Far-infrared radiation heating furnace for steel sheet for hot stamping

A far-infrared radiation multi-stage type heating furnace for a steel sheet for hot stamping, the far-infrared radiation multi-stage type heating furnace comprising:

• a heating unit and a metallic furnace body frame disposed around the heating unit,
• the heating unit comprising:
• blocks comprising a thermal insulation material, each of the blocks being disposed surrounding a periphery of a respective space having rectangular outer shape for accommodating one of the steel sheets for hot stamping, the blocks provided in a horizontal plane of the space for accommodating the steel sheet, the blocks comprising a pair of fixed blocks extending parallel straight and facing each other in a horizontal direction and sandwiching the horizontal plane of the space, a cover block arranged to be opened and closed to open and close an inlet or an outlet of the space that the steel sheet is passed through for hot stamping, and arranged to be sandwiched between upper side of the pair of fixed blocks in a closed position, the cover block disposed on a fixed base block sandwiched between lower side of the pair of fixed blocks, the cover block directly exposed to an area over the heating unit in the closed position, and the cover block with horizontal length between the pair of fixed blocks at least three times its vertical length;
• and
• far-infrared radiation heaters positioned above and below the steel sheet for hot stamping to heat the steel sheet for hot stamping,
• the far-infrared radiation heating furnace further comprising:
• spacers that space the heating unit apart from the furnace body frame and support the heating unit.