Abstract: Consumed energy is minimized to reduce running cost. Final formed products of uniform quality are successively obtained. High productivity is provided. A primary forming step of obtaining a primary formed product by plastically working a heated steel sheet with a primary forming die set for a predetermined time period, a secondary forming step of machining the primary formed product with the secondary forming die set for a predetermined time period to obtain a secondary formed product, and a hardening step of allowing a cooling die set placed in a hydraulic press controlled by a servomotor to hold the secondary formed product under pressure for a longer time period than the time period of each of the primary and secondary forming steps to obtain a hardened final formed product are successively performed in sequence. The hardening step is performed independently without coordinating with the primary and secondary forming steps.

Abstract: Consumed energy is minimized to reduce running cost. Final formed products of uniform quality are successively obtained. High productivity is provided. A primary forming step of obtaining a primary formed product by plastically working a heated steel sheet with a primary forming die set for a predetermined time period, a secondary forming step of machining the primary formed product with the secondary forming die set for a predetermined time period to obtain a secondary formed product, and a hardening step of allowing a cooling die set placed in a hydraulic press controlled by a servomotor to hold the secondary formed product under pressure for a longer time period than the time period of each of the primary and secondary forming steps to obtain a hardened final formed product are successively performed in sequence. The hardening step is performed independently without coordinating with the primary and secondary forming steps.

Abstract: An automobile bodyshell frame structure includes a generally elongated first panel member, and a generally elongated second panel member having opposite side edge portions connected to the first panel member to define a hollow between the first and second panel members. A filler is disposed within a portion of a cross-section of the hollow between the first and second panel members. This filler is provided on an inner surface of one of the first and second panel members and has an average compressive strength equal to or greater than 4 Pa and/or a maximum bending strength equal to or greater than 10 MPa.