Press die set for forming flange and flange forming method
The present invention relates to a press die set for forming a flange that bends an edge of a part, such as a door panel and a hood panel, at a right angle in a press-forming direction and bends an edge adjacent to the edge at a negative angle, and a flange forming method. The press die set for forming a flange according to the present invention can accomplish the flange formation described above in one step, has a simple structure, and is easy to maintain.
1. A press die set for forming a flange that bends an edge of a panel at a right angle in a press-forming direction and an edge adjacent to the right angle edge at a negative angle, comprising:
an upper die having a fixed die used for right-angle bending and a slide cam used for negative-angle bending; and
a lower die having a fixed punch associated with said fixed die, a fixed punch associated with said slide cam and a driver cam for guiding the slide cam,
wherein a bending blade of said slide cam has a right-angle bending forming portion provided at the bottom of the bending blade, and a negative-angle bending forming portion immediately following the right-angle bending forming portion and including a slanted surface positioned at the top of the bending blade; and
a panel lifter that abuts against an end face of a negative-angle flange to release the panel from the lower die;
wherein the panel lifter has a plurality of ejectors that abut against the end face of the negative-angle flange of the panel, a coupling board to which the ejectors are integrally attached, a plurality of pressing means that operate within a predetermined range in a releasing direction in which said negative-angle flange is released from the lower die and urge the coupling board in the releasing direction, and a cam follower that abuts against the slide cam to maintain said coupling board in a predetermined position when said negative-angle flange is being worked.
2. A flange forming method comprising bending an edge of a panel at a right angle in a press-forming direction and an edge adjacent to the right angle edge at a negative angle, wherein a part bent at a right angle and a part bent at a negative angle are adjacent to each other at a parting line, and the panel has a transitional part between the right angle edge and the negative angle edge, and a bending blade for a part bent at a right angle has a protrusion for bending said transitional part, and the bending blade for a part bent at a negative angle bends the negative angle edge and does not interfere with said protrusion.
3. The flange forming method according to claim 2 , wherein the parting line intrudes into the edge to be bent at a negative angle from the edge to be bent at a right angle.
4. A press die set for forming a flange that bends an edge of a panel at a right angle in a press-forming direction and an edge adjacent to the right angle edge at a negative angle, comprising:
an upper die having a fixed die used for right-angle bending and a slide cam used for negative-angle bending;
a lower die having a fixed punch associated with said fixed die, a fixed punch associated with said slide cam and a driver cam for guiding the slide cam,
wherein a bending blade of said slide cam has a right-angle bending forming portion provided at the top thereof and a negative-angle bending forming portion immediately following the right-angle bending forming portion; and
a panel lifter that abuts against an end face of a negative-angle flange to release the panel from the lower die,
wherein the panel lifter has a plurality of ejectors that abut against the end face of the negative-angle flange of the panel, a coupling board to which the ejectors are integrally attached, a plurality of pressing means that operate within a predetermined range in a releasing direction in which said negative-angle flange is released from the lower die and urge the coupling board in the releasing direction, and a cam follower that abuts against the slide cam to maintain said coupling board in a predetermined position when said negative-angle flange is being worked.