Composite camshafts are increasing in importance, as they decrease in weight, providing more opportunities for automotive manufacturers. The heat-shrink processachieves new levels of flexibility thanks to the new SFC 600 heat-shrink machine from EMAG.
Camshaft variants are joined via heat-shrink in quick succession
The heat-shrink assembly of camshafts provides the automotive industry with many advantages. For one, the design is based on a tube, howevers it’smuch lighter, compared to the traditional monoblock design. Another plus is that manufacturers can use the ideal material for each individual camshaft component. For instance, the cams are sintered, whereas subordinate components – such as plugs and end pieces – are made of more favorable materials. This approach reduces costs and makes production planning and implementation of the camshaft easier.
New Opportunities for Heat-Shrink Technology
For over 20 years EMAG Automation has developed its patented heat-shrink technology. The cam is heated inductively, where it then expands, and is fitted onto the shaft with no force involved. The whole process is carried out at a temperature level generated to suit the specific material and component geometry. The heat-shrink process starts when the component is subsequently quenched. The result is an air-tight shrink-fit. With their new SFC 600 shrink-fit machine, the creators of this technology open up new opportunities, where the shrink-fitting of camshafts up to 600 mm length gets even faster and noticeably more flexible.
At the center of the solution are particularly fast and precise NC axes with linear motor technology. With this technology, it is possible to control the whole production process with an NC program – which is necessary for flexibility. Depending on the camshaft model, it is sometime sufficient to simply adjust the NC program.The whole user interface is made to suit the programming of the machine tool. All data is stored in the control system. “The changeover from one camshaft production to another takes less than ten minutes”, explains Mr. Wolfgang Bohn, Application Engineer at EMAG Automation. The system is particularly effective where retooling is a frequent requirement, as most tools in the SFC 600 do not have to be retooled.
60 Second Assembly
The cycle times for the actual shrink-fit process are also very short. The gantry loader picks up two shaft components simultaneously and takes them to the two inductors to be heated. An NC-controlled twin-gripper then takes over the two components and pushes them onto the shaft, as described. Making it possible to completely assemble a standard 4-cylinder camshaft in about 60 seconds. “The SFC 600 makes the process faster, more flexible and easier to control”, summarizes Mr. Bohn. “We’re sure that our combination of heat-shrinking and NC-based drives will chave a major impact in camshaft production.”