Home | About Us | Products | Contact Us

 


Hydraulic Presses or Electro-Mechanical Presses
Mechanical Press Simulator
Remanufactured Presses

 


Hydra-Chief Mechanical Press Simulator

Precision Compacting Technologies, Inc. new Hydra-Chief "mechanical press simulator" combines all the advantages of a mechanical press with the flexibility of a hydraulic press. We found many of our customers were replacing their old mechanical presses for hydraulic presses. These hydraulic presses provide a free range of motion to produce complicated parts that may not be made easily on a mechanical press, as our customers were producing these complicated parts they were also using these presses for their simple parts. Many times, these simple parts could be made faster and easier on the old mechanical presses. Our engineers at Precision Compacting Technologies, Inc. started coming up with ways to meet all our customers' needs and the mechanical press simulator was created. The Hydra-Chief mechanical press simulator combines the ease of setup of the mechanical press with the flexibility of the hydraulic press.

How it works
The two key compaction properties that the mechanical press simulator is based on are the press cam profiles and the programmable limit switch. The cams in a mechanical press along with the crank angle, create the motions of the press. The programmable limit switch creates a 360 degree reference to one stroke of the press. The mechanical press simulator takes these cam profiles and maps them along a 360 degree reference via software. Each axis of the hydraulic press has a cam profile to follow just as the motions of the mechanical press follow the internal cams. As the virtual master cam rotates 360 degrees the hydraulic axis follow their cam profiles creating the same motion as the mechanical press. Because the hydraulic press is freely programmable it is not limited to the fixed profile of a mechanical press. The positions of each axis are set to limit the travel of the axis and still fit the cam profile of the axis. This saves resource in the hydraulics providing a higher speed.
One of the great advantages of a mechanical press was the coordinated motion of multiple axes, for example, the ram moves up while the die table and feed shoe are simultaneously moving to fill position. This was not typical with hydraulic presses. Hydraulic presses in the past tended to move one axis at a time. Now the coordinated motion of the Hydra-Chief "mechanical press simulator" provides an efficient press cycle with no wasted motion, similar but better than the mechanical press.
Because the mechanical press simulator is software driven it is just another variable in the press setup. This mode of operation is enabled or disabled and stored in the setup of the part. So, as with all other part variables the mode of the press is loaded with the part data during setup.

Ram Motions
The ram motions of a mechanical press are somewhat simple and efficient. However, we have been able to make some improvements to the ram motions. In a typical mechanical press the ram can have wasted motion at the top of the stroke. Many times the top punch will travel very high based on the cam profile of the press. With our simulator, you can provide an amount from TDC to limit the up motion of the ram. If it is not needed for clearance of the feed shoe it is wasted motion and wasted resources in a hydraulic press. Therefore, we can limit the upward travel of the ram and use the hydraulic resources in the other parts of the cycle.
As with most hydraulic presses we can go to a position or a pressure. We have applied this same concept to our mechanical press simulator. If the tonnage set point is reached before the ram gets to the position programmed, the travel of the ram will be limited at that tonnage. The virtual master cam is not affected by this and continues the cycle. When the cam gets to the limited position on the up stroke the ram will resume the cam profile. This allows us to run to a tonnage on each cycle creating equal density parts, and option not available on a mechanical press.
Other advantages to the ram motions are dwells at press position. We also have the ability to give a custom eject motion of the ram. We can emulate the gradual lift off of the upper ram during ejection. Also, because the speed of the upper ram is set by the RPM of the master cam, no speed settings are applied to the ram during setup. Less parameters to be set during setup allows for faster setup.

Table Motions
Like the ram, we have been able to make many improvements to the motions of the table in a mechanical press. Because the cam profile is electronic, we are able to freely adjust the motions of the die table providing many prepress options. One of the challenges of a mechanical press is repeating equal density of the part. We are able to adjust the motions of the die table to emulate the motions of an opposed ram press creating equal density in the part and still maintain the cam profile of a mechanical press. Because we are not limited to the cam motion on the table we can provide overfill and under fill motions with the table easily.

Feed Shoe Motions

The feed shoe setup on a mechanical press is very efficient in motion, however, can be one of the most challenging aspects of a setup. On a standard mechanical press the feed shoe motions are related to an external cam on the main crank. By adjusting the two halves of this cam the feed shoe extend and retracts are set. If shakes are needed in the cycle, many times different speed bumps are added to the cam to give shaking motions. Our feed shoe is following the virtual master cam which gives several advantages. First the extend and retract of the shoe is set by a degree of the master cam. This allows precise timing of the feed shoe to the ram and die table. The number of shakes needed is just entered along with the position parameters. Any extra motions needed for part removal are added into the setup electronically.

Multi Platen Motions

The motions of the extra platens in a multi platen press are still very flexible. The motion can be allowed to follow the motion of any other axis of the virtual master axis or both. Pressure control can also be added to enable limited motion or tonnage on the platen. If slide blocks or any other on/off devices are used, they can be referenced to the virtual master much like a programmable limit switch on a mechanical press. Die fault inputs can be created in the same manner using on/off degrees of the master.
Automation
Many times when automation is added to a mechanical press, the press must be stopped or a dwell added for removal of the part. By creating a cam profile for the automation that follows the virtual master, the part removal process can be added into the press cycle with little to no delay. Grippers and vacuum can be reference to the virtual master for on/off degrees. All the variables added by the automation are stored with the part setup to ensure quick repeat setups.

Setup

The setup time of a press has quickly become a point of concern with our customers. Many times our customers are making more setups a day than they did in a week a few years ago. A traditional mechanical press setup is hindered by not being able to retrieve the positions of a previous job. The Hydra-Chief presses do not have this problem as we save the part parameters to a recipe system. However, a hydraulic press with all its options can create a big task for initial setup. With our Hydra-Chief "mechanical press simulator" software we have combined the good parts of each setup and limited the bad. Because the speed of the press is based on the the RPM of the virtual master axis all speed settings are reduced to just one RPM setting. Many times during the setup of a mechanical press the press is inched through the cycle to ensure the operation of the press. This feature has been added to our "mechanical press simulator". Not only can we inch through the cycle a few degrees at a time, can also reverse the cycle and inch backwards. Because this is based on the virtual cams we can also remove axis from the inch mode. For example, we can disable the ram and feed shoe axis and just inch through the table and extra platens of a multi platen system. This proves to be a major benefit when using automation. Being able to move back and forth around the pickup position drastically reduces setup time and scrap parts created during setup.
 


 

 

Precision Compacting Technologies
12182 Peach Orchard Road, Bentonville, AR 72712
 Phone: 479-271-0032 | FAX: 479-271-7180
sales@precisioncompactingtech.com

All Content Copyright 2005 - 2017 Precision Compacting Technologies - All Rights Reserved - Design by Aponi

www.precisioncompactingtech.com