1. Composition of CNC machine tools
A CNC machine tool consists of a main body, a CNC device, a drive device, auxiliary devices, programming, and other ancillary equipment.
(1) Host: The host is the main part of a CNC machine tool, including mechanical components such as the body, columns, spindle, and feed mechanism, mainly used to complete various cutting processes.
(2) Numerical control device: The numerical control device is the core of the numerical control machine tool, including hardware (printed circuit board, CRT display, keyboard, paper tape reader, etc.) and corresponding software, used to input digital processing programs, and complete the storage of input information, data transformation, interpolation calculation, and implementation of various control functions.
(3) Drive device: The drive device is the driving component of the CNC machine tool actuator, including the spindle drive unit, feed unit, spindle motor, and feed motor. The driving device achieves spindle and feed drive through an electrical or electro-hydraulic servo system under the control of a numerical control device. When several feed rates are linked, the machining of positioning, straight lines, planar curves, and spatial curves can be completed.
(4) Auxiliary device: Auxiliary device refers to some necessary supporting components of the CNC machine tool, used to ensure the operation of the CNC machine tool, such as cooling, chip removal, lubrication, lighting, monitoring, etc. Auxiliary devices include hydraulic and pneumatic devices, chip removal devices, exchange workbenches, CNC turntables, and CNC indexing heads, as well as cutting tools and monitoring devices.
(5) Programming and other ancillary equipment: can be used for programming, storage, etc. of parts outside the machine. Taking the outline drawing of a small vertical machining center as an example, the basic components of a CNC machine tool can be intuitively seen.
The working process of a CNC machine tool is generally as follows: the computer inside the CNC device processes a series of information recorded in numerical and character encoding through the input device, and then sends instructions to the machine tool spindle and feed execution mechanism through the servo system and programmable controller. The machine tool body, with the cooperation of the detection feedback device, automatically controls various actions required for workpiece processing, such as the motion trajectory, displacement, and feed rate of the tool relative to the workpiece, thereby completing the machining of the workpiece. The working principle of CNC machine tools can be simply summarized as follows: through a computer control system, the machining program is converted into machine tool control signals, which control the machine tool to perform various movements and machining operations in three-dimensional space, thereby achieving the machining of workpieces.