Fuel injector armature with a spherical valve seat

A method of assembling a fuel injector for use with an internal combustion engine, the method comprising:

• assembling a valve group subassembly including a fuel tube and a non-magnetic sleeve extending along a longitudinal axis, the valve group subassembly further including a valve body having an armature, a ball valve fixed to the armature and a valve seat aligned with the longitudinal axis and a first fastening surface;
• assembling a coil group subassembly including a housing generally surrounding a solenoid coil, the coil group subassembly further including an overmold generally encasing the housing and a second fastening surface;
• relatively pressing the valve group and the coil group subassemblies along the longitudinal axis such that the fuel tube extends inside the overmold;
• and
• matingly engaging the first fastening surface of the valve group subassembly and the second fastening surface of the coil group subassembly so that the valve group subassembly is secured to the coil group subassembly.

A fuel injector for use with an internal combustion engine, the fuel injector comprising:

• a valve group subassembly being insertable with a coil group subassembly;
• the valve group subassembly including:
• a valve body extending along a longitudinal axis, the valve body being connected to a non-magnetic sleeve;
• a valve seat secured to the valve body, the valve seat defining an outlet opening through which fuel flows;
• an armature movable along the longitudinal axis with respect to the valve body;
• and
• a valve ball fixed to the armature, the valve ball being moved between an open position wherein the valve ball is spaced from the valve seat such that fuel flow through the outlet opening is permitted and a closed position wherein the valve ball contiguously engages the valve seat such that fuel flow is prevented;
• a first fastening surface;
• and
• a coil group subassembly including:
• a solenoid coil operable to displace the armature with respect to the valve body;
• a housing generally surrounding the solenoid coil and matingly engaged to the valve body of the valve group subassembly;
• and
• a second fastening surface fixed in contiguous engagement with the first fastening surface so that the valve group subassembly is secured to the coil group subassembly.