Commercial vehicle production: aiming to reduce component costs
03/05/2014 - Oliver Hagenlocher
The market for commercial vehicles is experiencing a lively development. For example, emerging economies have a great need for new technologies in the production of HGVs or agricultural machines, to enable them to achieve the desired growth in construction industry and agriculture. At the same time, competition is hotting up. New manufacturers from, for instance, China intensify the price war. Against this kind of background today’s production planners are coming under considerable pressure. The future of commercial vehicle production lies in being faster, more energy efficient and more flexible. For the turning experts at EMAG these are very familiar conditions. With their vertical pick-up turning machine VL 8 for workpieces of up to 400 mm diameter they offer a highly efficient solution for the production of commercial vehicle components.
Large vehicles = large constituent components. This is the simplest way to describe commercial vehicle production. However, the manufacture of especially large and heavy components (for instance for the powertrain of HGVs, earthmovers or buses) poses a particular set of questions. How can a large clamped component be machined economically and, at the same time, at the highest precision? Does the demanding workhandling of such components not result in endlessly long production processes? The vertical pick-up turning machine VL 8 from EMAG’s machine builders provides the answer. They have transferred all the advantages of their VL series directly to a machine specially designed for the handling of large components, where a number of different turning and milling operations are carried out within the framework of a single close-loop production process, with integrated automation providing the speed required and a vertical layout ensuring a high degree of process integrity where chip flow causes no problem. The results achieved with this design often become apparent within a very short time. Subcontractors and component suppliers benefit from short idle times, high component quality and sinking unit costs. The VL 8 is rapidly becoming a true “cost-killer“ in the production of commercial vehicles.
Tried and tested basic construction – optimal price-performance ratio
The basic design of the VL 8 closely follows that of the successful VL series. Sturdy machine construction, dynamic axes and simple operation are the main characteristics of these machines. They are also based on a completely new machine concept that allows for a variety of production technologies for soft and hard machining to be combined to achieve a very attractive price-performance ratio. The following major components ensure the production process on the VL is also highly efficient:
- The corner stone is a machine base in the polymer concrete MINERALIT that guarantees vibration resistant processes, providing for an excellent tool life and an outstanding machining quality.
- The front of the machine base features a compound slide carrying the vertical main spindle that traverses the Z- and X- axes with great dynamic.
- With a chuck diameter of 500 mm the pick-up spindle accepts workpieces of up to 400 mm diameter.
- The machining process uses a main spindle with 60 kW rating, a torque of up to 1.220 Nm and speeds of up to 2.850 rpm.
- The turret accommodates 12 turning or, optionally, 12 driven drilling and milling tools.
- The workpieces are loaded into the carrier prisms of a conveyor belt and positioned via NC axis.
The pick-up spindle collects the workpieces from the lateral conveyor belt and takes them to the machining area. It is here that short travels ensure short chip-to-chip times. The machining process is a highly flexible one that allows for the use of a large variety of tools. It is also possible to link up two machines and a component turnover station to create a flexible production cell – for instance to machine the first and second sides of a workpiece complete in one cycle. Furthermore, the integration of a Y-axis in the turret allows for the “off-centre” machining of more complex geometries.
Precision is built in
Other features ensure the precision of the machining process. There is – for instance – the, where short distances between the bearings, the use of high-precision separable bearings in a tandem-O-tandem arrangement and support bearings with length compensation, at the spindle end, provide for a particularly sturdy construction – an important basic condition for micrometre-precision turning processes. A further help in maintaining precision is the integration of an inspection process into the cycle sequence. The required probe is installed outside the machining area and checks the workpiece while it is still clamped. Any corrective data is sent to the CNC control and the process adjusted accordingly. This guarantees consistent high precision even during automatic operation. Other pluses in the production of components for commercial vehicles are the ease of operation and control of this machine. All service units are easily accessible, with tool changes just as easy to carry out, as the distance from operator to turret is just 400 mm.
The machine builders at EMAG have always put their trust in tried and tested components that are considered standard in manufacturing circles. This ensures that the VL 8 can be available within a few weeks – and at a very attractive price-performance ratio. In short, the VL 8 combines all the factors that make it possible to reduce component costs in commercial vehicle production: low investment costs, flexible and fast production processes and a sturdy machine construction.