Robots Automate Assembly of Auto Parts

In some cases, SCARA robots replaced pneumatic or servo-driven pick-and-place mechanisms.

Photo courtesy Epson Robots

SCARA robots load and unload pallets. The robots provide flexibility to handle different components or different shipping trays.

Photo courtesy Epson Robots

Some robots at Husco have been running for more than 14 years.

Photo courtesy Epson Robots

Husco engineers developed a modular automated assembly system consisting of a pallet-transfer conveyor and 10 Epson SCARA robots for most of the material handling.

Photo courtesy Epson Robots

Based in Waukesha, WI, Husco International is a family-owned, privately held manufacturer of hydraulic and electromechanical control systems for automotive and off-highway applications. In business for more than 75 years, the company employs more than 1,500 people worldwide and tallied sales of more than $500 million last year.

The company’s automotive division builds control valves, fuel injection systems, solenoids, turbochargers and EV systems for leading manufacturers of cars and trucks. Its off-highway division builds hydraulic and electromechanical control systems for agricultural, construction, material handling and commercial equipment.

While many manufacturers, including Husco, have been devoting more and more of their efforts to EVs, increasing the efficiency of internal combustion engines remains important.

One crucial development has been the use of variable-force solenoids in car and truck engines. These small devices optimize the opening of the valves that let fuel and air into the cylinders at the heart of each engine, helping to increase both fuel efficiency and horsepower.

Husco has been working on its own version of the technology for several years and introduced a new solenoid to the market last year.

“Our goal in manufacturing was to build a cost-competitive production line capable of producing more than 2 million of these parts each year, running two eight-hour shifts, five days a week,” says Jake Wampole, technical director of the advanced manufacturing group (AMG) at Husco Automotive.

AMG is Husco’s in-house factory automation arm. It designs and builds most of the manufacturing lines for Husco, and it recently began offering its services to outside clients as well.

To reach its goal, the plant would have to produce a fully assembled and tested solenoid every 6.1 seconds.

To make that possible, the AMG team developed a modular automated assembly system consisting of a pallet-transfer conveyor and 10 Epson SCARA robots for most of the material handling. They settled on one Epson G6, two G3, and seven T-Series systems.

“We’ve had a long history with Epson robots,” says Wampole.

For nearly 15 years, the company has used Epson SCARA and six-axis robots to produce tens of millions of engine control systems, often on lines running 24 hours a day, seven days a week, 365 days a year.

“We like to stress that we’re a manufacturer first and an integrator second, and we know what it takes to build systems that run smoothly, last a long time, and can meet the demands of high-speed, high-precision manufacturing,” says Aaron Gietzel, programs director for AMG.

“We’ve had really good experiences with Epson robots,” he adds. “It comes down to cost, speed, flexibility, service and support.”

The system consists of three cells. “In the first, we load armatures, c-pulls, caps, and coil assemblies, combine them, press them together and crimp them,” Wampole explains. “In the second, we test for air leaks and do force vs. distance curve testing of the finished products. Finally, we pack them out into a set of vacuum-form trays for shipping to customers.”

To assemble parts at the necessary speed, “we have to load and unload the pallets with robots, and we need flexibility to handle component variations or to adjust for the trays we use for shipping,” he adds.

Husco and AMG most often use Epson T-Series robots for pick and place operations, but upgrade to the G-Series when they need higher speed and accuracy.

“The T-Series offers a very cost-effective solution for moderately complex or quick movements, and its built-in controller is an excellent option for quick installation and easier integration,” says Wampole. “Its cost effectiveness gives us the flexibility to replace pneumatic or servo-driven pick-and-place stations with a robot.”

“The ease of programming, flexibility of movement, placement accuracy and speed common to Epson robots, together with our years of success using them, were all factors in our decision to design a robotic production line,” Gietzel adds.

He says the decision has paid off handsomely, with the line functioning almost flawlessly since its startup last fall.

Variable Displacement Control Valves

Another technology improving the efficiency of internal combustion engines is variable displacement, which allows a larger engine, while under a light load, to deactivate some of its cylinders for improved fuel economy. Husco produces a variable displacement engine control valve that is widely used in the automotive and truck industries.

“The valve itself has perhaps 15 subcomponents that we assemble here in Waukesha,” Gietzel explains. “It travels down a palletized assembly line, and we use a number of Epson robots to load the various components. Once the valve is completely assembled, it’s crimped to hold the parts together. And then we fully test it before it ships.”

Last year, Husco produced more than 4.2 million of these valves, and demand continues to grow. “Since the line runs 24 hours a day, seven days a week, any effort to increase output means decreasing the cycle time,” Wampole says.

One bottleneck has been the crimping operation at the end of the assembly, which uses a machine Husco purchased from an external machine builder. “Up until last fall, we were running a pneumatic slide to move the parts to and from the crimp station,” he says. The machine picked a part from the pallet, flipped it vertically, then placed it into the crimp nest.

“We were able to run simulations with an Epson C4 six-axis robot that showed an ability to reduce the cycle time from 7.5 seconds to 6.5 seconds,” Gietzel recalls. That would mean an increase of 13 percent, or almost 550,000 parts per year.

Because it was an existing product, Gietzel’s AMG team built the robotic setup parallel to the assembly line, together with a secondary electrical cabinet and a direct drop to power the new robot. That way, once everything was ready, they were able to switch out the old pneumatic system with the robot with just three days of downtime.

This project, completed at the end of last year, was a resounding success, meeting its goals for cycle time reductions and increased productivity.

“Crucial to the success of the project was our ability to power on and test the new robot, and pretty much do all the movement simulations in our build area before we took the old machine down,” Wampole adds.

A New Pick-and-Place Operation

As the team was rebuilding the crimping station, they turned their attention to one of the pick-and-place operations on the same variable displacement control valve line.

“Here, we were trying to achieve that same 6.5-second cycle time, so that the entire line would be able to produce the parts at the higher speed,” Gietzel explains. “But this station was using an older, pneumatic-style material handling machine that was simply not as fast as our Epson robots.”

They had another major goal: “We needed more uptime. Our mechanical system was highly constrained, very difficult to get perfectly aligned, and thus subject to breakdowns. Using another Epson T-Series robot, we felt we could increase robustness, minimize downtime, and maintain that 6.5-second cycle.”

The team is finalizing the switch-over to the new operation, but indications are that it will be every bit as successful as the other improvements they have undertaken.

Moving Forward

In the automotive industry, technology constantly changing. “We’re now expanding our portfolio with systems for electric vehicles,” Wampole says.

As the company moves forward, Wampole and Gietzel agree that they will continue their relationship with Epson.

“For the most part, we’re getting five, six, seven years out of the standard SCARA robots without having to replace many, if any, components. In fact, we have some Epson robots that have been running for over 14 years. And I can’t say we run them in clean rooms—they do their work in oily, dirty situations. We put them through the ringer!”

“When there is a problem,” Gietzel adds, “Epson has been very responsive. Our local Epson vendor, Doig Corp. of Cedarburg, WI, has been great to work with as well.”

Both agree that great automation products and great support will be crucial to Husco and AMG’s ongoing work.

“The areas we’ve upgraded with Epson robots are now our biggest hitters, whereas they once were the ones that caused the biggest headaches,” Wampole says.

After 15 years, their confidence in the speed, robustness, serviceability and support of the Epson robots continues to grow.

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