Sign of the Times--Automation Strategies Change with the Economy
For the past several years, many contract stampers keenly focused on protecting all possible flexibility in their pressroom-automation purchasing patterns. For example, a typical press and transfer RFQ would entail a 1500- to 3000-ton press, left-to-right bed size in the 240 to 288-in. range, dual rolling bolsters, and a fully programmable press-mounted transfer system prepped with quick-die-change (QDC) automation, and tooling provisions to optimize flexibility.
As often as not, this same RFQ also would include a blank destacker configured to be continuous-run and to handle an array of blank sizes and shapes, different blank-material compositions, and perhaps even packaging within the same footprint as the coil-feed equipment.
Considering the logistics, commissioning, press-pit work and other incidental costs, this once-typical project can become a mammoth undertaking requiring a sizeable budget. Given the current financial issues among U.S. automakers and their tier suppliers, and the overall global economy, it’s no surprise that business expansions, new facilities and large capital initiatives have all but dried up for the time being.
The good news? We still see RFQ activity at the two extreme ends of the press-automation spectrum. Unique “one-off” nontraditional applications still are out there, as are basic full-mechanical in-die transfer jobs.
The automation projects we see in the one-off realm involve hydroforming, hot stamping and general press-tending applications. These projects often feature specialized parts and tooling requirements, and the use of 3D design tools typically prove critical to their success, as this allows for a complete understanding and concurrent design by the entire team tasked with completing the project, including designers, controls and development engineers, software experts, and marketing and sales personnel. Design iterations can be pushed out to a secure website for collective review by the press-automation OEM, tooling providers, press manufacturers and end users. This collaboration occurs real time, and often in several geographic locations. Design reviews can be conducted more often, promoting better communication due to the elimination of travel time and expense. In recent years, this process has eliminated many surprises during equipment installations.
Advanced process simulations also allow the team to breathe life intodesigns and quickly achieve complete clarity with all stakeholders. How do you introduce a part? What about the sequence for die changes? Guarding and press-attachment surfaces? Does the customer understand exactly how this solution works? If a picture is worth a thousand words, then an animation can save a full day of talking.
These nontraditional applications still are viable because they make unique parts, not commodity stampings. They still warrant investment in new technology and equipment in spite of the dried up capital-spending market. Projects in this arena often require heavy payloads and long—to 20-ft.—centerline-to-centerline reaches, with demanding accelerations. Specialty tooling tasks can demand repeatability of less than 0.010 in., with payloads exceeding 350 lb. Compound motions often are used to attain these travels with adequate structural support. Accelerations to satisfy cycle times can exceed 1.5 G. The solid design environment allows for complete finite-element analysis and motion kinematics to be performed inhouse and several times throughout the design cycle, as needed to verify group decisions and ensure that the application stays on the correct path.
Here is where collaboration between customer and supplier becomes critical. The customer knows the fine details of his challenges with part and process; the automation OEM understands very well what is required to create a machine that will cycle millions of times to handle a given task. But several critical questions might arise whose answers might not be immediately known, such as:
How does repeatability impact an automated hydroforming application?
How do you clear a press and tooling with automation to allow for QDC?
What precautions work well to protect cabling, sensors and lube lines in a high-heat application?
How do you position, reference and introduce a 1700 F part into dies accurately, and what end-of-arm tooling is needed to remove that part after its been struck?”
These comprise just the beginning of an entire series of meetings required to bridge the knowledge gap and successfully create a one-off machine that works properly—from the first cycle. HMS Products Co., Troy, MI, is seeing an uptick in plate-mounted all-mechanical equipment orders. At first this came as a bit of a surprise, but after taking a step back, the explanation makes perfect sense. There still are new parts that will require transfer because of material savings or process requirements—complex tooling or part rotation to do more work parallel to the bolster. The market seeks a low-cost and simple automation solution.
The Business Case
The business case for investing in a transfer-press line is difficult to make in this economic environment. There also is a disadvantage to running smaller parts in a larger-frame transfer press with high-end automation; thus the need for a plate-mounted in-die transfer or a press-mounted system on a smaller press. These fully mechanical solutions are simple and present lower risk than does moving to a low-cost country for production. Mechanical automation can accommodate the needs of a process for about 30 percent of the cost of a fully programmable electronic transfer system. A die-contained transfer may be quickly and inexpensively moved from press to press and plant to plant.
Typically, during conversations with customers relative to all-mechanical automation, the conventional thinking is that this solution can prove very restrictive. While such a setup may not offer the same level of flexibility as a fully programmable servo transfer system, some extra up-front consideration can allow processing of a nice array of parts in one mechanical-transfer stamping cell.
For Example: Oakland Tool and Manufacturing
Oakland Tool and Manufacturing (OTM), Fraser, MI, part of an umbrella group that also includes Madison Die and Engineering—a prototype and die-build company—and medium-volume stamper Gaylord Precision Tool, sits in the shadows of several now-closed automotive tier stampers. OTM remains viable because of several strategies, including paying attention to employing best practices in running production parts.
OTM supports the Tier One and Tier Two markets with medium- to high-volume stampings, including stamping of one key structural component for the Ford F-250 and F-550 trucks. OTM also performed prototyping and development work for the program.
Once prototyping activities were completed, OTM’s customer was to market-test the part for production. In order to be competitive and secure the business, OTM evaluated material savings from nesting the blanks in an offline operation, hand loading the blanks into a blank feeder, and running the process with a mechanical transfer system. It already had a 300-ton mechanical press with an 84 by 48-in. bed and a 16-in. stroke. It sought an inexpensive method to apply transfer automation to the press and to present blanks to the automation. Working with HMS Products Co., OTM purchased a hand-loaded blank feeder and a Series 500 full-mechanical transfer system, with part-specific engineered finger tooling integrated into the die design.
Because of the limited press size, HMS faced a number of challenges in fitting the automation, dies and transfer finger tooling through the press uprights. Arial cam elements in the dies needed to be watched closely to avoid timing-curve interference in the 16 in. of press stroke.
Design collaborations between OTM and HMS overcame these challenges and resulted in a line that operates at 15 strokes/min., and which has produced 375,000 stampings/yr. for several years now.
Says Jim Tomlin, OTM engineering and tooling manager: “The transfer and loader unit have exceeded our expectations. Aside from lubrication and the most basic preventive maintenance, this system just runs. Other benefits include built-in error proofing of the finished parts, and less downtime than many of our progressive applications.” MF
See also: HMS Products Co.
Related Enterprise Zones: Automation
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