Fuel injection valve having different fuel injection angles at different opening amounts

A fuel injection valve, comprising:

• a valve body including a fuel passage inside thereof, a concave conical surface formed in a tip portion of the valve body, and a plurality of fuel injection holes extending from said concave conical surface to an outside of the valve body with a slant angle relative to a central axis of the valve body,
• a needle valve movable in said valve body and including a cylindrical shaft portion, a conical surface adjacent to a tip portion of said cylindrical shaft portion and having a conical angle with respect to said central axis smaller than that of said concave conical surface of the valve body, a lower edge of the conical surface defining a contact line separably contacting with said concave conical surface of the valve body, and a control surface formed in a tip portion of the needle valve to face said plurality of fuel injection holes, having a conical angle with respect to said central axis greater than said slant angle of said concave conical surface of the valve body and arranged such that the distance between the control surface and each said fuel injection hole becomes greater due when a lift amount of the needle valve, with separates said needle valve from said valve body, is increased, said fuel injection hole being located downstream of said contact line when the contact line contacts with said concave conical surface of the valve body, and
• fuel swirling means arranged in said fuel passage for swirling the fuel flow through the fuel passage around said needle valve;
• wherein said needle valve further includes a second conical surface between said first conical surface adjacent to the tip portion of said cylindrical shaft portion and said control surface, said second conical surface having a conical angle substantially equal to that of said concave conical surface a the valve body.

A fuel injection valve, comprising:

• a valve body including a fuel passage inside thereof, a concave conical surface formed in a portion of the valve body, and a plurality of fuel injection holes extending from said conical surface to an outside of the valve body with a slant angle relative to the central axis of the valve body, and
• a needle valve movable in said valve body and including a cylindrical shaft portion, a seat portion adjacent to a tip portion of said cylindrical shaft portion and separably contacting with said concave conical surface of the valve body, and a fuel flow rate control portion formed at a lower end of said seat portion to face said plurality of fuel injection holes, having a conical angle greater than that of said concave conical surface of the valve body and arranged such that the distance between the control portion and each said fuel injection hole is increased when a lift amount of the needle valve, which separates said needle valve from said valve body, is increased, said fuel injection hole being located downstream of said seat portion when said seat portion contacts with said concave conical surface of the valve body;
• wherein said needle valve further includes a second conical surface between said first conical surface adjacent to the tip portion of said cylindrical shaft portion and said control portion, said second conical surface having a conical angle substantially equal to that of said concave conical surface of the valve body.

A fuel injection valve, comprising:

• a valve body including:
• a) surfaces forming a fuel passage inside thereof, b) a concave conical surface formed in a tip portion of the valve body, having an angle relative to a central axis of the valve body, and c) surfaces forming a plurality of fuel injection holes extending from said concave conical surface to outside of the valve body, and
• a needle valve movable in said valve body and including a cylindrical shaft portion with a lowermost tip portion, a conical surface adjacent to the tip portion of said cylindrical shaft portion and having a conical angle with respect to said central axis smaller than that of said concave conical surface of the valve body, a lower edge of the conical surface defining a contact line separably contacting with said concave conical surface of the valve body, and a control surface formed in a tip portion of the needle valve to face said plurality of fuel injection holes, having a conical angle with respect to said central axis greater than that of said concave conical surface of the valve body,
• said surfaces of said valve body and needle valve formed such that a distance between the control surface and each said fuel injection holes becomes greater when a lift amount of the needle valve, which separates said needle valve from said valve body, is increased, and such that when the distance becomes smaller, an atomized fuel injection angles from the injection hole is increased due to an increased fuel flow speed, but when the distance becomes larger, a wider flow sectional area and reduced fuel flow speed is obtained, said fuel injection hole being located downstream of said contact line when the contact line contacts with said concave conical surface of the valve body;
• wherein said needle valve further includes a second conical surface between said first conical surface adjacent to the tip portion of said cylindrical shaft portion and said control surface, said second conical surface having a conical angle substantially equal to that of said concave conical surface of the valve body.