Abstract: A planar fuel cell apparatus (1), as viewed in a stacking direction, includes a first rectilinear line which connects a centroid Cfi of fuel gas inlets and a centroid Cfo of fuel gas outlets, and a second rectilinear line which connects a centroid Cai of oxidizer gas inlets and a centroid Cao of oxidizer gas outlets cross each other. The planar fuel cell apparatus employs cross-flow design in which a fuel gas flow channel and an oxidizer gas flow channel cross each other. In the planar fuel cell apparatus of the cross-flow design, as viewed in the stacking direction, the centroid Cao of the oxidizer gas outlets is located closer to the centroid Cfi of the fuel gas inlets than to the centroid Cfo of the fuel gas outlets.

Abstract: A planar fuel cell apparatus (1) characterized in that, as viewed in a stacking direction, a first rectilinear line which connects a centroid Cfi of fuel gas inlets and a centroid Cfo of fuel gas outlets, and a second rectilinear line which connects a centroid Cai of oxidizer gas inlets and a centroid Cao of oxidizer gas outlets cross each other. That is, the planar fuel cell apparatus employs cross-flow design in which a fuel gas flow channel and an oxidizer gas flow channel cross each other. In the planar fuel cell apparatus of the cross-flow design, as viewed in the stacking direction, the centroid Cfo of the fuel gas outlets is located closer to the centroid Cai of the oxidizer gas inlets than to the centroid Cao of the oxidizer gas outlets.

Abstract: An intake sensor includes a detection element, a heater, a housing, and a protector. The protector has two or more tubular portions spaced from one another in the radial direction. Of any two adjacent tubular portions, a second tubular portion on the outer side has tubular walls present in the penetration direction of first through holes of a first tubular portion on the inner side. Second through holes of the second tubular portion have an area equal to or greater than that of the first through hole. When the intake sensor is disposed in a model gas mixture of butane and air having air-fuel ratio of about 13, pressure of about 0.11 MPa, temperature of about 20° C., and flow rate of about 0 m/sec, and the heater heats the solid electrolyte member to the target temperature, no combustion flame is visually recognized on the outer surface of the protector.

Abstract: A spark plug where a predetermined cross section of a noble metal tip is divided by a vertical line into two half cross sections having a first half cross section and a second half cross section. The first half cross section satisfies h1/t?0.2 and Rw1/Rt1?1.03, and the second half cross section satisfies h2/t?0.2 and Rw2/Rt2?1.03. At a welding interface, an oxidation scale progresses in a direction away from an axis along side surfaces and changes the progressing direction at the end points so as to progress in a direction toward the axis along bottom surfaces. The progress of the oxidation scale is restrained. Since the noble metal tip is held by an engagement portion of a ground electrode, separation of the noble metal tip from the ground electrode 40 can be restrained.

Abstract: In process of threadably fitting a metal shell having a surface formed with an Ni plated layer into a mounting hole, in a state where a gasket made of stainless steel is uncompressed while being interposed between a protrusion part and an opening periphery, a surface of the gasket is out of contact with another surface thereof. When the gasket is viewed on a cross section in a direction of an axial line O, the gasket contacts with the protrusion part at one point of a point X, the gasket contacts with the opening periphery flat one point of a point Y, and the point Y is located outside of the point X in a radial direction. Further, the point Y is located inside of a maximum outer diameter Dz of a seating surface of the protrusion part in the radial direction.

Abstract: A spark plug where a predetermined cross section of a noble metal tip is divided by a vertical line into two half cross sections having a first half cross section and a second half cross section. The first half cross section satisfies h1/t?0.2 and Rw1/Rt1?1.03, and the second half cross section satisfies h2/t?0.2 and Rw2/Rt2?1.03. At a welding interface, an oxidation scale progresses in a direction away from an axis along side surfaces and changes the progressing direction at the end points so as to progress in a direction toward the axis along bottom surfaces. The progress of the oxidation scale is restrained. Since the noble metal tip is held by an engagement portion of a ground electrode, separation of the noble metal tip from the ground electrode 40 can be restrained.

Abstract: In process of threadably fitting a metal shell having a surface formed with an Ni plated layer into a mounting hole, in a state where a gasket made of stainless steel is uncompressed while being interposed between a protrusion part and an opening periphery, a surface of the gasket is out of contact with another surface thereof. When the gasket is viewed on a cross section in a direction of an axial line O, the gasket contacts with the protrusion part at one point of a point X, the gasket contacts with the opening periphery at one point of a point Y, and the point Y is located outside of the point X in a radial direction. Further, the point Y is located inside of a maximum outer diameter Dz of a seating surface of the protrusion part in the radial direction.

Abstract: In a crankshaft of an in-line four-cylinder engine, an arm that is closest to a flywheel has a greater average thickness in a direction of the rotation axis of the crankshaft than those of other arms. Two of the arms that are coupled to both sides of the third journal from the flywheel each have a center of gravity closer to its own counterweight compared to the centers of gravity of the arms that face the two arms with corresponding crankpins in between. Accordingly, the rigidity against torsional deformation and the thickness of oil films on the journals are reliably maintained while suppressing increase in the weight of the entire crankshaft.

Abstract: In a crankshaft of an in-line four-cylinder engine, an arm that is closest to a flywheel has a greater average thickness in a direction of the rotation axis of the crankshaft than those of other arms. Two of the arms that are coupled to both sides of the third journal from the flywheel each have a center of gravity closer to its own counterweight compared to the centers of gravity of the arms that face the two arms with corresponding crankpins in between. Accordingly, the rigidity against torsional deformation and the thickness of oil films on the journals are reliably maintained while suppressing increase in the weight of the entire crankshaft.