This press has a 175 ton cushion. what is that. Just curious.

http://www.youtube.com/watch?v=eDF9jBJQ7Sk


Cushion is adjusted using Pins. ???

I'm a "chip making" machinist, don't know much about the forming end
of the business.

Thank You,
Randy

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On Nov 8, 8:32*am, Randy wrote:
This press has a 175 ton cushion. *what is that. *Just curious.

http://www.youtube.com/watch?v=eDF9jBJQ7Sk

Cushion is adjusted using Pins. * ???

I'm a "chip making" machinist, don't know much about the forming end
of the business.

Thank You,
Randy

Remove 333 from email address to reply.

Here's an article on the subject:
http://www.redstag.com/files/metal_forming.pdf
While I'm not an expert, I think that the pins limit the travel of the
press so that the part in the press being drawn, doesn't tear. The
article focusses on intelligent hydraulic control for deep drawing.

On Mon, 08 Nov 2010 09:32:17 -0500, Randy wrote:

This press has a 175 ton cushion. what is that. Just curious.

http://www.youtube.com/watch?v=eDF9jBJQ7Sk

Cushion is adjusted using Pins. ???

I'm a "chip making" machinist, don't know much about the forming end
of the business.

Thank You,
Randy

I don't have much experience around hydraulic presses such as that
one, but have much experience around mechanical presses. I'm sure that
the cushion serves the same purpose on the hydraulic press as on a
mechanical press.

The cushion is a pneumatic system under the bottom bed of the press
and acts as a giant spring providing a reaction force to the ram's
stroke. It gets it's power from general pressurized shop air feed. It
consists of a series of pneumatic cylinders which act as springs
supporting a steel or iron "pad" which travels up and down under the
bottom press bed. By regulating the pressure in this system, the
reaction force of this "spring" can be varied. The die bottom is set
on the bottom press bed, the die top is set and attached to the top
press bed of the ram (obviously).

The spring power of the cushion is accessed by "pins" which fit
through holes in the bottom press bed and come into direct contact
with the pad. The die bottom is then set and bolted to the bottom
press bed. The die bottom shoe has holes which allow the cushion's
pins to contact various mechanical components within the die itself
and supply spring force to those components. Generally, these pins
will supply the force to operate "kicker pins" that bump the web (this
is the sheet metal moving through the various stations of a
progressive die) up and out of preform and final form stations within
the die. They also usually bump up the web guide rails (as the ram
stroke recedes) which guide the stock through the die. Depending upon
the part, this spring force can also be used for other functions in
the stamping process.
Dave