초록 ▼

An object of the present invention is to provide a die set, which is capable of removing the influence of heat expansion and the change of the number of the collared holes and improving the accuracy of the collar height. In a die set including an upper die and a lower die wherein a metal plate havin

An object of the present invention is to provide a die set, which is capable of removing the influence of heat expansion and the change of the number of the collared holes and improving the accuracy of the collar height. In a die set including an upper die and a lower die wherein a metal plate having a collared hole is provided between the dies to form a flange section at an end of the collar, a flare-punch is provided to the upper die and is capable of vertically moving therein. The flare-punch has a flange forming section for forming the flange section. A biasing member biases the flare-punch toward the lower die. A level pin for defining a lower dead point of the flare-pin is provided to the lower die. The level pin is capable of coming into contact with the flare-punch, which has been in the collar, when the upper die and the lower die are closed.

대표청구항 ▼

In a die set comprising: an upper die; and a lower die being capable of relatively moving to and away from said upper die, wherein a metal plate having a through-hole, which is rounded by a collar with prescribed height, is provided between said upper die and said lower die, and a flange section is

In a die set comprising: an upper die; and a lower die being capable of relatively moving to and away from said upper die, wherein a metal plate having a through-hole, which is rounded by a collar with prescribed height, is provided between said upper die and said lower die, and a flange section is formed at an end of said collar when said upper die and said lower die are closed, wherein the improvement comprises: a flare-punch being provided to said upper die and being capable of vertically moving therein, said flare-punch having a flange forming section for pressing the end of said collar to form said flange section, said flange forming section being provided in an end part of said flare-punch, which is capable of getting into said collar when said upper die and said lower die are closed; a biasing member for biasing said flange forming section of said flare-punch toward said lower die with elastic force equal to or greater than a pressing force for forming said flange section; and a level pin provided in said lower die, said level pin solely defining a lower dead point of said flare-punch without reference to said upper die, said level pin being capable of coming into contact with an end of said flare-punch, which has been in said collar, when said upper die and said lower die are closed.