What are the components of CNC lathe machine tools?
What are the components of CNC lathe machine tools?
CNC lathe machine tools generally consist of a numerical control system, a servo system including a servo motor and a detection feedback device, a main drive system, a high-power control cabinet, a machine tool body, and various auxiliary springs. The dotted line can be used to indicate the basic working process of CNC machining. For CNC machine tools with different functions, the components are slightly different.
1, the CNC system
It is the core of automatic machining of lathe machine tools. It mainly consists of operating system, main control system, programmable controller and various output interfaces. The operating system consists of a display and a keyboard, and the display has various forms such as a digital tube, a CRT, and a liquid crystal. The main control system is similar to the computer motherboard, and is mainly composed of a CPU, a memory, a controller, and the like. The numerical control system controls the mechanical quantity such as the position, angle and speed of the general object, as well as the physical quantities such as temperature, pressure and flow.
The control method can be divided into two categories: data operation processing control and sequential logic control. The interpolation operation module in the main controller is processed according to the read part program, through decoding, compiling and other information processing. The tool path is interleaved and controlled, and the displacement of each coordinate axis of the machine tool is controlled by comparing with the position and speed feedback signals of each coordinate servo system; and the sequential logic control is usually mainly performed by the programmable controller PLC, which is based on the machine tool. Each action in the machining process requires coordination, and logical determination is performed according to each detection signal, thereby controlling the various components of the machine tool to work in an orderly manner.
2, the servo system
It is the electric drive connection between the CNC system and the machine body. Mainly composed of servo motor, drive control system and position detection feedback device. The servo motor is the actuator of the system, and the drive control system is the power source of the servo motor. The command signal generated by the numerical control system is compared with the position detection feedback signal as a displacement command, and then driven by the drive control system to drive the motor to operate, thereby dragging the table or the tool holder to move through the mechanical transmission device.
The servo system is an important part of the CNC machine tool, which is used to realize the feed servo control and spindle servo control of CNC machine tools. The function of the servo system is to accept the command information from the numerical control device, and then convert it into linear displacement or angular displacement motion of the machine tool by power amplification and shaping. Since the servo system is the last link of the CNC machine tool, its performance will directly affect the technical indexes such as the precision and speed of the CNC machine tool. Therefore, the servo drive device of the CNC machine tool is required to have good fast response performance, and accurately and sensitively track the numerical control device. The digital command signal is sent and the instructions from the numerical control device can be faithfully executed to improve the dynamic follow-up characteristics and static tracking accuracy of the system.
The servo system consists of two parts: the drive unit and the actuator. The drive unit is composed of a spindle drive unit, a feed drive unit, a spindle servo motor, and a feed servo motor. Stepper motors, DC servo motors and AC servo motors are commonly used drives.
The measuring component detects the actual displacement value of each coordinate axis of the CNC machine tool and inputs it into the numerical control device of the machine tool through the feedback system. The numerical control device compares the actual displacement value returned by the numerical control device with the command value, and outputs the set value to the servo system. The required displacement command.
3, the processing program carrier
When the CNC machine is working, it is not necessary for the worker to directly operate the machine tool. To control the CNC machine tool, the machining program must be programmed. The part processing program includes the relative motion trajectory of the tool and the workpiece on the machine tool, the process parameters (feedrate spindle speed, etc.) and auxiliary motion. The part processing program is stored in a program carrier, such as a punched paper tape, a cassette tape, a floppy disk, etc., with a certain format and code, and the program information is input to the CNC unit through the input device of the numerical control machine tool.
