Adjustable lower die mechanism of metal plate bending die

The invention discloses an adjustable lower die mechanism of a metal plate bending die. The adjustable lower die mechanism comprises a lower die holder, wherein a left lower module group formed by connecting a plurality of left lower modules and a right lower module group formed by connecting a plurality of right lower modules are arranged on the lower die holder; the left and right lower module groups are driven by a power mechanism, and are capable of sliding along left and right key grooves formed on the lower die holder through left and right sliding keys fixed to the bottoms of the left and right lower module groups, respectively; and an acute included angle is formed between the left and right key grooves. The adjustable lower die mechanism of the metal plate bending die is capable of controlling the opening of the lower die at any size within a dimensional range according to requirements so that the processing range of bent pieces is expanded; the technical bottleneck that the dimension adjustment range of the opening of the common inserted block type adjustable lower die is limited by the thickness specification of the inserted block is broken through; and simultaneously, the lower die of the adjustable lower die mechanism greatly improves production efficiency and reduces the labor intensity of workers for an inserted slide rail type automatic opening adjustable mechanism.