Abstract: The present invention has an object to improve the flow property so as to increase the gas flow amount, to inhibit the gas from staying within a valve chamber, and to enhance the gas-replacement property such as evacuation performance and purge performance. A housing (2) is provided with a first flow passage (7), a valve chamber (9) of a shut-off valve (8) and a second flow passage (10) in the mentioned order. A diaphragm (13) is arranged so that it hermetically covers the valve chamber (9). The first flow passage (7) has an inner end opened into an inner surface of the valve chamber (9) to which a mid portion of the diaphragm (13) is opposed. A valve seat (15) is formed around this opening. The shut-off valve (8) is opened and closed by allowing the diaphragm (13) to approach and separate from the valve seat (15). A groove portion (18) is formed in the inner surface of the valve chamber (9) around the valve seat (15).

Abstract: In an air cleaner casing 10 including an upper casing 11 and a lower casing 12, a stopper mechanism is formed in the upper casing 11 and the lower casing 12 to prevent relative movement between the upper casing 11 and the lower casing 12 after assembly. The air cleaner casing 10 has a hinge pin 17 and a hinge retainer 18 for receiving the hinge pin 17 therein. The hinge retainer 18 has a lateral U-shaped cross section having opposed surfaces 18a and 18b, at least one of which is tapered.