What is numerical control

What is numerical control

CNC is a kind of computer numerical control (CNC) tool machine, which uses digital signal operation system to control the process equipment in the production system. Nowadays, most CNC machine tools use computers for calculation and control.

The biggest feature of CNC is that it stores many different series of cutting operations in the controller, so it can perform many different steps according to the program without manual intervention. Therefore, the operator can start the specified program by typing the program number to process a series of different workpieces.

The basic models of CNC machine tools are lathes and machining centers.

NC machining

Numerical control machining is a kind of computer numerical control machining machine tool, that is, the high-tech version of the general traditional machine tool.

CNC mainly relies on computer CAM software and programming ability.

The rest depends on the experienced manual NC operation to adjust the machine tool, processing parameters and correct the tool.

CNC lathe is used for processing circular workpieces, such as rings, rods, etc

NC milling machine processing is not limited, as long as the program runs out of things can be done, including various mechanical parts, mobile phone mold and so on.

NC machining program

NC program can be divided into main program and subprogram (subprogram). The part of repeated processing can simplify the design of the main program by writing subroutines.

Character (numeric data) → character language → single section → processing program.

As long as the Notepad is opened in the windows operating system, the NC code can be edited, and the NC program written can use simulation software to simulate the correctness of the tool path.

Before introducing the working principle of CNC machine tools, we need to understand the predecessor of CNC machine tools - CNC machine tools.

Before the emergence of numerical control machine tools, precision machining must rely on numerical control, that is, numerical control machine tools. You should have found that the missing C is computer C; What is the difference between CNC machine tools and CNC machine tools?

In the late 1940s, the US air force needed an effective precision machining method to manufacture the propeller of helicopters. In 1950, CNC machine tools came into being. The main function is to allow the engineer to input accurate processing parameters, such as cutting radian, distance, etc., and allow the computer to carry out accurate processing according to the numerical value.

You may be curious to see this. Since CNC machine tools also use computers, what is the meaning of extra C on CNC machine tools? In fact, this C refers to the later microprocessor!

When using a numerical control machine tool, the engineer must use a series of command codes consisting of characters, numbers and symbols to inform the machine tool of the operation to be performed in detail. The input process is complex, low elasticity and difficult to copy.

In order to overcome this problem, CNC machine tools convert instructions into software codes, and use advanced microprocessors to translate the program language into actual instructions that can be executed automatically. Engineers can easily write and copy NC code through any computer and apply it to different components and new systems. For the simplest example, a programmer can write ten different processing methods in advance and apply them to 100 machines. Operators only need to select the corresponding combination according to the products they produce, and then make on-site fine-tuning to produce diversified products.

CNC not only realizes greater flexibility and automation, but also opens up the possibility of more precise processing, such as converting 3D design drawings into CNC code for direct processing through special software. In short, the working principle of CNC machine tool is to convert the program written by the engineer into action instructions and carry out precision machining on the target.

Advantages and disadvantages of CNC machine tools

CNC machine tools are more suitable for small-scale precision machining due to their high price and strong manufacturing flexibility. The advantages and disadvantages of several CNC machine tools are listed below for your reference.

Advantages:

Advantages in production

 high efficiency, high quality and high yield. This is more obvious in the production of complex and delicate products.

 high processing flexibility, suitable for a small number of diverse production modes.

 data is easy to store, and the same product does not need to be redesigned.

 well designed programs can be used with a variety of tools.

 high degree of automation, automatic tool change, feeding, etc.

 unattended and still working, large machine capacity

Advantages of personnel management

 reduce personnel costs. One operator can operate multiple machines at the same time.

 the processing time and unit cost are easy to grasp, which can reduce the material consumption