Answer: A. Use stepper motor servo system, B. CPU can use single-chip microcomputer, C. Only equipped with necessary CNC functions.
Answer analysis:
Economic CNC machine tools, also known as simple CNC lathes, have a series of unique characteristics. For the given options, we can analyze them one by one:
A. Use stepper motor servo system:
Economic CNC machine tools usually use open-loop servo systems driven by stepper motors. This is because stepper motors have the advantages of simple control and low cost, which are suitable for the needs of economical machine tools. Therefore, this option is correct.
B. CPU can use single-chip microcomputer:
The controller of economical CNC system generally uses single-chip microcomputer, such as 8-bit, 16-bit or 32-bit, etc. Such a design saves costs and meets basic control needs. Therefore, this option is also correct.
C. Only equipped with necessary CNC functions:
Economical CNC machine tools focus on practicality in functional design, and are usually only equipped with necessary CNC functions to reduce costs and meet general processing needs. This feature makes economical CNC machine tools competitive in price, and at the same time, they are also an efficient processing tool. Therefore, this option is also correct.
D. Closed-loop control system must be adopted:
In fact, economical CNC machine tools do not necessarily have to adopt closed-loop control systems.
Although closed-loop control can improve processing accuracy and stability, its cost is relatively high.
In order to reduce costs, economical CNC machine tools often use open-loop control systems or control systems with simple feedback. Therefore, this option is incorrect.
In summary, the characteristics of economical CNC machine tools include:
* A. Use stepper motor servo system
* B. CPU can use single-chip microcomputer
* C. Only equipped with necessary CNC functions
And option D "must use closed-loop control system" is not accurate.