V=πdn/60, where d is the diameter of the workpiece and n is the selected rotation speed. Multiply it by the rotational speed and divide it by 60 seconds.
Linear speed is the speed at which the tool tip moves on the workpiece. For example, turning a workpiece with a diameter of 400 on a lathe requires a linear speed of 80m/min, so one turn is 400*3. 14= 1256mm, and if 80m is required, it is 80000/ 1256=63.7 turns.
This linear speed comes from the machining manual, and there is no difference between different materials and different tools. Generally speaking, iron castings can reach 80 meters, and steel parts are about 40 meters. After checking, there will be an accurate value.
Extended data
Servo and measurement feedback system
Servo system is an important part of CNC machine tools, which is used to realize feed servo control and spindle servo control of CNC machine tools. The function of the servo system is to convert the command information received from the numerical control device into linear displacement or angular displacement of the execution part of the machine tool after power amplification and shaping. Servo system is the last link of CNC machine tools, and its performance will directly affect the accuracy and speed of CNC machine tools and other technical indicators. Therefore, the servo drive device of CNC machine tools is required to have good fast response performance, accurately and sensitively track the digital instruction signals sent by CNC machine tools, and faithfully execute the instructions sent by CNC machine tools, so as to improve the dynamic tracking characteristics and static tracking accuracy of the system.
The servo system consists of two 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 motor, DC servo motor and AC servo motor are commonly used driving devices.
The measuring element detects the actual displacement values of each coordinate axis of the NC machine tool and inputs them into the NC device of the machine tool through the feedback system. The NC device compares the feedback actual displacement value with the command value, and outputs the displacement command needed to reach the set value to the servo system.
Machine tool body
Machine tool host is the main body of CNC machine tools. It comprises a lathe bed, a base, an upright post, a cross beam, a sliding seat, a workbench, a spindle box, a feeding mechanism, a tool rest and an automatic tool changing device. It is a mechanical part that automatically completes all kinds of cutting processing on CNC machine tools. Compared with traditional machine tools, the main body of CNC machine tools has the following structural characteristics:
1. Adopt a new machine tool structure with high rigidity, high earthquake resistance and small thermal deformation. Usually, methods such as improving the static stiffness of structural system, increasing damping and adjusting the mass and natural frequency of structural parts are used to improve the stiffness and seismic capacity of machine tool body, so that the machine tool body can meet the needs of continuous automatic cutting of CNC machine tools. The influence of thermal deformation on the main engine can be reduced by improving the structural layout of machine tools, reducing heating, controlling temperature rise and adopting thermal displacement compensation.
2. The wide application of high-performance spindle servo drive and feed servo drive device shortens the transmission chain of CNC machine tools and simplifies the structure of mechanical transmission system of machine tools.
3. Adopt transmission devices and moving parts with high transmission efficiency, high precision and no clearance, such as ball screw nut pair, plastic sliding guide rail, linear rolling guide rail and hydrostatic guide rail.
Auxiliary device of numerical control machine tool
In order to ensure the full play of the functions of CNC machine tools, auxiliary equipment is essential. Commonly used auxiliary devices include: pneumatic and hydraulic devices, chip removal devices, cooling and lubricating devices, rotary table and numerical control indexing head, protection, lighting and other auxiliary devices [1]?
Reference Baidu Encyclopedia CNC Machine Tool