Three-way control valve

摘要

A fuel injector comprising a valve needle (20) for controlling fuel injection through an injector outlet, a control chamber (18) for receiving fuel and a three-way control valve that controls fuel pressure within the control chamber (18) to control opening and closing movement of the valve needle to control fuel injection through the outlet. The three-way control valve controls communication between (a) a first passage (38) and a second passage (36) and (b) a third passage (30) and the second passage (36), and includes a first housing (14) provided with a guide bore (34) for a control valve member (32a, 32b), whereby movement of the control valve member (32a, 32b) is guided within the guide bore (34) and a first valve seat (48), defined by a second housing (12), with which an end of the control valve member is engageable to control communication between the first and second passages (38, 36). The first housing (14) is a control valve housing and the second housing (12) is an injector housing, the injector housing (12) being provided with a guide bore (22) for the valve needle or a part (20) carried by the valve needle. The control valve also defines a second valve seat (50) defined by the first housing (14) with which the control valve member is engageable to control communication between the second and third flow passages (36, 30), and an intermediate housing (16) located between the first and second housings (14, 12), wherein the second passage (36) is defined within the intermediate housing (16).