The main content of CNC machine tool programming
Analyze the part drawing, determine the machining process, perform mathematical processing, write the program list, make the control medium, check the program, enter the program and test cut the workpiece.
Steps of a CNC machine
Analyze the part drawings and process treatment, analyze the geometric shape and size of the parts and the technical requirements according to the drawings, clarify the content and requirements of processing, decide the processing plan, determine the processing sequence, design the fixture, select the tool, determine the reasonable route and select the reasonable cutting amount.
At the same time, the function of the CNC system and the ability of the CNC machine tool itself should be brought into play, and the correct selection of tool setting points and cutting methods should be used to minimize auxiliary time such as tool change and indexing.
Mathematical processing
Before programming, according to the geometric characteristics of the part, establish a workpiece coordinate system.
The function of the numerical control system is to formulate the processing route according to the requirements of the part drawing, and first calculate the movement trajectory of the tool on the established workpiece coordinate system. For parts with simple shapes, such as parts composed of straight lines and arcs, you only need to calculate the coordinate values of the starting point, end point, center of the arc, intersection or tangent point of the geometric element.
Write a list of parts programs
After the processing route and process parameters are determined, the part program list is prepared according to the specified code and program segment format specified by the numerical control system.
The structure of a CNC machining program
1. Composition of the program: It is composed of multiple program segments.
O0001;O(FANUC-O,AB8400-P,SINUMERIK8M-%) function specifies program number, each program number corresponds to a machined part.
N010 G92 X0 Y0; semicolon indicates the end of the segment
N020 G90 G00 X50 Y60;
...; Subroutines can be invoked.
N150 M05;
N160 M02;
2. Segment format:
(1) Word address format: such as N020 G90 G00 X50 Y60;
The most commonly used format, modern CNC machines are using it. Address N is the program segment number, and address G and the number 90 constitute the word address for the preparation function,....
(2) Variable program segment format: such as B2000, B3000, B, B6000;
Use the divider B to open each word, if there is no data, the divider cannot be omitted. It is commonly found in CNC wire cutting machines, in addition, there are formats such as 3B programming.
(3) Fixed-order program segment format: such as 00701+0;
The robot controlled by Siemens system is wrong, the above program paragraph means: N007 G01 X+02500 Y-13400 F15 S30 M02;