Vehicle body frame, die-cast product, mold for die-cast product and die-cast method

A mold for a die-cast product in which a main frame which is contiguously formed with a head pipe constitutes a portion of a hollow light-weight-metal-made vehicle-body frame, comprising:

• a core which serves to form an inner space of the die-cast product, the core including:
• a core body;
• and
• a plurality of splints mounted on the core body, the splints having approximately elliptical cross-sectional shapes,
• wherein side surfaces of the splints are formed into flat surfaces, and each of the flat surfaces is set parallel to a mold split surface of the mold,
• wherein at least one of the plurality of splints is mounted on each of two non-parallel surfaces of the core body,
• wherein each of the splints projects in a direction that is orthogonal relative to the respective non-parallel surface of the core body, and
• wherein a long axis direction of each of the plurality of splints is arranged parallel to the lone axis direction of every other one of the plurality of splints.