Abstract: A fuel cell has a membrane electrode assembly and first and second metal sheet separators. The first metal sheet separator has a fuel gas passage defined on a surface thereof. The fuel gas passage has a plurality of embossed bodies projecting from the surface which faces the membrane electrode assembly, and pairs of guide ribs provided by joining two or more of the embossed bodies.

Abstract: A fuel cell stack is mounted in a front box of a fuel cell vehicle. The fuel cell stack has a vertical stack of unit cells. The number of unit cells is increased to produce a higher output from the fuel cell stack. For a higher output from the fuel cell stack, therefore, the fuel cell stack is elongated only in the vertical direction, and does not increase its dimension in either a longitudinal direction or a transverse direction of the fuel cell vehicle.

Abstract: A first unit cell of a fuel cell stack has a first joint body sandwiched between a first separator and a second separator. The second separator has a first metal sheet having a region where grooves and ridges alternate with each other and a second metal sheet having a region where grooves and ridges alternate with each other, and a leaf spring interposed between the first and second metal sheets. The leaf spring is held against crests of the ridges of the first and second metal sheets. The grooves of the first metal sheet face the ridges of the second metal sheet across the leaf spring, and the ridges of the first metal sheet face the grooves of the second metal sheet across the leaf spring.

Abstract: A cell assembly is formed by stacking a first unit cell and a second unit cell to each other. The first unit cell includes a first unified body, and the second unit cell includes a second unified body. In the cell assembly, the first and second unit cells have structures different from each other.

Abstract: A cell assembly includes a first unit cell and a second unit cell stacked to each other. The first unit cell includes a first unified body, and the second unit cell includes a second unified body. In the cell assembly, oxidizing gas passages and fuel gas passages are provided in parallel along the first and second unit cells.

Abstract: A regulator for compressed natural gas is prevented from being frozen and from being heated to higher than a degree appropriate for prevention of the freezing.A hot-water passage 11 for circulating a portion of the engine cooling water is provided adjacent to a gas passage 24 equipped with a reducing valve 21 in the primary decompression section A of the regulator. A hot-water outlet member 10 is provided at the outlet aperture of the hot-water passage 11. A temperature sensitive valve 42 is mounted in the hot-water outlet member 10 and is set so that the hot-water passage 11 is closed with the valve body 48 when the temperature of the hot-water exceeds the degree appropriate for prevention of the freeze at the outlet aperture.