Abstract: A coil spring includes a wire rod and an elastic coat provided on the wire rod. The coil spring includes a coil section including a plurality of coil portions. The wire rod includes a round cross-sectional portion, a cross-section varying portion, and a rectangular cross-sectional portion along the longitudinal direction of the wire rod. The cross section of the rectangular cross-sectional portion is substantially square and has a first plane and a second plane. The first plane and the second plane oppose each other in the coil section. The elastic coat is provided on at least one of the first plane and the second plane. The elastic coat is continuous from the round cross-sectional portion to the cross-sectional variation portion and the rectangular cross-sectional portion.

Abstract: A preservation assembly of a PEFC stack which is capable of sufficiently inhibiting degradation of performance of the PEFC stack particularly during a time period that elapses from when the stack is placed in the uninstalled state until it is placed in the installation position and is practically used. The PEFC stack is provided with an oxidizing agent passage having an inlet and an outlet and extending through a cathode and a reducing agent passage having an inlet and an outlet and extending through an anode. The PEFC stack is preserved in an uninstalled state in such a manner that an interior of the oxidizing agent passage and an interior of the reducing agent passage are set in a pressure-reduced state.

Abstract: A preservation assembly of a PEFC stack which is capable of sufficiently inhibiting degradation of performance of the PEFC stack particularly during a time period that elapses from when the stack is placed in the uninstalled state until it is placed in the installation position and is practically used. The PEFC stack is provided with an oxidizing agent passage having an inlet and an outlet and extending through a cathode and a reducing agent passage having an inlet and an outlet and extending through an anode. The PEFC stack is preserved in an uninstalled state in such a manner that an interior of the oxidizing agent passage and an interior of the reducing agent passage are set in a pressure-reduced state.

Abstract: Provided is a method of preserving a PEFC stack, which is capable of controlling degradation of performance of the PEFC stack during a time period that elapses from when the stack is placed in an uninstalled state until it is placed in an installation position and is practically used. Provided is a preservation assembly of the PEFC stack which is capable of sufficiently inhibiting degradation of performance of the PEFC stack particularly during a time period that elapses from when the stack is placed in the uninstalled state until it is placed in the installation position and is practically used.

Abstract: A preservation assembly of a polymer electrolyte fuel cell stack is provided. The assembly includes an uninstalled polymer electrolyte fuel cell stack and sealing units. The uninstalled polymer electrolyte fuel cell stack is provided with an oxidizing agent passage having an inlet and an outlet and extending through a cathode and a reducing agent passage having an inlet and an outlet and extending through an anode. The sealing units include sealing plugs or containers and are configured to seal the inlet and the outlet of the oxidizing agent passage within which an oxygen concentration has been decreased and to seal the inlet and the outlet of the reducing agent passage within which the oxygen concentration has been decreased. The uninstalled polymer electrolyte fuel cell stack is in a state before an assembled polymer electrolyte fuel cell stack is incorporated into a fuel cell system.

Abstract: Provided is a method of preserving a PEFC stack, which is capable of controlling degradation of performance of the PEFC stack during a time period that elapses from when the stack is placed in an uninstalled state until it is placed in an installation position and is practically used. Provided is a preservation assembly of the PEFC stack which is capable of sufficiently inhibiting degradation of performance of the PEFC stack particularly during a time period that elapses from when the stack is placed in the uninstalled state until it is placed in the installation position and is practically used.

Abstract: A method of preserving a PEFC stack of the present invention is a method of preserving a PEFC stack that is provided with an oxidizing agent passage having an inlet and an outlet and extending through a cathode and a reducing agent passage having an inlet and an outlet and extending through an anode. The method comprises preserving the polymer electrolyte fuel cell stack in an uninstalled state under a condition in which an oxygen concentration within the oxidizing agent passage and within the reducing agent passage is lower than an oxygen concentration in atmospheric air.

Abstract: Provided is a method of preserving a PEFC stack, which is capable of controlling degradation of performance of the PEFC stack during a time period that elapses from when the stack is placed in an uninstalled state until it is placed in an installation position and is practically used. Provided is a preservation assembly of the PEFC stack which is capable of sufficiently inhibiting degradation of performance of the PEFC stack particularly during a time period that elapses from when the stack is placed in the uninstalled state until it is placed in the installation position and is practically used.

Abstract: A preservation assembly of a polymer electrolyte fuel cell stack is provided. The assembly includes an uninstalled polymer electrolyte fuel cell stack and sealing units. The uninstalled polymer electrolyte fuel cell stack is provided with an oxidizing agent passage having an inlet and an outlet and extending through a cathode and a reducing agent passage having an inlet and an outlet and extending through an anode. The sealing units include sealing plugs or containers and are configured to seal the inlet and the outlet of the oxidizing agent passage within which an oxygen concentration has been decreased and to seal the inlet and the outlet of the reducing agent passage within which the oxygen concentration has been decreased. The uninstalled polymer electrolyte fuel cell stack is in a state before an assembled polymer electrolyte fuel cell stack is incorporated into a fuel cell system.

Abstract: The present invention is intended to enable efficient assembly of a fuel cell stack without causing any damage to the conductive separator. In a fuel cell including an anode, a cathode, an electrolyte membrane interposed between the anode and the cathode, and conductive separators each having manifold apertures 12 and a flow channel 16 for supplying a gas to the anode or the cathode, manifold aperture connecting portions 15 are formed at an inlet-side end and an outlet-side end of the flow channel 16, respectively. Each of the manifold aperture connecting portions 15 is recessed below the upper surface of the conductive separator 11. Cover plates are fitted and fixed to the recessed portions, respectively.

Abstract: There are provided measuring units of measuring the amount of fluoride ions in the waste material from a fuel cell which receives a fuel gas and an oxidizing agent gas containing oxygen to undergo electrochemical reaction by which electricity is generated and a life predicting unit of predicting the life of the fuel cell by the use of the amount of fluoride ions thus measured.

Abstract: Provided is a method of preserving a PEFC stack, which is capable of controlling degradation of performance of the PEFC stack during a time period that elapses from when the stack is placed in an uninstalled state until it is placed in an installation position and is practically used. Provided is a preservation assembly of the PEFC stack which is capable of sufficiently inhibiting degradation of performance of the PEFC stack particularly during a time period that elapses from when the stack is placed in the uninstalled state until it is placed in the installation position and is practically used.

Abstract: The present invention is intended to enable efficient assembly of a fuel cell stack without causing any damage to the conductive separator. In a fuel cell including an anode, a cathode, an electrolyte membrane interposed between the anode and the cathode, and conductive separators each having manifold apertures 12 and a flow channel 16 for supplying a gas to the anode or the cathode, manifold aperture connecting portions 15 are formed at an inlet-side end and an outlet-side end of the flow channel 16, respectively. Each of the manifold aperture connecting portions 15 is recessed below the upper surface of the conductive separator 11. Cover plates are fitted and fixed to the recessed portions, respectively.

Abstract: Disclosed is a fuel cell comprising: a hydrogen-ion conductive polymer electrolyte membrane; a pair of electrodes sandwiching the hydrogen-ion conductive polymer electrolyte membrane; a first separator plate having a gas flow path for supplying a fuel gas to one of the electrodes; and a second separator plate having a gas flow path for supplying an oxidant gas to the other of the electrodes, wherein each of the electrodes has an electrode catalyst layer comprising at least a conductive carbon particle carrying an electrode catalyst particle and a hydrogen-ion conductive polymer electrolyte, the electrode catalyst layer being in contact with the hydrogen-ion conductive polymer electrolyte membrane, and at least one of the electrodes comprises a catalyst for trapping the fuel gas or the oxidant gas which has passed through the hydrogen-ion conductive polymer electrolyte membrane.

Abstract: A method of preserving a PEFC stack of the present invention is a method of preserving a PEFC stack that is provided with an oxidizing agent passage having an inlet and an outlet and extending through a cathode and a reducing agent passage having an inlet and an outlet and extending through an anode. The method comprises preserving the polymer electrolyte fuel cell stack in an uninstalled state under a condition in which an oxygen concentration within the oxidizing agent passage and within the reducing agent passage is lower than an oxygen concentration in atmospheric air.

Abstract: There are provided measuring units of measuring the amount of fluoride ions in the waste material from a fuel cell which receives a fuel gas and an oxidizing agent gas containing oxygen to undergo electrochemical reaction by which electricity is generated and a life predicting unit of predicting the life of the fuel cell by the use of the amount of fluoride ions thus measured.

Abstract: A method for easily, quickly and accurately detecting a cross leak or a micro short-circuit in a unit cell or group of cells of a fuel cell stack is provided by determining an electric output of the unit cell or group of cells after stoppage of fuel and/or oxidant and preferably during the introduction of a non-fuel and non-oxidant gas to the cell.

Abstract: Disclosed is a fuel cell comprising: a hydrogen-ion conductive polymer electrolyte membrane; a pair of electrodes sandwiching the hydrogen-ion conductive polymer electrolyte membrane; a first separator plate having a gas flow path for supplying a fuel gas to one of the electrodes; and a second separator plate having a gas flow path for supplying an oxidant gas to the other of the electrodes, wherein each of the electrodes has an electrode catalyst layer comprising at least a conductive carbon particle carrying an electrode catalyst particle and a hydrogen-ion conductive polymer electrolyte, the electrode catalyst layer being in contact with the hydrogen-ion conductive polymer electrolyte membrane, and at least one of the electrodes comprises a catalyst for trapping the fuel gas or the oxidant gas which has passed through the hydrogen-ion conductive polymer electrolyte membrane from the other electrode toward the electrode catalyst layer of the one of the electrodes.