Hollow poppet valve and method of manufacturing

A method for manufacturing a poppet valve, the method comprising the steps of:

• forming a valve stem;
• forming a valve body having, along a longitudinal axis, a first end and a second end;
• forming the valve body to comprise a cavity with a first opening disposed towards the first end and a second opening disposed towards the second end;
• forming the valve body to comprise a coaxially arranged neck portion at the first end of the valve body;
• connecting the valve stem to the neck portion at the first end of the valve body;
• forming the valve body to comprise a first outer contact face portion at the second end of the valve body;
• forming the valve body such that the first outer contact face portion comprises a circumferential groove portion;
• forming a valve cap configured to close the second opening of the valve body, the valve cap comprising a second outer contact face portion;
• forming the valve cap such that the second outer contact face portion comprises a groove portion;
• forming the valve cap such that the valve cap comprises a cylindrical upright wall, wherein the cylindrical upright wall extends into the second opening of the cavity of the valve body, and wherein the cylindrical upright wall is configured to center the valve cap to the valve body;
• arranging the valve cap coaxially with the second end of the valve body such that the first and second outer contact face portions form a valve head contact face and, such that the circumferential groove portions of the first and second outer contact face portions join to form a curved circumferential face groove;
• connecting the valve cap to the valve body by arranging a weld between the first and second outer contact face portions;
• and covering the weld along the curved circumferential face groove with a layer of seat facing material.

A hollow poppet valve comprising:

• a valve stem;
• a valve body comprising a longitudinal axis with a first end and a second end;
• the valve body comprising a cavity with a first opening disposed at the first end of the valve body and a second opening disposed at the second end of the valve body;
• the first end of the valve body comprising a coaxially arranged neck portion;
• the second end of the valve body comprising a first outer contact face portion;
• the valve body comprising a first inner contact face portion arranged coaxially on the longitudinal axis of the valve body and comprising a first weld surface extending at an angle from the first outer contact face portion;
• wherein the first inner contact face portion transitions in an outward direction into the first weld surface;
• a valve cap disposed coaxially on the second end of the valve body, the valve cap configured to seal the second opening of the valve body;
• the valve cap comprising a second outer contact face portion;
• the first outer contact face portion and the second outer contact face portion are joined to form a curved valve head contact face;
• wherein the valve cap comprises a cylindrical upright wall, wherein the cylindrical upright wall extends into the second opening of the cavity of the valve body, and wherein the cylindrical upright wall is configured to center the valve cap to the valve body;
• the valve cap further comprises:
• a second inner contact face portion arranged coaxially with the longitudinal axis of the valve cap;
• and
• a second weld surface extending at an angle from the second outer contact face portion;
• wherein the second inner contact face portion abuts the first inner contact face portion, and
• wherein the first weld surface contacts the second weld surface.

A poppet valve, comprising:

• a valve stem;
• a valve body having along a longitudinal axis, a first end and a second end,
• the first end of the valve body comprising a coaxially arranged neck portion,
• the second end of the valve body comprising a first outer contact face portion;
• the valve body further comprising a cavity with a first opening disposed towards the first end and a second opening disposed towards the second end;
• and
• a valve cap coaxially arranged on the second end of the valve body, the valve cap configured to close the second opening of the valve body;
• wherein the valve cap comprises a cylindrical upright wall, wherein the cylindrical upright wall extends into the second opening of the cavity of the valve body, and wherein the cylindrical upright wall is configured to center the valve cap to the valve body;
• the valve cap comprising a second outer contact face portion forming a valve head contact face with the first outer contact face portion;
• the first outer contact face portion comprising a first circumferential groove portion and the second outer contact face portion comprising a second circumferential groove portion, the first circumferential groove portion and the second circumferential groove portion forming a curved circumferential face groove in the poppet valve.