Husqvarna is the world’s largest chainsaw manufacturer. Many pros even consider them to be the best on the market. Lumberjacks that use chainsaws go through an average of one chainsaw per year – in other words, we're talking large manufacturing volumes. Vital drive components like crankshafts have long been manufactured in the Husqvarna factory in the western Swedish town of Brastad. Now, the chainsaw clutch drums are also manufactured there – with the help of an ODEN press from AP&T.
The Husqvarna factory in Brastad manufactures 1.6 million crankshafts a year – but that is not only to supply the company’s chainsaw production, but also other equipment like hedge clippers and clearing saws. When it was time to refurbish production of clutch drums, which are important component to drive the chainsaw chain, the company decided to situate this in Brastad. The clutch drums come in about 50 different versions and are manufactured though means such as sheet metal pressing – something that was a new experience for the factory in Brastad.
New to sheet metal forming
“Hardening is the heart of our operations and we have vast experience in machining, but sheet metal pressing is new to us,” explains Patrik Rutgersson, production manager at the Husqvarna factory.
Investing in the future
Husqvarna was planning to modernize an old press before it became apparent that a new hydraulic press would shorten cycle times and increase production capacity. They also wanted to ensure that the new production solution could handle new, future product variants in other versions. The company contacted several different suppliers before choosing AP&T.
High demands
“We have a strong tradition of production technology, high machine efficiency and streamlined production. The demands we place on our production equipment are extremely high for the industry. While we know how to handle production, forming technology was new to us. So, we needed the help of a partner with sheet metal forming expertise,” explains Patrik Rutgersson.
Complete line
We found the partner we needed in AP&T and the production solution was a press line consisting of an ODEN hydraulic press with 1,600 kN press force that is supplied by a coil line consisting of decoiler, straightener, servo roll feeder and lubrication station. The decoiler, straightener and roll feeder were supplied to AP&T by the French company Dimeco. Thanks to the LOGOS software developed in-house at AP&T, the parameters of Dimeco and other component units could be integrated into the hydraulic press control system. This means that the entire production line is controlled from a single operator panel – which makes things easier for the operator when the production rate is high.
“From a sheet metal forming perspective, the product is relatively simple. The challenge lies in keeping cycle times short while maintaining a high level of production quality,” says AP&T project manager Jan Kronvall.
Cycle time cut in half
The previous production solution for forming the clutch drums had a pressing cycle time of about seven seconds. The new press line from AP&T does the same job in three seconds. This cuts cycle time by more than half for parts that are produced in quantities of hundreds of thousands per year. This increases capacity in the factory while reducing production cost for each part.
New product variants
Increased efficiency creates opportunities to manufacture even more product variants. The next step will probably be a refined clutch drum at a lower weight. However, this variant is more complicated to produce since sheet metal forming takes up to eight steps using progressive tooling. But, now that the company has gotten a taste of sheet metal forming, Patrik Rutgersson looks forward to the challenge.
“For lumberjacks who spend their entire workday with a chainsaw in their hands, each ounce you save is an improvement to ergonomics. Naturally, we want to incorporate that into our manufacturing,” says Patrik Rutgersson.
