I have been involved with tooling for many years and have never heard of it, but that does not mean that someone is not doing it.
In theory getting the punch to rotate in fine blanking, or even conventional blanking would not be a problem, as you would just drive it from a helix, but as it passes through the stock it would still be rotating, so that would rule strip out.
I guess it might be possible with just a blank, driving the punch from a helix, and having the same helix on the die, although getting the two to line up, especially with regrinds would be a nightmare.
Good luck with your quest, I will keep an eye on this thread, as this would be new technology to me.
Are you interested only in stamping/fineblanking of thin, sheet-based materials? I have read several papers that describe tool setups for forging helical gears using moving die segments. But this is for forging bar stock, not sheet materials. Let me know if you are interested in the references.
Not if you fineblank you won’t, many automotive parts like gears and window winders are finished fine blanked with no secondary operations.
Plasgears, I started out many years ago working for Belsize, I will try and dig out some old contacts (assuming any of them still work there) and find out if anyone there knows more. I trust it is okay to reference to a specifc company?
Plasgears,
You've aroused my curiosity.
Material, thickness, hardness? Application (if allowed)? Required surface finish?
Depending on the parameters required, this could be done on a cnc punch, at least the cruder prototypes for proof-of-concept. Depending on the machine and tooling, I'd guess less than $5000 for the initial pieces including tooling, say 50 or so.
Griffy,
It is an automotive application to start, but there are other applications begging for this technology. PM is OK for structurally sound gears, but the cost is still high.
Thickness is on the order of .125"+, LC steel/hardenable, finish: commercially smooth. The sample I saw had smooth reflectivity on the tooth surface.
Here is a list of articles that describe techniques for forging helical gears:
J. Cai, et al, "Alternative die designs in net-shape forging of gears", Journal of Materials Processing Technology 150 (2004) 48-55
T. Dean, "Precision forging", Proceedings of the IMechE Vol 214, 2000, Part C (Journal of Mechanical Engineering Science), 113-126
T. Dean, "Net shape forming of gears", Materials and Design 21 (2000) 271-278
Z. Hu, et al, "Properties and performance of forged gear forms", Proceedings of the International Conference on Mechanical Transmissions, 2001, 123-127
T. Dean, et al, "Net-shape forged gears - The state of the art", Proceedings of the International Conference on Mechanical Transmissions, 2001, 25-31
Y. Park, et al, "Finite element analysis for precision cold forging of helical gear using recurrent boundary conditions", Proceedings of the IMechE Vol 212, 1998, Part B (Journal of Engineering Manufacture), 231-240
E. Doege, et al, "Closed die technologies for hot forging", Journal of Materials Processing Technology 98 (2000) 165-170
V. Vazquez and T. Altan, "New concepts in die design - physical and computer modeling applications", Journal of Materials Processing Technology 98 (2000) 212-223
The first 5 papers are from the same research group at the University of Birmingham in the UK, so there is some overlap in the content, but Prof. Dean is one of the foremost experts on this subject. Prof. Doege and Prof. Altan are two of the other leading experts in this type of work. Some of the papers have a lot of theoretical discussion and computer modeling, but they all show examples of tool designs capable of forming/forging helical gear teeth. Best of luck on your endeavor.
