Punch press application

[dmason83]

Hi, my company is looking into designing a press capable of punching twenty two(22) 3/8 dia holes spaced 2.5 inches apart(picture a flange bearing hole pattern) through 10 gage steel 140 times per minute. calcs make this approx. a 140 ton press.

We are looking for a viable option such as 22 small punching motors that have an end view profile of no larger then 2.5X2.5 inches and capable of 5 tons.

Anyone have any ideas?

 

[MikeHalloran]

Stagger the punch lengths a little and you can use a smaller press.

... running scary fast.



Mike Halloran
Pembroke Pines, FL, USA

 

[BrianPetersen]

A 140 ton conventional mechanical (flywheel/clutch/brake) press is a fair sized machine! You can do this sort of work with that type of machine no problem, though ... except for the strokes per minute that you are talking about. Most presses this size are around half that, tops, and beat themselves to death quickly when pushed so hard. And that's if you have material handling equipment that can keep up. Much of that depends on the shape and size of the workpiece.

If you use hydraulics, 5 tons = 10,000 lbs = roughly a 2" bore cylinder at 3000 psi, of course the outside dimensions of this cylinder will be a bit more. And hydraulics don't deliver the "hit" that a mechanical press can to get the punching action started. 140 strokes per minute will be another interesting challenge with a hydraulic machine. Even if you can cut the stroke down to (say) 1/2", you're talking about something like 42 US gallons per minute to extend and retract, and at 3000 psi, you'll need a 100 horse hydraulic pack to deliver enough volume and pressure. Smart design of the cylinders might cut down the volume on the retract stroke to less than the advance stroke to cut down the pump size somewhat.

A mechanical press will do it with a smaller motor because of the flywheel impact, although with that kind of cycling rate, the motor size is still going to be up there.

Big regular stamping press with say 600 tons and tooling that can handle 4 shots at a time at 35 strokes per minute would be a "normal" way to do this job. A 600 ton press is a big, heavy, machine ...

 

[dmason83]

Using the idea of the hydraulic cylinders would be very hard to do. there would have to be 22+ cylinders acting at the exact same time to handle the punching rate, plus the insanely large power station like u mentioned.

If 35 strokes/minute is a 'standard' punching rate for a 600 ton or lower machine then that may be the route to take.

I'll look into that one a little further.

Thank you both for the input

DM

 

[arto]

How about an Ironworker?

http://www.scotchman.com/

http://www.americanmachinetools.com/Ironworker.htm

 

[Pressed]

If you modify the geometry of the punch from flat, you can reduce the incremental press force. If you are punching multiple holes, changing the piercing height succession will reduce the incremental press force. (Meaning you distribute the load through the stroke, instead of at one single point).

I don't know your exact situation, but would a ferris wheel type press work for you. Or something similar to a high speed pill making machine, which is basically a cam. I saw one of those on "How it is made".

If you are currently buying the flange, would having them quote the holes be beneficial?



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