Perforated panel excess punching tool - GIF

[Altair]

Perforated panel excess punching tool.




Previously:

Chunks of ice fall from skyscraper nearly hitting pedestrian - GIF
Washer stamping machine - GIF
Autobody panel stamping press - GIF
Stamping plant die change - GIF
Stamping press - GIFs

[Toolmaker51]

Unsure why this is needed. Most injection molds "shut off" to prevent flash. Might be inadequate clamp pressure; large hydraulic cylinder opens and closes the mold halves. Tonnage required is calculated mainly by total surface area and injection pressure x time needed to fill while the material is still hot enough to flow. This drain thing might need 1200+ tons.
Largest molds I ever built and hung ran in a 3000 ton press. Just 1 mold half, 29,000 pounds. The busboy box that's about 18"x 20" x 24" started as a pair of 11 ton blocks. With all the machine work carving out the cavity and cooling holes, took out about 3 thousand pounds, which the core made up. Wall thickness of the box is .125.
In dieset terminology the punch enters the die opening, just like a paper punch. In molds, the 'punch' is the core, die is the 'cavity'. . ., and cores in casting are the interior of a body, such as a manifold or valve.

[mdhatter3]

We learn something new every day. Thanks Toolmaker 51 for the education.

[Frank S]

You can't appreciate the amount of work involved in mold making until you are asked to make one large or small the devil is in the fit and intricacy of design. Try making one for a 12x4.00x8 semi solid neoprene tire on a Bridgeport with full manual only with little more than an18" rotary table with a 36" face plate mounted on it as the only special tooling available Fortunately we started out with a 2" thick plate than had been Blanchard ground on both flat faces to make the upper and lower cavities the core started out as a 3 inch thick disk. the core was easy done mostly on the lathe, but the cavity plates were too large for me to chuck and swing in my lathe. Hallowing out the shapes of the tire wasn't too bad just a lot of material to be removed but when it came time to add the raised lettering of all the text that had to be done with a dermal and a template I made. All in all a fun though arduous project for a small machine shop just starting out back in the early 1990s

[carl blum]

Hi Gang: Also don't forget the coefficient of expansion! Molds are run hot and the parts still need to fit when hot to avoid flash. And the problem gets worse as molds get larger. We were running a headlight mold in Michigan and had to build a wall around the press to keep outside cold air away. The mold made 4 headlights in two shots, one clear and one black. The mold base was a 5 foot cube.