At the end of last year, Guangxi Liugong Group Co., Ltd. (hereinafter referred to as "Liu Gong") developed the "Key Technology and Application of Vibration and Noise Reduction Commonality for Engineering Machinery Features" (hereinafter referred to as "Vibration and Noise Reduction Technology"). China Machinery Industry Science and Technology Progress Award. For Liugong's R&D team, this is undoubtedly the best recognition for their efforts.
After millions of trials, it has overcome hundreds of technical difficulties. From the successful development of the first subsystem "muffler" in 2008, to the formation of the first complete machine in 2011, and now to the formation of technology application platform, Liu The R&D team has been a tool for the high-end machinery market in foreign countries for several years.
Liu Chang, chief scientist of Liugong, and head of the R&D team for vibration and noise reduction technology, said that the loader “Liugong CLG856III” using this technology is an example. The current driver's position noise is 71 decibels, which is not only far below the national standard. 89 decibels, EU standard 80 decibels, even one decibel lower than the standard for the high-end products 950H loader of Caterpillar, the international construction machinery benchmark.
"Don't underestimate these decibels. Every 3 decibels is a quantity value, which means that the energy transmitted by the sound needs to be reduced by half." Chu Changxiang said, "With the successful development of this technology, Liugong is currently in noise. The indicators have reached the international leading level."
Entering the international market, product noise is "blocking the road"
The management of noise pollution has always been a blind spot in the formulation of China's construction machinery product standards. Although since the 1980s, the domestic regulations on noise pollution of construction machinery have been formulated, but they are relatively broad. With the development of the industry, the quality and reliability of China's construction machinery products have increased significantly, and noise control has received more and more attention. In the latest national mandatory standards for earth-moving machinery, the first place is the Earth Machinery Noise Limit.
“In foreign markets, the standards and emission standards for noise pollution are equally strict. Compared with the products of international benchmark companies, noise pollution control is the soft underbelly of domestic machinery products. Unlike domestic machinery product procurement, foreign requirements for operational comfort are very high. High, only to meet the needs of foreign customers, can enhance the competitiveness of domestic machinery products in foreign markets." Chu Changxiang told China Economic Weekly.
In 1998, Liugong introduced a wheel loader model of Caterpillar, an international mechanical benchmarking company. During the research process, Liugong R&D team noticed the processing technology of this model for vibration and noise. According to Chu Changxiang, at the time, domestic machinery products did not have specific technology for noise treatment. However, in view of the technical difficulties at that time, the focus was on power and mechanical operation. Liugong did not pay attention to noise treatment.
In 2002, Liugong began to propose an internationalization strategy, gradually pushing products to the Asian market, Latin America and Europe and the United States. When entering the European market, the noise indicators that were ignored in the past have become “roadblocks”.
It is understood that all products must obtain CE certification before entering the EU market. This is a safety certification mark and is regarded as a passport for manufacturers to enter the European market. The certification has two mandatory standards for mechanical product noise, including driver position noise and off-board radiation noise, which are far below the Chinese noise limit at the time.
Chu Changxiang recalled that Liugong’s mechanical products encountered “difficulty” when entering the European market. “In the case of the Swedish market, Liugong’s products need to be modified at a base near the Port of Amsterdam before entering Stockholm. The cost of the conversion is very high. A machine costs about 2,000 Euros and can only reduce the noise. Just met the market access standards.” Chu Changxiang told China Economic Weekly that it was not only Liugong’s products, but domestic mechanical products encountered the same problems when entering the European market. “Foreign buyers joked that your products are too noisy and we can’t make our little animals irritating, so it’s not working.”
Using vibration and noise reduction technology, the sales of new products exceeded 1.7 billion yuan. In the face of such a dilemma, Liugong decided to set up a special R&D team to develop technology for noise. In October 2008, Chu Changxiang, then dean of the Liugong Loader Research Institute, took up his post and served as the head of the R&D team for vibration and noise reduction technology.
“Different from other systems, noise is invisible. Engineering machinery noise comes from multiple systems, such as power, heat, suspension, hydraulics and transmission. Each system contains various components and accessories. Finally, we must solve the problem of sound resonance transmission. This is a very large project involving vocal music, fluid dynamics, heat transfer, and structural dynamics. It is impossible to completely rely on the existing team of Liugong. Covered." Chu Changxiang recalled that Liugong's "scientist system" played a key role at this time.
The "Scientist System" has always been at the core of Liugong's R&D team building. Liugong adopted the "specially hired scientists" model to find the best researcher in China for the urgently needed technology of Liugong. Liugong formed a team to technically connect with them to jointly develop research projects to fill the technical gap of Liugong.
After a nationwide “human flesh search”, Chu Changxiang and Professor Ji Zhenlin of Harbin Engineering University cooperated. Ji Zhenlin is quite versed in the research of NVH (noise, vibration and harshness). With the help of Ji Zhenlin, it was originally necessary to cost tens of thousands of yuan to reduce a decibel muffler. Now it only costs a few hundred yuan to reduce the two or three decibels. From this, Liugong gradually overcomes the power, heat, and cab subsystems, and gradually integrates sporadic technologies. After solving the problem of multi-system matching coupling, in November 2011, the first application of the technology was completed. Machine molding.
Subsequently, Liugong integrated the basic theories, design methods, test evaluation, software and hardware and database involved in technology research and development, forming a common key technology platform, which can be customized on more models. At present, Liugong owns four product lines, and a total of 21 models use this technology to reduce vibration and noise.
Chu Changxiang introduced to the media that after the mechanical products using this technology entered the European market again, the response was very good. “Our products are there, next to Caterpillar and Volvo. The dealers are very confident to say to the customers, you can go up and have a look. Liugong’s overseas market sales have also improved significantly, new products bring The sales exceeded 1.7 billion yuan." Chu Changxiang said.
The successful research and development of vibration and noise reduction technology is inseparable from Liugong’s tradition of advocating technology for many years. Liugong's predecessor was Huadong Electric Machinery Factory. At the beginning of the construction of the factory, Liugong had a large number of skilled craftsmen who were skilled in craftsmanship. Their experience and craftsmanship were well-received in Liugong. Some structural parts used by Liugong have been used so far. Manufacturing techniques are brought by these masters.
In addition to inheritance, technological R&D innovation is also very important. As an engineering machinery manufacturing enterprise, the product is the best embodiment of Liugong's comprehensive capabilities. To do a good job, technology must go first, and innovation ability is crucial. Liugong has always regarded the innovation and research and development of new technologies as the top priority, with R&D personnel accounting for about 10%.
The core technology of construction machinery is reflected in the development of parts and components, which is also the core competitiveness of engineering machinery products. At present, we still have a long way to go in the innovation of component technology. In addition to component technology, Chinese construction machinery manufacturers are facing another challenge, basic technology and basic industry research.
Faced with the general trend of informationization and intelligence in the global manufacturing industry, China's construction machinery manufacturing industry needs to take every step in a down-to-earth manner, put quality labels, focus on technological innovation, and manufacture engineering machinery products with the spirit of artisans.
Experts commented on Xu Gening, executive director of the China Society of Construction Machinery: Chinese manufacturing companies must have the courage to do their best. When domestic engineering machinery products are compared with the world benchmark products, they tend to pay more attention to hard and functional technical indicators. Power, matching, function, ability and so on. Soft, environmentally friendly technical indicators such as pollution emissions are often overlooked. When domestic products participate in the competition in foreign markets, these soft indicators that are not valued have become a serious injury and shortcoming that restricts the "going out" of domestic products. Taking the European and American markets as an example, the pollution emission standards in Europe and the United States are generally higher than the current domestic standards, and vibration and noise pollution is a technical barrier for foreign high-end products market access.
Under the pressure of the market, Liugong actively responded and achieved breakthroughs in vibration and noise reduction technology. In the entire construction machinery industry, it has reached the world's advanced level, and individual models are even higher than the level of foreign engineering machinery benchmark products. This is very commendable. Moreover, the technology not only faces a single specific product, but also establishes a common key technology platform to meet the needs of different products, significantly reduces the vibration and noise of engineering machinery products, and breaks the technology of Chinese construction machinery products entering the high-end market in Europe and America. barrier.
For the entire construction machinery industry, the research and development of Liugong vibration and noise reduction technology has great practical significance. Whether China's construction machinery products can "go out" and "go out" can "use", first of all, to pass the "high quality" threshold. Faced with the high standards of foreign markets, domestic construction machinery manufacturing enterprises must ignore the importance, from helplessness to fearlessness, and must have the courage to dare to slap hard bones, down-to-earth serious research and development, and challenge the high-tech of international benchmark enterprises.
Through vibration and noise reduction treatment of various parts, the driver's position noise of Liugong CLG856III wheel loader (standard) is 71 decibels, and the radiation noise outside the machine is 102 decibels.

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