U.S. patent application number 11/367412 was filed with the patent office on 2006-09-21 for heat exchange apparatus.
This patent application is currently assigned to THE JAPAN STEEL WORKS, LTD.. Invention is credited to Yoshinori Kawaharazaki, Mitsuo Koda, Yasushi Owaki.
Application Number | 20060207745 11/367412 |
Document ID | / |
Family ID | 37009092 |
Filed Date | 2006-09-21 |
United States Patent
Application |
20060207745 |
Kind Code |
A1 |
Koda; Mitsuo ; et
al. |
September 21, 2006 |
Heat exchange apparatus
Abstract
A heat exchange apparatus comprises a heat exchanging portion
being disposed so as to surround the outer peripheral surface of a
columnar or cylindrical heat exchange target, wherein the heat
exchanging portion comprises therein a hollow space for passing
heat medium therethrough and is so flexible as to expand toward at
least the inner peripheral side by pressure of the heat medium.
Heat medium is fed to the heat exchanging portion by a pump. By
introducing the heat medium into the heat exchanging portion, the
heat exchanging portion expands toward the inner peripheral side,
and an inner surface of the heat exchanging portion close contacts
with the outer peripheral surface of the heat exchange target,
thereby greatly enhancing the heat transfer efficiency. When using
a hydrogen storage/discharge container in which hydrogen storage
alloy is accommodated as the heat exchange target, hydrogen storage
or discharge can be efficiently carried out.
Inventors: |
Koda; Mitsuo; (Muroran-shi,
JP) ; Kawaharazaki; Yoshinori; (Muroran-shi, JP)
; Owaki; Yasushi; (Muroran-shi, JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
THE JAPAN STEEL WORKS, LTD.
|
Family ID: |
37009092 |
Appl. No.: |
11/367412 |
Filed: |
March 6, 2006 |
Current U.S.
Class: |
165/46 ;
165/80.5 |
Current CPC
Class: |
Y02E 60/32 20130101;
F28D 7/106 20130101; F28D 1/06 20130101; Y02P 90/45 20151101; F17C
11/005 20130101; F28D 2021/0047 20130101; F28D 7/024 20130101 |
Class at
Publication: |
165/046 ;
165/080.5 |
International
Class: |
F28F 7/00 20060101
F28F007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 16, 2005 |
JP |
P2005-074520 |
Claims
1. A heat exchange apparatus comprising a heat exchanging portion
being disposed so as to surround an outer peripheral surface of a
heat exchange target, wherein the heat exchanging portion comprises
therein a hollow space for passing heat medium therethrough and is
so flexible as to expand toward at least an inner peripheral side
thereof by pressure of the heat medium.
2. The heat exchange apparatus according to claim 1, wherein the
heat exchanging portion is designed in a shape of a tube so as to
be wound around the outer peripheral surface of the heat exchange
target.
3. The heat exchange apparatus according to claim 1, wherein the
heat exchanging portion is designed in a cylindrical shape so as to
surround the outer peripheral surface of the heat exchange
target.
4. The heat exchange apparatus according to claim 1, wherein the
heat exchange target is designed to be circular in outer peripheral
cross section.
5. The heat exchange apparatus according to claim 1, wherein a
cylindrical case for supporting the heat exchanging portion is
provided at the outer peripheral side of the heat exchanging
portion.
6. The heat exchange apparatus according to claim 1, wherein the
heat exchange target is a hydrogen storage/discharge container in
which hydrogen storage alloy is accommodated.
7. The heat exchange apparatus according to claim 1, wherein the
heat exchanging portion is disposed so as to surround the outer
peripheral surface of a columnar or cylindrical heat exchange
target.
8. The heat exchange apparatus according to claim 1, wherein the
heat exchanging portion expands toward at least the inner
peripheral side thereof so as to contact with the outer periphery
surface of the heat exchange target by pressure of the heat
medium.
9. The heat exchange apparatus according to claim 1, wherein the
heat exchanging portion is disposed at an inner diameter which is
larger than an outer diameter of the heat exchange target.
Description
[0001] This application is based on Japanese Patent Application No.
2005-074520, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a heat exchange apparatus
for efficiently cooling or heating a hydrogen storage container for
accommodating hydrogen storage alloy therein, etc.
[0004] 2. Description of the Related Art
[0005] The hydrogen storage alloy has a feature that heat is
generated when hydrogen is absorbed, so that the hydrogen
absorption reaction is not continued unless the heat is removed by
some method, and also the hydrogen absorption rate is also greatly
affected by the heat removing speed. With respect to a hydrogen
stocking container that uses hydrogen storage alloy and has no
cooling pipe for passing medium such as water or the like
therethrough (hereinafter MH canister), a cooling method for
cooling through the surface of the surface layer of the MH canister
is adopted.
[0006] As the cooling method through the surface layer surface is
normally adopted a method of directly immersing the surface of MH
canister with fluid such as air, water or the like, a method of
blowing the fluid to the surface of the MH canister, or a method of
carrying out cooling through a cooling jacket or the like that is
formed of metal or the like in conformity with the shape of the MH
canister and through which a medium is passed.
[0007] FIG. 4 shows an example of a direct cooling apparatus using
a medium tank.
[0008] A medium bath 10 has a take-in port 11 for liquid medium,
and a discharge port 12 for the liquid medium, and they are
connected to a medium tank 15 through a medium pipe 13. A pump 16
is interposed between the medium tank 15 and the take-in port 11 in
the medium pipe 13. The above structure makes it possible to
circulate the liquid medium 20 between the medium tank 15 and the
medium bath 10. The medium tank 15 is provided with a thermostat
device 17, and the thermostat device 17 adjusts or cools the liquid
medium to a predetermined temperature. A device group shown in FIG.
18 may be replaced by the supply of city water from a tap for tap
water.
[0009] Furthermore, hydrogen storage alloy (not shown) is
accommodated in the MH canister 1 immersed in the medium bath 10,
and a hydrogen pipe 2 is connected to the MH canister 1 so that
ventilation can be performed between the MH canister 1 and the
hydrogen pipe 2. A hydrogen supply device (or steel cylinder) 5 is
connected to the other end of the hydrogen pipe 2 through a
shut-off valve 3 and a pressure adjusting valve 4.
[0010] Next, the operation of the direct cooling apparatus will be
described.
[0011] The apparatus is classified into a medium pipe system and a
hydrogen pipe system. The medium pipe system is mainly constructed
by the medium bath 10, a thermostat bath 17, a pump 16 and a medium
pipe 13 for connecting the respective parts, and functions as a
cooling apparatus.
[0012] The MH canister 1 is disposed in the medium bath 10, and
liquid medium 20 which is adjusted in temperature or cooled in the
thermostat device 17 is fed through the medium pipe 13 to the
medium bath 10 by a pump 16. The liquid medium introduced from the
take-in port 11 of the medium bath 10 into the medium bath 10 cools
the surface of the MH canister 1 while moving upwardly in the
medium bath 10, and overflows from the discharge port 12 of the
medium bath 10. The liquid medium which increases in temperature
due to heat exchange with the MH canister 1 and overflows is
returned through the medium pipe 13 to the medium tank 15, adjusted
in temperature and then circulated through the medium pipe by the
pump 16 again to cool the MH canister 1 continuously.
[0013] In the hydrogen pipe system, hydrogen which is supplied from
the hydrogen supply device 5 and adjusted to some pressure by the
pressure adjusting valve 4 is supplied into the MH canister 1. At
this time, the shut-off valve 3 is kept open. The hydrogen storage
alloy in the MH canister 1 absorbs the hydrogen amount conformed
with the relationship between the hydrogen supply pressure and the
hydrogen storage alloy temperature, so that hydrogen is filled in
the MH canister.
[0014] In the MH canister in which the hydrogen storage alloy is
filled till the center portion of the container, the alloy layer is
thicker in proportion to the distance from the surface of the
container to the center. This means that the heat transfer
coefficient to the medium is lowered, and causes delay of the
hydrogen filling time. The hydrogen absorption time between the MH
canisters that are perfectly identical in the inner structure, the
hydrogen storage alloy amount, etc. is dependent on the heat
transfer coefficient of the surface of the MH canister except for
the temperature/pressure conditions of hydrogen to be absorbed.
When the medium and the medium flow amount are the same, direct
cooling using no jacket is better as the method of increasing the
heat transfer coefficient.
[0015] However, when the MH canister is directly cooled with safe
and easily-treatable liquid medium such as water or the like except
for gas medium by using the cooling apparatus described above, the
surface of the MH canister is contaminated by the medium, and also
it is required to clean the surface of the MH canister by wiping
the surface of the MH canister or the like after the filling work
is finished. With respect to gas medium such as air, etc., the
contamination problem can be solved, but it has a physical property
that the heat transfer coefficient thereof is small, which delays
the hydrogen filling time.
[0016] On the other hand, when the metal cooling jacket is used so
as to cover the surface of the MH canister, the medium
contamination problem can be solved, but an air layer remains
between the surface of the MH canister and the cooling jacket and
it is difficult to bring the surface of the MH canister and the
cooling jacket into perfectly close contact into each other,
thereby causes the delay of the hydrogen filling time. Furthermore,
the cooling jacket may be fastened by a screw or the like to
enhance the degree of adhesion. However, there occurs a problem
that not only it does not perfectly nullify the air layer, but also
the number of working steps is increased.
SUMMARY OF THE INVENTION
[0017] The present invention has been implemented to solve the
problem of the related art as described above, and has an object to
provide a heat exchange apparatus suitable for a cooling apparatus
that can shorten a hydrogen filling time without contaminating the
surface of an MH canister by changing the structure and material of
a jacket.
[0018] That is, according to a first aspect of the invention, a
heat exchange apparatus comprises a heat exchanging portion being
disposed so as to surround an outer peripheral surface of a
columnar or cylindrical heat exchange target, wherein the heat
exchanging portion comprises therein a hollow space for passing
heat medium therethrough and is so flexible as to expand toward at
least an inner peripheral side thereof by pressure of the heat
medium.
[0019] According to a second aspect of the invention, the heat
exchanging portion is designed in a shape of a tube so as to be
wound around the outer peripheral surface of the heat exchange
target.
[0020] According to a third aspect of the invention, the heat
exchanging portion is designed in a cylindrical shape so as to
surround the outer peripheral surface of the heat exchange
target.
[0021] According to a fourth aspect of the invention, the heat
exchange target is designed to be circular in outer peripheral
cross section.
[0022] According to a firth aspect of the invention, a cylindrical
case for supporting the heat exchanging portion is provided at the
outer peripheral side of the heat exchanging portion.
[0023] According to a sixth aspect of the invention, the heat
exchange target is a hydrogen storage/discharge container in which
hydrogen storage alloy is accommodated.
[0024] According to the invention, the heat exchanging portion is
disposed so as to surround the outer peripheral surface of the heat
exchange target, and the heat medium is introduced into the hollow
space thereof, so that the heat exchanging portion expands, and the
heat exchanging portion comes into close contact with the outer
peripheral surface of the heat exchange target, thereby greatly
enhancing the heat transfer efficiency. For example, by using
cooling medium as heat medium, the heat exchange target can be
effectively cooled through the heat exchanging portion.
Furthermore, by using the heating medium as heat medium, the heat
exchange target can be effectively heated through the heat
exchanging portion. The introduction of the heat medium into the
heat exchanging portion can be performed by a supply device such as
a pump or the like. The heat medium is continuously introduced into
the heat exchanging portion by the supply device, and the
heat-exchanged heat medium is continuously discharged from the
heats exchanging portion, whereby the heat exchange target is
continuously heat-exchanged.
[0025] As the heat exchanging portion is selected a material having
flexibility under pressure of the heat medium. The material having
flexibility may be used for the overall heat exchanging portion or
for only the inner peripheral side of the heat exchanging portion.
The material having flexibility is not limited to a specific one in
the present invention, but resin or resin-coated rubber may be
used.
[0026] Furthermore, it is sufficient only that the heat exchanging
portion can be disposed so as to surround the outer peripheral
surface of the heat exchange target, and for example, it may be
disposed by designing the heat exchanging portion in the form of a
tube so that it is spirally wound around the outer peripheral
surface of the heat exchange target, or by designing the heat
exchanging portion in a cylindrical shape so that it is engagedly
fitted to the heat exchange target.
[0027] Furthermore, the heat exchanging portion expands toward the
inner peripheral side by the pressure of the heats medium
introduced into the hollow space, whereby the heat exchanging
portion is effectively brought into close contact with the heat
exchange target to enhance the heat transfer efficiency.
Accordingly, with respect to the arrangement of the heat exchanging
portion to the heat exchange target, it is disposed so as to
surround the heat exchange target in consideration of the degree of
the expansion. Accordingly, it is desired that the heat exchange
target or the heat exchanging portion is detachable when the
pressure of the heat medium is eliminated or the pressure is
weakened so that the arrangement of the heat exchanging portion to
the heat exchange target can be released as occasion demands after
the heat exchanging portion is set up.
[0028] Therefore, it is desired that the heat exchanging portion is
disposed at an inner diameter which is slightly larger than the
outer diameter of the heat exchange target. In order to make sure
the close contact with the heat exchange target by the expansion of
the heat exchanging portion, it is desired that the shape of the
heat exchange target is set to a circular cylinder or column and
the heat exchanging portion is disposed along the outer peripheral
surface of the heat exchanging portion. Accordingly, the heat
exchanging portion expansion to the inner peripheral side comes
into close contact with the surface of the heat exchange target
flatly and under uniform pressure. In addition, air is easily
discharged from the gap between the heat exchanging portion and the
heat exchange target, thereby achieving a cooling jacket having no
air layer and excellent adhesiveness.
[0029] Furthermore, a cylindrical case for supporting the heat
exchanging portion can be arranged at the outer peripheral side of
the heat exchanging portion. When the heat exchanging portion
expands toward the outer peripheral side by the pressure of the
heat medium, the cylindrical case serves to restrict the expansion
concerned and promote the heat exchanging portion to expand toward
the inner peripheral side and come into close contact with the heat
exchange target.
[0030] The heat exchange target is heat-exchanged (cooled or
heated) with the outside if necessary, and it may be applicable to
various fields. However, the present invention is optimally applied
to a hydrogen storage alloy container which is greatly different in
hydrogen storage/discharge efficiency in accordance with the
heat-exchange efficiency. In the hydrogen storage alloy container,
cooling or heating is effectively carried out, so that hydrogen
storage or discharge can be efficiently carried out.
[0031] In the present invention, the heat exchange purpose may be
both the cooling and heating, and cooling and heating may be
switched to each other if necessary.
[0032] As described above, according to the present invention,
there is provided the heat exchanging portion that is disposed so
as to surround the outer peripheral surface of a columnar or
cylindrical heat exchange target, contains therein a hollow space
for passing heat medium therethrough and is so flexible as to
expand toward at least the inner peripheral side by pressure of the
heat medium. Therefore, the heat-exchange can be efficiently
performed with the heat exchange target. Further, the following
effects can be achieved.
[0033] (1) There is an effect that when heat exchange with a
hydrogen storage alloy container is carried out, the hydrogen
filling time can be shortened by the heat exchanging portion having
no air layer and the excellent adhesiveness.
[0034] (2) There is an effect that the liquid medium does not come
into contact with the heat exchange target, and thus sub-zero
cooling by brine for low temperature which takes a lot of trouble
to wipe the surface can be easily performed.
[0035] (3) Since the force of fastening the heat exchange target is
generated by expansion of the heat exchanging portion due to the
pressure of the heat medium, and thus the heat exchange target can
be prevented from dropping off and thus can be fixed. When the flow
of the medium is stopped, the liquid pressure is nullified, and
also the expansion of the heat exchanging portion is stopped, so
that the heat exchange target can be easily taken out. That is,
there is an effect that the heat exchange target is brought with
high detachability.
[0036] (4) Neither a jacket fastening work nor a fixing work is
needed, and thus the working step number can be reduced.
[0037] (5) There is an effect that not only cooling, but also
heating can be performed by likewise varying the medium
temperature
[0038] (6) There is an effect that the present invention can be
used for the efficient surface heating/cooling in various
fields.
[0039] (7) There is an effect that the present invention can be
used for positioning and fixing of parts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] FIG. 1 is a diagram showing a heat exchange apparatus
according to an embodiment of the present invention;
[0041] FIG. 2 is a cross-sectional view showing a heat exchange
apparatus according to another embodiment;
[0042] FIG. 3 is a graph showing the comparison in hydrogen filling
amount and filling time among the cooling apparatus of the present
invention, the direct cooling apparatus and the cooling apparatus
based on the metal water cooling jacket; and
[0043] FIG. 4 is a diagram showing a case where a related direct
cooling apparatus is used.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] A cooling apparatus according to an embodiment of the
present invention will be described with reference to FIG. 1.
[0045] The cooling apparatus is equipped with a cylindrical case 7
having a take-in port 6 for liquid medium and a discharge port 8
for liquid medium, and a medium pipe 13 is connected to the take-in
port 6 and the discharge port 8 from the outside of the cylindrical
case 7. The medium pipe 13 is connected to a medium tank 15 through
a pump 16, and the above structure circulates the liquid medium 20
serving as heat medium between the medium tank 15 and the
cylindrical case 7. A thermostat device 17 is affixed to the medium
tank 15, and adjust the temperature of the liquid medium 20 to a
predetermined temperature. A device group indicated by reference
numeral 18 may be replaced by tap water supply.
[0046] An MH canister 1 serving as a heat exchange target disposed
in the cylindrical case 7 is designed in a cylindrical form, and
sealed at both the ends thereof. Hydrogen storage alloy (not shown)
is accommodated therein. In the MH canister 1, a hydrogen pipe 2 is
connected to the MH canister 1 from the outside so that ventilation
can be performed between the hydrogen pipe 2 and the hydrogen
storage alloy. The hydrogen pipe 2 is connected to a hydrogen
supply device 5 through a shutoff valve 3 and a pressure adjusting
valve 4. A hydrogen pipe system is constructed as described
above.
[0047] In the cylindrical case 7, a resin tube 9 serving as a heat
exchanging portion is spirally wound and disposed in the
cylindrical shape so as to achieve an inner peripheral diameter
which is slightly larger than the outer peripheral diameter of the
MH canister 1, and both the end portions of the tube 9 are
connected to the take-in port 6 and the discharge port 8. The outer
peripheral side of the tube 9 is substantially along the inner
peripheral surface of the cylindrical case 7, and it is supported
by the cylindrical case 7. The tube 9 has such flexibility that by
making the heat medium flow through the tube 9, the tube 9
increases in diameter and expands by the pressure of the heat
medium. A medium pipe system is constructed by the medium tank 15,
the medium pipe 13, the pump 16, the thermostat device 17, the
cylindrical case 7 and the tube 9.
[0048] Next, the operation of the apparatus will be described.
[0049] First, the MH canister 1 is disposed at the center of the
inner peripheral side of the resin tube 9 which is spirally wound
in the cylindrical case 7. The liquid medium which has been
adjusted in temperature or cooled in the thermostat device 17 is
passed through the medium pipe 13 and fed to one end of the
spirally wound resin tube 9 by the pump 16. The liquid medium 20
passed through the take-in port 6 and introduced into the hollow
space of the resin tube 9 flows from the other end side to the
discharge port 8 side along the spiral path of the tube 9.
[0050] The liquid medium 20 has pressure because of the discharging
action of the pump 16, and thus it spreads the inner diameter of
the resin tube 9 having flexibility. Accordingly, the inner
peripheral side of the resin tube 9 comes into contact with the
outer peripheral surface of the MH canister 1. At this time, the
neighboring turns of the spiral resin tube 9 likewise expand to
each other, and thus the cross-section of the resin tube 9 is
designed in a semi-cylindrical shape so that the MH canister 1 side
thereof is a flat surface. In addition, the spiral overall internal
efficiently comes into close contact with the surface of the MH
canister 1 because of the relationship between the air discharging
performance and the liquid pressure at the contact face. This
contributes to prevention of reduction of the heat transfer area
and increase of the heat transfer coefficient due to the close
contact, so that the efficient heat exchange between the liquid
medium 20 and the MH canister 1 can be performed. At this time, the
expansion of the resin tube 9 to the outer peripheral side is
restricted by the cylindrical case 7, and the close contact of the
inner peripheral side of the resin tube 9 with the MH canister 1 is
promoted.
[0051] The liquid medium 20 which has completed the heat-exchange
in the spiral resin tube 9 is returned to the medium tank 15
through the discharge port 8 and the medium pipe 13, and adjusted
in temperature by the thermostat device 17. Then, it is circulated
by the pump 16 again, and can continuously cool the MH canister
1.
[0052] In the hydrogen pipe system, hydrogen that is supplied from
the hydrogen supply device 5 and adjusted to some pressure by the
pressure adjusting valve 4 is supplied to the canister 1. At this
time, the shut-off valve 3 is opened. The hydrogen storage alloy in
the MH canister 1 absorb the amount of hydrogen consistent with the
relationship between the hydrogen supply pressure and the hydrogen
storage alloy temperature to be filled with hydrogen by the
efficient heat removing action of the medium pipe system described
above. When the operation of the pump 16 is stopped, the
introduction of the liquid medium into the tube 9 is also stopped,
the expansion of the tube 9 is released, and the diameter of the
tube is reduced to the original dimension. Accordingly, when it is
required to detach the MH canister 1, the detaching work can be
easily performed.
[0053] In the above-described embodiment, the heat exchanging
portion is constructed by the spirally wound tube. In the present
invention, the heat exchanging portion may be constructed by not
only the tube-shaped member, but also a cylindrical-shape member.
This structure will be described with reference to FIG. 2. The same
constituent elements as the above-described embodiment are
represented by the same reference numerals, and the description
thereof is simplified.
[0054] That is, a hollow bag body 19 that is designed in a
cylindrical shape and has a bottom portion as shown in FIG. 2 is
prepared as a heat exchanging portion, and disposed in the
cylindrical case 7 in the same manner as described above. The bag
body 19 intercommunicates with the take-in port 6 at the lower end
thereof, and intercommunicated with the discharge port 8 at the
upper end thereof.
[0055] When the above-described apparatus is operated, the MH
canister 1 is disposed at the center of the inner peripheral side
of the bag body 19 so that the outer periphery of the MH canister 1
is surrounded by the bag body 19. When liquid medium is made to
flow through the medium pipe 13 into the bag body 19, the liquid
medium introduced through the take-in port 6 into the hollow
section of the bag body 19 makes the bag body 19 expand to the
inner peripheral side and come into close contact with the outer
peripheral surface of the MH canister 1. The liquid medium is
passed through the hollow section and discharged form the discharge
port 8. By subsequently introducing the liquid medium into the bag
body 19, the close contact with the outer peripheral surface of the
MH canister 1 is kept, and the MH canister 1 can be efficiently
cooled. At this time, the expansion of the bag body 19 to the outer
peripheral side is restricted by the cylindrical case 7 as in the
case of the above-described embodiment. The operation in the
hydrogen pipe system is the same as the above-described embodiment.
When the introduction of the liquid medium into the bag body 19 is
stopped after the operation is finished, the expansion of the bag
body 19 is stopped, and the MH canister 1 can be easily taken out
as occasion demands.
[0056] The MH canister was cooled by using the cooling apparatus of
the present invention shown in FIG. 1, a direct cooling apparatus
shown in FIG. 4 and a cooling apparatus based on a metal cooling
jacket, and the effect on the hydrogen filling time was tested in
each of the above cases. The results are shown in the graph of FIG.
3. The abscissa axis represents the filling time (minute), and the
ordinate axis represents the hydrogen filling amount (NL). The
testing was carried out on the same MH canister under the condition
that each of the hydrogen supply pressure, the liquid medium
temperature and the liquid medium circulating flow amount was
identical among the above cases. A solid line in the graph
represents the result based on the direct cooling apparatus, a
dotted line represents the result based on the cooling apparatus of
the present invention, and a one-dotted chain line represents the
result based on the metal cooling jacket apparatus.
[0057] It has been found from the graph that the cooling apparatus
of the present invention can fill hydrogen in the MH canister
substantially in the same filling time as the direct cooling.
Furthermore, a clear difference is observed in the comparison of
the filling time with the metal cooling jacket corresponding to the
indirect cooling, and the effect of the present invention is
sufficiently shown.
[0058] The above-described embodiment uses the liquid medium,
however, it may be likewise applicable to a case where gas medium
is used.
[0059] The present invention has bee described on the basis of the
above-described embodiment. However, the present invention is not
limited to the content of the foregoing description, and
modifications may be made in the scope of the present
invention.
* * * * *