NON-RETURN VALVE STRUCTURE, DIAPHRAGM PUMP, AND BLOOD PRESSURE METER

摘要

A non-return valve structure wherein deformation of a diaphragm-like non-return valve is suppressed. A gas suction valve (20) has a non-return valve structure which permits flow of gas from an inner space of a diaphragm pump toward a pump chamber and prohibits flow in the reverse direction. The gas suction valve (20) is mounted between a space (25) and the inner space of the diaphragm pump and is provided with a valve housing (16) having formed therein a communicating hole (23) for interconnecting the space (25) and the inner space of the diaphragm pump, an elastic diaphragm body (21) for covering the space (25) side of the communicating hole (23) to prevent reverse flow of the gas, an elastic member (22) having a wall section (22c) which surrounds the communicating hole (23) and holding the elastic diaphragm body (21), and a gas collecting body (17) having formed thereon a projection (24) for limiting positional displacement of the wall section (22c) to suppress deformation of the elastic diaphragm body (21) caused by strain of the elastic diaphragm body (21).