Turning Center’s Dual Drive Train Speeds Tool Transitions

The Traub TNL32-11 sliding/fixed headstock automatic lathe has a headstock movable in the Z axis, an upper and identical lower turret with X, Y and Z axes, and a counter spindle movable in the X and Z directions. It offers a new front working attachment which sits on an additional cross-slide moving in the X and Z axes, providing the user with as many as three additional, freely positionable tools working simultaneously and independently of each other. The 11-axis machine is designed to save machining time for components requiring extensive drilling.

In addition to the two linear X and Z axes, the front working attachment features a CNC circular axis. By the interpolation of the rotary axis with the X and C axes of the main spindle, the front working attachment can also be used in the Y direction using an interpolated Y axis. When a drilling tool needs to be corrected to exact center, the necessary corrections can be performed simply via the CNC controller.

The front working attachment includes eight tool stations plus a station for a workpiece gripper that can unload a machined workpiece from the counter spindle. While the finished workpiece is discharged from the counter spindle, the next part can be machined with two tools at the main spindle. The tool drive in the front working attachment maintains productivity with 3.4 kW of power and a maximum speed of 12,000 rpm. Robust, stiff toolholders provide a mounting shank diameter of 36 mm. Individually controllable coolant pressure ranging to 80 bar is available at every station.

An internally meshing planetary gear enables the NC rotary axis to control tool turret indexing without requiring a mechanical locking mechanism. The turret’s free positioning enables multiple tool assignment at each station. The turret’s dual drive trains reduce non-machining time. While one tool is in use, the tool intended for the next work step can be accelerated up to the desired speed and is immediately available at full speed after the turret indexing operation.