What is a CNC machine tool? Composition of CNC machine tools


&Nbsp& Nbsp& Nbsp; Numerical Control Machine Tools, abbreviated as CNC machine tools, is a control technology that applies digital computing technology to machine tools. It represents various control information during the machining process in coded numbers and inputs it into the CNC device through an information carrier. After calculation and processing, various control signals are sent out by the CNC device to control the action of the machine tool. The parts are automatically processed according to the shape and size requirements of the drawing. CNC machine tools have effectively solved complex, precise, small batch, and multi variety part processing problems. They are a flexible and efficient automated machine tool, representing the development direction of modern machine tool control technology and a typical mechatronics integrated product. (Shenzhen Jingdiao CNC)

&Nbsp& Nbsp& Nbsp; Composition of CNC machine tools:



The basic components of CNC machine tools include machining program carriers, CNC devices, servo drive devices, machine body, and other auxiliary devices. Below is a summary explanation of the basic working principles of each component< Br/>


1. Processing program carrier



When working on CNC machine tools, it is not necessary for workers to directly operate the machine tool. To control the CNC machine tool, a machining program must be developed. In the part machining program, it includes the relative motion trajectory of the tool and workpiece on the machine tool, process parameters (feed rate, spindle speed, etc.), and auxiliary motion. Store the part processing program in a certain format and code on a program carrier, such as perforated paper tape, cassette tape, floppy disk, etc., and input the program information into the CNC unit through the input device of the CNC machine tool< Br/>


&Nbsp& Nbsp; 2. CNC device



&Nbsp& Nbsp; The CNC device is the core of CNC machine tools. Modern CNC devices all adopt the form of CNC (Computer Numerical Control), which generally uses multiple microprocessors to implement CNC functions in a programmed software form, hence also known as Software NC. The CNC system is a position control system that interpolates the ideal motion trajectory based on input data, and then outputs it to the executing components to process the required parts. Therefore, the CNC device mainly consists of three basic parts: input, processing, and output. And all these tasks are organized reasonably by the computer's system programs, enabling the entire system to work in a coordinated manner< Br/>


&Nbsp& Nbsp; (1) Input device; Input CNC instructions to the CNC device, and there are different input devices according to the different program carriers. At present, there are mainly keyboard input and disk inputConvert to linear or angular displacement motion of machine tool execution components. As the servo system is the final stage of CNC machine tools, its performance will directly affect the technical indicators such as accuracy and speed of CNC machine tools. Therefore, for the servo drive device of CNC machine tools, it is required to have good fast response performance, accurately and sensitively track the digital command signals issued by the CNC device, and be able to faithfully execute commands from the CNC device, improving the dynamic tracking characteristics and static tracking accuracy of the system< Br/>


&Nbsp& Nbsp; The servo system consists of two main parts: the driving device and the executing mechanism. The driving device consists of a spindle driving unit, a feed driving unit, a spindle servo motor, and a feed servo motor. Stepper motors, DC servo motors, and AC servo motors are commonly used driving devices< Br/>


&Nbsp& Nbsp; The measuring element detects the actual displacement values of each coordinate axis of the CNC machine tool and inputs them into the CNC device of the machine tool through the feedback system. The CNC device compares the feedback actual displacement values with the command values, and outputs the displacement instructions required to reach the set values to the servo system< Br/>


&Nbsp& Nbsp; 4. Machine body



&Nbsp& Nbsp; The machine tool host is the main body of CNC machine tools. It includes mechanical components such as the bed, base, column, crossbeam, slide, workbench, spindle box, feed mechanism, tool holder, and automatic tool changing device. It is a mechanical part that automatically completes various cutting processes on a CNC machine tool. Compared with traditional machine tools, the main body of CNC machine tools has the following structural characteristics:



&Nbsp& Nbsp; (1) Adopting a new machine tool structure with high stiffness, high seismic resistance, and small thermal deformation. Usually, methods such as increasing the static stiffness of the structural system, increasing damping, adjusting the mass and natural frequency of structural components are used to improve the stiffness and seismic resistance of the machine tool main body, so that the machine tool main body can adapt to the needs of continuous and automatic cutting processing of CNC machine tools. Measures such as improving the layout of the machine tool structure, reducing heat generation, controlling temperature rise, and adopting thermal displacement compensation can reduce the impact of thermal deformation on the machine tool host< Br/>


&Nbsp& Nbsp; (2) Widely adopting high-performance spindle servo drive and feed servo drive devices shortens the transmission chain of CNC machine tools and simplifies the structure of the machine tool mechanical transmission system< Br/>


&Nbsp& Nbsp; (3) Adopting high transmission efficiency, high precision, and gapless transmission devices and moving components, such as ball screw nut pairs, plastic sliding guides, linear rolling guides, static pressure guides, etc< Br/>


&Nbsp& Nbsp; 5. Auxiliary devices for CNC machine tools



&Nbsp& Nbsp; Auxiliary devices ensure the full utilization of CNC machine tool functionsVarious auxiliary devices such as lighting< Br/>


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