Application of Numerical Control System in Aviation Manufacturing

First, foreign CNC systems occupy half of the country

According to statistics, our company has nearly 10,000 sets of various types of equipment, including nearly 2,800 various types of metal cutting machine tools, of which numerical control equipment accounts for less than 20%. This is determined by the types of production that aerospace manufactures, that is, the parts are manufactured in small quantities, have many types, the product trial production period and long lead time, and the long production preparation period, and the numerical control equipment generally has high costs and a long production cycle. The long cycle of technology introduction, these factors have restricted the share of numerical control equipment. The numerical control system as a core component of CNC machine tools is a key indicator to examine the performance of CNC machine tools. Its technical level affects the performance, quality and efficiency of CNC machine tools, and directly determines the movement accuracy and overall performance of the equipment. At present, the numerical control system of CNC equipment of our group company is basically configured according to two major series: Siemens system, FANUC system, these two major numerical control systems account for 92%, and the rest are Italy FIDIAC2 numerical control system, Cincinnati ACRAMATIC2100 numerical control system, HAAS numerical control system , MAZATROL CNC system, special process equipment configuration process control industrial control system. The ratio of the above numerical control system is shown in the drawing, for example.

(1) Germany Siemens includes many types of systems, each of which has its place in the high and low end of the mechanical processing field. For example, for a two-axis linkage plus a frequency conversion controlled spindle speed lathe, use Siemens802S CNC The system is sufficient to meet the requirements, and its price is not high. Its standard configuration function fully meets the user's processing requirements. However, for the processing of aerospace main components such as aircraft wings, sterns, brackets, beams, joints, and shells, due to the complex space configuration of the components, high precision requirements, and long processing cycles (the center is not Quasi-stop). Therefore, the Siemens 840D or 840Di system is generally required to be installed on a machine bed with high rigidity. This is mainly due to the high resolution of the 840D CNC system, high dynamic response of the servo system, and readability of the program. Strong, five-axis linkage function, high spindle speed, coordinates can be quickly positioned and other key features.

(2) The fine characteristics of the Siemens CNC system and its detailed knowledge of the details of the aviation manufacturing industry in China determine its market share. At the same time, we must not overlook the other major CNC system manufacturer - FANUC, in fact it is the first to enter China's aviation manufacturing CNC system, such as FANUC6M, FANUC7M system. For the FANUC series, the FSPowerMate is a high-reliability, compact CNC, mainly used for point motion control, such as the 0 series can be used to control two-axis small lathes, servo system to replace the stepper motor; and FS0I series of overall software package Powerful, easy to operate, and intelligent, it can realize high-speed and high-precision processing, and has a network function. It is used in machining centers and milling machines and other equipment that require high precision machining and high efficiency. Based on this, FANUC launched the ultra-compact, ultra-thin FS15I/16I/21I system with network function. The control unit and LCD are integrated into one body. It has network function and its I/O link function is particularly powerful. High-speed fiber-optic serial data communication (FSSB), 18I maximum controllable 6-axis, 4-axis linkage; FSl5I-MB, maximum controllable 6-axis, 5-axis linkage; 16I interpolation, position detection and servo control in nanometers The maximum controllable 8-axis, 6-axis linkage; This series of CNC system is fully applicable to the requirements of the processing space complex contours of the workpiece and the logic of the machine side circuit complex large-scale 5-coordinate equipment or automated assembly line. In order to occupy the high-end market of numerical control systems, FANUC launched the FS30iCNC in the last two years, which also belongs to the nano-scale resolution control level. The HMI interface is more friendly and incorporates process optimization software. In 5-coordinate machining, in order to ensure machining accuracy and improve surface quality, SMOOTHEDTCP(TOOLCENTERPOINTCONTROL) function has been specially developed. The CNC system is small in size, and the CNC and PLC are highly integrated, with controllable 8 channels, 32 axes, and 8 spindles. , The maximum number of linkage axes is 24 axes.

(3) Italian FIDIAC2 numerical control system also enters into the mechanical processing field of aviation manufacturing industry. It is mainly used for the processing of metal and quartz sand mold tires. The CNC machine tool equipped with this CNC system features five-axis linkage and high spindle speed up to 24000r. /min, drive bus transmission rate of 100M, the use of fiber optic transmission, contouring function is perfect, can be used to contour the surface of any complex contour of the aircraft parts mold tires, very suitable for the processing of aircraft large model tires. In addition, the Cincinnati ACRAMATIC 2100 numerical control system, HAAS numerical control system, and MAZATROL numerical control system also have their own advantages in the processing of three-dimensional parts.

Second, the difficulty of domestic CNC system

The author has been engaged in numerical control technology for 15 years. The CNC equipment of the Unified Viewing Group Corporation has basically belonged to the above-mentioned foreign mature numerical control systems. So when “foreign powers” ​​seize and share the market of China’s aviation manufacturing numerical control system, why is it difficult for China’s independently developed CNC system? What about traces?

(1) As early as the end of the 1970s, China had introduced CNC equipment such as FANUC and Cincinnati CNC systems, as well as production technologies for spindles and servo systems, and worked closely with machine tool manufacturers to develop suitable aviation manufacturing at the time. CNC milling machines, such as XK715B, XK715F, V2AB-1250, SH1600B, and FS41, have promoted the development of the national CNC machine tool business. However, in the early 1990s, China’s aviation industry ushered in an important period of accelerating development, and its production capacity expanded rapidly. The previous level of machinery manufacturing has failed to meet the requirements. The foreign CNC machine tools and numerical control systems can meet the needs of the aviation manufacturing market. As a result, a large number of CNC machine tools and numerical control systems (including spare parts) were imported, which caused a huge impact on the domestically-developed CNC industry.

(2) The domestic CNC system is used in the high-end areas of aviation manufacturing, such as complex contours and curved surface forming processes; heavy load, high-speed, high-precision, profiling, and other applications are basically in the blind area. This is due to the following reasons: Resulting: 1 The software technology of the 5-axis linkage processing of domestic CNC systems is not yet mature, which limits its application areas can only be limited to the low-end market of manufacturing, while aviation manufacturing mostly involves 5-coordinate complex contours. , surface processing. 2 The software function of the domestic CNC system is not powerful enough. For example, foreign CNC systems embed ARTISCNC, OMAT and other tool management and optimize the milling system. They mainly use them to optimize the cutting power load of the CNC machine tool spindle and increase the roughing efficiency of the existing CNC machine tools. In addition, software development technologies such as networking configuration software and DNC functions are involved in the cutting-edge of numerical control systems. The domestic CNC system is far from the international popular numerical control system. 3 The internationally popular numerical control systems are all open systems. For example, the FANUC and Siemens systems provide users with a wealth of resources, such as the acquisition of peripheral signals of machine tools, the reference and processing of system variables, Ethernet interfaces, and the extended definition of hotkeys. And so, if you use these resources, you can develop a powerful CNC system. However, at present, we have only stayed in the initial application stage and have not yet reached the stage of “digest and reabsorb innovation after introducing technology”. 4 The relative backwardness of the related industries such as servo units, sensors, encoders, gratings, and composite pendulum heads in CNC systems has also hindered the development of CNC systems. 5 The stability of the numerical control system is an important index to measure the performance of the numerical control system. The author believes that in the aviation manufacturing enterprises, stability is a threshold that restricts the domestic CNC system from entering the enterprise.

(3) Foreign CNC system companies have long-term strategic plans for the Chinese market. For example, internationally popular CNC system manufacturers have technical support centers in the country. Their business contents include after-sales services, user visits, tracking, product application evaluation, and education. Training, spare parts maintenance and products are customized according to user's scope. This poses a severe challenge to the popularization and application of CNC systems independently developed in China.

In fact, domestically-manufactured numerical control systems have the advantageous conditions of “climate, geography, and human harmony”. Compared with foreign numerical control systems, it is self-evident that China has entered the Chinese market. The author is pleased to see that domestic CNC systems are relatively The same type of foreign CNC system has absolute advantages in terms of after-sales service, cost-effectiveness, etc. In the low-end applications, the domestic CNC system not only has an absolute price advantage, but also is not inferior to any foreign manufacturers in terms of product quality and reliability. product. It is important to note that in aviation manufacturing enterprises, the replacement of equipment is very fast. Equipment with backward production capacity and high energy consumption will be eliminated. Afterwards, technological transformation will be carried out. This is a huge potential market. At the same time, it is a domestically-manufactured numerical control system that enters aviation. An opportunity for the manufacturing industry to seize the opportunity to catch up is a historic opportunity for the domestic CNC system to break through and reshape itself.