Abstract: A flow passage coupling unit is provided for connection and disconnection of pipings e.g. on a tooling die exchanger of a press or a former machine, in which both the cylindrical body and the valve head of a slide valve actuated for communication and discommunication between flow paths are slidably fitted into the small and large diameter bores of a main body respectively which is designated as a housing for the slide valve, so that the sliding distance of the slide valve can be determined by summing up of the sliding lengths of their respective small and large diameter bores. Accordingly, the entire length of the main body is minimized and thus, the flow passage coupling unit will become compact in size while assuring consistent action in coupling the flow passages. Also, the flow passage coupling unit is further reduced in the overall size by improviding both the sealing arrangement in the sliding regions and the opening arrangement in the cylindrical body.

Abstract: A flow passage coupling unit (1) for flow passages (2, 4) of movable and fixed members (3, 5), which includes a cylindrical body (6) secured to the movable member and having a large bore (10) communicating with the flow passage, a small bore (11) and a value seat (12) formed between the large and small bores; a sliding valve (7) having a cylindrical sliding surface (7a) which slidably fits in the small bore and has an axial passage (14), a valve head (17) movable within the large bore, and a through-hole (16) provided through the cylindrical sliding surface adjacent the valve head; a coil spring (13) provided within the large bore for biasing the valve head against the valve seat so that communication between the large bore and the axial passage is normally cut off; and the valve seat (12) made in a plane which is perpendicular to an axis of the sliding valve.