Development prospect of key basic components techn

Prospects for the development of key basic components of construction machinery

at present, the average proportion of key components (such as engine, transmission, hydraulic components, control and electrical system) in the cost of the whole machine in several typical construction machinery produced in China

1. The important role and strategic significance of key basic components of construction machinery

construction machinery is an important industry in the machinery industry, Its development level directly affects and restricts the construction of urban infrastructure such as transportation, energy development, industrial and civil construction, and has become the main force and pioneer of the country's modernization. Whether there is a developed construction machinery manufacturing industry has become one of the important symbols of economic power and developed countries. The key basic components of construction machinery are the foundation, support and restriction bottleneck of the development of construction machinery products. When the construction machinery develops to a certain stage, the research of high technology in the industry mainly focuses on the key components such as engine, hydraulic, transmission and control technology. Mastering and relying on high-quality and distinctive key basic components has become one of the main strategies for manufacturing enterprises' core competitiveness. Internationally, construction machinery and its key basic components are also fully market-oriented strategic pillar industries

at this stage, the key basic components of strategic construction machinery are mainly clean power units, efficient hydraulic components and systems, computer-controlled transmissions, intelligent controllers, etc

regarding the competitiveness of key basic components of domestic construction machinery, we should first start with the main engine of construction machinery. In terms of international competitiveness, domestic construction machinery enterprises are still only based on the domestic market, and their competitiveness in product models is gradually differentiated. Traditional models, such as loaders, bulldozers, forklifts, cranes, graders, etc., use domestic key components, while taking advantage of scale and marketing means, which has an absolute competitive advantage; Some types of machines, such as pavers, concrete machines, rollers, etc., adopt foreign advanced key components, coupled with years of digestion, absorption and innovation on the basis of imported technology, which have relatively produced systematic path dependence and considerable competitiveness; It is not competitive in some large-scale products, high-grade intelligent products and emerging professional products, such as loaders of more than 6 tons, bulldozers of more than 220 horsepower, engineering drilling rigs, etc; Excavators, a typical earth moving equipment that is increasingly widely used, almost give in to each other due to the lack of control technology and manufacturing know-how of key components

the competitiveness of key components is related to their corresponding supporting host at this time

2 development status and trends at home and abroad

2.1 development and trends of key components of foreign construction machinery in recent years

1) mergers and acquisitions have intensified worldwide, and production concentration has further improved

2) the degree of professional production has increased, and more and more enterprises have become assembly plants. The engines, transmission systems, hydraulic systems and control systems are basically outsourced to professional plants, such as Cummins company in the United States and defaults company in Germany, ZF company in Germany and Allison company in the United States, Rexroth company in Germany, which produce hydraulic parts Sauer company and others in the United States are developing rapidly; Integration is also taking place within the giant enterprises. For example, although caterpillar has dozens of construction machinery plants, the power shift transmission is concentrated in the East Peoria factory of the company. In this way, flexible production lines are widely used for box processing, and efficient equipment is used for flexible processing units, gear processing, planetary carrier processing, clutch housing processing and gear heat treatment. Hydraulic cylinders of all factories are manufactured in Juliet factory and drive axles are manufactured in Aurora factory. For another example, Liebherr also has dozens of construction machinery plants, but most of the slewing bearings and hydraulic cylinders are produced in Kirchhoff excavator plant, except for some outsourcing. Through specialized production, the manufacturing of key components can form a reasonable economic scale, while ensuring the quality of components and relying on components to realize the technical characteristics of the enterprise itself

3) the continuous integration of hydraulic technology and electronic control technology has led to the alliance of some hydraulic companies and electronic technology companies. Such as the merger of the famous Rexroth company and Bosch Company

4) localized production, shortened ordering and delivery time, production close to users, and the manufacturing center of developed countries shifted to Asia and Latin America

2.2 current situation and trend of technology development

1) pay attention to the integrated design of key components and main engine, further improve the standardization and generalization rate of parts and components, and simplify maintenance to the greatest extent, which is an important symbol of the development of advanced technology of foreign construction machinery

2) take electronics and information technology as the guide, comprehensively tighten the emission and environmental maintenance standards, and achieve a high degree of harmony and unity of human, machine and environment. For example, the full life cycle and 3R (reduce, reuse, recycle) plan of construction machinery fully implemented by Komatsu company of Japan clearly puts forward the medium-term technical development goal of reducing the environmental impact of construction machinery products: from 2005, CO emissions will be reduced by 5% to 2010, 10%; By 2005, the recycling rate of key basic components will reach 97%, and by 2010, this index will exceed 99.5%. Cat company of the United States has launched a new series of engines that are considered the cleanest in the world, and Cummins company has also put forward an emission solution for the Euro 4 standard

3) the operating parameters of the host and the status of key components are detected, diagnosed and controlled, and their reliability is greatly improved

4) the hydraulic technology continues to develop towards the closed ring with high pressure, large flow, high power, good static and dynamic characteristics, and the high-level direction of simple structure, light weight, low cost, reliability and durability. Further combine with microelectronics technology to maximize power utilization, reduce reactive power consumption, and widely use hydrostatic transmission technology. The following table 3 shows the current situation of static pressure technology in foreign countries

the development of hydraulic components is mainly reflected in the variable form of pumps, and always focuses on the word "energy saving". The combination of piston pump and electronic technology is carried out around the variable control form of pump. At present, the variable forms of plunger pump include manual servo, handwheel control, constant power control, constant pressure variable, load sensing variable, constant power constant pressure variable, computer-controlled proportional variable and other ways, so as to meet the different needs of various hosts and achieve the purpose of comfortable operation and energy saving of modern engineering machinery

2.3 achievements and foundation of China's "Ninth Five Year Plan" and "Tenth Five Year Plan"

in order to fundamentally change the low-level vicious competition of domestic enterprises, and go out of the simple and repeated process of "Introduction digestion re introduction re digestion", so that enterprises can have the ability of innovation and sustainable development, the National 863 robot theme has implemented the "Ninth Five Year Plan" project "mechanized construction machinery" and the "Tenth Five Year Plan" project "cluster intelligent construction machinery". It should be said that these projects have achieved great results, and are achieving results. They have developed a number of core technologies such as the integration of machinery, electricity, hydraulics and telecommunications, launched a number of breakthrough products in the market, and achieved great economic and social benefits. However, there are many deep-seated problems coming down to the key basic components, especially the intelligent key components of electromechanical hydraulic integration. High performance domestic host computers must be supported by domestic key components with high performance price ratio in order to achieve the purpose of mass marketing and competition with large foreign companies. If the dynamometer is not installed horizontally before and after, in order to maximize the benefits and functions of these two projects, it is necessary to deepen its research direction and extend it to the key components of intelligent construction machinery during the Tenth Five Year Plan period

3. key problems restricting the development of domestic basic components

although the construction machinery parts and components have formed a national, regional and enterprise three-level professional production and sales and supporting network, after the reform and opening up, a large number of key basic parts and components manufacturing technologies have been introduced, such as diesel engine, slewing ring, drive axle, four-wheel belt, cab, oil cylinder, hydraulic components, power box A batch of products with certain quality and technical level, such as instruments and instrument panels. Especially in recent years, the pace of joint venture cooperation has been accelerated, and a number of new parts and components products with reliable quality, advanced technology and perfect services have emerged in the industry. However, compared with the development of host products and market demand, the parts and components industry still has a very large gap with foreign multinational companies in terms of production scale, technical level, market share, product grade, quality reliability, price trend and economic benefits

3.1 technical problems

compared with foreign advanced products, the key basic components of domestic construction machinery, whether in technical performance or quality reliability index, generally differ by about 20 years. The service life is generally 1/2 ~ 1/3 of that of imported parts, and the product variety is only 1/5 of that of foreign countries

domestic construction machinery basic components enterprises have small scale, scattered structure, low level of intelligence and weak overall competitiveness; Overcapacity of medium and low-end products, and some large, special and high-performance products