Hot press apparatus and a hot press method for thin plate-like workpieces

A hot press apparatus for hot pressing a thin plate-like workpiece, comprising:

• (1) a base,
• (2) a lower heating plate adiabatically placed on an upper face of the base,
• (3) a lower mold member arranged on an upper face of the lower heating plate and having a flat and horizontal upper face,
• (4) a lower frame member erected on the base and surrounding the lower mold member,
• (5) a taking-out unit for taking out the workpiece placed on the upper face of the lower mold member,
• (6) supporting poles erected on the base,
• (7) an upper press plate fixed at upper portions of the supporting poles,
• (8) an upper heating plate adiabatically arranged under a lower face of the upper pressing plate,
• (9) an upper frame member arranged on a lower face of the upper heating plate and having a bottom face of a lower end portion thereof to be brought into contact with an upper face of an upper end portion of the lower frame member,
• (10) a heat-resistant and stretchable film member stretched at and covering the lower end portion of the upper frame member,
• (11) a heat medium filled in a heat medium-filling space defined by the upper heating plate, the upper frame member and the heat-resistant and stretchable film member,
• (12) a heat medium passage adapted to feed and discharge the heat medium for the heat medium-filling space,
• (13) a film member-horizontally holding member adapted to substantially horizontally hold the heat-resistant and stretchable film member while preventing the film member from hanging, said film member-horizontally holding member being fitted to keep the film member at a substantially constant position as viewed in a horizontal direction, and
• (14) a driving unit for relatively moving the lower mold member and the upper frame member and bringing the bottom face of the lower end portion of the upper frame member into contact with the upper face of the upper end portion of the lower frame member and spacing the former from the latter,
• (15) wherein the bottom face of the lower end portion of the upper frame member is brought into contact with the upper face of the upper end portion of the lower frame member by relatively moving the lower mold member and the upper frame member, the lower face of the heat-resistant and stretchable film member is brought into contact with the upper face of the workpiece on the lower mold member in the state that the heat-resistant and stretchable film member is held substantially horizontally while being prevented from hanging, the workpiece is preheated with the upper and lower heating plates, the workpiece is subjected to a predetermined hot press working with the heat resistant and stretchable film member by applying a pressure to the heat medium inside the heat medium-filling space while the film member being prevented from expanding radially outwardly at an outer periphery thereof.