The composition of the data machine

1. The composition of CNC machine tools CNC machine tools generally consist of input and output equipment, numerical control devices (CNC), servo units, driving devices (or actuators), programmable controllers (PLC) and electrical control devices, auxiliary devices, machine tool bodies and measuring devices composition. 
(1) Input and output device of CNC machine tool factory. It is an interactive device for the machine tool numerical control system and the operator to exchange information and realize man-machine dialogue. 
The function of the input device is to turn the numerical control code on the program carrier into the corresponding electrical pulse signal, and transmit it into the numerical control device. At present, the input devices of CNC machine tools include keyboards, disk drives, photoelectric readers, etc., and the corresponding program carriers are magnetic disks and perforated paper tapes. The output device is a display, there are two kinds of CRT display or color liquid crystal display. The function of the output device is: the numerical control system provides the necessary information for the operator through the display. The displayed information can be the program being edited, the coordinate value and the alarm signal, etc. 
(2) Numerical control device (CNC device). It is the core of the computer numerical control system, which is composed of hardware and software. It receives the pulse signal from the input device. After the signal is compiled, operated and logically processed by the system software or logic circuit of the numerical control device, it outputs various signals and instructions to control various parts of the machine tool to make it perform specified, appropriate sequenced actions. The most basic signals in these control signals are the feed speed, feed direction and displacement command of each coordinate axis (that is, each executing part for feeding motion) (sent to the servo drive system to drive the executing part for feeding motion), There are also the speed change, reversing and start and stop signals of the spindle, the tool command signal for selecting and exchanging tools, controlling the start and stop of coolant and lubricating oil, controlling the loosening and clamping of workpieces and machine parts, and controlling the indexing table indexing. Auxiliary command signal, etc. 
The numerical control device mainly includes a microprocessor (CPU), a memory, a local bus, a peripheral logic circuit, and an interface with other components of the CNC system. 
(3) Programmable logic controller (PLC). CNC machine tools complete control functions through CNC and PLC. Among them, CNC mainly completes functions related to digital operations and management, such as editing of part programs, interpolation operations, decoding, and position servo control of tool motion. The PLC mainly completes some actions related to logic operations. It receives the control code M (auxiliary function), S (spindle speed), T (tool selection, tool change) and other switching action information of the CNC, and carries out the switching action information. Decode, convert into corresponding control signals, and control auxiliary devices to complete the corresponding switching actions of the machine tool, such as workpiece clamping, tool replacement, coolant switching and other auxiliary actions. It also receives the instructions from the machine tool operation panel, on the one hand, it directly controls the action of the machine tool (such as manually operating the machine tool), and on the other hand, it sends a part of the instructions to the numerical control device for the control of the processing process. 
In the FANUC system, the PLC specially used to control the machine tool is recorded as PMC, which is called the programmable machine tool controller. 
("Servo unit. The servo unit receives the speed and displacement commands from the numerical control device. After these commands are transformed and amplified by the servo unit, they are converted into the speed, direction and displacement of the machine tool feed movement through the driving device. Therefore, the servo unit is a numerical control device. The link with the machine tool body, it amplifies the weak command signal from the numerical control device into a high-power signal to control the drive device. The servo unit is divided into a spindle unit and a feed unit, and the servo unit has an open-loop pump for its system. system, semi-closed loop system and closed loop system.
(5) Drive device. The drive device converts the command signal amplified by the servo unit into mechanical motion, and drives the machine tool table through the mechanical connecting parts, so that the table can be accurately positioned or make strict relative motion according to the specified trajectory, and the shape, size and precision meet the requirements. Components. At present, the commonly used drive devices include DC servo motors and AC servo motors, and AC servo motors are gradually replacing DC servo motors. 
The servo unit and the drive device are collectively called the servo drive system, which is the power device for the machine tool to work. The instructions of the computer numerical control device are implemented by the servo drive system. The servo drive device includes the spindle drive unit (mainly controls the speed of the spindle), To the drive unit (mainly controls the speed and position of the feed system). Servo drive system is an important part of CNC machine tools. In a sense, the function of the CNC machine tool mainly depends on the CNC device, and the performance of the CNC machine tool mainly depends on the servo drive system. 
(6) The machine body. That is, the mechanical parts of the CNC machine tool, including the main moving parts, the execution parts of the feeding movement (the table, the carriage and its transmission parts) and the supporting parts (the bed, the column, etc.), and also include the cooling, lubrication, indexing and clamping. Auxiliary devices for tight and other functions. CNC machine tools such as machining centers also have tool magazines for storing tools, manipulators for tool exchange and other components. The composition of CNC machine tools is similar to that of ordinary machine tools. Due to the high speed, high precision, large cutting amount and continuous processing requirements of CNC machine tools, its mechanical components have higher requirements in terms of precision, stiffness, and vibration resistance. 
In addition, in order to ensure the full play of the functions of CNC machine tools, there are some auxiliary systems, such as cooling system, lubrication system, hydraulic (or pneumatic) system, chip removal system, protection system, etc.