Method for producing a built hollow valve of an internal combustion engine

A method of manufacturing a hollow valve for an internal combustion engine, comprising:

• providing a valve stem, a valve bottom and a valve cone;
• mounting the valve bottom centrally in an assembly device;
• arranging the valve stem concentrically onto the valve bottom;
• joining the valve stem to the valve bottom to form a metallurgical joint encircling the valve stem;
• inserting the valve stem through the valve cone until a periphery of the valve cone overlays a corresponding periphery of the valve bottom;
• joining the valve cone together with the valve bottom;
• and
• joining the valve cone together with the valve stem;

A method of assembling a hollow valve, comprising:

• providing a hollow valve stem, a valve bottom having an outer edge, and a valve cone having an outer edge and an inner annular region defining an opening;
• centring the valve bottom in a mounting;
• abutting an end of the valve stem against the valve bottom, and aligning the valve stem concentrically with the valve bottom;
• joining the valve stem with the valve bottom forming a metallurgical joint encircling the end of the valve stem;
• inserting the valve stem through the opening of the valve cone, and abutting the outer edge of the valve cone against the outer edge of the valve bottom;
• preloading at least one of (i) the valve cone against the valve bottom and (ii) the valve cone against the valve stem;
• joining the outer edge of the valve cone with the outer edge of the valve bottom forming a metallurgical joint encircling the valve cone and valve bottom;
• and
• joining the inner annular region of the valve cone with the valve stem forming an encircling metallurgical joint.