FUEL INJECTION VALVE AND METHOD OF FORMING INJECTION HOLE THEREOF

摘要

A fuel injection valve which realizes uniform spray distribution of fuel even when an average rotation speed is varied due to the change of a fuel injection direction or fuel pressure. A valve seat (12) has a fuel passage (11f), a valve seat part (12a) having a shape of a truncated cone tapered toward a downstream side, and an injection hole (11) continued to the valve seat part (12a).The injection hole (11) is constituted by combining a first cylindrical inclined hole (11a) and a second cylindrical inclined hole (11b) whose center axes (22) have inclinations different from each other with respect to the rotation center axis (21). The center axis (22) of the second cylindrical inclined hole (11b) is inclined in a target injection direction. The rotation center axis (21) does not cross with the inner wall surface of the injection hole (11) and passes through the inside of the injection hole (11). The center (11d) of the injection hole exit port is near the rotation center axis (21). Therefore, at the injection hole exit port (11c), the uniformity of the rotation speed of the fuel is secured and the uniformity of distribution in the circumferential direction of the injected fuel is also maintained, so that the fuel spray distribution becomes uniform.