Innovation and Development of Intelligent Technology for CNC Machine Tools
In recent years, in order to better meet the requirements of machine tool users for CNC machine tools "high speed, high precision, compound, intelligent and environmental protection", domestic and foreign CNC machine tool enterprises have continuously developed various CNC machine tools with intelligent functions. Especially in recent years, with the development and application of machine tool design technology, Internet and information technology and artificial intelligence technology, NC machining gradually presents the trend of networking and intelligence, and the intelligent function of NC machine tool is becoming more and more mature.
The author participated in the China International Machine Tool Exhibition (Beijing, CIMT) and China CNC Machine Tool Exhibition (Shanghai, CCMT) hosted by China Machine Tool Industry Association in recent years. He was deeply touched by the intelligent technology of some foreign brand CNC machine tool enterprises and the development status of domestic CNC machine tools. This paper analyzes the technical characteristics of several typical foreign brand CNC machine tools in intelligent technology, and puts forward some thoughts and suggestions on the intelligent technology of domestic CNC machine tools.
The new intelligent technology of CNC machine tools is mainly reflected in the exhibits of world-famous CNC machine tools and CNC system enterprises, such as Mazak, DMG mori, Okuma, hurco, starrag, Mikron, Siemens, FANUC, heindenhain, etc.
1. Intelligent technology of Okuma (Okuma) Company in Japan
The intelligent technology of Okuma company in Japan mainly includes:
(1) Processing condition search function: machiningnavi system relies on advanced detection and control functions to help users find the best processing conditions. It can not only improve the quality of machined surface, but also play an important role in shortening machining time, improving production efficiency, prolonging tool life and integrating processes.
(2) Anti collision machine function: when multi-faceted machining with complex actions is carried out, the risk of collision inside the machine tool increases. Okuma company uses advanced control technology to realize the function of anti-collision machine, which can stop the action before the collision when the machine tool operates automatically and manually. The operator can concentrate on processing, which greatly shortens the processing time of tooling and test pieces.
(3) Servo control optimization function: improve machining accuracy and machining surface quality through automatic optimization of servo control. In particular, it can improve the acceleration of the machining center and shorten the machining time. In addition, the reverse protrusion or abnormal sound, vibration, crease and scale mark caused by long-term use of the machine tool can be eliminated immediately, and the high-precision and stable operation can be maintained for a long time.
(4) Function of measuring and compensating geometric error: when the 5-axis machining machine tool obliquely processes shaft parts and polyhedral parts, it will produce a variety of "geometric errors" such as axis offset of rotating axis. For a long time, the four geometric errors can only be compensated by manual operation. The 5-axisauto tuning system can measure and automatically compensate up to 11 geometric errors in only 10 minutes.
(5) Accurately control the regular thermal displacement, that is, the "thermal affinity" function: the temperature change around the machine tool and the heat generated in the machining process will have a great impact on the machining accuracy. Okuma has designed a machine tool structure that accepts temperature changes and is good at controlling thermal displacement. It is only necessary to confirm the size once when installing the machine tool, which can greatly reduce the subsequent compensation times.
Measured effect of "thermal affinity" function of Okuma machine tool
2. Intelligent technology of Mazak company in Japan
Mazak's smooth technology reflects the company's latest development in machine tool intelligent technology. Its CNC system mazatrol smooth is equipped with windows8 PC CNC system and advanced software, which greatly improves the machining efficiency. By controlling the optimal acceleration of linear axis and rotating axis, the efficiency of 5-axis linkage machining is improved by 30%; Using the simple tuning function, the parameters such as acceleration, rotation angle accuracy and smoothness can be freely adjusted according to the processed workpiece to optimize it. Customers can simply and conveniently make personalized choices such as processing time priority, processing surface accuracy priority or processing shape priority.
Smooth technology CNC system
Mazak CNC machine tool interconnection structure
In addition, Mazak CNC machine tools also have the function of "comprehensive factory operation support". Through open system structure design and Internet technology, the operation status of machine tools and equipment is monitored with the help of smart phones, tablet computers and other external terminals. At the same time, international standard communication protocol is adopted to enable communication between different devices of multiple different companies.
3. Intelligent technology of FANUC (FANUC) Company in Japan
FANUC system aims to improve the intelligence of machine tool control, and intelligent function groups are standard equipped on its new system 0imf, including intelligent overlap control, intelligent feed shaft acceleration and deceleration, intelligent spindle acceleration and deceleration, intelligent adaptive control, intelligent reverse gap compensation, intelligent machine tool front-end point control and intelligent rigid tapping.
Fanuc CNC system intelligent function group
4. Intelligent technology of hurco
Hurco mainly designs and manufactures various vertical machining centers, horizontal machining centers, 5-axis machining centers and turning centers, all supporting its winmax Control system. Its machine tool products emphasize simplifying the process from drawing design to part manufacturing, and assist the operator to realize simple and high-quality processing. Its two main intelligent features are:
Conversational programming: quickly turn drawings into parts through graphic verification. Only three steps are needed: coordinate setting, programming and machining verification;
NC / G-code programming: the control software is equipped with an enhanced NC editor to enhance the compatibility of CAD / CAM. Checking the program graphically on the controller makes it easy to see which code is being executed.
Smart machine tools exhibited by hurco in the United States
3 Analysis on the characteristics of intelligent technology of NC machine tool
1. The development of intelligent technology of NC machine tool aims at the actual demand
The main function of NC machine tool is to execute machining program and complete part machining efficiently. At the same time, the stability, reliability and economy of processing are maintained through various methods. We can see that the research and development of intelligent technology of foreign NC machine tools mainly aims at the above functions, that is, focus on NC machining itself. For example, heck believes that the relationship between people and technology is that technology should assist the operator rather than interfere with the operator's thinking. Technology should minimize cumbersome and repetitive tasks to make the work of mechanics more effective. Technology must support the mechanic, not control him. HEC advocates to support and help users to complete the process from drawings to parts faster.
2. Intelligent Collaborative Innovation of machine tool mechanical design and NC system
In the process of realizing the application of intelligent technology of NC machine tools, foreign machine tool enterprises and NC system enterprises have their own emphasis. Machine tool enterprises focus on the innovation of the overall structure of machine tools, and NC system enterprises focus on the improvement of the intelligent function of NC system, but only when they cooperate with each other can they realize real intelligence. For example, Okuma's "thermo friendly" concept emphasizes that the mechanical design of machine tools should be based on the unique idea of "accepting the temperature changes of machine tool environment and processing process", so that users can realize high-precision processing in ordinary factories without taking special measures. Okuma's thermal compensation scheme can be used under the conditions of machine tool startup, reprocessing, ambient temperature change, etc. In this case, if there is no innovation in the structural design of the machine tool, the intelligent function of the NC system cannot be realized.
Effect of thermal error compensation of Okuma machine tool
3. The application of new technologies such as Internet promotes the development of intelligent technology of NC machine tools
In the early days, the intellectualization of NC machine tools abroad focused on the intellectualization of NC machine tools and NC machining process. In recent years, foreign machine tool enterprises have also accelerated the application of new technologies such as Internet and industrial software in the intelligent technology of NC machine tools, promoted the interconnection of machine tools, integrated automation equipment such as robots, and built intelligent factories.
For example, Mazak believes that the requirements of modern machining plants for intelligent machine tools should include: access to the Internet; It can provide its own relevant information to the network in real time (such as operation status, work content, process data, work progress, etc.); Be able to receive various required data from the network (such as processing program, production plan, process data, production preparation information, etc.); Minimize production preparation through intelligent functions; It has certain adaptive and self diagnosis ability.
Mazak's "intelligent equipment Internet" structure diagram
4 Some suggestions on the development of intelligent technology of domestic CNC machine tools
1. Aim at the actual needs of users and realize differentiated development
Combined with the visit of cimt2019 and the visit of key users, the intelligent technology of NC machine tool can also be divided into two categories according to the actual needs of users: high-end function and universal function. High end functions include thermal cycle control of machine tools, anti-collision of machine tools, application of new generation artificial intelligence technology, graphical simulation and programming. Popular functions include thermal error compensation, servo optimization, spatial error compensation, intelligent rigid tapping, intelligent acceleration and deceleration, etc. Domestic CNC machine tool enterprises can choose the development direction that users urgently need and have their own development ability according to the actual situation and technical complexity of the enterprise.
2. Deep cooperation and collaborative innovation between machine tool enterprises and CNC system enterprises
Machine tool enterprises and CNC system enterprises have their own advantages. If the machine tool enterprise has rich user processing experience, it can innovate in the mechanical structure of the machine tool on the basis of being familiar with and understanding the needs of users. CNC system enterprises can provide stable and reliable CNC system platform, open secondary development interface and HMI customization function for machine tool enterprises. With deep integration and collaborative innovation, the two sides will be able to develop practical and effective intelligent functions. In the cooperation between the two sides, the intelligent control requirements, processing technology and use characteristics required by machine tool enterprises can be easily integrated into the NC system; The sales of intelligent machine tools in machine tool enterprises can further strengthen the machine tool brand of the main engine plant and increase users' loyalty to the main engine plant.
3. Explore the deep integration of new generation artificial intelligence technology and numerical control technology
In recent years, big data, cloud computing and a new generation of artificial intelligence technology have made group and revolutionary breakthroughs. The new generation of intelligent manufacturing technology formed by the deep integration of the new generation of artificial intelligence technology and advanced manufacturing technology has become the core driving force of the new round of industrial revolution. Experts believe that under the situation that the country vigorously promotes intelligent manufacturing, machine tools as industrial mother machines should accelerate to take the lead, take a parallel and integrated development of Chinese intelligent manufacturing technology, and develop to high quality and innovation. In this context, CNC machine tool enterprises need to actively explore how to speed up the development and application of intelligent machine tools, whether to follow the pace of foreign machine tool enterprises step by step, or to innovate and develop
