Hydraulic Press Brake Operation (Hydraulic Circuits)

I am a "new" Electronic Engineer (well at least that is my title)..

I'm glad your not like this guy........ At Least Have Some Experience

Sounds like you upgrading for safety reason maybe and after rereading your comment over, yes..........

I myself had to upgrade a press brake due to insurance audit...... the best thing I can say right now is that you should contact HTC on this, and purchase a manual and schematics........ this is the start.

Jeez, with 50 years under your belt, I think you should have some ideas.

First, how will you make it "safer"? Photo beams/cells? Another type of prox sensor? Dual actuator buttons?

Has it been immune from OSHA regulation?

What controls are in place now?

911 has a point. Someone at the factory may help you.

You might get some help from a used equipment dealer, if you can find the right one.

Not knowing what is there now, I'd get a meter and start probing.

Some of these I can answer atleast for myself. the OP may differ but I really don't think the reason matters...............

Has it been immune from OSHA regulation?

With older machines, in a way yes......... some of it could be to ensure both hands are out of the way when the brake in bending...... by holding down (2) 'good to go' buttons, ???????? that's what my insurance auditor from where the company is insured through dictated.... does not pay to argue even if new machines do not have it.......

But the reason can vary........ the other options that I considered was purchasing a later press brake that had the safety features.......

imo...... the auditor, will always side on the side of safety even if it renders the machine basically inoperable..... can't get more safer than that.......

one finds out to do as he said, and if your question for more details ......... the audit write-up does get longer with tangencies..........

Still, depending on age and features, these things can't have that many different cylinders to control.

Back when OSHA first came along our model shop had a small foot operated shear. Maybe 36 inch. After the required finger guards were installed it was totally useless for shearing anything narrower than 3 inches.

Although it was used by dozens of people every day, with zero injuries for years prior, that made no difference.

I had a similar situation about 20 years ago so I'm not sure the solution would still be applicable relating to OSHA's approval. As Lynn recommended, a photo beam near the hazardous area, (the costliest method of the two) and an el-cheapo pair of wrist restraints on a leash that would not allow the operator to get his hands/fingers into the pinch areas. (doesn't help production by a long shot.)

Personally I prefer the photo beam, but there could well be other methods at this point in time. As others have recommended, a machine tool manufacture/sales rep. could offer the latest requirements, as well as methods to meet the requirements and pricing.

Thanks All.

After I posted this, I continued to look on line then... I did what some of you suggested and designed a generic Print. I know that I have to control on /off. I have to control motor(s) run / stop and interlocks. So I did a generic ladder to start and in the mean while notified the customer. We also have controls for E-Stop, Top of stroke, Bottom of stroke, "Test" Position (approximate 1/8" from product), Foot Pedals, Palm stations and Supervisory Control... there are more but these are the "Standard". I guess I was just out of my comfort zone because I ALWAYS get electrical prints (even if they are OLD)... ha ha.

Well thanks all for the help.

~ole Sarge~

I have installed several different systems over the years on metal brakes.

First you must determine which type of system to use:

1. Light Curtain Monitoring such as a Merlin system. (This works well in the rear of the brake but requires "blanking" if used on the front side when the part rotates through the sensing field which in my opinion defeats the personnel safety protection during that brief period of time.)

2. Constant pressure switches that require each hand to be pressing on an individual switch (total of 2).

3. I would suggest using a combination of a light curtain in the rear coupled with constant pressure monitoring hand switches.

The interlocks from both systems would be installed is series with the machine main contactor so that all power is removed from the machine if/when an safety interlock is actuated.

Thanks,

We are installing light curtain in the front and we install a "standard" blanking switch along with a Supervisory Control to put the equipment in a INCH mode where movement CAN ONLY happen my degrees and each REQUIRING the Palm Buttons (Momentary Switches) to be remade (this is checked with timers and "AND" Logic). We do several other "Safe Guards" as well as light Shields (unmanned sides and rear), Light Scanners, and many many others.

I did not really need much help with the safety item (but I do appreciate the input). I was HOPING for a site that had old press prints. I have some place to acquire them but not for the HTC press line. ;)

Here are a couple of sites that I have had good luck with.

I have another site and will post it later today.

http://www.umanuals.com/

http://www.manualsonline.com/

Very true.

Thanks for the great Info and advice!