The machine tool numerical control PLC gradually replaces the relay

In recent years, the machine tool industry has experienced a recession after maintaining a high growth rate. Among them, the impact of ordinary machine tools is particularly obvious, inventory has started to increase, and the impact of CNC machine tools has been slightly less, thus reshuffling the industry. The development of high-end CNC machine tools has brought huge plc and motion controller/card requirements. In the future, the direction of machine tools is numerically controlled and progressively high-end. These machines require the use of a large number of PLCs and motion controllers/cards to gradually replace relays or mechanical controls, so that the overall performance of the machine tool is improved. Therefore, in the long run, plc and sports There is still potential for controller/card applications in the machine tool industry.

CNC machine tool is a machine and electric integration product that integrates computer technology, PLC technology, and automation technology. As the core of the CNC machine tool, the control system directly relates to the normal operation of the equipment. By utilizing the powerful functions of the CNC machine tool PLC, it can make full use of CNC machine tools. The role of the control system can also bring great convenience to the fault diagnosis and maintenance of CNC machine tools. The safety control function designed by the author to prevent the machine from colliding with the machining center effectively eliminates the hidden danger that the machine tool spindle collides with the fixtures and workpieces due to the operator's mistakes, ensures the safety of production, and has good economic benefits.

PLC is a programmable controller. PLC used on CNC machine tools is also called PMC. It has the following advantages: Fast response. High control accuracy, good reliability, control program can be changed with different applications, and the interface with the computer and easy maintenance. In general, PLC programs used on CNC machine tools include system programs and user programs. The system program includes monitoring program, compiler program and diagnostic program, etc., provided by the PLC manufacturer, and solidified in the EPROM, the user can not directly access, and does not require user intervention. The Libya user program is an application program compiled by the PLC program language according to the needs of on-site control to achieve various control requirements. The commonly used PLC programming languages ​​mainly include trapezoidal frames, statement tables, and function block diagrams.

Because many actuators of CNC machine tools are controlled by PLC control commands, PLC can be used to quickly detect and repair CNC machine tools, or modify and write PLC programs to add an executable action to CNC machine tools. Or function.

The application of PLC in the machine tool industry is dominated by small PLCs. Japanese PLC has a great advantage in the field of small PLCs. Therefore, Japanese PLC accounts for most of the market share in the machine tool industry, while Mitsubishi PLC, Siemens PLC, and ge-fanuc are used for CNC. The system has an advantage in the machine tool industry and therefore has a place in the machine tool industry. PLC brand concentration in the machine tool industry is relatively high, mainly in the Japanese brand (Mitsubishi, Omron PLC) and Siemens, Taiwan brand Delta PLC also occupy a certain market share, while other brands are mainly Fuji, Beckhoff, ls Schneider, Koyo, Abb, Yokogawa, etc.