February 2003

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Welcome to the premiere issue of Braking News. We at MC Machinery Systems have created this newsletter to keep our customers and prospective customers better informed about all sorts of issues relating to our Press Brakes Division. In these monthly newsletters we will discuss - in great detail - the features and benefits of our Mitsubishi-distributed and serviced Toyokoki press brakes. In addition, we will also provide answers to some sales, service, and maintenance Frequently-Asked-Questions. Occasionally, we will also highlight a customer success story - anybody want to see your name in print? We hope you enjoy this first issue of Braking News and look forward to them each month. Please fill out the reply card and let us know if you find these articles helpful.

Pressing Announcements

Mitsubishi has press brakes! Over 500 units have been sold since their inception. We have delivered up to 88 tons of bending power for a variety of applications. Five years ago, Mitsubishi acquired the rights to market the world's most accurate line of downacting press brakes from Toyokoki Co. Ltd. of Nagoya, Japan. Patented and unique in numerous design features, this new line of AC servo presses feature large ball screw drive train to ± 1 micron. Read on to find out more about these all-electric press brakes.

 Brakethrough Applications
  • No hydraulic oil.
  • Perfect repeatability of saved programs (±39 millionths inch).
  • Recall program and press Start. No referencing or "tweaking" required.
  • Equipped for European Quick Change Dies (US Tooling optional).

For prototyping, the user friendly color CRT and control make "one-sies" or "two-sies" a fast and accurate task. There are even HELP screens available with the push of a button.

All-electric Benefits

No hydraulic fluid means that full tonnage can be achieved throughout the stroke. Our press brakes do this via heavy duty BALL SCREWS. See the illustration below. These screws are strong enough to withstand 3X the rated tonnage of the machine.

 Punching applications are even possible with no added wear and tear. In I I years of service in Japan, not a single screw has been replaced or serviced.

Current Comparisons
On Accuracy

Hydraulic machines, as shown in the schematic below, overbend by as much as two degrees as they warm.

Even when fully warmed, oil still flows through the solenoids (at dead bottom center) causing piston vibration and further limiting repeatability.

How much repeatability are we talking about?

SPC histograms indicate that a hydraulic machine (as depicted above) typically holds a tolerance of ±0.009" over time. Tested against similar applications, the electric press brake showed +/-0.003". Total working tolerance of 6 thousandths vs. 18 thousandths a 3-fold difference. The APB series' is more precise which in shop terms equates to a much tighter angular repeatability.

 

 

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