Structure composition of NC milling machine

① Cooling system. The cooling system of machine tool consists of cooling pump, water outlet pipe, return pipe, switch and nozzle. The cooling pump is installed in the inner cavity of the machine tool base. The cooling pump pumps the cutting fluid from the reservoir in the base to the water outlet pipe, and then sprays it through the nozzle to cool the cutting area.

② Lubrication system and mode. The lubricating system consists of a manual lubricating oil pump, an oil separator, a throttle valve and an oil pipe. The machine tool adopts periodic lubrication mode, uses manual lubricating oil pump, and lubricates the spindle sleeve, longitudinal and transverse guide rails and three-way ball screw through the oil separator, thus improving the service life of the machine tool.

From the characteristics of digital control technology, because the CNC machine tool adopts servo motor, the working sequence and movement displacement of the executive parts of the machine tool are directly controlled by digital technology, and the gearbox structure of the traditional machine tool is cancelled or partially cancelled, thus greatly simplifying the mechanical structure. Digital control also requires the mechanical system to have high transmission stiffness and no transmission clearance to ensure the execution of control instructions and the realization of control quality. At the same time, due to the continuous improvement of computer level and control ability, more functional components can be allowed to perform various auxiliary functions on the same machine tool at the same time, so the mechanical structure of CNC machine tools requires higher integrated functions than traditional machine tools.

From the requirements of manufacturing technology development, with the emergence of new materials and new processes, as well as the requirement of low cost in market competition, metal cutting is developing towards higher cutting speed and accuracy, higher production efficiency and more reliable system. This requires that the CNC machine tools developed on the basis of traditional machine tools have higher precision, higher driving power, better dynamic and thermal rigidity of mechanical mechanisms, more reliable operation, long-term continuous operation and as little downtime as possible. The milling head part consists of a step (or stepless) gearbox and a milling head. The spindle of the milling head is supported on a high-precision bearing, which ensures the high rotation accuracy and good rigidity of the spindle; The spindle is equipped with a quick tool change nut, and the front taper is 1$0505. The spindle adopts mechanical stepless speed change, with wide adjustment range, stable transmission and convenient operation. The braking mechanism can make the spindle brake quickly, saving auxiliary time. When braking, the brake handle opens the stop ring to brake the spindle immediately. When starting the main motor, pay attention to loosen the spindle brake handle. The milling head part is also equipped with a servo motor, an internal toothed pulley, a ball screw pair and a spindle sleeve, which form a feed transmission chain in the vertical direction (Z direction) to make the spindle move vertically and linearly.

The workbench and saddle are supported on the wide horizontal guide rail of the lifting platform, and the longitudinal feed of the workbench is driven by a servo motor installed at the right end of the workbench. The precision ball screw is driven by an internal toothed pulley, so that the workbench can be fed longitudinally. The left end of the workbench is equipped with a handwheel and a dial for manual operation. The vertical and horizontal guide surfaces of the bed saddle adopt the viscoplastic surface of TuRcllE B, which improves the wear resistance, motion stability and accuracy retention of the guide rail and eliminates the phenomenon of low-speed crawling. The basic parts of CNC milling machine usually refer to the machine bed, column, beam, workbench, base and other structural parts, which are large in size (commonly known as large pieces), and the well constitutes the basic framework of the machine tool. Other components are attached to the base member, and some components need to move along the base member. Because the foundation piece plays a supporting and guiding role, the requirement for the foundation piece is good rigidity.

Working principle (Figure):

Frequency converter/inverter

Frequency conversion drive is a power control device that uses frequency conversion technology and microelectronics technology to control AC motor by changing the frequency mode of motor working power supply. In CNC machine tools, frequency converter is mainly used to control the motion of spindle.