The status quo and development of high-efficiency flexible CNC manufacturing technology (1)

The development of high-efficiency, flexible and high-precision manufacturing technology with CNC machine tools as the core, and research in five main directions: high speed, high efficiency, high precision, composite, reconfigurable and networked new progress. In the 21st century, China's machine tool manufacturing industry is faced with the opportunity of the development of manufacturing equipment caused by the demand for upgrading the level of machinery manufacturing industry. It also encounters the pressure of fierce market competition after joining the WTO. From a technical perspective, accelerating the promotion of high-efficiency flexible manufacturing technology with CNC technology as the core will be the key to solving the sustainable development of the machine tool manufacturing industry.

CNC machine tools and manufacturing systems consisting of CNC machine tools are important basic equipment for transforming traditional industries and building digital enterprises. Its development has been receiving much attention. CNC machine tools have attracted the attention of excellent flexible automation performance, excellent and stable precision, and agile and diversified functions, which has created a precedent for the development of mechanical products to mechatronics. Therefore, CNC technology has become the core technology in advanced manufacturing technology. One. On the other hand, through continuous research, the deepening application of information technology has promoted the further improvement of CNC machine tools. Therefore, this paper will focus on the current situation and trends of numerical control technology, and explore the role of high-efficiency flexible manufacturing technology in promoting the development of machine tool manufacturing.

CNC machine tool basic evaluation index

Cost, quality, productivity and output, and delivery time are the four factors that measure the production capacity of the enterprise and the competitiveness of the market. The traditional non-CNC production methods can only achieve the above four aspects in large-scale production with a certain threshold. Unity. However, in the current fierce market competition environment, the production-centered, enterprise-led seller market has turned to a market-driven, user-driven buyer market with market demand, and product demand is diversified and personalized. Moreover, the economic life of the product is greatly shortened. This will first form a production environment in which the production mode of multiple varieties and batches is the mainstream. Secondly, the first factor to measure the competitiveness of enterprises is also changed from cost to delivery date.

To this end, the development of CNC manufacturing technology equipment and manufacturing systems for flexible structural systems is the key to achieving flexible and fast response to user-driven market demand in a fast and volatile market environment. The so-called flexibility of manufacturing equipment and manufacturing systems means that when the variety requirements of products change, they can still achieve the ability to adapt to timely production under the premise of meeting economics. At the same time, continuous improvement of economic processing accuracy is another major goal to adapt to market competition. As a basic indicator for evaluating the performance of CNC machine tools and systems, it will also be measured by the traditional work accuracy and cutting capacity to the extent of efficient flexibility and high refinement.

Efficient flexibility

Although the traditional non-CNC machine tool also has a certain flexibility, it can not achieve high performance and stable accuracy, and is not suitable for the processing of complex profiles. Therefore, the highly efficient flexible manufacturing equipment based on numerical control technology and its manufacturing system must have the following characteristics:
* High flexibility and rapid adaptability for multi-variety production;

* Efficient production capacity, including: high productivity - by means of high speed and improved metal removal rate; high stability - for optical and mechanical integrated CNC machine tools, it is required to reduce failure rate, improve reliability, and improve manufacturing equipment And the system's starting rate (utilization rate).

Efficient flexibility and high refinement respectively reflect the two most important requirements of the manufacturing industry in the highly competitive market environment, namely, the agility of product production transformation and the continuous improvement of product quality.

High refinement

The precision of product parts directly affects its working performance, life, energy consumption and noise. Therefore, the high precision of CNC machine tools is the inevitable result of market demand and technology development.

Analyze the accuracy requirements of certain key parts of the car, such as the engine block, cylinder head, crankshaft, camshaft, connecting rod, carburetor, brake, damper valve body, pump body, disc and mold, etc. There has been a marked improvement in the past decade.

From the 1980s to 2002, the process of improving the working precision of advanced CNC machine tools at home and abroad increased by an average of 10% per year, that is, the error was reduced by half every 8 years. In this regard, some well-known machine tool companies in Europe, America and Japan are committed to technological innovation and research and development of new products, leading to the development of CNC machine tools, such as Ingersoll and the German Wheeler Joy Company for the automotive industry and aviation. Development of industrial high-speed CNC milling machine, Japan's Makino's contribution to high-efficiency precision machining center, Germany's WALDRICH's development of heavy-duty gantry five-face milling and milling machine, and Japan's Mazak company's turning and milling center for efficient composite machining Advance and so on. Table 3 takes the medium-sized machining center of No. 40 tool holder as an example. The advanced products at home and abroad have made significant progress in efficiency, precision and reliability in recent years.

Based on this reality, in order to accelerate the revitalization of China's machine tool manufacturing industry, it is currently necessary to strengthen five research and development work:
* Improve the overall performance of CNC machine tools with high speed as the guide;
* Accelerate the pace of development of high-efficiency flexible and high-precision CNC machine tools, and promote the planning and implementation of acid-grade precision machine tools;
* Strengthen the development of multi-functional composite machining CNC machine tools to improve the machining accuracy and high flexibility of single and medium and small batches;
* For medium to large volume production, the development of Rapid Restructuring Manufacturing Systems (RRMS) and Reconfigurable Machine Tools (RMT) will be a reasonable solution;
* Develop network manufacturing units to accommodate the construction of digital enterprises.

The following sections will provide a brief description of the above five directions.

Composite Drainage Net

HDPE Three dimensional composites drainage net is a new type of drainage geotextile material. It is one three-dimension geonet composited with two needle-punched non-woven geotextiles. Three dimensional composites drainage network consists of a tri-dimension thick vertical rib, and a inclined rip on the top and bottom. Double sided adhesive seepage geotextiles form a"filtration - drainage - ventilation - ." overall performance, and can replace the traditional sand and gravel.wildly used in erosion control, foundation wall drainage, landfill leakage collection, leakage detection, methane gas collection,pond leak detection, roadway and pavement drainage and other subsurface drainage system applications.

Property	Unit	NLDG 50/D200	NLDG 63/D200	NLDG 70/D200	NLDG 80/D200	NLDG 90/D200	Test Standard
Drainage Net Specification
Hydraulic conductivity (MD)	m2/s	2.8×10-3	2.8×10-3	3.2×10-3	4.0×10-3	5 x10-3	ASTM D4716
Puncture Resistance	KN/m	0.17	0.17	0.17	0.17	0.17	ASTM D7005
Core Material Geonet Specification
Thickness	mm	5	6.3	7	8	9	ASTM D5199
Density	g/cm-3	0.94	0.94	0.94	0.94	0.94	ASTM D1505
Carbon Black Content	%	2	2	2	2	2	ASTM D1603
Tensile strength (MD)	kN/m	8	10	12	14	16	ASTM D7199
Hydraulic conductivity (MD)	m2/s	6	8	10	12	14	ASTM D4716
Geotextile Specification
Unit weight	g/m2	200	200	200	200	200	/
Geotextile type	Continuous filament non-woven geotextile

Dam Liner,Pond Liner,Composite Drainage Net,Hdpe Geomembrane Dam Liner

Shandong Jinruixiang Geotextile Material Co., Ltd , https://www.jrxgeosynthetics.com