U.S. patent number RE42,720 [Application Number 11/545,821] was granted by the patent office on 2011-09-20 for fuel cell mounting structure.
This patent grant is currently assigned to Toyota Jidosha Kabushiki Kaisha. Invention is credited to Akira Aoto, Toru Bisaka, Yutaka Hotta, Hiroaki Nishiumi, Susumu Oda, Shunichi Shibasaki, Hideyuki Tanaka.
United States Patent |
RE42,720 |
Tanaka , et al. |
September 20, 2011 |
Fuel cell mounting structure
Abstract
A housing case that houses a fuel cell is provided with mounts
for fixing two ends of a lower surface of an end plate that retains
stacked unit cells of the fuel cell, and a mount for fixing a
central portion of a lower surface of another end plate. Using
these three mounts, the fuel cell is fixed to the housing case.
Inventors: |
Tanaka; Hideyuki (Kariya,
JP), Bisaka; Toru (Kariya, JP), Aoto;
Akira (Okazaki, JP), Nishiumi; Hiroaki (Toyota,
JP), Hotta; Yutaka (Toyota, JP), Shibasaki;
Shunichi (Toyota, JP), Oda; Susumu (Seto,
JP) |
Assignee: |
Toyota Jidosha Kabushiki Kaisha
(Toyota-shi, JP)
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Family
ID: |
27346888 |
Appl.
No.: |
11/545,821 |
Filed: |
October 11, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
10158906 |
Jun 3, 2002 |
6803142 |
Oct 12, 2004 |
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Foreign Application Priority Data
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Jun 6, 2001 [JP] |
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2001-171442 |
Jun 7, 2001 [JP] |
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2001-172121 |
Jun 11, 2001 [JP] |
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2001-175510 |
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Current U.S.
Class: |
429/469; 429/511;
429/467; 429/470 |
Current CPC
Class: |
H01M
8/2485 (20130101); H01M 8/2475 (20130101); H01M
8/04067 (20130101); H01M 8/2415 (20130101); H01M
8/241 (20130101); H01M 8/248 (20130101); H01M
8/04559 (20130101); H01M 8/04029 (20130101); H01M
2250/20 (20130101); Y02T 90/40 (20130101); Y02E
60/50 (20130101) |
Current International
Class: |
H01M
2/20 (20060101) |
Field of
Search: |
;429/34,35,37,36,30,38,39,22 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
100 49 801 |
|
Apr 2001 |
|
DE |
|
60062064 |
|
Apr 1985 |
|
JP |
|
62184777 |
|
Aug 1987 |
|
JP |
|
01279575 |
|
Nov 1989 |
|
JP |
|
03067468 |
|
Mar 1991 |
|
JP |
|
04075263 |
|
Mar 1992 |
|
JP |
|
04296463 |
|
Oct 1992 |
|
JP |
|
05-041228 |
|
Feb 1993 |
|
JP |
|
HEI 05-047407 |
|
Feb 1993 |
|
JP |
|
05082157 |
|
Apr 1993 |
|
JP |
|
05089801 |
|
Apr 1993 |
|
JP |
|
06275307 |
|
Sep 1994 |
|
JP |
|
2007-014589 |
|
Jan 1995 |
|
JP |
|
HEI 08-162143 |
|
Jun 1996 |
|
JP |
|
HEI 08-171926 |
|
Jul 1996 |
|
JP |
|
09083616 |
|
Mar 1997 |
|
JP |
|
10189025 |
|
Jul 1998 |
|
JP |
|
10-509841 |
|
Sep 1998 |
|
JP |
|
10308229 |
|
Nov 1998 |
|
JP |
|
10340736 |
|
Dec 1998 |
|
JP |
|
HEI 11-185789 |
|
Jul 1999 |
|
JP |
|
HEI 11-185790 |
|
Jul 1999 |
|
JP |
|
2001030771 |
|
Feb 2001 |
|
JP |
|
(P) 2001-76751 |
|
Mar 2001 |
|
JP |
|
2001143740 |
|
May 2001 |
|
JP |
|
2002235801 |
|
Aug 2002 |
|
JP |
|
2002367852 |
|
Dec 2002 |
|
JP |
|
WO 96/20510 |
|
Sep 1996 |
|
WO |
|
Other References
German Language Version of German Office Action for Appln. No. 102
24 962.8-45 dated Mar. 9, 2005. cited by other .
English Translation of German Office Action for Appln. No. 102 24
962.8-45, issued Mar. 9, 2005. cited by other .
Japanese Language Version of Japanese Office Action, Appln. No.
2001-171442 dated Jun. 26, 2007. cited by other .
English Translation of Japanese Office Action, Appln. No.
2001-171442 dated Jun. 26, 2007. cited by other .
Japanese Language Version of Japanese Office Action, Appln. No.
2001-171442 dated Oct. 18, 2005. cited by other .
English Translation of Japanese Office Action, Appln. No.
2001-171442 dated Oct. 18, 2005. cited by other .
Japanese Language Version of Japanese Office Action, Appln. No.
2001-175510 dated Aug. 23, 2005. cited by other .
English Translation of Japanese Office Action, Appln. No.
2001-175510 dated Aug. 23, 2005. cited by other .
Japanese Language Version of Japanese Office Action, Appln. No.
2001-172121 dated Sep. 26, 2006. cited by other .
English Translation of Japanese Office Action, Appln. No.
2001-172121 dated Sep. 26, 2006. cited by other.
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Primary Examiner: Alejandro; Raymond
Attorney, Agent or Firm: Kenyon & Kenyon LLP
Claims
What is claimed is:
.[.1. A fuel cell assembly comprising: a fuel cell stack having a
plurality of stacked unit cells and having a first electrode in a
first end portion of the fuel cell stack and a second electrode in
a second end portion which is opposite side of the first end
portion of the fuel cell stack; a first end portion retaining
member having a first retaining portion in a first end portion of a
lower surface of the first end portion retaining member and having
a second retaining portion in a second end portion of the lower
surface of the first end portion retaining member, and which is
directly or indirectly fixed to one end portion of the fuel cell
stack; a second end portion retaining member having a third
retaining portion in a central portion of a lower surface of the
second end portion retaining member, and which is directly or
indirectly fixed to the other end portion of the fuel cell stack;
and a fuel cell housing case that houses the fuel cell stack
sandwiched by the first end portion retaining member and the second
end portion retaining member, the fuel cell stack being fixed to
the fuel cell housing case via the first retaining portion, the
second retaining portion and the third retaining portion..].
.[.2. The fuel cell assembly according to claim 1, further
comprising a reinforcing member that reinforces a bottom surface
portion which includes a position of the third retaining portion
and which extends perpendicularly to a stacking direction of the
unit cells..].
.[.3. The fuel cell assembly according to claim 1, wherein the
first end portion retaining member and the second end portion
retaining member are plate members..].
.[.4. The fuel cell assembly according to claim 1, wherein the
first end portion retaining member and the second end portion
retaining member have a mounting portion respectively for
installation in a vehicle body..].
.[.5. A fuel cell assembly comprising: a plurality of fuel cell
stacks having a plurality of stacked unit cells and having a first
electrode in a first end portion of the fuel cell stack and a
second electrode in a second end portion which is opposite side of
the first end portion of the fuel cell stack, and which are
provided in parallel each other; a first end portion retaining
member having a first retaining portion in a first end portion of a
lower surface of the first end portion retaining member and having
a second retaining portion in a second end portion of the lower
surface of the first end portion retaining member, and which is
directly or indirectly fixed to one end portion of the fuel cell
stack and extends over the one end portions of the fuel cell
stacks, a second end portion retaining member having a third
retaining portion in a central portion of a lower surface of the
second end portion retaining member, and which is directly or
indirectly fixed to the other end portion of the fuel cell stack
and extends over the other end portions of the fuel cell stacks;
and a fuel cell housing case that houses the fuel cell stack
sandwiched by the first end portion retaining member and the second
end portion retaining member, the fuel cell stack being fixed to
the fuel cell housing case via the first retaining portion, the
second retaining portion and the third retaining portion..].
.[.6. The fuel cell assembly according to claim 5, further
comprising a fluid supply/discharge portion that supplies and
discharges a fluid with respect to the fuel cell stacks, and which
is provided in one of the first end portion retaining member and
the second end portion retaining member..].
.[.7. The fuel cell assembly according to claim 6, wherein the
fluid supply/discharge portion comprises: a first fuel
supply/discharge portion that supplies and discharges a first fuel
with respect to a first electrode side; a second fuel
supply/discharge portion that supplies and discharges a second fuel
with respect to a second electrode side, and a coolant
supply/discharge portion that supplies and discharges a coolant for
cooling the fuel cell stacks..].
.[.8. The fuel cell assembly according to claim 6, further
comprising an insulating member that is formed with an electrically
insulating material as a plate member having a predetermined
thickness, and that is disposed between one of the first end
portion retaining member and the second end portion retaining
member and the fuel cell stacks..].
.[.9. The fuel cell assembly according to claim 8, further
comprising a voltage detecting sensor, wherein the fluid
supply/discharge portion has a water supply/discharge portion that
supplies and discharges a water, and wherein the predetermined
thickness is such a thickness that, when the fuel cell has a short
circuit that includes as portions thereof a signal line of the
sensor connected to the fuel cell stacks and the water present in a
water supply/discharge passage provided in the insulating member,
the insulating member keeps an electric current that flows through
the signal line to within a range of current such that the signal
line is not broken..].
.[.10. The fuel cell assembly according to claim 8, wherein the
predetermined thickness is at least 3 mm..].
.[.11. The fuel cell assembly according to claim 6, further
comprising a pressure exerting member that is disposed inwardly of
the second end portion retaining member and that exerts a pressure
in the stacking direction on each of the fuel cell stacks..].
.[.12. The fuel cell assembly according to claim 11, wherein the
pressure exerting member includes a plurality of coned disc
springs..].
.[.13. The fuel cell assembly according to claim 11, wherein the
pressure exerting member includes bolts that extend through the
fuel cell stacks..].
.[.14. The fuel cell assembly according to claim 5, further
comprising a series connecting member that is formed into a plate
shape from an electrically conductive material and connects
electrically plurality of adjacent fuel cell stacks in
series..].
.[.15. The fuel cell assembly according to claim 14, wherein the
plurality of fuel cell stacks are two fuel cell stacks, and the
series connecting member is disposed inwardly of the first end
portion retaining member and connects a first end portion of a
first fuel cell stack and a second end portion of a second fuel
cell stack adjacent to the first fuel cell stack..].
.[.16. The fuel cell assembly according to claim 15, further
comprising a positive output terminal and a negative output
terminal that are disposed on the second end portion retaining
member..].
.[.17. The fuel cell assembly according to claim 14, wherein the
plurality of fuel cell stacks are more than three fuel cell stacks,
and a first series connecting member disposed inwardly of the first
end portion retaining member connects the first end portion of one
fuel cell stack and the second end portion of one adjacent fuel
cell stack, and a second series connecting member disposed inwardly
of the second end portion retaining member connects the second end
portion of the one fuel cell stack and the first end portion of the
another adjacent fuel cell stack..].
.[.18. A fuel cell assembly comprising: a fuel cell stack having a
plurality of stacked unit cells and having a first electrode in a
first end portion of the fuel cell stack and a second electrode in
a second end portion which is opposite side of the first end
portion of the fuel cell stack; a first end portion retaining
member having a first retaining portion in a first end portion of a
lower surface of the first end portion retaining member and having
a second retaining portion in a second end portion of the lower
surface of the first end portion retaining member, and which is
directly or indirectly fixed to one end portion of the fuel cell
stack; a second end portion retaining member having a third
retaining portion in a central portion of a lower surface of the
second end portion retaining member, and which is directly or
indirectly fixed to the other end portion of the fuel cell stack;
and a supporting member fixed to the fuel cell stack via the first
retaining portion, the second retaining portion and the third
retaining portion, the fuel cell stack being sandwiched by the
first end portion retaining member and the second end portion
retaining member..].
.Iadd.19. A fuel cell assembly comprising: at least one fuel cell
stack having a plurality of stacked unit cells and a lower surface;
and end plates clamping the at least one fuel cell stack; wherein
one end plate of the end plates is supported at two points by first
and second mounts, while another end plate of the end plates is
supported at one single point by a third mount, and wherein each of
the first, second, and third mounts extends vertically downward
from the lower surface of the fuel cell stack. .Iaddend.
.Iadd.20. The fuel cell assembly according to claim 19, further
comprising a reinforcing member that reinforces a bottom surface
portion which includes a position of the one single point and which
extends perpendicularly to a stacking direction of the unit cells.
.Iaddend.
.Iadd.21. The fuel cell assembly according to claim 19, wherein the
end plates have a mounting portion respectively for installation in
a vehicle body. .Iaddend.
.Iadd.22. The fuel cell assembly according to claim 19, further
comprising a fluid supply/discharge portion that supplies and
discharges a fluid with respect to the at least one fuel cell
stack, and which is provided in one of the end plates.
.Iaddend.
.Iadd.23. The fuel cell assembly according to claim 22, wherein the
fluid supply/discharge portion comprises: a first fuel
supply/discharge portion that supplies and discharges a first fuel
with respect to a first electrode side; a second fuel
supply/discharge portion that supplies and discharges a second fuel
with respect to a second electrode side, and a coolant
supply/discharge portion that supplies and discharges a coolant for
cooling the at least one fuel cell stack. .Iaddend.
.Iadd.24. The fuel cell assembly according to claim 22, further
comprising an insulating member that is formed with an electrically
insulating material as a plate member having a predetermined
thickness, and that is disposed between one of the end plates and
the at least one fuel cell stack. .Iaddend.
.Iadd.25. The fuel cell assembly according to claim 24, further
comprising a voltage detecting sensor, wherein the fluid
supply/discharge portion has a water supply/discharge portion that
supplies and discharges a water, and wherein the predetermined
thickness is such a thickness that, when the fuel cell has a short
circuit that includes as portions thereof a signal line of the
sensor connected to the fuel cell stacks and the water present in a
water supply/discharge passage provided in the insulating member,
the insulating member keeps an electric current that flows through
the signal line to within a range of current such that the signal
line is not broken. .Iaddend.
.Iadd.26. The fuel cell assembly according to claim 24, wherein the
predetermined thickness is at least 3 mm. .Iaddend.
.Iadd.27. The fuel cell assembly according to claim 22, further
comprising a pressure exerting member that is disposed at an end
plate and that exerts a pressure in the stacking direction on the
at least one fuel cell stack. .Iaddend.
.Iadd.28. The fuel cell assembly according to claim 27, wherein the
pressure exerting member includes a plurality of coned disc
springs. .Iaddend.
.Iadd.29. The fuel cell assembly according to claim 27, wherein the
pressure exerting member includes a bolt. .Iaddend.
.Iadd.30. The fuel cell assembly according to claim 27, wherein the
pressure exerting member is disposed at the end plate supported at
one single point. .Iaddend.
.Iadd.31. The fuel cell assembly according to claim 27, wherein the
pressure exerting member is disposed at the end plate supported at
two points. .Iaddend.
.Iadd.32. The fuel cell assembly according to claim 19, further
comprising a series connecting member that is formed into a plate
shape from an electrically conductive material and electrically
connects a plurality of adjacent fuel cell stacks in series.
.Iaddend.
.Iadd.33. The fuel cell assembly according to claim 32, wherein the
plurality of fuel cell stacks are two fuel cell stacks, and the
series connecting member is disposed inwardly of an end plate and
connects a first end portion of a first fuel cell stack and a
second end portion of a second fuel cell stack adjacent to the
first fuel cell stack. .Iaddend.
.Iadd.34. The fuel cell assembly according to claim 33, wherein the
series connecting member is disposed at the end plate supported at
one single point. .Iaddend.
.Iadd.35. The fuel cell assembly according to claim 33, wherein the
series connecting member is disposed at the end plate supported at
two points. .Iaddend.
.Iadd.36. The fuel cell assembly according to claim 33, further
comprising a positive output terminal and a negative output
terminal that are disposed on the end plate supported at the one
single point. .Iaddend.
.Iadd.37. The fuel cell assembly according to claim 32, wherein the
plurality of fuel cell stacks are more than three fuel cell stacks,
and a first series connecting member disposed inwardly of the end
plate supported at two points connects a first end portion of one
fuel cell stack and the second end portion of one adjacent fuel
cell stack, and a second series connecting member disposed inwardly
of the end plate supported at the one single point connects a
second end portion of the one fuel cell stack and the first end
portion of the another adjacent fuel cell stack. .Iaddend.
.Iadd.38. A fuel cell assembly comprising: a fuel cell stack having
a lower surface; end plates to retain the fuel cell stack; and a
support system applied to the end plates at three points and no
more than three points, wherein the support system includes first,
second, and third mounts, and wherein each of the first, second,
and third mounts extends vertically downward from the lower surface
of the fuel cell stack. .Iaddend.
.Iadd.39. The fuel cell assembly of claim 38, wherein the support
system comprises a first mount associated with a first end plate,
and second and third mounts associated with a second end plate.
.Iaddend.
.Iadd.40. The fuel cell assembly of claim 38, further comprising a
housing to contain the fuel cell stack. .Iaddend.
.Iadd.41. A fuel cell assembly comprising: a fuel cell stack having
a lower surface; a housing for the fuel cell stack; and three
mounts and no more than three mounts which extend vertically
downward from the lower surface of the fuel cell stack.
.Iaddend.
.Iadd.42. The fuel cell assembly of claim 41, wherein a first mount
is arranged at a first end of the fuel cell stack, and second and
third mounts are arranged at a second end of the fuel cell stack
opposite the first end. .Iaddend.
.Iadd.43. The fuel cell assembly of claim 19, wherein the plurality
of stacked unit cells are stacked horizontally and the end plates
clamp the plurality of stacked unit cells from either side thereof.
.Iaddend.
.Iadd.44. The fuel cell assembly of claim 38, wherein the fuel cell
stack includes a plurality of stacked unit cells stacked
horizontally and the end plates clamp the plurality of stacked unit
cells from either side thereof. .Iaddend.
.Iadd.45. The fuel cell assembly of claim 41, wherein the fuel cell
stack includes a plurality of stacked unit cells stacked
horizontally and end plates which clamp the plurality of stacked
unit cells from either side thereof. .Iaddend.
.Iadd.46. The fuel cell assembly of claim 19, wherein the three
mounts are arranged on a floor of a housing. .Iaddend.
.Iadd.47. The fuel cell assembly of claim 38, wherein the three
mounts are arranged on a floor of a housing. .Iaddend.
.Iadd.48. The fuel cell assembly of claim 41, wherein the three
mounts are arranged on a floor of the housing. .Iaddend.
Description
INCORPORATION BY REFERENCE
The disclosure of Japanese Patent Application No. 2001-175510 filed
on Jun. 11, 2001, No. 2001-172121 filed on Jun. 7, 2001 and No.
2001-171442 filed on Jun. 6, 2001 including the specification,
drawings and abstract are incorporated herein by reference in their
entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a fuel cell and, more particularly, to a
housing case that forms an outside surface of a fuel cell.
2. Description of the Related Art
Research and development is now carried out on a vehicle equipped
with a fuel cell electricity generating system capable of utilizing
electricity generated during reaction between hydrogen and oxygen.
Normally, fuel cells incorporated in a fuel cell electric power
generating system are provided in the form of a fuel cell stack
having many stacked unit cells. With regard to a fuel cell stack, a
securing method has been proposed in which a fuel cell stack is
secured by a pair of end plates that are disposed on both sides of
the stack in the direction of stacking unit cells.
If a fuel cell having a fuel cell stack as mentioned above is
installed in a vehicle, there arise dangers of positional deviation
and deformation of stacked unit cells being caused by a torsional
force applied to the fuel cell due to a torsion of a body of the
vehicle or vibrations that occur in the vehicle. Such a slight
deviation or deformation may cause leakage of a cooling gas, a fuel
gas or the like. Furthermore, such a deviation or deformation will
reduce the stability of the mounting fixture of the piping for
supplying and discharging a fuel gas, an oxidative gas and a
coolant, and the electric system wiring, etc. to the stack, and
will reduce the mounting precision thereof. Considering stable
installation of the fuel cell into a vehicle, the installation must
be performed separately for each fuel cell stack, so the
installation man-hours will increase.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a fuel cell that is
able to solve the aforementioned problems. More specifically, a
major object of the invention is to prevent occurrence of torsion
of a fuel cell stack disposed in a fuel cell housing case.
In order to achieve the aforementioned object, a fuel cell in
accordance with an aspect of the invention includes: a fuel cell
stack having a plurality of stacked unit cells and having a first
electrode and a second electrode in two end portions of the fuel
cell stack; a first end portion retaining member and a second end
portion retaining member disposed in the two end portions of the
fuel cell stack; and a fuel cell housing case that houses the fuel
cell stack sandwiched by the first end portion retaining member and
the second end portion retaining member and that retains the fuel
cell stack by using a first retaining portion that retains a first
end portion of a lower surface of the first end portion retaining
member, a second retaining portion that retains a second end
portion of the lower surface of the first end portion retaining
member, and a third retaining portion that retains a central
portion of a lower surface of the second end portion retaining
member.
And a plurality of fuel cell stacks are provided in parallel, and
the first end portion retaining member extends over the one end
portions of the fuel cell stacks, and the second end portion
retaining member extends over the other end portions of the fuel
cell stacks.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and further objects, features and advantages of the
invention will become apparent from the following description of
preferred embodiments with reference to the accompanying drawings,
wherein like numerals are used to represent like elements and
wherein:
FIG. 1 is a schematic perspective view of a housing case 10 that
houses a fuel cell 20 in accordance with a first embodiment of the
invention;
FIG. 2a is an elevation of the fuel cell 20.
FIG. 2b is a sectional view of the fuel cell 20;
FIG. 3 is a sectional view of a structure of a mount 86;
FIG. 4 is a sectional view of the fuel cell 20;
FIG. 5 is a perspective view of a specific example of the
reinforcement member 300;
FIG. 6 is a sectional view of an example of the structure of a
mount 82;
FIG. 7 is a schematic plan view of a fuel cell 120 in accordance
with a second embodiment of the invention;
FIG. 8 is a sectional view of the fuel cell 120 shown in FIG.
7;
FIG. 9 is an enlarged view of an end plate 126-side pressurizing
mechanism 150 of a fuel cell stack 122a and its adjacent
portions;
FIG. 10 is an enlarged sectional view of end plate 124-adjacent
portions of the cooling water channels formed in the fuel cell
stack 122a;
FIG. 11 is a circuit diagram that electrically illustrates a short
circuit;
FIG. 12 is a diagram schematically illustrating a construction of a
fuel cell 220 in accordance with a third embodiment of the
invention;
FIG. 13 is a diagram schematically illustrating a construction of a
fuel cell 320 in accordance with a fourth embodiment;
FIG. 14a is a plan view of the fuel cell 320; and
FIG. 14b is an enlarged sectional view.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The invention will be described hereinafter with reference to
preferred embodiments thereof.
(First Embodiment)
FIG. 1 is a schematic perspective view of a fuel cell 20 in
accordance with an embodiment of the invention. A housing case 10
is formed from a metal such as aluminum or the like, and is fixed
to a vehicle body 30 via frames 12, 14, 16 and 18. The housing case
10 contains a fuel cell stack 52.
The fuel cell stack 52 is formed by stacking a plurality of unit
cells 40 with separators 50 disposed therebetween. The fuel cell
stack 52 is clamped from opposite sides by end plates 60, 62 that
are formed from a metal, a resin or the like. Each unit cell 40 is
made up of a polyelectrolyte film (e.g., a fluorocarbon based
resin-formed ion exchange film having a thickness of 100 .mu.m to
200 .mu.m) and two electrodes (an anode and a cathode) sandwiching
the polyelectrolyte film.
The end plate 60 is provided with a pressurizing mechanism 70 for
pressurizing the fuel cell stack 52 from the two sides. In this
embodiment, a pressurizing member that forms the pressurizing
mechanism 70 is a bolt that extends through a through-hole of the
end plate 60. By tightening the bolt, the stacked unit cells 40 are
pressed. The end plate 62 may also be provided with a similar
pressurizing mechanism.
Each unit cell 40 has a cooling water hole, a fuel gas hole, and an
oxidative gas hole (not shown). When a plurality of unit cells 40
are stacked, these holes form passages for the cooling water, the
fuel gas and the oxidative gas which extend through the stacked
unit cells 40.
A reinforcement member 300 may be provided between the frames 12
and 14 of the housing case 10 (FIG. 1 shows a case provided with a
reinforcement member 300). The reinforcement member 300 will be
described later.
FIG. 2a is an elevation of the fuel cell 20. FIG. 2b is a sectional
view of the housing case 10 that contains the fuel cell stack 52,
the view being taken on line 2b-2b in FIG. 2a. As shown in FIG. 2b,
the housing case 10 is fixed to the vehicle body 30 via the frames
16, 18. The end plate 62 of the fuel cell stack 52 is fixed, at
opposite ends of a lower surface of the end plate 62, to the
housing case 10 via mounts 86, 88.
FIG. 3 is a sectional view of the housing case 10 showing an
example of the construction of the mounts 86, 88. A seat plate 123
is fixed to the housing case 10 via a bolt 100 and a nut 110.
Similarly, a seat plate 123 is fixed to the housing case 10 via a
bolt 102 and a nut 112. The end plate 62 is fastened to the seat
plate 123 via a seat table 130 by tightening a bolt 104. An
electrical insulator 125 is provided between the bolt 104 and the
seat plate 123, so that the end plate 62 and the housing case 10
are electrically insulated from each other. An inner surface of the
housing case 10 is coated with an insulating material (not shown).
Thus, the insulation characteristic between the end plate 62 and
the fuel cell 20 improves.
FIG. 4 is a sectional view of the housing case 10 that contains the
fuel cell stack 52, the view being taken on a line 4-4 in FIG. 2a.
In FIG. 4, the housing case 10 is fixed to the vehicle body 30 via
the frames 12, 14. The end plate 60 of the fuel cell stack 52 is
fixed, at a central portion of a lower surface of the end plate 60,
to the housing case 10 via a mount 82. An example of the structure
of the mount 82 may be the same as that of the mounts 86, 88.
As described above, the fuel cell stack 52 contained in the housing
case 10 is fixed to the housing case 10 at the three sites, that
is, the mounts 82, 86, 88. Therefore, a lower surface of the fuel
cell stack 52 is determined over a triangular plane defined by the
three points of the mounts 82, 86, 88. Hence, even if a torsion
occurs in the vehicle body 30 or the housing case 10, the effect of
the torsion on the fuel cell stack 52 can be avoided or reduced.
Therefore, leakage of a gas caused by deviation of a unit cell 40
in the stack can be prevented. Furthermore, it also becomes
possible to prevent the stability of the mounting fixture of the
piping for supplying and discharging a fuel gas, an oxidative gas
and a coolant, and the electric system wiring, etc. to the fuel
cell stack and the mounting precision thereof from being reduced by
a positional deviation of a stacked unit cell 40.
The fuel cell housing case in accordance with the invention may
also have a reinforcement that reinforces a bottom surface portion
which includes the position of the aforementioned third retaining
portion and which extends in a direction perpendicular to the
stacking direction. More specifically, a bottom surface portion of
the housing case 10 where the mount 82 is positioned is preferably
reinforced by, for example, the reinforcement member 300 having a
structure as shown in FIG. 5. FIG. 6 shows a sectional view of the
mount 82 that is reinforced by the reinforcement member 300. Due to
the reinforcement employing the reinforcement member 300, the
housing case 10 acquires a structure that withstands the load of
the fuel cell stack 52 that concentrates on the site of the mount
82.
As can be understood from the above description, the invention is
able to prevent occurrence of a deviation of a unit cell 40 in the
stack of the fuel cell 20 even if a deviation occurs in the housing
case 10 or the vehicle body 30.
(Second Embodiment)
Now, a second embodiment of the invention will be described. FIG. 7
is a schematic plan view of a fuel cell 120 in accordance with an
embodiment of the invention. FIG. 8 is a sectional view taken on a
line 8-8 in FIG. 7. The fuel cell 120 has two rows of fuel cell
stacks 122a, 122b, two end plates 124, 126, four tension plates
128a, 128b, 129a, 129b, a fuel-or-the-like supply/discharge piping
140, and a pressurizing mechanism 150. Each of the fuel cell stacks
122a, 122b is formed by stacking a plurality of unit cells 121. The
end plates 124, 126 are disposed on opposite sides of the fuel cell
stacks 122a, 122b and astride the two stacks. The tension plates
128a, 128b, 129a, 129b extend between the two end plates 124, 126
and over upper and lower surfaces of the fuel cell stacks 122a,
122b. The fuel-or-the-like supply/discharge piping 140 supplies and
discharges hydrogen as a fuel, air as an oxidizer, and cooling
water with respect to the two fuel cell stacks 122a, 122b. The
pressurizing mechanism 150 applies pressure to the two fuel cell
stacks 122a, 122b in the stacking direction.
The two fuel cell stacks 122a, 122b are electrically connected in
series by a terminal plate 132 that is disposed at a side of the
end plate 124. Similarly to the end plate 124, the terminal plate
132 lies astride the two fuel cell stacks 122a, 122b.
Electric power can be extracted from the fuel cell stacks 122a,
122b, via a plus-side output terminal 138 and a minus-side output
terminal 139. The plus-side output terminal 138 is provided on an
end plate 126-side end portion of the fuel cell stack 122a. The
minus-side output terminal 139 is provided on an end plate 126-side
end portion of the fuel cell stack 122b.
An insulator plate 134 formed from an electrically insulating
material (e.g., a resin) is disposed between end plate 124 and the
terminal plate 132. Thus, the end plate 124 and the terminal plate
132 are insulated from each other. Each of the end plate 124, the
terminal plate 132 and the insulator plate 134 has six supply holes
and six discharge holes. The supply holes supply hydrogen, air and
cooling water to the two fuel cell stacks 122a, 122b. The discharge
holes discharge hydrogen, air and cooling water from the two fuel
cell stacks 122a, 122b.
Although not shown in the drawing, each of the fuel cell stacks
122a, 122b has six channels that extend therethrough in the
stacking direction. The end plate 124-side channels are connected
to twelve holes (six supply holes and six discharge holes) that are
formed in the end plate 124, the terminal plate 132 and the
insulator plate 134. Therefore, by connecting the fuel-or-the-like
supply/discharge piping 140 to the six supply holes and the six
discharge holes of the end plate 124, and by supplying hydrogen,
air and cooling water, the two fuel cell stacks 122a, 122b generate
electric power.
FIG. 9 is an enlarged view of the end plate 126-side pressurizing
mechanism 150 of the fuel cell stack 122a and its adjacent
portions. As shown in FIG. 9, the pressurizing mechanism 150 is
disposed between the end plate 126 and a insulator plate 136
disposed at an end of the fuel cell stack 122a. The pressurizing
mechanism 150 is formed by a pressure exerting plate 151, a first
dish spring 152, a force receiving upper member 153, a screw member
154, a stopper 155, and a second dish spring 156. The pressure
exerting plate 151 exerts pressure on the fuel cell stack 122a via
the insulator 136 in the stacking direction. The first dish spring
152 exerts force on the pressure exerting plate 151. The force
receiving upper member 153 receives force opposite to the first
dish spring 152. The screw member 154 receives force from the force
receiving upper member 153 and adjusts the pressure on the fuel
cell stack 122a. The stopper 155 receives force of the screw member
154. The second dish spring 156 is disposed between the stopper 155
and the end plate 126. A similar pressurizing mechanism 150 is
disposed on the fuel cell stack 122b as well. In this construction,
the dish springs 152, 156 are pressure exerting members.
As shown in FIG. 8, a mounting metal piece 162 is provided at a
central site in a lower portion of the end plate 124, and two
mounting metal pieces 164, 166 are provided at two sites on
opposite end portion of a lower portion of the end plate 126. (In
FIG. 8, the mounting metal piece 164 is hidden behind the mounting
metal piece 166.)
The fuel cell 120 is mounted to the vehicle body at the three sites
of the mounting metal pieces 162, 164, 166. Although in the second
embodiment, the fuel cell 120 is mounted to the vehicle body via
the three mounting metal pieces 162, 164, 166, the fuel cell 120
may also be mounted to the vehicle body via rubber mounts.
According to the above-described fuel cell 120 of the second
embodiment, the two fuel cell stacks 122a, 122b are retained by
disposing the two end plates 124, 126 on the opposite ends of the
fuel cell stacks 122a, 122b and astride the two stacks. Therefore,
the two fuel cell stacks 122a, 122b can be handled as a single
unit. As a result, the stability of the mounting fixture of the
fuel-or-the-like supply/discharge piping 140 and the mounting
precision thereof can be improved.
Furthermore, in the second embodiment, the two fuel cell stacks
122a, 122b can be handled as one unit. Therefore, since the fuel
cell 120 can be mounted to the vehicle body via the three fittings,
that is, the mounting piece 162 provided on the end plate 124 and
the mounting pieces 164, 166 provided on the end plate 126, this
embodiment can reduce the man-hours for the mounting operation, in
comparison with the case where fuel cell stacks are individually
mounted to a vehicle body.
According to the fuel cell 120 of the second embodiment, the
terminal plate 132 is disposed on the end plate 124 side so as to
connect the two fuel cell stacks 122a, 122b in series, and the
fuel-or-the-like supply/discharge piping 140 is provided on the end
plate 124 side. Therefore, hydrogen, air and cooling water can be
supplied and discharged at sites of equal electric potentials. As a
result, it becomes possible to prevent the hydrolysis of water that
can be caused by supplying water to sites of different electric
potentials and to reduce electric loss. Due to the above-described
arrangement, the output terminals 138, 139 of the fuel cell 120 can
be provided at the end plate 126 side, which is opposite from the
fuel-or-the-like supply/discharge piping 140. Therefore, the degree
of freedom in designing the wirings for electric power can be
increased. In the fuel cell in this aspect of the invention,
positive and negative output terminals for supplying electric power
may be disposed at a side of one of the two end portion retaining
members.
According to the fuel cell 120 of the second embodiment, the
fuel-or-the-like supply/discharge piping 140 is provided at the end
plate 124 side, and the pressurizing mechanism 150 is provided at
the opposite side, that is, the end plate 126 side. Therefore, it
is no longer necessary to consider the displacement of the stack
caused by, for example, adjustment of the pressure exerted on the
fuel cell stacks 122a, 122b with respect to the mounting of the
fuel-or-the-like supply/discharge piping 140. As a result, the
mounting characteristic of the fuel-or-the-like supply/discharge
piping 140 can be improved, and the sealing characteristic
regarding hydrogen, air and cooling water can be secured without a
need to adopt a complicated construction.
FIG. 10 is an enlarged sectional view of end plate 124-adjacent
portions of the cooling water channels formed in the fuel cell
stack 122a. As described above, the terminal plate 132 and the
insulator plate 134 are disposed between the end plate 124 and the
adjacent unit cell 121 in an end plate 124-side end portion of the
fuel cell stack 122a. The insulator 134 has such a thickness a that
the electric current that flows through a signal line of a sensor
provided in the fuel cell stack 122a (e.g., a signal line for
detecting the voltage of a unit cell) at the time of a formation of
short circuit that includes, as portions of the short circuit, the
signal line and water present in a channel 134a of the insulator
134 is within a range of electric current that does not break the
signal line.
FIG. 11 is a circuit diagram that electrically illustrates a short
circuit. Normally, the fuel cell stack 122a is electrically
insulated by the insulator 136 disposed at the end plate 126 side.
A case where the fuel cell stack 122a has a short circuit formed by
a signal line connected to the fuel cell stack, the tension plate
128a, and the cooling water present in the channel 134a of the
insulator 134 will now be considered. The electric current through
the signal line is determined by the value of resistance of the
cooling water in the channel 134a of the insulator 134. The value
of resistance is determined by the length of the channel 134a, that
is, the thickness .alpha. of the insulator 134. In the fuel cell
120 of the embodiment, breakage of the signal line caused by
short-circuit current is prevented by forming an insulator 134
having a thickness of at least 3 mm based on experiments or the
like. The thickness .alpha. of the insulator 134 is determined by
the material and the sectional area of the signal line used, the
property of the cooling water, etc.
In the fuel cell 120 of the second embodiment, the insulator 134
formed from an electrically insulating material as a plate member
having a certain thickness that is determined by a signal line of a
sensor or the like attached to the fuel cell stack is disposed at
the side of the end plate 124 where the fuel-or-the-like
supply/discharge piping 140 is connected. Therefore, even if a
short circuit that includes the signal line as a portion thereof is
formed, breakage of the signal line is prevented.
Although in the fuel cell 120 of the second embodiment, the two end
plates 124, 126 are disposed at the opposite ends of the two fuel
cell stacks 122a, 122b and astride the two stacks, it is also
possible to dispose two end plates at opposite ends of more than
two fuel cell stacks, for example, four stacks, six stacks, etc. so
that the end plates extend over the ends of all the stacks.
Although the fuel cell 120 of the second embodiment is described
above on the assumption that the fuel cell 120 is installed in a
vehicle, it is not necessary to install the fuel cell 120 in a
vehicle.
(Third Embodiment)
In the first and second embodiments, positional deviation of a fuel
cell stack is prevented by making it less likely that vibration or
deformation of a body of the vehicle where the fuel cell is
installed is transferred to the fuel cell stack. Thus, gas leakage
is prevented. Countermeasures to be taken if a fuel gas leaks from
a fuel cell stack due to a positional deviation will be described
below as third and fourth embodiments.
A fuel cell stack for use in vehicles is normally sealed by a seal
member so that there is no leakage of hydrogen as a fuel gas, air
as an oxidizer, or cooling water from the fuel cell stack, except
for slight penetration of hydrogen, air or cooling water via a seal
member. The fuel cell stack is contained in a tightly sealed case
in order to prevent entrance of rainwater or the like from outside
and prevent the imparting of an electrical shock to a person or the
like.
No problem is caused by the slight penetration of air or cooling
water through the seal member caused by deviation or deformation of
a fuel cell stack caused by vibrations or torsion transmitted from
the vehicle body to the fuel cell. However, as for the hydrogen
passed through the seal member, there is a need for release from
the housing case to the outside, considering the flammability
thereof.
The seal member for preventing leakage of hydrogen or air normally
undergoes aging during use. In some cases, hydrogen or air leaks
from a fuel cell stack. If this happens, it becomes necessary to
release hydrogen from the case to the outside. Furthermore, if
hydrogen leaks from a fuel cell stack, there arises a need for a
countermeasure against a rapid pressure rise in the fuel cell
stack-housing case caused by ignition of hydrogen leak.
FIG. 12 is a diagram schematically illustrating a construction of a
fuel cell 220 in accordance with the third embodiment of the
invention. A housing case 210 in this embodiment has, in its
uppermost portion, a ventilation portion 228 that has a ventilating
opening 224 and a hydrogen-permeable membrane 226 that seals the
ventilating opening 224. The entire housing case 210, except the
ventilation portion 228, is sealed so as to completely seal the
enclosed fuel cell stack 222 from the outside.
The hydrogen-permeable membrane 226 is formed from a material that
allows permeation of gases such as hydrogen, air, etc., but does
not allow permeation of water, for example, a porous material.
Assuming for illustration purposes that a small amount of hydrogen
as a fuel passes through a seal member from the fuel cell stack 222
contained in the housing case 210 of the third embodiment, or that
hydrogen leaks due to deterioration of the seal member, hydrogen
from the fuel cell stack 222 diffuses into the housing case 210,
and gathers in the ventilation portion 228 provided in an uppermost
portion of the housing case 210 because hydrogen is lighter than
air. The hydrogen gathering in the ventilation portion 228
permeates through the hydrogen-permeable membrane 226, and is thus
discharged out of the housing case 210.
According to the fuel cell 220 of the third embodiment, the small
amount of hydrogen penetrating the seal member of the fuel cell
stack 222 and the amount of hydrogen leaking from the fuel cell
stack 222 is discharged via the ventilation portion 228. Therefore,
rise of hydrogen concentration in the housing case 210 can be
curbed. Furthermore, since the ventilation portion 228 is provided
in an uppermost portion of the housing case 210, the hydrogen
ventilation efficiency can be improved.
In the fuel cell 220 of the third embodiment, the ventilation
portion 228 is provided in an uppermost portion of the housing case
210. However, the ventilation portion 228 does not need to be
located in an uppermost portion as long as the ventilation portion
228 is provided in an upper portion of the housing case 210 and
allows ventilation of the housing case 210. Although in the fuel
cell 220 of the third embodiment, only one ventilation portion 228
is provided in the uppermost portion of the housing case 210, it is
also possible to provide a plurality of ventilation portions.
(Fourth Embodiment)
Next described will be a fuel cell 320 of a fourth embodiment of
the invention. FIG. 13 is a diagram schematically illustrating a
construction of the fuel cell 320 of the fourth embodiment. FIG.
14a is a plan view of the fuel cell 320. FIG. 14b is an enlarged
sectional view taken on line 14b-14b in FIG. 14a. In the fuel cell
320 of the fourth embodiment, a pressure release portion 322 formed
by sealing a pressure release hole 324 with a pressure release lid
326 via a double-sided adhesive tape 328 having a predetermined
adhesion strength is provided in a case-side portion. At the site
of the pressure release portion 322 as well, sealing is
accomplished so that an enclosed fuel cell stack (not shown) is
completely sealed from outside.
The area of opening of the pressure release hole 324 is calculated
so that when a predetermined pressure (e.g., 6 kPaG) less than or
equal to the breaking pressure of the case occurs, the force that
acts on the pressure release lid 326 overcomes the adhesion
strength of the double-sided adhesive tape 328. This predetermined
pressure is set by the material of the case or the like.
Next considered will be a case where hydrogen leaks from the fuel
cell stack provided in the fuel cell 320 of the fourth embodiment
constructed as described above, and is ignited for a certain cause.
Hydrogen, when ignited in the presence of oxygen, burns in an
explosive manner. At the time of such an explosive combustion,
pressure in the housing case 310 sharply increases. When the
internal pressure of the housing case 310 reaches a predetermined
pressure, the force acting on the pressure release lid 326 based on
the internal pressure of the housing case 310 overcomes the
adhesion strength of the double-sided adhesive tape 328. Therefore,
the pressure inside the housing case 310 is kept below a
predetermined pressure. The predetermined pressure is set at or
below the breaking pressure of the housing case 310. Hence, it is
possible to prevent breakage of the housing case 310 caused by an
abnormal pressure rise even if hydrogen should explosively burns.
The pressure value (predetermined pressure) for releasing pressure
at the pressure release portion 322 may be determined by the
adhesion strength of the double-sided adhesive tape 328 and the
area of opening of the pressure release hole 324.
According to the fuel cell 320 of the fourth embodiment, provision
of the pressure release portion 322 prevents the internal pressure
of the housing case 310 from becoming abnormally high. As a result,
it becomes possible to prevent breakage of the housing case 310 due
to abnormal pressure rise.
Although in the fuel cell 320 of the fourth embodiment, the
pressure release lid 326 is adhered via the double-sided adhesive
tape 328 so as to seal the pressure release hole 324, the
double-sided adhesive tape 328 may be replaced by a seal member and
the pressure release lid 326 may be attached to the pressure
release hole 324 by using bolts. In this case, it is appropriate to
adopt an arrangement in which when the force based on a
predetermined pressure acts on the pressure release lid 326, the
internal gas is released overcoming the bolt fastening
strength.
Although in the fuel cell 320 of the fourth embodiment, the
pressure release portion 322 is provided in a side surface of the
housing case 310, the pressure release portion 322 may be provided
in an upper surface or a lower surface of the housing case 310.
Furthermore, although in the housing case 310 of the fourth
embodiment, only one pressure release portion 322 is provided, it
is also possible to provide a plurality of pressure release
portions.
Although the fuel cell 220 of the third embodiment and the fuel
cell 320 of the fourth embodiment are separately described, it is
also appropriate to provide a fuel cell equipped with a housing
case that has a ventilation portion 228 described in conjunction
with the fuel cell 220 of the third embodiment and a pressure
release portion 322 described in conjunction with the fuel cell 320
of the fourth embodiment.
The fuel cell 220 of the third embodiment and the fuel cell 320 of
the fourth embodiment have been separately described. Technical
ideas that can be grasped from the embodiments will be mentioned
below.
A fuel cell including a housing case that has a gas-permeable
portion that allows permeation of gas but does not allow permeation
of liquid.
In the fuel cells equipped with housing cases as described above,
the gas-permeable portion allows permeation of gas but does not
allow permeation of liquid. That is, the gas-permeable portion
allows permeation of gas while preventing entrance of a liquid such
as rainwater or the like. Therefore, the internal space of the
housing case can be ventilated.
A housing case-equipped fuel cell wherein the aforementioned
gas-permeable portion is a hydrogen-permeable portion that does not
allow permeation of water but allows permeation of at least
hydrogen.
A housing case-equipped fuel cell wherein the aforementioned
hydrogen-permeable portion has a through-hole formed in the housing
case and a hydrogen-permeable membrane that seals the
through-hole.
In the housing case-equipped fuel cells described above, at least
hydrogen can be released from the housing case to the outside.
A housing case-equipped fuel cell wherein the gas-permeable portion
is formed in an upper portion of the housing case.
In this housing case-equipped fuel cell, hydrogen, which is lighter
than air, can be passed in an increased amount to the outside, so
that the ventilation efficiency can be improved.
A fuel cell including a housing case that houses a fuel cell stack
and that has a pressure release portion that releases pressure from
the housing case when the pressure in the housing case reaches a
predetermined pressure.
In this housing case-equipped fuel cell, the pressure release
portion releases pressure when the pressure in the housing case
reaches the predetermined pressure. Therefore, it is possible to
prevent abnormal pressure in the housing case.
A housing case-equipped fuel cell wherein the pressure release
portion has a through-hole that is formed in the housing case and
that has a predetermined area, and a seal member that seals the
through-hole with a predetermined adhesion strength.
A housing case-equipped fuel cell wherein the predetermined area is
an area that causes a force that overcomes the predetermined
adhesion strength when the predetermined pressure acts thereon.
In this housing case-equipped fuel cell, if the air pressure in the
housing case reaches or exceeds a predetermined value, gas can be
discharged via the pressure release portion.
While the invention has been described with reference to what are
presently considered to be preferred embodiments thereof, it is to
be understood that the invention is not limited to the disclosed
embodiments or constructions. To the contrary, the invention can
also be carried out in various other manners without departing from
the sprit of the invention.
* * * * *