P/M 150 Press - Designed and built in Brazil Fernando Iervolino Technical Director Qualisinter Produtos Sinterizados Ltda Keywords: Compaction, Press, Tool Abstract: The Brazilian market doesn t have a local P/M mechanical press manufacturer. This leaves two options: Import an equipment or design and build one. The second option was the one chose by Qualisinter, but in a different way: The idea was to give all the necessary information to a press manufacturer in order to create a supplier in Brazil that could take care of manufacture, maintenance, training and technical support. Besides that, this manufacturer should have the capability to expand the line of presses with different capacities and capabilities. Financial aid available in Brazil, like FINAME, can also be used in this case. The Companies: Qualisinter Produtos Sinterizados Ltda, a P/M parts and bearings manufacturer and Prensa Jundiaí, a press manufacturer, both located in Brazil, joined forces in order to make a local P/M press. Qualisinter is a 10-year-old P/M industry that reached a leading position in the Brazilian bearing market. In 1993, also started to produce structural parts. With the experience and knowledge acquired during these years, Qualisinter was able to give all the necessary information about powder compaction. This, in fact, was the second time that Qualisinter made a partnership with a press manufacturer in order to build equipment. The first time was with Prensa Ciola, in 1994, a hydraulic press manufacturer. The result was a reliable 63ton die-set hydraulic press. Prensa Jundiaí is a 50-year-old company, very well known in the Brazilian market as a mechanical C press manufacturer for stamping. On the last 20 years, Prensa Jundiaí got specialized on several other kinds of mechanical presses and, in 1999, made an agreement with Prensa Ciola to also product hydraulic presses. Because of its engineering and production capabilities, Qualisinter elected this company to develop the P/M mechanical press.
Technical Information: Design: Die-set, single action, withdrawal ejection press Speed: 8 to 25 strokes/min Max daylight clearance: 1950mm Main motor: 30KW (40HP) Upper Ram: Capacity: 150 ton Stroke: 220mm Adjustment: 70mm Top punch hold down: 0 to 1 ton Top punch pre-press: 0 to 18 ton Die float: Stroke: 0 to full lower punch compaction Die float stop: Mechanical, up to 100 ton Ejection force: 100 ton Fill: Depth of fill: 170mm Underfill: 0 to 30mm Overfill: 0 to 30mm Core rod: Stroke: Up to 250mm, limited on die-set tool stops Core rod active force: 0 to 1.5ton upward; 0 to 1 ton downward Core rod counter force: 0 to 6 ton upward; 0 to 10 ton downward Feeder: Servo motor drive, controlled by PLC Stroke: 457mm Movement description: PLC Controls: The press is totally controlled by a PLC. Height, weight, die-float start and end, core rod movement, under and overfill, upper punch pre-press and top punch hold down can all be adjusted when press is running: The operator select the position that he want to change, press a value in millimeters and when entered, the PLC drives the selected motor at the proper time with encoder feedback. Everything monitored to avoid any damage caused by improper value changes. An encoder located in the crankshaft gives the exact position of the press during all the cycle. Future development looks for adapting external measure devices (scale, height meters), giving statistical figures about the production and correcting the press to allow 100% production control.
Upper ram: It is mechanical. A main shaft with a pair of pinions drives the crankshaft that has two gears equally located on each side of the connecting rod. The connecting rod transmits movement to a guided piston that is connected to the upper ram. The upper ram is guided by four cylindrical columns, constantly lubricated with oil bath. There is a sealed protection for the columns to avoid oil contamination. The upper ram has a hydraulic piston with 150mm travel to allow top punch hold down and pre-press operation. Die float: The die plate has a controlled start and finish movement. The starting movement is driven by a pair of hydraulic cylinders located on the upper ram that can apply up to 12-ton force to the die plate. The movement finishes when a mechanical block is reached, allowing up to 100ton compaction over the die. During the movement, a 0 to 28-ton counter force can be applied. Ejection: Mechanical, driven by a pair of cams located on each side of the crankshaft. Core rod: Hydraulic driven. Having a 250mm stroke, can be moved up or down up to 2 times per cycle. A counter force can be applied during compaction and/or ejection. All the movements are fully programmable by PLC. The movement is limited by the tool system. Fill: Die-set fill position can happen before, during or after the filler movement. Feeder speed, number of shakes, shake speed and travel can all be programmed by the PLC. Underfill to reduce weight variation and overfill to improve density distribution along the part can be used separately or combined.
Auxiliary Movement: Multi platen system can be easily adapted: The PLC was prepared to control 4 solenoids and to receive eight confirmation positions. The solenoid action can be programmed to act at any point of the cycle and the confirmation for the advanced and back position can be monitored and programmed to stop the press if not confirmed. Hydraulics: The press movement supports all the hydraulic system. There is no huge hydraulic pump, except for a small one that refills losses or make low oil consumption movement (eg: core rod). The system consist of pressurized oil accumulators that release the oil on the proper moment and receive it back when the actuator is forced back by the press mechanical movement. Possible customizations: - Tonnage indicator with over and under limits - Pick-up system - Self-adjustment of height and weight - Double upper punch (or more) Final comments: This press is a prototype where all the functions for a complete single action press are being applied. The computer system has an open program design that can be adapted for new options. The press manufacturer is completely capable of developing new mechanical systems that would allow, for instance, multi-platen action. Everything can be custom made: A different movement, a change in size to allow different customer s die-set standard, travel distance, extraction cam design, etc. On the other hand, simple design presses with small tonnage capacity are also the targets of this development.
Credits: - Qualisinter - Basic design, specification, project coordination. - Prensa Jundiaí Detailed design, manufacturer. - Blaine Stebick, Eng. - USA Consultant: Basic concept design, hydraulics - Jonfra Automação Ltda PLC program, electrical project and electrical assembly. - Américo Brancalana, Eng. Hydraulic design