AUTOMATIC COMPLETE MACHINING OF PRISMATIC AND CASE-STYLE PARTS

HEC 500/630/800 Athletic series medium-sized horizontal machining centers from <b>StarragHeckert</b> use an NC-controlled rotating and tilting unit that also reduces setup times, eliminates additional adjustment work, makes door-to-door times faster and lowers costs per unit with increased machining accuracy – all at the same time.

The StarragHeckert (Geneva, Switzerland) horizontal machining centers of the medium-size HEC 500/630/800 Athletic series have become even more effective thanks to an NC-controlled rotating and tilting unit that turns the models of the Athletic series 5-axis machining centers. Thus, automatic complete machining of prismatic and case-style workpieces with edge lengths up to 1,400 mm and up to 1,000 kg in weight becomes possible in one clamping position. For the user, this means reduced setup times, no additional adjustment work, faster door-to-door-times and lower costs per unit, with increased machining accuracy at the same time.

The range of workpieces which can be machined is derived from the following parameters:
• Pallet size: 630 x 630 mm (optional 800 x 630 mm)
• Workpiece interference range: 1,250 mm
• Max. workpiece weight: 800 kg
• X/Y/Z travels: 1,200 / 950 / 1,200 mm

The NC-controlled rotating and tilting unit allows machining of inclined surfaces and holes without axis interpolation by superimposing the B rotary axis and the A swivel axis. The directly driven B axis provides a working range of 0 to 360 deg and a maximum speed of 70 rpm. The clamping torque is 8,000 Nm. High rigidity and stability are also characteristic for the A axis, which is clamped with bearings on both sides. The swing area extends between minus 45 and 91 deg, and the maximum speed is 15 rpm. A 6-fold hydraulic clamping fixture is integrated into the B axis as an option. Absolute, direct position transducers ensure extremely precise positioning and thus optimum machining accuracy.

The rotating and tilting unit meets a high safety standard. This includes clamping of the rotary axes via a hydraulic safety circuit, additional mechanical clamping of the A axis, and pallet clamping by way of mechanically locked clamping cones. Controlled shutdown of the axes using the available residual energy is provided in emergency cases or in case of mains power failure. This relieves the stress otherwise placed on workpiece, tool and machine.

When developing the machining centers of the Athletic series, the company devoted particular attention to high energy efficiency. Examples are the hydraulic system with accumulator charging circuit, regenerative feedback during braking of the motors, use of a warm-up program, energy-neutral counterweight balancing, and the function principles of the pneumatic system. The cost advantage for a machine runtime of 4,800 hours will be approximately $11,000.

Additional benefits include:
• High time-cutting volumes through powerful and dynamic horizontal work spindle with drive power up to 67 kW/25 percent c.d.f.
• Dynamic digital AC feed drives
• High machining accuracy and long-time stability through generously dimensioned sectional rail guides and ball screws in all linear axes
• Quick automatic pallet change with hydraulic lifting/swing changer
Innovative tool handling with chain magazine for 80 tools or tower magazine with 180, 240 or 320 magazine locations for tools up to 800 mm in length
• Highly dynamic tool change thanks to hydraulic dual-arm gripper and tool assignment in the magazine parallel to the spindle
• Thermal stability and high rigidity of all main assemblies
• High-speed swarf disposal with high removal capacity

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