Electromagnetic solenoid and fuel injection valve

A fuel injection valve comprising:

• a valve seat and a valve body opening and closing a fuel passage in cooperation with each other;
• a movable element having at one end thereof the valve body and having at the other end thereof a movable core;
• and
• a fixed core attracting the movable core by exerting a magnetic attraction force on the movable core, and wherein
• the movable core has an end surface that is formed between an inner circumferential surface and an outer circumferential surface of the movable core,
• the fixed core has an end surface that is formed between an inner circumferential surface and an outer circumferential surface of the fixed core and faces the end surface of the movable core,
• a ring-shaped protruding portion is formed at at least either one of the end surface of the movable core or the end surface of the fixed core and contacts the fixed core or the movable core respectively which the protruding portion faces,
• the protruding portion is provided at a position that is shifted to a radially inner circumferential side of the end surface where the protruding portion is provided,
• a length between an apex and an inner circumferential edge of the protruding portion is shorter than a length between the apex and an outer circumferential edge of the protruding portion,
• the protruding portion is formed by a first curved surface whose radius of curvature is R01 at an outer circumferential side of the protruding portion and a second curved surface whose radius of curvature is R02 at an inner circumferential side of the protruding portion with the apex being a boundary,
• a relationship of R01>R02 is satisfied, and
• the apex where the first curved surface and the second curved surface are connected is formed by a curved surface.