The CNC machining center is a high-efficiency automatic machine tool that is composed of mechanical equipment and a CNC system suitable for processing complex parts. The CNC machining center is also one of the world's highest output and most widely used CNC machine tools. It has strong comprehensive processing capabilities. The workpiece can be clamped to complete a lot of processing content at a time, with high processing accuracy and a tool magazine, which is suitable for single-piece processing with complex shapes and high precision requirements or medium and small batches of multi-variety production.
Generally, the workpieces processed by CNC will be clamped with flat-nose pliers or three-jaw chucks, some are pressed with a pressure plate, and some workpieces need to be clamped by tooling. Due to the different materials and the different processing shapes, the clamping force is different. The size and pressure balance will affect the accuracy of the workpiece processing and the deformation of the workpiece after processing.
Colleagues often use flat-nose pliers to clamp the workpiece. When making a fine hole, the gauge can go down before loosening the pliers. When the pliers are loosened, the gauge can't go down. This is because the clamping force has not been mastered. The large clamping force, deformed workpiece, small clamping force are all not good during CNC machining. There are main points in CNC machining as follow.
Ⅰ. Zero return of CNC machining (return to machine origin)
Before tool setting, the zero return (return to the machine origin) operation must be performed so as to clear the coordinate data of the last operation. Note that the X, Y, and Z axes need to be zeroed.
Ⅱ. The spindle of CNC machining is rotating forward
In the MDI mode, the spindle rotates forward by inputting the command code and maintains a medium rotation speed. Then change to the handwheel mode, and move the machine tool by switching the adjustment rate.
Ⅲ. X-direction tool setting for CNC machining
Gently touch the tool on the right side of the workpiece to clear the relative coordinates of the machine tool; lift the tool in the Z direction, and then move the tool to the left of the workpiece, and move the tool and the workpiece down to the same height along Z. Gently touch, lift the tool, record the X value of the relative coordinate of the machine tool, move the tool to half of the relative coordinate X, record the X value of the absolute coordinate of the machine tool, and press (INPUT) to enter the coordinate system.
Ⅳ. Y-direction tool setting for CNC machining
Gently touch the tool in front of the workpiece to clear the relative coordinates of the machine tool; lift the tool in the Z direction, and then move the tool to the back of the workpiece, and move the tool and the workpiece down to the same height as before. Gently touch, lift the tool, record the Y value of the relative coordinate of the machine tool, move the tool to half of the relative coordinate Y, record the Y value of the absolute coordinate of the machine tool, and press (INPUT) to enter the coordinate system.
Ⅴ. Z-direction tool setting for CNC machining
Move the tool to the surface of the workpiece to be zero in the Z direction, slowly move the tool to lightly touch the upper surface of the workpiece, write down the Z value in the coordinate system of the machine tool at this time, and press (INPUT) to input just in the coordinate system.
Ⅵ. The spindle of CNC machining stops rotating
Stop the spindle first, move the spindle to a suitable position, call the processing program, and prepare for formal processing.