Patent attributes
A fuel injection valve is provided with a main body and a valve member. The main body has a fuel passage and a fuel injection opening formed at the downstream-end of the fuel passage. The valve member is provided in the fuel passage. The valve member is configured to move between a first position in which the valve member closes the fuel injection opening and a second position in which the valve member opens the fuel injection opening. A hardened layer is formed on abutment surfaces of the valve member and the main body that abut with each other. The hardness of this hardened layer is lower in its surface side than in its bottom side. According to this structure, the stress generated inside the hardened layer is suppressed, and breakage and detachment of the hardened layer are prevented.
