Domestic high-precision equipment is needed to sol

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Domestic high-precision equipment is needed to solve the problems of marine supporting.

the shipbuilding industry is a technology intensive, capital intensive and labor-intensive industry. In the past 10 years, China's shipbuilding industry has given full play to China's comparative advantage in labor costs and achieved rapid development. Its share in the global market is rising significantly, and China has become one of the important shipbuilding centers in the world

according to the statistical data of China Shipbuilding Industry Association, in the first half of 2008, the tunnel Expressway in the north of Hokkaido, Japan, made use of waste tire fragments of passenger cars to replace gravel ships, with a completion volume of 10.24 million deadweight tons, an increase of 36% year-on-year; The new ship orders received were 36.64 million deadweight tons, a year-on-year decrease of 14%; Hand held ship orders were 192.17 million deadweight tons, an increase of 82% year-on-year. According to the statistics of Clarkson research on the world's total shipbuilding volume, China's shipbuilding completion, new ship orders and hand-held ship orders account for 26%, 39% and 34% of the world market shares respectively

the big market brings new opportunities

industrial transfer of international manufacturing industry, "It provides a great opportunity for the development of China's shipbuilding industry. But the backward design ability and the lagging development of supporting industries will be the main bottleneck restricting the development of the industry.

according to the medium and long term plan for the shipbuilding industry" China will focus on building three shipbuilding bases around the Bohai Bay, the Yangtze River Estuary and the Pearl River Estuary. By 2010, the main ships independently developed and built by China will reach the international level, with an annual shipbuilding capacity of 23million deadweight tons and an annual output of 17million deadweight tons. The average installation rate of domestic marine equipment will reach more than 60%. At the end of the 11th five year plan, China's shipbuilding output will account for more than 25% of the world market share; By 2015, China's shipbuilding output will account for more than 35% of the world, becoming a world-class shipbuilding country

although China's shipbuilding volume has ranked in the forefront of the world, the shipbuilding technology is more than 10 years behind the advanced level of foreign countries. In particular, the lack of ship supporting capacity and the dependence on import of key supporting parts have become the bottleneck of the development of China's shipbuilding industry. Almost 80% of the key marine equipment needs to be imported, and the self-sufficiency rate of Japan and South Korea is more than 90%. Therefore, the key to the development of China's shipbuilding industry is to solve the problem of marine supporting equipment and the key parts that China has completely "reduced" to a mineral raw material supplier

the development of shipbuilding industry has significantly increased the demand for machine tool industry, providing rare business opportunities for the development and improvement of China's machine tool industry. To develop China's shipbuilding industry, we must overcome the bottleneck of relying on imports of key supporting equipment for ships and improve the independent development and manufacturing capacity of key supporting equipment. One of the main reasons for the bottleneck of the dependence on imports of marine key supporting equipment is that the high-grade heavy-duty CNC processing equipment can not meet the processing requirements of key parts of ships. Therefore, it is urgent to solve the high-grade CNC machine tools urgently needed for the manufacturing of marine key supporting equipment, especially heavy-duty and precision CNC machine tools

most of them are large and heavy equipment

the machining of the engine base, frame, crankshaft, connecting rod, cylinder head, propeller, rudder shaft and other large parts of medium and low speed diesel engines is the focus of the technical transformation equipment investment of shipbuilding enterprises. The processing equipment of the machine base and frame is mainly CNC gantry boring and milling machine and gantry machining center. The gantry width is required to be no less than 8m, the positioning accuracy ≤ 0.016/1000mm, and the repeated positioning accuracy ≤ 0.01mm. At present, the frame of medium and low speed diesel engine The main processing equipment of the rack is Germany vadrich "Kobold's CNC gantry boring and milling machine, domestic gantry mobile CNC boring and milling machine and CNC vertical lathe. The main equipment for crankshaft processing of low-speed diesel engines are heavy-duty crankshaft whirlwind machining center, crankshaft grinder and horizontal turning and milling center. The key equipment for large marine propeller processing are five coordinate linkage CNC gantry milling machine and five coordinate linkage CNC vertical milling lathe. At present, South Korea has a propeller with a maximum diameter of 11m CNC gantry milling machine; The equipment produced in Germany and Japan can process a maximum propeller diameter of 10.4m; The largest propeller diameter that can be processed in China is 9m

the main processing equipment for diesel engine connecting rod, crank, cylinder head and other parts are CNC gantry boring and milling machine, large CNC vertical lathe, Heavy CNC sleeper and horizontal machining center

the key supporting equipment of modern large ships has large geometric dimensions and high accuracy requirements, so it is required that the processing equipment has large specifications, high power, large torque and high accuracy. For example, at present, the maximum propeller diameter that can be processed in China is 9m. With the development of large ships, a 7-axis 5-linkage CNC lathe milling machine that can process propeller with diameter of 11m is needed, and higher requirements are put forward for machining accuracy and surface roughness

modern large ships require higher propulsion efficiency, lower noise, and high processing accuracy of key supporting equipment such as propeller. Therefore, it is necessary to use the turning milling compound machine tool to complete the forming process at one time. Such as turning the inner hole and thread of the wheel hub; Finish the machining of propeller blade surface and blade back, guide and trailing edge contour, hub and blade surface transition fillet and other surfaces by milling

the equipment used for processing large low-speed diesel engine bases and frames requires not only high spindle power and torque, but also high processing accuracy, and is equipped with corresponding testing equipment. For the processing of low-speed diesel engine crankshafts, CNC heavy-duty turning and milling composite machining centers are mostly used, which require large rotation diameter and nearly 100 tons of bearing capacity

optimize the cutting parameters and process methods according to the characteristics of the parts. For example, according to the geometric characteristics of the propeller, the machining surface of the blade is divided into non overlapping areas and overlapping areas, and the standard milling head and special milling head are used respectively to solve the machining problem of the blade root. However, for large propellers, the life of the machine tool is greatly affected due to the excessive overturning torque borne by the ram, Therefore, it is still a difficult problem to be solved

in addition, the measurement and quality evaluation function of large propeller based on three-dimensional digital model needs to solve the planning of measurement points and the automatic generation technology of measurement trajectory, the calculation and estimation technology of machining allowance based on blade surface matching, and the quality evaluation technology of propeller blades; Based on the three-dimensional digital model of large propeller casting blank error and machining allowance rapid measurement technology. It is also the direction of domestic equipment in the future

generally speaking, the key processing parts of large ships are concentrated in the engine base, frame, cylinder block, cylinder head piston rod, crosshead, connecting rod, crankshaft of high-power diesel engine, as well as the transmission shaft, rudder shaft and propeller (propeller) of reduction gearbox. The key processing parts are made of special alloy steel, which are generally processed in small batches, and the processing yield is required to be 100%. Key machined parts have the characteristics of heavy weight, complex shape, high precision and great processing difficulty. They need heavy and Super Heavy CNC machine tools and special processing machines with high power, high torque, high reliability and multi axes, such as CNC gantry boring and milling machines, large cyclone lathes, CNC heavy gantry milling machines and Heavy CNC floor boring machines after the copper alloy new material products developed by heavy and super heavy Guoliang copper materials have obtained the certification of national authorities CNC lathes, grinding machines, deep hole drilling machines, as well as large steel plate pressing, pickling, heat treatment and flame cutting machines

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