Machine Overview
1.General layout of the machine
GMB1840 overall adopts gantry frame layout, mainly consists of base, table, column, crossbeam, slider, ram, lubrication system, cooling system, pneumatic system, safety protection, guide rail protection, CNC system, electrical control, tool magazine system and other parts.
The main parts including base, table, column, beam, slider, ram, etc. are designed by 3D finite element optimization, using European "M" Mihanna casting quality standards, adding non-ferrous metals, with resin sand casting process, and after perfect heat treatment process (rough machining and then secondary aging treatment, etc.) to eliminate casting, cutting residual stress, so that the casting has good rigidity, no deformation, to ensure the strength, rigidity and stability of the machine.
1) X axis: The worktable adopts a double-layered rib hollow anti-vibration structure (Fig.1). The worktable moves along the heavy-duty linear roller guide rail of the bed, and its X-axis drive is driven by an AC servo motor, which drives the ball screw to rotate to realize the longitudinal movement of the worktable. X-axis drive adopts AC servo motor through precision coupling to drive ball screw rotation to realize the longitudinal movement of the worktable.
2) Y axis: the slider is a ring structure body (see Figure 2), network type structure design, good stability, Y axis uses two heavy-duty linear roller guide orthogonal vertical and combined with a rectangular hard rail, constituting a unique structure of "linear - hard combination", good rigidity, fast response time; its Y-axis drive adopts AC servo motor through precision gear reducer, driving the ball screw rotation to realize the lateral movement of the slider along the beam, the beam uses a large cross-sectional barrel structure, and the internal "sun-shaped Mi-zi type" ribbed plate arrangement structure(Fig.3), so that they all have high resistance to bending and twisting characteristics. The crossbeam is fixed to the top of the column on both sides of the machine and the Y-axis has good vibration damping performance to ensure the stability of cutting.
The columns all adopt the imitation "boot type" design (Fig. 4), which effectively improves the inclination of the columns and enhances the stability of the whole machine.
3) Z-axis adopts the four-sided ring hugging hard rail square ram structure (Fig.5), ram cross-section 410mm x 410mm (450mm × 450mm for Z – axis travel 1250mm), material QT600, and by manual scraping, not only to ensure the accuracy of the guide rail and can greatly increase the life of the hard rail; Z-axis drive using AC servo motor drive, through the precision gear reducer, drive the ball screw rotation, to achieve the ram along the slider of the vertical movement.
Both sides of the ram are symmetrically arranged with liquid nitrogen balancing cylinders, and the pivot points of the two balancing cylinders are in the same line with the center of gravity of the ram, in line with the "center of gravity drive" design concept, which reduces the deflection torque of the ram up and down movement, and also reduces the vibration caused by the frictional force of the deflection torque, thus increasing the machining accuracy of the machine.
2. Machine transmission system
1) Feed transmission system:
The machine X/Y/Z axis adopt AC servo motor to connect directly with precision ball screw through precision planetary reducer, drive the precision ball screw rotation, drive the movable parts moving along heavy-duty linear guides (or hardened hard gauges) on fixed parts. Ball screw adopts fixed support pre-stretch structure at both ends to achieve smooth, accurate and fast movement. Ball screw support bearings at both ends adopt imported famous brand, special ball screw support bearings.
2) Main transmission system
The servo main motor is placed on the top of the ram and directly connected to the spindle unit through the China gearbox + carbon fiber coupling to realize the spindle cutting processing. The motor is placed on the top of the ram, which can reduce the heat transfer from the motor to the ram, reduce the thermal deformation of the ram, and the motor vibration source is far away from the cutting area, which makes the machining more smooth.
The gearbox is made by China, which has the features of constant cutting force in large speed range, low vibration, low noise, smoother cutting process and better surface craftiness of workpiece, compact structure and high transmission efficiency.
Equipped with Taiwan BT50-190 direct drive spindle unit (see figure on the right), the main
characteristic parameters:
Spindle taper: BT50-190
Pulling force: 18000N±10%
Max. torque: 800Nm, Short-time overload 1000Nm
Max. speed: 6000rpm
Spindle upper bearing inner diameter: 90mm
Spindle lower bearing inner diameter: 100mm
3. Coolant, lubrication system
The machine tool is equipped with cutting fluid filtration and cooling supply system, equipped with Taiwan high flow cooling pump and large capacity water tank to fully ensure the circulation cooling. The spindle end adopts the jet cooling during processing, and the outside of the table is cleaned with a water gun.
4. Pneumatic system: The pneumatic system of this machine adopts imported famous brand, mainly completes the following functions: spindle front seal, spindle taper hole blowing, tool changing pneumatic door, etc. The configured pneumatic two-piece can filter the impurities and moisture in the air source to prevent the impure gas from damaging and corroding the machine parts. The solenoid valve set is controlled by PLC program to ensure that the spindle loosening, spindle center blowing and spindle tool clamping are completed quickly and accurately.
The machine requires supporting air source pressure ≥ 0.6MPa, filtration precision 100μm, to ensure the normal working performance of the equipment, if the air source compressed air that can not meet machine air source requirements, a set of air source purification device (dehumidification, oil removal, filtration) should be added to the machine before the machine inlet air.
5. Machine guard
The machine adopts CE safety standard shield, which not only prevents coolant from splashing, but also ensures safe operation and pleasant appearance. The machine bed guide adopts stainless steel telescopic shield protection, and the cross beam guide adopts organ type shield, and all adopt labyrinth type dustproof to prevent chips and coolant from entering into the machine, so that the guide and ball screw are protected from wear and corrosion.
Standard configuration: The whole machine adopts semi-protection, the observation window adopts tempered glass, and the protection door opens for power-off protection (*Non-standard configuration, special order required).
6. Chip conveyor system
Double screw type chip conveyor is configured on the left and right sides of the machine table, and chain plate type chip conveyor and chip collecting car (optional configuration) can be configured to facilitate the collection of iron chips at the tail.
7. Cleaning system
In order to clean up the iron chips inside the protection in time and facilitate the regular cleaning of the operator, the handheld high-pressure cleaning water gun is configured on the protection side.
8. Lubrication system
The lubrication of the machine tool guide rail is directly lubricated by the timing and quantitative centralized lubrication pump to the moving parts to lubricate the three coordinate guide rail surface: bed - table guide rail surface, slider - cross beam guide rail surface, slider - ram guide rail surface and screw nut. After the machine is powered on, the lubrication pump motor makes the lubricating oil injected from the oil pump to the slider and ball screw nut of each guideway through the oil pipe and connector. Timing lubrication device with oil level switch, when the oil tank lubricating oil level is lower than the set height, the machine will alarm. Generally, oil should be added to the oil tank every two weeks or so.