Formax Plus for Large Parts
 

National Machinery LLC continues to be the leader in the world cold forming market.  Through the new leadership of Andrew Kalnow, 2002 was a successful year as the company returned to prosperity.  2002 also marked a milestone with the 750th FORMAX machine sold in December.  Also evident last year were attempts to duplicate the FORMAX Plus for Large Parts and its’ concepts and features.  However, FORMAX still holds the lead in the industry for quality and efficiency.  But what are the real benefits of FORMAX for the customer?  Everyone understands the quick changeover concepts of FORMAX, but what about the real test……the part applications?

Quality Design Features

Large FORMAX Plus machine are designed from the wire payoff and feed to the heading slide for greater part improvement such as:

    • Higher Quality Parts
    • Improved Accuracies
    • Near Net Shape
    • Reduced Secondaries

    The machine features needed to accomplish these improvements all work together to make FORMAX really work.  (Figure 1 – FORMAX Plus for Large Parts)

    Formax Plus for Large Parts
    Power feed, linear drawer
The Wireline of the FORMAX Plus for Large Parts takes into account the large diameter of wire and the difficulty in handling this wire.  It all starts with the Power Payoff System that pre-feeds the wire.  The wire is then straightened with a 10 roll wire straightener in both the vertical and horizontal planes.  The next step is a whole system that includes a Power Feeder, Integrated Wire Drawer, and Linear Feed.  The Power Feeder “inches” the wire through the integrated wire drawer and into the Precision Linear Feed.  During wire changes, the draw die cassette is a quick change feature where cassettes are simply exchanged.  The Linear Feed is a combination of moveable and stationary grips that are cam controlled to give an accurate feed with each and every stroke of the machine.  Feed length and diameter adjustments to the linear feed and integrated wire drawer are all computer controlled. (Figure 2 - Power feed, wire drawer, and linear feed). 

Reducing changeover time is critical, and that is addressed in a manner of ways.  For those that prefer the latest technology, the Programmable Tool Changer is available.  (Figure 3 -  Programmable Tool Changer).  It can be programmed to change individual cassettes or the entire set of tools.  Even more impressive, the Tool Changer works while the operator performs other changeover tasks, such as changing the wire coil.  An individual cassette can even be presented to the operator’s station for inspection or individual tooling exchange.  Also available is the manual or operator assist changeover system.  This flexible system allows the operator to exchange single cassettes or the entire tool set with a simple jib crane.

Tool Changer
presettable adjustments

Computer controlled adjustments are an important factor in repeatable and efficient cold forming production.  The FORMATROL PC Controls include date on job storage, maintenance checks, fault screens, production information, and machine adjustments. (Figure 4 – Powered presettable adjustments)  The kickout, feed length, and wedge settings can all be adjusted “on the fly” while the machine is running.  What this means is good quality parts and the ability to compensate for tooling changes without stopping the machine.  Many other adjustments such as heading slide positioning, finger opening/closing timings and wire diameter are also part of the control package.

The Pick-Move-Place transfer is designed to not only handle short, difficult to transfer parts, but also efficiently transfer long parts.  The unit has a lifting motion that allows the part to be grasped along different areas to gain better control.  Better control translates into higher running speeds and more efficient operation.  (Figure 5 -  Pick-Move-Place transfer)

Features for Part Quality

It takes even more specific machine features to realize part quality improvements, so National engineers looked into many components that have a critical affect on part quality.  Additional thoughts included in part improvement are:

  • Improved Ram Guiding
  • Better Punch to Die Registration
  • Expanded Die Space
  • Extended Die Kickout & Punch Kickout
  • Longer Tool life
Pick move place transfer
Precision heading slide

The heading slide operates with a 5 degree wing liner and “Zero Clearance” Heading Slide Guidance.  (Figure 6 – Precision heading slide guidance system)  The liners are sealed from contamination and pressure lubricated for longer life.  The combination of the liner and Zero Clearance Slide guiding takes control of the heading slide during the work stroke of the machine for a consistent path, even under off-center heading loads.

The die space is itself has clear advantages with increased tooling support, the ability to do deep backward extrusions, deeper die pockets, long die kick, and extended tko capabilities.  The following parts highlight the precision part capabilities of the FORMAX Plus for Large Parts.

1. This pinion gear blank, made of SAE 5130 show the ability to improve parallelism (Figure 7)

2. This valve spring retainer is an example of taper position accuracy (Figure 8)
Pinion gear blank
Valve spring retainer

3. This spark shell body shows the improvement in TIR(Figure 9)

4. This bearing cup is an example of a secondary operation, ID grinding, being eliminated (Figure 10)
Spark plug shell
Bearing cup

Ability to Partner with Customers
National Machinery works with customers to ensure their machine delivers the best in efficiency.   This usually means tooling and machine capabilities coming together to provide precision forming.  

The example of a valve spring retainer made on a FXP66S shows how National partnered with a Korean customer to design and develop a part in conjunction with a new machine purchase.  While valve spring retainers are not new to the cold forming community, this part represents particular challenges due to its configuration.  The part has a small protrusion above the head and a counterbore above the tapered hole.  These different features require a different forming sequence, compared to conventional methods.  The challenge was to find a way to get the material to flow in two directions and finish filling all of the cavities at the same time. National used the DEFORM forming simulation package to model several different methods.  It was then determined which sequence had the best opportunity for success.  The last forming station was the difficult area with a concentration of stress.(Figure 11) Therefore, corrective tooling design was performed and a precision part was formed quickly.  This project shows how the combination of software and tooling design experience can lead to a quality part ready for production.

Summary

Creating a high quality machine to form precision parts is a difficult task.  National Machinery has made a commitment to the industry to supply the best possible cold former with FORMAX.For more information on FORMAX machines contact us at www.nationalmachinery.com or at our Italian office, Agenzia Corvetta.
Valve spring retainer sequence
 
Italian Fasteners N. 29