and reduce the manufacturing cost, and also
stabilize the heat exchange performance of the heat exchanger member.
Moreover, when the annular corrugate fin 421 is damaged, the heat exchanger element
42 can be taken out of and removed from the body 41. This permits easy replacement as
required, and thus helps alleviate the economic burden on the user in the event of repair and
solve recycling problems.
Furthermore, in the heat exchanger element 42 used in this embodiment, the annular
corrugate fin 421 and the inner ring-shaped member 422 are integrated together by brazing,
soldering, or the like, and thus exhibit better thermal conductivity than where they are left
unintegrated. This helps increase heat exchange efficiency.
Next, a third embodiment of the invention will be described. Fig. 9 is a plan view of
a portion of the heat rejector 4 of this embodiment, as seen axially. The heat rejector 4 of
this embodiment, like that of the first embodiment described earlier, is composed of a heat
exchanger element 42, consisting of an annular corrugate fin 421 and an inner ring-shaped
member 422 brazed inside it, and a body 41 into which the heat exchanger element 42 is fitted.
First, the manufacturing method of the annular corrugate fin 421 used in this
embodiment will be described. Figs. 10A and 10B show the manufacturing procedure of the
annular corrugate fin 421. Fig. 10A is a plan view of the linear corrugate fin 420, Fig. 10B
is an enlarged plan view of the linear corrugate fin 420 in a rounded state with both ends
thereof brought close together, and Fig. 10C is an enlarged plan view of a portion of the
annular corrugate fin 421 in its finished state.
As Fig. 10A shows, the linear corrugate fin 420 has contiguous grooves 420e each
having a V-shaped section. At one end of the linear corrugate fin 420 is a V-shaped groove
420a, and at the other end thereof is an inverted-V-shaped groove 420b. The endmost side
420c of the groove 420a and the endmost side 420d of the groove 420b are so formed that
their length L3 is shorter than the length L of the slant sides between the tops and bottoms
420f and 420f of the grooves 420e in between.
The linear corrugate fin 420 is bent in the directions indicated by arrows F1 and F2 in
Fig. 10A so as to be formed into a cylindrical shape so that the endmost sides 420c and 420d
are put together (Fig. 10B). Then, the surfaces of those endmost sides 420c and 420d, to
which adhesive 16 such as instant adhesive has been applied beforehand, are held in contact
with each other for a while so that they are bonded together. In this way, the annular
corrugate fin 421 as shown in Fig. 10C is produced. Reference numeral 421f represents the
bonded portion.
As Figs. 2A and 9 show, the inner ring-shaped member 422 is placed in contact with
the inner periphery of the annular corrugate fin 421 so that they are coaxial with each other.
Here, the diameter of the circle formed by smoothly connecting all the bottoms 421b of the
annular corrugate fin 421 (i.e. the internal diameter of the annular corrugate fin 421) is made
substantially equal to the external diameter of the inner ring-shaped member 422.
The annular corrugate fin 421 and the inner ring-shaped member 422 are joined
together with a ring-shaped brazing metal 13. Specifically, as Fig. 2B shows, the brazing
metal 13 is placed where the annular corrugate fin 421 and the inner ring-shaped member 422
make contact with each other and is heated so that the molten brazing metal 13 flows down
along the bottoms 421b of the annular corrugate fin 421.
As a result, as Fig. 3 shows, the brazing metal 13 is applied substantially evenly to
where the annular corrugate fin 421 and the inner ring-shaped member 422 make contact with
each other. When the brazing metal 13 hardens, the annular corrugate fin 421 and the inner
ring-shaped member 422 are joined together and thereby integrated together. Instead of
brazing specifically mentioned above, soldering or the like may be used.
The heat exchanger element 42 described above is inserted into a body 41 shown in
Fig. 1 so that they are coaxial with each other, and thereby the heat rejector 4 is produced.
The heat exchanger element 42 is inserted into the body 41 by the following mechanism. As
shown in Fig. 4, which is a sectional outline of the body 41 and the heat exchanger element 42,
both ends of the body 41 are tapered so that the wall thickness thereof becomes smaller
towards the ends along the axis thereof (these portions are referred to as the tapered portions
41a).
Moreover, the external diameter of the heat exchanger element 42 (i.e. the external
diameter of the annular corrugate fin 421) R1 (= B) is made slightly smaller than the
maximum internal diameter R2 (= B + α1) of the body 41 at both ends thereof, and slightly
greater than the internal diameter R3 (= B - α2) of the body 41 in the portion thereof
between the tapered portions 41a.
Thus, when the heat exchanger element 42 is inserted into the heat exchanger element
42 from one end thereof, the insertion requires a small force at first. Since the internal
diameter of the body 41 gradually becomes smaller until it eventually becomes smaller than
the external diameter R1 of the heat exchanger element 42, as the heat exchanger element 42
is inserted, the force required to do so gradually increases. In this way, the heat exchanger
element 42 can be inserted into the body 41 easily.
Here, since the bottoms 421b of the annular corrugate fin 421 are fixed to the inner
ring-shaped member 422, the annular corrugate fin 421 thus fitted into the body 41, of which
the internal diameter R3 is smaller than the external diameter R1 of the annular corrugate fin
421, is brought into a state in which the grooves 421a are so pressed as to be wider open, and
this produces a resilient force acting radially outward.
Moreover, since the external diameter R1 of the annular corrugate fin 421 and the
depth of the grooves 421a are constant along the axis, the aforementioned resilient force
presses the heat exchanger element 42 onto the inner surface of the body 41 with a uniform
force all around and thereby keeps it in position. Here, the annular corrugate fin 421 and the
inner ring-shaped member 422 are firmly fixed together, and thus are not deformed.
As described above, in this embodiment, the inner ring-shaped member 422 can be
fixed in the desired position inside the body 41 without the use of adhesive or solder. This
helps simplify the manufacturing procedure and reduce the manufacturing cost, and also
stabilize the heat exchange performance of the heat exchanger member.
Moreover, when the annular corrugate fin 421 is damaged, the heat exchanger element
42 can be taken out of and removed from the body 41. This permits easy replacement as
required, and thus helps alleviate the economic burden on the user in the event of repair and
solve recycling problems.
Furthermore, in the heat exchanger element 42 used in this embodiment, the annular
corrugate fin 421 and the inner ring-shaped member 422 are integrated together by brazing,
soldering, or the like, and thus exhibit better thermal conductivity than where they are left
unintegrated. This helps increase heat exchange efficiency.
Next, a fourth embodiment of the invention will be described. Fig. 11 is a plan view
of a portion of the heat rejector 4 of this embodiment, as seen axially. The heat rejector 4 of
this embodiment, like that of the first embodiment described earlier, is composed of a heat
exchanger element 42, consisting of an annular corrugate fin 421 and an inner ring-shaped
member 422 brazed inside it, and a body 41 into which the heat exchanger element 42 is fitted.
First, the manufacturing method of the annular corrugate fin 421 used in this
embodiment will be described. Figs. 12A to 12C show the manufacturing procedure of the
annular corrugate fin 421. Fig. 12A is a plan view of the linear corrugate fin 420, Fig. 12B
is an enlarged plan view of the linear corrugate fin 420 in a rounded state with both ends
thereof brought close together, and Fig. 12C is an enlarged plan view of a portion of the
annular corrugate fin 421 in its finished state.
As Fig. 12A shows, the linear corrugate fin 420 has contiguous grooves 420e each
having a V-shaped section. At one end of the linear corrugate fin 420 is a V-shaped groove
420a, and at the other end thereof is an inverted-V-shaped groove 420b. The endmost side
420c of the groove 420a and the endmost side 420d of the groove 420b are so formed that
their length L4 is shorter than the length L of the slant sides between the tops and bottoms
420f and 420f of the grooves 420e in between.
The linear corrugate fin 420 is bent in the directions indicated by arrows F1 and F2 in
Fig. 12A so as to be formed into a cylindrical shape so that the endmost sides 420c and 420d
are put together (Fig. 12B). Then, the surfaces of those endmost sides 420c and 420d, to
which solder in the form of paste has been applied uniformly beforehand, are held in contact
with each other and heated for a while so that they are soldered together. In this way, the
annular corrugate fin 421 as shown in Fig. 12C is produced. Reference numeral 421g
represents the soldered or welded portion.
As Figs. 2A and 11 show, the inner ring-shaped member 422 is placed in contact with
the inner periphery of the annular corrugate fin 421 so that they are coaxial with each other.
Here, the diameter of the circle formed by smoothly connecting all the bottoms 421b of the
annular corrugate fin 421 (i.e. the internal diameter of the annular corrugate fin 421) is made
substantially equal to the external diameter of the inner ring-shaped member 422.
The annular corrugate fin 421 and the inner ring-shaped member 422 are joined
together with a ring-shaped brazing metal 13. Specifically, as Fig. 2B shows, the brazing
metal 13 is placed where the annular corrugate fin 421 and the inner ring-shaped member 422
make contact with each other and is heated so that the molten brazing metal 13 flows down
along the bottoms 421b of the annular corrugate fin 421.
As a result, as Fig. 3 shows, the brazing metal 13 is applied substantially evenly to
where the annular corrugate fin 421 and the inner ring-shaped member 422 make contact with
each other. When the brazing metal 13 hardens, the annular corrugate fin 421 and the inner
ring-shaped member 422 are joined together and thereby integrated together. Instead of
brazing specifically mentioned above, soldering or the like may be used.
The heat exchanger element 42 described above is inserted into a body 41 shown in
Fig. 1 so that they are coaxial with each other, and thereby the heat rejector 4 is produced.
The heat exchanger element 42 is inserted into the body 41 by the following mechanism. As
shown in Fig. 4, which is a sectional outline of the body 41 and the heat exchanger element 42,
both ends of the body 41 are tapered so that the wall thickness thereof becomes smaller
towards the ends along the axis thereof (these portions are referred to as the tapered portions
41a).
Moreover, the external diameter of the heat exchanger element 42 (i.e. the external
5 diameter of the annular corrugate fin 421) R1 (= B) is made slightly smaller than the
maximum internal diameter R2 (= B + α1) of the body 41 at both ends thereof, and slightly
greater than the internal diameter R3 (= B - α2) of the body 41 in the portion thereof
between the tapered portions 41a.
Thus, when the heat exchanger element 42 is inserted into the heat exchanger element
42 from one end thereof, the insertion requires a small force at first. Since the internal
diameter of the body 41 gradually becomes smaller until it eventually becomes smaller than
the external diameter R1 of the heat exchanger element 42, as the heat exchanger element 42
is inserted, the force required to do so gradually increases. In this way, the heat exchanger
element 42 can be inserted into the body 41 easily.
Here, since the bottoms 421b of the annular corrugate fin 421 are fixed to the inner
ring-shaped member 422, the annular corrugate fin 421 thus fitted into the body 41, of which
the internal diameter R3 is smaller than the external diameter R1 of the annular corrugate fin
421, is brought into a state in which the grooves 421a are so pressed as to be wider open, and
this produces a resilient force acting radially outward.
Moreover, since the external diameter R1 of the annular corrugate fin 421 and the
depth of the grooves 421a are constant along the axis, the aforementioned resilient force
presses the heat exchanger element 42 onto the inner surface of the body 41 with a uniform
force all around and thereby keeps it in position. Here, the annular corrugate fin 421 and the
inner ring-shaped member 422 are firmly fixed together, and thus are not deformed.
As described above, in this embodiment, the inner ring-shaped member 422 can be
fixed in the desired position inside the body 41 without the use of adhesive or solder. This
helps simplify the manufacturing procedure and reduce the manufacturing cost, and also
stabilize the heat exchange performance of the heat exchanger member.
Moreover, when the annular corrugate fin 421 is damaged, the heat exchanger element
42 can be taken out of and removed from the body 41. This permits easy replacement as
required, and thus helps alleviate the economic burden on the user in the event of repair and
solve recycling problems.
Furthermore, in the heat exchanger element 42 used in this embodiment, the annular
corrugate fin 421 and the inner ring-shaped member 422 are integrated together by brazing,
soldering, or the like, and thus exhibit better thermal conductivity than where they are left
unintegrated. This helps increase heat exchange efficiency.
Next, a fifth embodiment of the invention will be described. Fig. 13 is a plan view of
a portion of the heat rejector 4 of this embodiment, as seen axially. The heat rejector 4 of
this embodiment, like that of the first embodiment described earlier, is composed of a heat
exchanger element 42, consisting of an annular corrugate fin 421 and an inner ring-shaped
member 422 brazed inside it, and a body 41 into which the heat exchanger element 42 is fitted.
First, the manufacturing method of the annular corrugate fin 421 used in this
embodiment will be described. Figs. 14A to 14C show the manufacturing procedure of the
annular corrugate fin 421. Fig. 14A is a plan view of the linear corrugate fin 420, Fig. 14B
is an enlarged plan view of the linear corrugate fin 420 in a rounded state with both ends
thereof brought close together, and Fig. 14C is an enlarged plan view of a portion of the
annular corrugate fin 421 in its finished state.
As Fig. 14A shows, the linear corrugate fin 420 has contiguous grooves 420e each
having a V-shaped section. At both ends of the linear corrugate fin 420 are inverted-V-shaped
grooves 420b. The endmost side 420c of the groove 420a and the endmost side 420d
of the groove 420b are so formed that their length L5 is shorter than the length L of the slant
sides between the tops and bottoms 420f and 420f of the grooves 420e in between.
The linear corrugate fin 420 is bent in the directions indicated by arrows F1 and F2 in
Fig. 14A so as to be formed into a cylindrical shape so that the endmost sides 420c and 420d
are put together (Fig. 14B). Then, the endmost sides 420c and 420d are, with the surfaces
thereof held in contact with each other over their entire surfaces, coupled together with a
coupling member 18 made of a highly resilient material and having a C-shaped section. In
this way, the annular corrugate fin 421 as shown in Fig. 14C is produced.
As Figs. 2A and 13 show, the inner ring-shaped member 422 is placed in contact with
the inner periphery of the annular corrugate fin 421 so that they are coaxial with each other.
Here, the diameter of the circle formed by smoothly connecting all the bottoms 421b of the
annular corrugate fin 421 (i.e. the internal diameter of the annular corrugate fin 421) is made
substantially equal to the external diameter of the inner ring-shaped member 422.
The annular corrugate fin 421 and the inner ring-shaped member 422 are joined
together with a ring-shaped brazing metal 13. Specifically, as Fig. 2B shows, the brazing
metal 13 is placed where the annular corrugate fin 421 and the inner ring-shaped member 422
make contact with each other and is heated so that the molten brazing metal 13 flows down
along the bottoms 421b of the annular corrugate fin 421.
As a result, as Fig. 3 shows, the brazing metal 13 is applied substantially evenly to
where the annular corrugate fin 421 and the inner ring-shaped member 422 make contact with
each other. When the brazing metal 13 hardens, the annular corrugate fin 421 and the inner
ring-shaped member 422 are joined together and thereby integrated together. Instead of
brazing specifically mentioned above, soldering or the like may be used.
The heat exchanger element 42 described above is inserted into a body 41 shown in
Fig. 1 so that they are coaxial with each other, and thereby the heat rejector 4 is produced.
The heat exchanger element 42 is inserted into the body 41 by the following mechanism. As
shown in Fig. 4, which is a sectional outline of the body 41 and the heat exchanger element 42,
both ends of the body 41 are tapered so that the wall thickness thereof becomes smaller
towards the ends along the axis thereof (these portions are referred to as the tapered portions
41a).
Moreover, the external diameter of the heat exchanger element 42 (i.e. the external
diameter of the annular corrugate fin 421) R1 (= B) is made slightly smaller than the
maximum internal diameter R2 (= B + α1) of the body 41 at both ends thereof, and slightly
greater than the internal diameter R3 (= B - α2) of the body 41 in the portion thereof
between the tapered portions 41a.
Thus, when the heat exchanger element 42 is inserted into the heat exchanger element
42 from one end thereof, the insertion requires a small force at first. Since the internal
diameter of the body 41 gradually becomes smaller until it eventually becomes smaller than
the external diameter R1 of the heat exchanger element 42, as the heat exchanger element 42
is inserted, the force required to do so gradually increases. In this way, the heat exchanger
element 42 can be inserted into the body 41 easily.
Here, since the bottoms 421b of the annular corrugate fin 421 are fixed to the inner
ring-shaped member 422, the annular corrugate fin 421 thus fitted into the body 41, of which
the internal diameter R3 is smaller than the external diameter R1 of the annular corrugate fin
421, is brought into a state in which the grooves 421a are so pressed as to be wider open, and
this produces a resilient force acting radially outward.
Moreover, since the external diameter R1 of the annular corrugate fin 421 and the
depth of the grooves 421a are constant along the axis, the aforementioned resilient force
presses the heat exchanger element 42 onto the inner surface of the body 41 with a uniform
force all around and thereby keeps it in position. Here, the annular corrugate fin 421 and the
inner ring-shaped member 422 are firmly fixed together, and thus are not deformed.
As described above, in this embodiment, the inner ring-shaped member 422 can be
fixed in the desired position inside the body 41 without the use of adhesive or solder. This
helps simplify the manufacturing procedure and reduce the manufacturing cost, and also
stabilize the heat exchange performance of the heat exchanger member.
Moreover, when the annular corrugate fin 421 is damaged, the heat exchanger element
42 can be taken out of and removed from the body 41. This permits easy replacement as
required, and thus helps alleviate the economic burden on the user in the event of repair and
solve recycling problems.
Furthermore, in the heat exchanger element 42 used in this embodiment, the annular
corrugate fin 421 and the inner ring-shaped member 422 are integrated together by brazing,
soldering, or the like, and thus exhibit better thermal conductivity than where they are left
unintegrated. This helps increase heat exchange efficiency.
Next, a sixth embodiment of the invention will be described. Fig. 15 is a plan view
of a portion of the heat rejector 4 of this embodiment, as seen axially. The heat rejector 4 of
this embodiment, like that of the first embodiment described earlier, is composed of a heat
exchanger element 42, consisting of an annular corrugate fin 421 and an inner ring-shaped
member 422 brazed inside it, and a body 41 into which the heat exchanger element 42 is fitted.
First, the manufacturing method of the annular corrugate fin 421 used in this
embodiment will be described. Fig. 16 shows the manufacturing procedure of the annular
corrugate fin 421. Fig. 16A is a plan view of the linear corrugate fin 420, Fig. 16B is an
enlarged plan view of the linear corrugate fin 420 in a rounded state with both ends thereof
brought close together, and Fig. 14C is an enlarged plan view of the annular corrugate fin 421
in its finished state. Fig. 17 is a perspective view of a principal portion of Fig. 16B.
As Fig. 16A shows, the linear corrugate fin 420 has contiguous grooves 420e each
having a V-shaped section. At both ends of the linear corrugate fin 420 are inverted-V-shaped
grooves 420b. The endmost side 420c of the groove 420a and the endmost side 420d
of the groove 420b are so formed that their length L6 is shorter than the length L of the slant
sides between the tops and bottoms 420f and 420f of the grooves 420e in between.
Moreover, as Fig. 17 shows, in the endmost sides 420c and 420d, slits 19 are respectively
formed in such a way that one slit extends from one flank 420g of the linear corrugate fin 420
halfway inward and the other slit extends from the other flank 420h of linear corrugate fin 420
halfway inward.
The linear corrugate fin 420 is bent in the directions indicated by arrows F1 and F2 in
Fig. 16A so as to be formed into a cylindrical shape so that the endmost sides 420c and 420d
are put together (Fig. 16B). Then, the endmost sides 420c and 420d are coupled together by
engaging together the slit 19 formed in the endmost side 420c and the slit 19 formed in the
endmost side 420d. In this way, the annular corrugate fin 421 as shown in Fig. 16C is
produced.
As Figs. 2A and 15 show, the inner ring-shaped member 422 is placed in contact with
the inner periphery of the annular corrugate fin 421 so that they are coaxial with each other.
Here, the diameter of the circle formed by smoothly connecting all the bottoms 421b of the
annular corrugate fin 421 (i.e. the internal diameter of the annular corrugate fin 421) is made
substantially equal to the external diameter of the inner ring-shaped member 422.
The annular corrugate fin 421 and the inner ring-shaped member 422 are joined
together with a ring-shaped brazing metal 13. Specifically, as Fig. 2B shows, the brazing
metal 13 is placed where the annular corrugate fin 421 and the inner ring-shaped member 422
make contact with each other and is heated so that the molten brazing metal 13 flows down
along the bottoms 421b of the annular corrugate fin 421.
As a result, as Fig. 3 shows, the brazing metal 13 is applied substantially evenly to
where the annular corrugate fin 421 and the inner ring-shaped member 422 make contact with
each other. When the brazing metal 13 hardens, the annular corrugate fin 421 and the inner
ring-shaped member 422 are joined together and thereby integrated together. Instead of
brazing specifically mentioned above, soldering or the like may be used.
The heat exchanger element 42 described above is inserted into a body 41 shown in
Fig. 1 so that they are coaxial with each other, and thereby the heat rejector 4 is produced.
The heat exchanger element 42 is inserted into the body 41 by the following mechanism. As
shown in Fig. 4, which is a sectional outline of the body 41 and the heat exchanger element 42,
both ends of the body 41 are tapered so that the wall thickness thereof becomes smaller
towards the ends along the axis thereof (these portions are referred to as the tapered portions
41a).
Moreover, the external diameter of the heat exchanger element 42 (i.e. the external
diameter of the annular corrugate fin 421) R1 (= B) is made slightly smaller than the
maximum internal diameter R2 (= B + α1) of the body 41 at both ends thereof, and slightly
greater than the internal diameter R3 (= B - α2) of the body 41 in the portion thereof
between the tapered portions 41a.
Thus, when the heat exchanger element 42 is inserted into the heat exchanger element
42 from one end thereof, the insertion requires a small force at first. Since the internal
diameter of the body 41 gradually becomes smaller until it eventually becomes smaller than
the external diameter R1 of the heat exchanger element 42, as the heat exchanger element 42
is inserted, the force required to do so gradually increases. In this way, the heat exchanger
element 42 can be inserted into the body 41 easily.
Here, since the bottoms 421b of the annular corrugate fin 421 are fixed to the inner
ring-shaped member 422, the annular corrugate fin 421 thus fitted into the body 41, of which
the internal diameter R3 is smaller than the external diameter R1 of the annular corrugate fin
421, is brought into a state in which the grooves 421a are so pressed as to be wider open, and
this produces a resilient force acting radially outward.
Moreover, since the external diameter R1 of the annular corrugate fin 421 and the
depth of the grooves 421a are constant along the axis, the aforementioned resilient force
presses the heat exchanger element 42 onto the inner surface of the body 41 with a uniform
force all around and thereby keeps it in position. Here, the annular corrugate fin 421 and the
inner ring-shaped member 422 are firmly fixed together, and thus are not deformed.
As described above, in this embodiment, the inner ring-shaped member 422 can be
fixed in the desired position inside the body 41 without the use of adhesive or solder. This
helps simplify the manufacturing procedure and reduce the manufacturing cost, and also
stabilize the heat exchange performance of the heat exchanger member.
Moreover, when the annular corrugate fin 421 is damaged, the heat exchanger element
42 can be taken out of and removed from the body 41. This permits easy replacement as
required, and thus helps alleviate the economic burden on the user in the event of repair and
solve recycling problems.
Furthermore, in the heat exchanger element 42 used in this embodiment, the annular
corrugate fin 421 and the inner ring-shaped member 422 are integrated together by brazing,
soldering, or the like, and thus exhibit better thermal conductivity than when they are left
unintegrated. This helps increase heat exchange efficiency.
Next, a seventh embodiment of the invention will be described. Fig. 18 is a plan
view of the heat rejector 4 of this embodiment, as seen axially. The heat rejector 4 of this
embodiment, like that of the first embodiment described earlier, is composed of a heat
exchanger element 42, consisting of an annular corrugate fin 421 and an inner ring-shaped
member 422 brazed inside it, and a body 41 into which the heat exchanger element 42 is fitted.
First, the manufacturing method of the annular corrugate fin 421 used in this
embodiment will be described. Figs. 19A to 19C show the manufacturing procedure of the
annular corrugate fin 421. Fig. 19A is a plan view of the linear corrugate fin 420, Fig. 19B
is a plan view of the annular corrugate fin formed by rounding the linear corrugate fin and
putting both ends of thereof together, and Fig. 19C is a top view of the cylindrical body 41.
As Fig. 19A shows, the linear corrugate fin 420 has contiguous grooves 420e each
having a V-shaped section. At both ends of the linear corrugate fin 420 are inverted-V-shaped
grooves 420b. The endmost side 420c of the groove 420a and the endmost side 420d
of the groove 420b are so formed that their length L7 is shorter than the length L of the slant
sides between the tops and bottoms 420f and 420f of the grooves 420e in between.
The linear corrugate fin 420 is bent in the directions indicated by arrows F1 and F2 in
Fig. 19A so as to be formed into a cylindrical shape so that the endmost sides 420c and 420d
are put together. Then, the linear corrugate fin 420 is held in a state in which the endmost
sides 420c and 420d are kept in contact with each other at least at their tips. In this way, the
annular corrugate fin 421 as shown in Fig. 19B is produced. As a result, the tip portions of
the endmost sides 420c and 420d form a protruding portion 421h that protrudes radially out of
the outer periphery of the annular corrugate fin 421 (i.e. the circle formed by smoothly
connecting all the tops 421c).
The internal diameter of the cylindrical body 41 is made substantially equal to the
external diameter of the annular corrugate fin 421. Moreover, as Fig. 19C shows, in one
position in the inner surface of the body 41, a groove 41a into which to fit the protruding
portion 421h of the annular corrugate fin 421 is formed so as to extend axially.
The annular corrugate fin 421 is then inserted axially into the body 41 with the center
of the former aligned with the center axis of the latter and with the protruding portion 421h of
the former fit into the groove 41a of the latter. Here, as Fig. 1 shows, the annular corrugate
fin 421 is inserted until one end thereof becomes flush with the open end of the body 41.
On the protruding portion 421h of the annular corrugate fin 421 acts a force that tends
to bring the annular corrugate fin 421 back into the original state of the linear corrugate fin
420. However, since the protruding portion 421h is trapped in the groove 41a, the force
converts to a force that tends to expand the annular corrugate fin 421 radially. Thus, the
annular corrugate fin 421 expands radially, and is thereby pressed onto the inner surface of
the body 41. This makes it possible to keep the annular corrugate fin 421 in the desired
position while maintaining its shape.
On the other hand, the external diameter of the cylindrical inner ring-shaped member
422 is made substantially equal to the internal diameter of the annular corrugate fin 421 (i.e.
the diameter of the circle formed by smoothly connecting all the bottoms 2b). The inner
ring-shaped member 422 is inserted axially into the annular corrugate fin 421 with the center
of the former aligned with the center axis of the latter. Then, the annular corrugate fin 421
and the inner ring-shaped member 422 are integrated together by brazing them together at
where the inner periphery of the former makes contact with the outer surface of the inner ring-shaped
member 422. In this way, the heat exchanger element 42 is fitted into the body 41,
and thereby the heat rejector 4 is obtained as shown in Fig. 18.
Thus, it is possible to eliminate the process of bonding or welding the annular
corrugate fin 421 to the body 41. This enhances productivity. Moreover, it is possible to
fix the annular corrugate fin 421 securely by press fitting, and achieve uniform contact all
round the annular corrugate fin 421. This helps manufacture the heat rejector 4 stably with
excellent performance.
Next, an eighth embodiment of the invention will be described. Fig. 20 is an external
perspective view of the heat rejector 4 serving as a heat exchanger member in this
embodiment. Fig. 21A is an external perspective view and an exploded perspective view,
respectively, of the heat exchanger element 42' incorporated in the heat rejector 4.
This heat exchanger element 42' is composed of an annular corrugate fin 421 and an
outer ring-shaped member 422'. The annular corrugate fin 421 is produced by the same
procedure as described earlier in connection with the first to seventh embodiments. The
outer ring-shaped member 422' is a cylindrical member made of a material having good
thermal conductivity and resilience.
As Fig. 21A shows, the outer ring-shaped member 422' is placed in contact with the
outer periphery of the annular corrugate fin 421 so that they are coaxial with each other.
Here, the external diameter of the annular corrugate fin 421 is made substantially equal to the
internal diameter of the outer ring-shaped member 422'. Moreover, as Fig. 22 shows, the
annular corrugate fin 421 and the outer ring-shaped member 422' are, like the annular
corrugate fin 421 and the inner ring-shaped member 422 of the first embodiment, bonded
together and fixed together with a brazing metal 13 or solder.
The heat exchanger element 42' described above is inserted into a body 41 shown in
Fig. 20 so that they are coaxial with each other, and thereby the heat rejector 4 is produced.
The heat exchanger element 42' is inserted into the body 41 by the following mechanism.
As shown in Fig. 23, which is a sectional outline of the body 41 and the heat exchanger
element 42', both ends of the body 41 are tapered in the same way as in the first embodiment
(these portions are referred to as the tapered portions 41a).
Moreover, the external diameter of the heat exchanger element 42' (i.e. the external
diameter of the outer ring-shaped member 422') R1' (= B') is made slightly smaller than the
maximum internal diameter R2' (= B' + α1') of the body 41 at both ends thereof, and slightly
greater than the internal diameter R3' (= B' - α2') of the body 41 in the portion thereof
between the tapered portions 41a.
Thus, as in the first embodiment described earlier, the tapered portions 41a permit the
heat exchanger element 42' to be inserted into the body 41 easily. Moreover, the heat
exchanger element 42' thus fitted into the body 41 is pressed onto the inner surface of the
body 41 and is thereby kept in position by the resilience that occurs in the annular corrugate
fin 421 and the outer ring-shaped member 422'. Here, the annular corrugate fin 421 and the
outer ring-shaped member 422' are firmly fixed together, and thus are not deformed.
As described above, in this embodiment also, the heat exchanger element 42' can be
fixed in the desired position inside the body 41 without the use of adhesive or solder.
Moreover, since the heat exchanger element 42' and the body 41 are not fixed together, the
former can be taken out of the latter freely. Moreover, since the annular corrugate fin 421
and the outer ring-shaped member 422' are integrated together, they exhibit still better
thermal conductivity.
Next, a ninth embodiment of the invention will be described with reference to the
drawings. Fig. 24 is an enlarged plan view of a portion of the heat rejector 4 of the
embodiment, as seen axially. Fig. 25 shows part of the manufacturing procedure of the heat
rejector 4; specifically, Figs. 25A and 25B are respectively sectional views of the heat rejector
before and after the heat exchanger element 42 is inserted into it from the guide member side
thereof.
As Figs. 25A and 25B show, a cylindrical body 41 is fixed, together with a guide
member 14, to a jig 15, with the axis of the body 41 kept substantially horizontal. The guide
member 14 is provided so as to abut the body 41, and has an external diameter substantially
equal to that of the body 41. The guide member 14 is so formed as to have a tapered cross
section inside, forming a tapered portion 14a, so that its internal diameter is equal to the
internal diameter of the body 41 at the joint and increases away therefrom.
Now, the manufacturing procedure of the heat rejector 4 of this embodiment will be
described with reference to Figs. 25A and 25B. An annular corrugate fin 421 is produced in
the same manner as described earlier in connection with the first to sixth embodiments, i.e. by
forming a linear corrugate fin 420 into a cylindrical shape and putting both ends thereof
together. The annular corrugate fin 421 is made of a highly flexible material that is easily
deformed when an external force is applied thereto.
In advance, an inner ring-shaped member 422, of which the external diameter is made
slightly greater than the external diameter of the annular corrugate fin 421, has been inserted
axially into the annular corrugate fin 421 to produce the heat exchanger element 42. Then,
as Fig. 25A shows, the heat exchanger element 42 is inserted axially into the guide member
14 from the open end thereof. Thus, the annular corrugate fin 421 is pushed gradually in
through the tapered portion 14a of the body 41, i.e. from the portion thereof having a greater
internal diameter to the portion thereof having a smaller internal diameter.
Then, as Fig. 25B shows, the insertion is stopped when one end surface of the annular
corrugate fin 421 becomes flush with the joint between the body 41 and the guide member 14.
Meanwhile, the tops 421c of the annular corrugate fin 421 rub against the inner surface of the
guide member 14, and they are thereby deformed from arc-shaped to flat. The degree of this
deformation is commensurate with how much the material of the guide member 14 is harder
than the material of the annular corrugate fin 421. As Fig. 24 shows, this increases the area
of contact between the annular corrugate fin 421 and the inner surface of the body 41. This
helps enhance the efficiency with which heat is transmitted from the annular corrugate fin 421
to the body 41 and thereby enhance the heat exchange performance of the heat rejector 4.
Next, a tenth embodiment of the invention will be described with reference to the
drawings. Fig. 26 is a plan view of the heat rejector 42 of this embodiment, Fig. 27 is a plan
view of the heat exchanger element 42, and Fig. 28 is a plan view of the cylindrical body.
Around the outer periphery of an annular corrugate fin 421', round, wave-shaped
projections 421k are formed so as to be in close contact with one another and at regular
intervals overall. On the other hand, a body 41 is produced by pouring a molten metal into a
mold and then cooling it. As Fig. 28 shows, the body 41 has wave-shaped depressions 41m
formed at regular intervals all around its inner surface so as to extend axially. These
depressions 41m are so shaped that the aforementioned wave-shaped projections 421k of the
annular corrugate fin 421' fit into them.
As Fig. 2A shows, in advance, an inner ring-shaped member 422, of which the
external diameter is made slightly substantially equal to the internal diameter of the annular
corrugate fin 421', has been inserted into the annular corrugate fin 421', and they have been
brazed together at where they make contact with each other, in order to produce the heat
exchanger element 42 shown in Fig. 27. Then, as Fig. 4 shows, the heat exchanger element
42 is inserted axially into the body 41, with the center of the former aligned with the center
axis of the latter. Here, as Fig. 26 shows, the projections 421k of the annular corrugate fin
421' fit into the depressions 41m of the body 41. This ensures that, in the heat rejector 4, the
heat exchanger element 42 is kept securely in position circumferentially inside the body 41.
Thus, in this embodiment, it is possible to keep the annular corrugate fin 421' in firm and
close contact with the inner surface of the body 41, and thereby secure a sufficiently large
area of contact all around the annular corrugate fin 421'. This helps manufacture the heat
rejector 4 stably with excellent performance.
Industrial applicability
As described hereinbefore, according to the present invention, a heat exchanger
element does not require bonding by hand when fitted into a body. This helps enhance the
productivity of a heat exchanger member and reduce its manufacturing cost. Moreover, the
heat exchanger member thus manufactured is less prone to variations in quality, and therefore
offers stable heat exchange performance.
Moreover, in a heat exchanger element, a corrugate fin and an inner or outer ring-shaped
member are integrated together. This enhances heat conductivity and thus heat
exchange efficiency.
Moreover, a heat exchanger element is kept in position inside the body of a heat
exchanger member by press fitting. This makes it possible to take the heat exchanger
element out of the body and remove it therefrom. Thus, even if the corrugate fin is damaged,
lowering the quality of the heat exchanger element, it is possible to replace the corrugate fin
easily as required. This makes the heat exchanger element very economical and recyclable.
In particular, in an arrangement in which the body of a heat exchanger member is
tapered at an end, a heat exchanger element can be inserted into it smoothly even when the
external diameter of the heat exchanger element is greater than the internal diameter of the
body.
Moreover, an annular corrugate fin need not be fitted into a cylindrical body by hand
by means of bonding or welding, but can be securely kept in position by press fitting simply
by inserting the former into the latter. This helps enhance the productivity of the heat
exchanger member. Moreover, uniform contact is achieved all around the annular corrugate
fin. This makes it possible to manufacture the heat exchanger member stably with excellent
performance.