| 摘要 |
<p>A check valve structure which is suitable for the back-flow prevention of a micro-pump suitably used in a small, trace-amount fluid feeder used in a medical instrument and chemical analyzing instrument, and which prevents the back-flow of both gas and liquid; and a retaining structure for the check valve; wherein a valve forming body is provided with a convex portion (11) at the center of a half-split circle on the side opposite to a receiving member, and with an annular close-contact member (13) in close contact at the flat surface thereof with the receiving member and located on the outer periphery of a thin-walled portion (14) having a contact portion in linear contact with the entire periphery of a ridge line of an inlet circumference of a hole (20a, 20b) of the receiving member and extending from the convex portion (11) at the center of the valve forming body toward the circumference, and stopper portions acting as steps for receiving each other are provided at a part of the outer periphery of a cylindrical pushing member for bringing a valve seat into close contact with a valve receiving seat and at a part of the inner wall of a cylindrical hole on a valve case side for receiving thereinto the pushing member so as to keep constant the pushing-in depth of the small-diameter tip of the pushing member into the inner tube hole of the valve case.</p> |
