Abstract: An imaging lens according to the present disclosure includes, in order from side of an object toward side of an image plane on which an imaging element is disposed: a front-group lens system having positive refractive power; and a rear-group lens system having, on side closest to the image plane, a lens surface that is concave to the image plane side in a vicinity of an optical axis and is convex to the image plane side in a peripheral part, and satisfies the following conditional expressions. 1.0<Gun2R2(sag6-sag10)/(TTL/2Y)<2.8??(1) 5.0(%)<ODMAX<20.

Abstract: An imaging lens of the present disclosure includes, in order from object side toward image plane side: a first lens having positive refractive power in the vicinity of an optical axis; a second lens having positive refractive power in the vicinity of the optical axis; a third lens having negative refractive power in the vicinity of the optical axis; a fourth lens having negative refractive power in the vicinity of the optical axis; a fifth lens having negative refractive power in the vicinity of the optical axis; a sixth lens having negative refractive power in the vicinity of the optical axis; and a seventh lens of which a lens surface on the image plane side has an aspheric shape having an inflection point.

Abstract: An imaging lens according to the present disclosure includes, in order from an object side toward an image plane side: a first lens having positive refractive power near an optical axis; a second lens having positive refractive power near the optical axis; a third lens having negative refractive power near the optical axis; a fourth lens whose lens surface on the image plane side has a concave shape toward the image plane side near the optical axis; a fifth lens whose lens surface on the image plane side has a concave shape toward the image plane side near the optical axis; and a sixth lens having negative refractive power near the optical axis. The fourth lens has negative refractive power. The fifth lens has positive refractive power.

Abstract: An imaging lens of the present disclosure includes, in order from object side toward image plane side, a first lens having a meniscus shape, the meniscus shape having a shape that is positioned near an optical axis and includes a convex surface that faces the object side, a second lens including a convex surface that faces, near the optical axis, the object side, and having, near the optical axis, positive refractive power, a third lens having, near the optical axis, negative refractive power, a fourth lens, a fifth lens, a sixth lens having, near the optical axis, positive refractive power, and a seventh lens having, near the optical axis, negative refractive power, and including a lens surface, the lens surface being positioned on the image plane side, and having an aspherical shape that has an inflection point.

Abstract: A start-up method for a fuel cell system that includes a fuel cell that carries out power generation by the electrochemical reaction between a fuel gas and the oxygen gas in the air; a fuel gas discharge path and a fuel gas supply path that are connected to the fuel cell; a fuel gas circulation path in which the fuel gas discharge path merges with the fuel gas supply path; and a purge valve provided on the fuel gas circulation path in order to discharge the circulating fuel gas from the fuel gas circulation path. The method includes the steps of opening the purge valve at the same time that the fuel gas is supplied to the fuel cell and replacing the nitrogen gas that originates in the air and is present in the fuel gas circulation path by fuel gas; and closing the purge valve after the nitrogen gas in the fuel gas circulation path has been replaced by the fuel gas.

Abstract: A start-up method for a fuel cell system that includes a fuel cell that carries out power generation by the electrochemical reaction between a fuel gas and the oxygen gas in the air; a fuel gas discharge path and a fuel gas supply path that are connected to the fuel cell; a fuel gas circulation path in which the fuel gas discharge path merges with the fuel gas supply path; and a purge valve provided on the fuel gas circulation path in order to discharge the circulating fuel gas from the fuel gas circulation path. The method includes the steps of opening the purge valve at the same time that the fuel gas is supplied to the fuel cell and replacing the nitrogen gas that originates in the air and is present in the fuel gas circulation path by fuel gas; and closing the purge valve after the nitrogen gas in the fuel gas circulation path has been replaced by the fuel gas.

Abstract: A start-up method for a fuel cell system that includes a fuel cell that carries out power generation by the electrochemical reaction between a fuel gas and the oxygen gas in the air; a fuel gas discharge path and a fuel gas supply path that are connected to the fuel cell; a fuel gas circulation path in which the fuel gas discharge path merges with the fuel gas supply path; and a purge valve provided on the fuel gas circulation path in order to discharge the circulating fuel gas from the fuel gas circulation path. The method includes the steps of opening the purge valve at the same time that the fuel gas is supplied to the fuel cell and replacing the nitrogen gas that originates in the air and is present in the fuel gas circulation path by fuel gas; and closing the purge valve after the nitrogen gas in the fuel gas circulation path has been replaced by the fuel gas.

Abstract: A start-up method for a fuel cell system that includes a fuel cell that carries out power generation by the electrochemical reaction between a fuel gas and the oxygen gas in the air; a fuel gas discharge path and a fuel gas supply path that are connected to the fuel cell; a fuel gas circulation path in which the fuel gas discharge path merges with the fuel gas supply path; and a purge valve provided on the fuel gas circulation path in order to discharge the circulating fuel gas from the fuel gas circulation path. The method includes the steps of opening the purge valve at the same time that the fuel gas is supplied to the fuel cell and replacing the nitrogen gas that originates in the air and is present in the fuel gas circulation path by fuel gas; and closing the purge valve after the nitrogen gas in the fuel gas circulation path has been replaced by the fuel gas.

Abstract: A start-up method for a fuel cell system that includes a fuel cell that carries out power generation by the electrochemical reaction between a fuel gas and the oxygen gas in the air; a fuel gas discharge path and a fuel gas supply path that are connected to the fuel cell; a fuel gas circulation path in which the fuel gas discharge path merges with the fuel gas supply path; and a purge valve provided on the fuel gas circulation path in order to discharge the circulating fuel gas from the fuel gas circulation path. The method includes the steps of opening the purge valve at the same time that the fuel gas is supplied to the fuel cell and replacing the nitrogen gas that originates in the air and is present in the fuel gas circulation path by fuel gas; and closing the purge valve after the nitrogen gas in the fuel gas circulation path has been replaced by the fuel gas.

Abstract: A start-up method for a fuel cell system that includes a fuel cell that carries out power generation by the electrochemical reaction between a fuel gas and the oxygen gas in the air; a fuel gas discharge path and a fuel gas supply path that are connected to the fuel cell; a fuel gas circulation path in which the fuel gas discharge path merges with the fuel gas supply path; and a purge valve provided on the fuel gas circulation path in order to discharge the circulating fuel gas from the fuel gas circulation path. The method includes the steps of opening the purge valve at the same time that the fuel gas is supplied to the fuel cell and replacing the nitrogen gas that originates in the air and is present in the fuel gas circulation path by fuel gas; and closing the purge valve after the nitrogen gas in the fuel gas circulation path has been replaced by the fuel gas.

Abstract: A start-up method for a fuel cell system that includes a fuel cell that carries out power generation by the electrochemical reaction between a fuel gas and the oxygen gas in the air; a fuel gas discharge path and a fuel gas supply path that are connected to the fuel cell; a fuel gas circulation path in which the fuel gas discharge path merges with the fuel gas supply path; and a purge valve provided on the fuel gas circulation path in order to discharge the circulating fuel gas from the fuel gas circulation path. The method includes the steps of opening the purge valve at the same time that the fuel gas is supplied to the fuel cell and replacing the nitrogen gas that originates in the air and is present in the fuel gas circulation path by fuel gas; and closing the purge valve after the nitrogen gas in the fuel gas circulation path has been replaced by the fuel gas.

Abstract: A start-up method for a fuel cell system that includes a fuel cell that carries out power generation by the electrochemical reaction between a fuel gas and the oxygen gas in the air; a fuel gas discharge path and a fuel gas supply path that are connected to the fuel cell; a fuel gas circulation path in which the fuel gas discharge path merges with the fuel gas supply path; and a purge valve provided on the fuel gas circulation path in order to discharge the circulating fuel gas from the fuel gas circulation path. The method includes the steps of opening the purge valve at the same time that the fuel gas is supplied to the fuel cell and replacing the nitrogen gas that originates in the air and is present in the fuel gas circulation path by fuel gas; and closing the purge valve after the nitrogen gas in the fuel gas circulation path has been replaced by the fuel gas.

Abstract: An air inlet is provided at the bottom of a vehicle to open downwardly. The air inlet is connected by a first tube to an air cooler for a PDU and a down converter. A fan for inputting the flow of air and turning its direction 90 degrees is connected at the downstream of the air cooler. The fan is further connected by a second tube to an exhaust outlet. The air inlet is located above a fuel tank thus to prevent any object jumping up from the road surface from straightforwardly entering the air inlet while the vehicle is running. The exhaust outlet is located above a silencer and can thus be prevented from being frozen in the winter. Using the above arrangement, the present invention embodies an air intaking and exhausting apparatus in an air cooling system for air cooling the PDU and the down converter at higher efficiency without the help of the air cooler mounted in the interior of the vehicle.

Abstract: Two embodiments of improved compact outboard motors that are designed so that the power head does not encroach into the associated watercraft forwardly of the hull when the motor is tilted up about its tilt axis. In each embodiment, the internal combustion engine of the power head is located in such a way that it can be conveniently serviced and yet will note encroach when the motor is tilted up. In one embodiment, the engine is disposed with its output shaft extending transversely and its cylinders inclined rearwardly. In the other embodiment, the cylinders are aligned and extend vertically so that the engine output shaft extends perpendicularly to the associated hull.