LITOSTROJ RAVNE LTD. Manufacturer of high quality custom-made industrial hydraulic and mechanical presses for sheet metal forming with nominal force from 400 to 40.000 kN, with length of a table up to 8 meters.
The skills and know-how of Litostroj RAVNE experts, the innovations and solutions being evolved and implemented in mechanical and hydraulic presses for more than forty years, are perfectly brought into use and combined in excellent custom designed TRANSFER PRESSES, which are a superior products of Litostroj RAVNE.
Ravne brand originates from 400 years of steel milling tradition. The presses production of mechanical and hydraulic presses for steel and sheet metal forming industry have been performed for more than 45 years. In this period, various mechanical and hydraulic presses and press line equipment were produced.
Sheet metal material is mostly used “body part material” in automotive and household appliances industry. Sheet metal forming presses are in this meaning very important structure of production process of automotive and household appliances industries, as also in electronic and other industries.
Deep drawing presses can be mechanical, hydraulic or combined. The technique of deep drawing can be used on all kinds of presses - transfer, progressive, tandem lines and single die. But usually when we speak about deep drawing presses, we are talking about double action (DA) sheet metal forming presses.
There are two technologies / versions of deep drawing of sheet metal parts. One is deep drawing with double action presses (DA), which have two slides – inner and outer.
The double action presses can be mechanical, hydraulic or combined (with one slide hydraulic and other mechanic). Another is deep drawing with mechanical or hydraulic press, where the blank holder is a part of die (tool) mounted on the slide of the press.
At deep drawing it is necessary to hold the sheet metal blank that is being drawn (formed) with the blank holder.
1. At mechanical or combined double action (DA) presses the function of “blank holding” is performed with the outer slide of the press, while the punch die mounted on inner slide (also sometimes called as punch) performs the “deep drawing” while punching through the blank and pushing it into matrix of the lower die.
2. Another technique of the deep drawing is performed on mechanical or hydraulic presses with hydraulic die cushion in the table of the press. On these presses the punch die mounted on the slide should also include the blank holder as part of the upper die.
3. Other versions and techniques are also possible, but not very common.
Die cushion can be installed in any (deep drawing) press to be used as main part of production technology or only to be used as ejector.
High reliability and excellent performance of deep drawing presses Litostroj RAVNE is achieved with synchronization of mechanics, hydraulics and other supporting mechanisms.