Fuel injector

A fuel injector for directly injecting fuel into a combustion chamber of an internal combustion engine, comprising:

• an actuator;
• and
• a valve needle which is actuatable by the actuator, the valve needle at a spray-discharge end having a spherical valve-closure member, which together with a single valve-seat surface configured on a valve-seat member, forms a sealing seat at a seat-contact point,
• wherein the valve-seat member and the valve-closure member are provided with at least one stiffness-reducing element in the region of the sealing seat,
• wherein the stiffness-reducing element is formed on the valve-closure member as a recess, which is a circumferential groove, which surrounds an outer periphery of the spherical valve-closure member,
• wherein the stiffness is reduced at least principally due to the recess, wherein the recess lies upstream from the single valve-seat surface or the seat-contact point,
• wherein a lower section of the spherical valve-closure member cooperates with the valve-seat surface of the valve-seat member to form the sealing seat such that, when the valve is closed, the sphere of the valve-closure member rests against the valve seat member which valve seat member is conically tilted or spherically concavely curved,
• wherein the valve-seat member is thin-walled at least in the area of the seat-contact point.