Assembly in Action: Nutrunners Decrease Cycle Times
Contract manufacturer New Era Ohio (Bryan, OH) has approximately 180 employees and a 300,000-square-foot facility where it manufactures diaphragm and piston pumps, as well as lubricating accessories. About a year ago, the company began an aggressive, comprehensive campaign to reduce cycle times in its diaphragm and piston pumps operations.
"We wanted to eliminate waste and unnecessary procedures in the total assembly process, beginning from the time the first part is picked up through the assembly process to packaging at the end of the line," says New Era Ohio manufacturing engineer Randy Allomong.
To this end, New Era created a dedicated team of manufacturing engineers, operators and maintenance workers to pinpoint critical areas for improvement in what the company calls an ACP, or accelerated change process. The company was committed enough to the exercise that it completely shut down its assembly lines for 4 days to evaluate manufacturing flow and identify solutions.
After receiving training in lean manufacturing and Six Sigma, New Era's workers applied 5-S and demand flow technology to reduce waste and operating costs, improve quality, and create a safe, organized and ergonomic environment for operators.
"By the last 2 days of the event, we were able to identify where we had extended walk times or handling times, and then we rebuilt and redesigned the assembly lines for products that were affected and came up with an entirely new manufacturing flow," Allomong says.
One of the primary issues uncovered by Allomong and his team was the time required to install fluid caps on the company's small pumps, a process that requires running down 24 separate bolts. Historically, operators would run down the bolts with an impact wrench, then go back over each bolt individually with a torque wrench. In addition to being cumbersome for operators, this approach took a tremendous amount of time.
To solve this problem, New Era re-equipped its operators with several models of QA4 series pneumatic nutrunners from Ingersoll-Rand (Annandale, NJ). These allow operators to install bolts with one tool, effectively cutting operator work in half, saving several minutes per pump on one of the lines. The nutrunners are available in both angle- and inline configurations, and provide torque up to 55 newton-meters. They are fully configurable in auto shut-off or stall modes, with fixed or floating spindle versions in a variety of drive sizes.
In addition to cutting bolt installation times by 45 percent, the nutrunners also improved torque accuracy. Previously, while a torque wrench would enable an operator to repeatedly apply the minimum amount of torque to a bolt, it was difficult to verify that the maximum torque specified had not been exceeded. Operators also benefited from the nutrunners' ergonomic design. Instead of handling both an impact wrench and a torque wrench 24 times each, they were able to do the same work with only one tool.
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