Roll forming machine

A roll forming machine comprising:

• a movable horizontal roll stand including one or a plurality of horizontal roll housings in each of which a pair of upper and lower horizontal rolls is housed, the horizontal roll housing including a pair of roll chock receivers with a top opened for removing the horizontal rolls upward through the opened top of the horizontal roll housing, the horizontal roll housing being configured to retreat from a position on a forming line to a position outside of the forming line on a retreating side that is one side of the forming line perpendicular to the forming line while being mounted on a carriage;
• a fixed stand with an overhang part jutting out from a main frame standing upright outside of the forming line on a counter-retreating side that is an opposite side of the forming line from the retreating side to extend over the forming line and being supported in a cantilever style by the main frame;
• and
• first and second roll chocks configured to respectively support opposite ends of the upper horizontal roll, wherein
• the horizontal roll housing which is returned to the position on the forming line is housed directly below the overhang part of the fixed stand, and
• the overhang part is provided with:
• first and second screw down devices for applying pressing forces respectively to the first and second roll chocks of the upper horizontal roll in the horizontal roll housing which is at the position on the forming line via the opened top, the first and second screw down devices being left at the overhang part when the horizontal roll housing is retreated to the position outside of the forming line;
• and
• housing supports engaged with the opened top of the horizontal roll housing in the forming line to support and lock the horizontal roll housing, wherein
• the overhang part of the fixed stand is supported in such a manner as to be movable together with the first and second screw down devices and the housing supports in an up-down direction relative to the fixed stand.