Hwacheon Machinery America at IMTS 2014 Booth S-8129 will demonstrate its high-precision machining centers for die-mold applications. Hwacheon’s Sirius range of 3-axis vertical machining centers feature 20,000-rpm high-speed spindles for the UM and UL+ models and 12,000 rpm spindle for the UX model.
A number of useful options make mold-die machining more efficient with Sirius machines. Equipped with integral motor spindles with jacket cooling and oil-jet cooled bearings and rigid roller linear guide ways, the machines deliver stable performance over long cycles. According to the company, the Sirius range of high speed die and mold machining centers provide the industry high capability, extreme precision at an attractive price.
The UM model demonstrated at Hwacheon’s open house featured a 850 mm (33.46”) x 500 mm (19.70”) work table with 800 kg (1764 lb) load capacity, strokes of (X, Y, Z) of 750 mm (29.53”) x 500 mm (19.70”) x 450 mm (17.72”), and rapid positioning of 24 m/min. The 40-taper (BBT & HSK optional) tools are changed in 2.5 seconds.
The bilateral gate structure in SIRIUS-UM effectively distributes the vibration, weight, and heat throughout the entire frame. Finite element analysis methods help to minimize the frame distortion which may be caused by machining conditions or environment. The distance between the spindle and the body is designed short, so the machine stays stable after a prolonged operation.
The spindle is integrated with the motor to limit vibration, noise, and power loss at high speed rotation. The cooled jets of oil are injected directly onto the spindle bearing for effective cooling, and the motor and the spindle assembly are jacket-cooled to limit the displacement caused by heat. To achieve greater precision, standard Hwacheon software (HSDC) monitors the spindle for possible thermal displacement and makes necessary adjustment in real time.
SIRIUS-UM provides powerful feed performance using the Z-axis 6-block LM guide. The servo motor is coupled directly to the drive; and while the tensile preload ball screws provide smooth operation, the roller linear guide allows for rapid feed and rigid performance.
Before final finish passes, Sirius machines can, with Hwacheon HFDC (Hwacheon frame displacement control system) software, dynamically compensate for any changes that may have occurred in machine kinematics due to temperature, vibration or changes in the tool itself.
Software is key
Hwacheon mold-making machine tools feature standard integrated software developed in conjunction with Fanuc CNC for thermal displacement control and compensation. Software measures thermal conditions in the machine during the cycle and uses the information collected to dynamically verify and control accuracy.
In this way, Hwacheon machine can control the kinematics of the machines for contour machining, optimizing machine performance for roughing, semifinish, and finish machining without employing a number of different programs.
The Sirius machines include software that other machines do not or offer only as options.
HTLD. Tool Load Detection software provides real time measurement of tool load ensuring consistent and safe machining. Constantly monitoring tool damage and deterioration for prevention of complete tool failure causing work piece damage, this software ensures accuracy and performance. Such a system will measures tool load very frequently, such as every 8 msecs.
HECC. Hwacheon high efficiency contour control system offers an easy to use programming interface system which provides a precise, custom contour control for the selected work piece while supporting longer machine life and reduced process time. Such software will offer different options for cutting speed and accuracy, and for surface finish and geometry. A customizable display provides real time monitoring and easy access. This software may be used with existing NC systems and is compatible with G-Code programming.
OPTIMA. A cutting feed optimization routine utilizes an adaptive control method to regulate the feedrate in real time to sustain a consistent cutting load while machining. As a result, cutting tools are less prone to damage and machining time is reduced. The system controls the feed velocity to maintain consistent cutting load. Features include a graphic display of tool load and feedrate, convenient operation using G-code programming, and a number of data sets for specific tool and process control.
Additionally, highly sensitive thermal sensors mounted at various locations in the machine castings where thermal displacement is possible can permit software monitoring and correction of detected thermal displacement.
HSDC. Hwacheon spindle displacement control is also possible with software. As a spindle rotates at high speed centrifugal forces and heat expand the spindle taper causing error in Z-axis. This axis accuracy is vital to precision mating of die components. In addition to a high precision cooled spindle, software can be used to constantly monitor temperature at a number of points within the spindle assembly predicting thermal displacement. The system can then makes necessary adjustments and effectively minimize thermal displacement, preventing Z-axis error due to taper expansion as the spindle rotates at high speed.