一、 preface
　　The car NVH(Noise, Vibration and Harshness,The characteristics of noise, vibration and irregularity is one of the five main performance indicators of automobiles (the other four performance indicators are safety, economy, environmental protection and reliability). The NVH control of automobile is realized by controlling the noise and vibration of the relevant parts and components in the vehicle, and it is the most direct and direct feeling for the automobile user. The NVH characteristic of the automobile is one of the comprehensive problems that the automobile industry and the related auto parts industry pay close attention to. Statistics show that the 1/3 failure is related to the NVH problem of automobiles. Nearly 20% of the world's major automobile companies spend on R & D expenses to solve the NVH problem of automobiles. Vehicle NVH problem involves multiple subsystems of vehicle, such as body / frame system, powertrain mounting system, suspension system and exhaust system, and the matching relationship among subsystems. It is a systematic and comprehensive problem involving multidisciplinary. So far, there is not a mature and universal product that can solve the vibration and noise problems encountered in the car. From the classification of automobile vibration damping function, the classification of NVH products is shown in Figure 1.

NVH System product classification chart

　　According to incomplete statistics, in recent years, the demand for domestic vehicle matching and repair market of NVH shock absorption products is about 25 billion yuan per year, while the international market is over 65 billion dollars, of which NVH rubber shock absorber accounts for about 20%. It can be seen that NVH rubber shock absorber is a subdivision industry of auto parts. This paper analyzes the current situation, market demand and development of NVH rubber damping industry in China automotive industry.
A brief introduction of two and NVH rubber damping elements
The automobile NVH rubber shock absorber is a metal rubber composite shock absorber. The metal rubber liquid damping element widely used in automobile industry, such as hydraulic mount and hydraulic bushing, is also classified as rubber shock absorber. According to the different position and function in the vehicle can be NVH rubber damping element is divided into two categories, one is the powertrain damping element, the typical products are: engine mount, gear box suspension and powertrain anti torsion rod, crankshaft torsional damper (or torsional damper), radiator support fan support, and so on; the two is the chassis damping element, the typical products are: suspension bushings, suspension, suspension damper upper end (Upper Strut Mount), supporting a variety of dynamic vibration absorber (Vibration Absorber), rubber stopper / buffer block, transmission shaft elastic coupling and exhaust pipe hanger, before and after axle suspension; three is the body of the damping element, such as vehicle suspension etc.. The semi-active suspension and active mount used in high-end cars are made up of metal rubber shock absorber, controller and actuator. From the specific specifications of the product, the rubber damping element has more than 10 varieties and more than 10000 specifications.
Thus, the rubber absorber in the field of automotive parts, its main function is to reduce the vibration of related components and subsystems, and adjust the important assembly system (such as the powertrain mounting system, transmission system) dynamic performance, reduce the vehicle NVH problem caused by the vibration of the structure. The performance of rubber damping elements has great influence on the control of the NVH and the reliability of the car. The design of NVH rubber shock absorber and its matching in vehicle development involve knowledge in many disciplines such as system dynamics, vibration mechanics, acoustics, material science and mechanical design. There are many problems to be solved in theoretical research and engineering application.
Analysis of domestic market demand of three 、 NVH rubber damping element
The rapid development of the automobile industry provides a broad market for the spare parts industry. With the increasing requirement of automobile comfort, the market space of NVH rubber damping element will be more and more big.
1. Total domestic market demand and growth rate
In the OEM market, a number of NVH rubber damping element in every car at an average of about 30, of which the amount of cars in general more than 50; according to the statistical data in 2006, the price of NVH rubber damping element of a car using the average at around 600 yuan, the price of NVH rubber damping element used car in the car in 800 yuan. According to the set number of use (a general term of all NVH rubber shock absorber components in a car), the market demand and growth of NVH rubber shock absorber components are shown in Table 1 and Figure 2 in every year's matching market.

Demand and growth of domestic auto matching market

 the data of auto production and growth rate are derived from the statistical information network of the China Auto Industry Association.

 NVH Domestic requirements and growth of rubber damping components

2、Demand estimation of domestic after-sales maintenance market
　　NVHRubber damping element is generally the life of 100 thousand kilometers, with each car traveling 300 thousand kilometers per car is calculated, at least for two times, with an average of 5 years per car traveling 100 thousand kilometers, in 10 years changed two times; in 2006 the price for example, each car has a total of 10 years the maintenance of 1200 yuan (600 x 2), an annual average of 120 yuan, the car needs 1600 yuan (800 x 2), an average of 160 yuan per year.
According to the statistics of the China Auto Industry Association, the number of cars kept in China at the end of 2006 was 41 million 990 thousand, of which about 20 million cars. As a result, the demand for the maintenance market in 2006 was 5 billion yuan, of which the car was 3 billion 200 million yuan.
According to the above analysis method, NVH rubber damping element in domestic maintenance market and demand is shown in Table 2 and figure 3.

table2 NVH Demand and growth of rubber damping components in domestic automobile maintenance market

Note: the data of car ownership and its growth rate are derived from the statistical information network of the China Auto Industry Association.
3. Domestic matching and maintenance demand and growth trend
The aggregate demand and growth trend of NVH rubber damping products in domestic matching and maintenance market is shown in Table 3. In 2006, the proportion of NVH rubber shock absorption products in the matching market and the maintenance market is shown in Figure .
Table 3 total output value of NVH rubber damping product in domestic matching and maintenance market and growth trend (billion yuan)

　　Can be seen from table 3, the total demand for the domestic automobile rubber damping element NVH is expected to soon exceed 10 billion yuan, become the auto parts industry in a large industry; with the change of China product structure of the automobile, car proportion increased year by year, NVH rubber damping element in the car that consumption will account for more than 70%. Take 2006 as an example, the proportion of NVH rubber damping components in the car and the proportion of other models are shown in Figure 5.
According to the statistics of the International Auto Manufacturers Association (OICA), there are about 60000000 cars in the world in 2006, and around 850 million cars in the world, including about 60% of the cars. According to the domestic year-on-year price calculation, NVH rubber components supporting the market demand of about 36 billion yuan, of which the supporting car market demand of about 28 billion 800 million yuan, accounting for 80%; demand customer service maintenance market is about 102 billion yuan, the car is 81 billion 600 million yuan, accounting for 80%. As a result, the total demand for the international market in 2006 is about 138 billion yuan, including 110 billion 400 million yuan in the car, which is expected to maintain an average growth rate of 7% per year.

Figure 3 demand and growth of rubber damping components in the domestic auto market (billion yuan)

Figure 4 2006 the proportion of NVH products in the matching market and the maintenance market

Figure 5 NVH rubber damping products used in cars and other models (2006)

　　Market prospect analysis of 4 and NVH rubber damping products
The global sourcing platform for international auto makers is starting to tend to Chinese suppliers. The main reason is that the share of cars produced by Asian countries has increased sharply in the international market. Especially in the European and American markets, international car manufacturers are facing serious cost pressures. They are eager to find low-cost suppliers. Therefore, the current Chinese component industry, such as Mexico, Brazil, Korea and Taiwan in 80s and 90s, will gradually become an international auto parts purchasing center.
At the same time, in recent years with the specialized division of labor, vehicle manufacturing enterprises have gradually most subsystems (such as the powertrain mounting system, suspension system and engine crankshaft vibration system) developed by the supplier, and the automobile assembly line part of the general assembly to assembly line outside, host plant only the performance of the integrated. At present, the domestic joint venture automobile factory is transitioning from the pure assembly plant to the automobile enterprise with certain research and development ability. The matching design of some key subsystems (assembly) and the production of components are also beginning in China.
In 2006, the total output of China's mainland cars reached 7 million 210 thousand, and China has become the world's second largest car producer and consumer after the United States. Under the drive of the automobile industry, the automobile rubber damping industry has also made great progress. China's NVH rubber damping element production enterprises have laid a solid foundation in the past development, and will certainly be able to play a great role in the future competition.
It is worth mentioning that with the rapid development of the domestic automotive industry, rubber and auto parts industry in Ninghai County, which is located in the central coast of Zhejiang, has sprung up, and the industrial cluster has gradually become a climate. Relevant data show that as of the end of 2006, Ningbo Ninghai County, engaged in the production of rubber components and related rubber auto parts enterprises reached 116, the annual output value of more than 2 billion yuan, some enterprises have become the Shanghai Volkswagen, FAW, Dongfeng Citroen and other well-known domestic automobile enterprises supporting fixed-point units, and the overall rise in raw material prices under the situation, the average profit growth of more than 20%.
Four. The main manufacturers and analysis of rubber damping components in China
Compared with other aspects of automotive technology, automotive NVH system design and development, the field of fault diagnosis and some high performance requirements of spare parts production (such as hydraulic suspension, semi-active suspension and engine crankshaft vibration damper), has not yet formed by the developed countries manufacturers monopoly. There are more than 600 enterprises that produce NVH rubber shock absorbing components in China, and more than 50 enterprises are specialized in car matching. Among them, the top ten sales enterprises of NVH rubber shock absorber account for 40% of the total demand of the domestic car supporting market.
1, producer concentration
From the statistical information industry seminars and related websites, the domestic engaged in the production of NVH rubber damping of the main elements of Ningbo Tuopu Damping System Co. Ltd., Shanghai caiaifu Zhongding rubber metal Technology Co., Ltd. Wuxi woke general engineering rubber, new sub branch parts (Anhui) Co. Ltd., Wuxi quelaibao damping system Ning Co. Ltd., Haijian new rubber and plastics Co., Zhejiang Rockwell Industrial Co., Ltd. and Shiyan huichinson-dfedc automotive seals Co. Ltd., Tokai rubber (Tianjin) Co. Ltd., Tianjin Ping and auto parts Co. Ltd., ten enterprises, about their sales accounted for the total demand of domestic car accessory market volume 40%. The market share of the NVH rubber shock absorber produced by the Ningbo tup shock absorption system Co., Ltd. is more than 10%.
The ten companies have the following characteristics: first, accounting for 40% of the total car market, therefore, the production capacity of the industry is concentrated trend; second, supporting the market "foreign brands" (i.e. products of joint ventures) share high, although is not a monopoly of foreign brands, but from the ten companies supporting the proportion of domestic, foreign brands to be higher than the ratio of total share of domestic brands of 12 percentage points; third, Ningbo Tuopu damping system limited company, using its own patented technology NVH Ju Wen rubber products industry leader, is one of the highlights of China's auto parts industry of national brands.
2. The characteristics of domestic independent brand enterprises
　　There are more than 600 enterprises that produce NVH rubber shock absorber and related products in China, which are relatively scattered, and less than 1/10 of the enterprises that can supply the whole vehicle factory. The rest of the enterprises can only supply after-sales service market. The China car industry started late, the vast majority of these enterprises are made from rubber, plastic, mold and die casting industry transformation, therefore, in product research and development capabilities, manufacturing technology, quality control, production scale, information technology and the per capita production value, there is a large gap from the international enterprises.
Domestic brands do better business, is the most typical with independent research and development ability of Ningbo Tuopu Damping System Co Ltd, other businesses of a certain size, or have joint ventures with foreign trade companies, either in technology development and quality management has not yet formed obvious characteristics. Ningbo Tuopu damping system limited company after 20 years of development and precipitation, has been achieved with the major OEMs synchronous R & D capability, especially in recent years, invested 40 million yuan million yuan to build in the performance of rubber damping products vehicle NVH test and NVH test technology, the NVH damping product development the ability of way ahead in the domestic counterparts, while its NVH cushioning products production scale in NVH rubber industry in China in the leading domestic.
3. The characteristics of the foreign brand and its impact on the domestic market
The joint venture or investment products including the basic specifications of various types of NVH rubber damping element, the main characteristics of these enterprises is: one is the leading automobile production enterprises and local tied together, this is the first step in the majority of foreign enterprises to enter the Chinese, thus strengthening the direct contact between the rubber damping products and automobile manufacturing plant the two is a joint venture or wholly owned enterprises; basic distribution in the main car Chinese several production bases, such as Shanghai, Tianjin, Changchun, Wuhan and Guangzhou, among which Shanghai most concentrated, about half built in Shanghai and its surrounding areas; three is the Japanese and Korean cars market respectively by the Japan Sea and Han Guoping and the dominant share in and around Chinese main regions are more than one car building factory, such as the Japan Sea Rubber Company in Tianjin, Dalian, and Guangzhou Some were built four hose and rubber products factory is a joint venture; four range from the production of rubber products to raw materials, rubber machinery and instrumentation etc., so as to further the close relationship between the upstream and downstream, formed a series, strengthen international. Five is the Chinese joint venture enterprises do not have the advantage, for example, Anhui tripod in sales is larger, more advanced equipment, but the NVH rubber damping products R & D by the German ZF (ZF) control of the company; also, Wuxi Zhongce (now renamed quelaibao) is one of the earliest period of industry representatives, since the development of and foreign joint venture, has been completely controlled by the foreign party, a group of old technical backbone experts continue to drain, the NVH rubber products in the domestic market continues to decline. Six, the foreign brands enter China later than before. Generally, they are all around 2004. Therefore, although the scale is not large, the development of foreign brands with obvious technological advantages will impact our national industry.
With the development of China automobile industry, and the foreign automobile enterprises continue to seize the China market, there will be some other foreign brands continue to appear in the domestic market, and seek to establish production bases, such as Condi Taco (Contitech), AVON, FOKOKU, Cooper (Cooper Standard) and so on.
Five, industry competition and development trend
　　1, the current situation of supply and demand in the industry
The contradiction between supply and demand Chinese NVH rubber components industry, it is difficult to use analytic figures quantitatively, although a large number of production enterprises, but due to scattered distribution, uneven production ability, can not meet the quality requirements of the market demand rapid growth and the increasingly high, especially the car strict requirements for NVH products.
However, if the NVH rubber damping element in the automotive rubber products industry environment, the supply and demand situation remarkable: 2006, automotive rubber products industry, the industrial added value of more than 7 billion yuan, sales income of 28 billion 500 million yuan, the average amount of 6 billion 800 million yuan of fixed assets. From the marketing scale of the whole market, the annual average demand growth rate of domestic automobile rubber market is more than 30%, which is far higher than the growth level of GDP in China. However, the automobile rubber products industry in China can not meet the needs of the development of the automobile industry. From the Chinese rubber products import and export situation, the export amount of non tire rubber products in China accounted for only about 28% of all rubber products exports, while imports accounted for 91%, 5 billion yuan of automotive rubber products in our country every year (the equivalent of automobile rubber industry annual sales of 20%) need to be imported from abroad, and a year by year trend. Why is there such a big trade deficit? The reason is that the small enterprises in the industry occupy the vast majority of the industry, and the technical force is weak.
2, analysis of the characteristics of industry competition
Brand is the foundation. Generally smaller scale strength of domestic production enterprises of NVH rubber damping element, and takes a long time to OEM strict certification, and was included in the supplier's directory. The brand includes subsystem synchronization development capabilities and product design capabilities, production scale, quality management, technical and financial strength and other content, only up to a certain scale of production, in order to have a good ability to control production and supply, in order to keep up with the development requirements of the host plant and the production schedule; only reached a certain quality requirements, in order to reduce the risk claims; only with a certain amount of capital, to take it leisurely and unoppressively to move toward the international market in talent reserve, new equipment investment and product test, etc.. These are the embodiment of the comprehensive strength of the enterprise and the basis of the market competition.
Price is the focus. In the market, in order to meet the requirements of the brand, the price is low, access difficulty is small; supporting the market is much higher than the quality requirements of customer service maintenance market, but the market has a lot of customer service product price is higher than the market, this is because the ability to choose direct demand products completely different, in supporting market demand is a powerful automobile manufacturers, and customer service market is weak consumers; many enterprises bid each other between the extrusion, is one of the reasons for falling prices. At present, under the "modular" integrated supply, production enterprises have been unable to avoid losses of individual varieties, and only try to maximize profits of the whole module.
The upper and lower double heads are squeezed seriously. The substantial increase of upstream raw materials (mainly metal and rubber) and the forced price reduction of downstream automotive main plants (a reduction in price per year over the past few years) has made the profit margins of domestic NVH rubber shock absorber manufacturers significantly reduced. This prompted many production providers to practice "internal strength", namely, tap the potential in the internal process, and strengthen the detailed management of all aspects, such as material procurement, production, process, technology and sales, so as to reduce operation cost. In this context, there will be a gradual adjustment of the competition pattern, and some small businesses that have been operating on a small profit will have a greater risk.
In addition, the products of the foreign brands are gradually eating out the sales share of domestic national enterprises, making the proportion of the sales of national enterprises declining. Foreign brands rely on their technological advantages and the existing supply relationship with the automobile giants, especially in the domestic automobile market, with the majority of foreign brands, and their market share is increasing. However, the national enterprise is also very obvious advantages, low production cost, more familiar with the domestic market service is convenient, and the production technology progress rapidly, especially the domestic individual enterprises (such as Ningbo Tuopu Damping System Co. Ltd.) has R & D capabilities synchronized with the host plant, which can support the national enterprises occupy a certain market share.
　　3, R & D capability will be the threshold of market access
Research and development ability, to say that parts suppliers and enterprises simultaneously design and development capabilities, to the new development requirements analysis, product design, proposed synchronization calculation subsystem and product technology and provide samples, which is a positive, active and strong ability to complete synchronization.
With the development of specialized division of labor, the importance of R & D ability has become more and more important. On the one hand, a lot of host plant in order to reduce the cost and risk transfer are based on the way of system development and production, so that the system will encounter NVH parts production enterprises R & D work; on the other hand, a new type of development cycle becomes shorter, which requires fast production speed of development, has with plant synchronous development ability of the enterprise, will highlight the competitive advantage; in addition, in 2006 the national independent brand car total sales accounted for 27% of the total, is expected in 2010 will reach 50%, an annual output of about 5 million vehicles, the independent brand car parts to supply by who? That's a supplier with R & D capability. Only suppliers with research and development capabilities can quickly make up for the lack of technology accumulation of their own brands.
4, leading product replacement and technology development trend
The technical difficulties and the leading products of automotive NVH rubber damping element mainly concentrated in the semi-active and active suspension (for the powertrain mounting system, suspension control arm and suspension shock absorber tube at the upper end of the support shaft coupling, etc.) (Flexible decoupler) and the complex structure of crankshaft vibration damper (multi-stage damping rubber shock absorber rubber or silicone oil damping shock absorber) and other products. Semi active suspension is mainly used for vibration isolation of vehicle powertrain, vehicle vibration is too large to solve the problem of engine idling, can also support upper suspension control arm bushing or shock absorber for solving the vibration of suspension system in a specific condition; the active mount launched a variety of machine speed range or vehicle the driving conditions are good vibration control components, but because of cost and reliability and other reasons, the current suspension only for high-end cars.
Drive shaft coupling elastic vibration can be reduced transmission greatly, but its complex manufacturing process, quality control is difficult, at present only in some luxury cars have been used. With the engine design of high power and light, the traditional single grade rubber damping type damper has been difficult to meet the crankshaft vibration and engine front end accessory decreases the driving requirements of vibration control system of rubber damping type multistage torsion damper, bending and torsional composite rubber damping type damper, damping silicone oil and rubber compound the crankshaft torsional damper etc. which have complicated structure and high damping performance of the damper, has been applied in engine.
In addition, the application of some new rubber materials in NVH rubber shock absorber, but also improve the NVH rubber damping products shock absorption and noise reduction performance, for example, recently successfully developed a new kind of rubber for materials to manufacture the rubber components, the material damping and noise reduction effect is good, can greatly improve the vehicle ride comfort. The new material is a combination of several rubber materials based on the Morphology theory and the company's own technology.
　For a long time, the developed countries have attached great importance to the problem of vehicle noise control, and have accumulated a lot of theoretical and technological research results and practical experience of solving problems. However, due to the complexity of the design and manufacture of NVH rubber shock absorber, there are still a lot of theoretical and technological blanks in the field, many of which are worldwide problems. But compared with other aspects of automotive technology, in the field of NVH rubber damping, there has not been a pattern of technological monopoly in developed countries. The domestic automobile industry should take full advantage of this opportunity. While tracking and learning foreign advanced technology, we will strive to get some breakthroughs in some areas in the short term, so as to drive the overall development of NVH rubber damping control technology.
Six, summary
Based on the above analysis, it is suggested that the NVH rubber damping element production enterprises in China develop to the following aspects:
First, to develop in the direction of specialization and scale production. At present, the development trend of international rubber product industry is: first, enterprises are developing towards large-scale economies of large scale and collectivization; the two is that factories are developing towards specialization and intensive production. The annual sales volume of overseas NVH super shock absorber components is up to 1 billion US dollars, and most of our rubber shock absorption products enterprises are small in scale and low in specialization, so it is difficult to participate in the international market competition, and it is difficult to adapt to the development requirements of China's automobile industry. In addition, with the rapid growth of domestic automobile demand, the domestic automobile main engine factory will gradually adjust the product structure and take the specialized and large-scale production road, so the spare parts enterprises must develop towards specialization and large-scale production.
Second, aim at the world's advanced level, and strengthen the synchronous development ability with the automobile mainframe factory. With the car factory in the development of new models to speed up, the host plant has not meet the NVH damping element production enterprises according to the drawing processing of rubber supporting requirements, but to NVH rubber damping components production enterprises according to the new model of the NVH control requirements, matching the design and development of NVH rubber damping element subsystems; in addition, with the rise of domestic brands, independent brands of "dependence on synchronous development capabilities" production enterprises will be greater; NVH rubber damping element production enterprises should establish different levels of product platform, good technical reserves, the development of passive to active development.
Third, actively explore the international and domestic two markets, supporting (Original equipment, OE) and after sale (After Market, AM) two kinds of markets. China's NVH rubber shock absorber manufacturers should comply with the new situation of automotive parts international procurement, aim at the needs of the international market, actively expand product exports, and actively explore the market place to replace imported products. At the same time, the huge demand for AM in China is short of professional brand management, and some international AM brands are gradually infiltrating, which should arouse enough attention of related enterprises.
Fourth, NVH rubber components production enterprises should be based on market demand, to the development of technological progress as the driving force, taking innovation as the main line, focus on the adjustment of industrial structure and product structure, the development of trans regional enterprises to the specialization of the products, production scale, management efficiency and system of the group, improve the overall economic benefits of industry and market competitiveness.
Fifth, actively develop a new generation of rubber damping components to adapt to the rapid development of the automobile industry. NVH rubber shock absorber manufacturers should not only strive for product development, reduce production costs and reliability, expand their applications in cars, but also strive to adapt to the continuous development of automotive technology, such as the promotion of hybrid electric vehicles.
Sixth, the design, development and production of rubber shock absorption products involve many public technologies. It is suggested that NVH rubber shock absorption industry association be established, and a public platform should be built to accumulate services for the industry and promote the technological progress of enterprises.
Wang Wulin, chief expert of China Automotive Technology Research Center
Wang Wulin, a male, was born in Lu'an County of Anhui province in April 1966. He graduated from Jiangsu Polytechnic University in March 1996. He received his Ph.D. in engineering. He is the chief expert of China Automotive Technology Research Center, and he is a senior researcher of the China Automotive Technology Research Center.
Since 1996, a number of national and provincial level scientific research projects have been chaired or participated. Among them, the catalytic converter system development project is at the leading level in China. Some of the achievements have reached the international advanced level, and the results have been successfully industrialized in Tianjin. At present, the catalytic products produced in this industrial base have been successfully set up for domestic host plants, and have strong competitiveness in China.
At present, research is mainly carried out in the field of vehicle emission control technology, automotive NVH control technology, and related technologies and products are being developed to solve the problems of low emission, low noise and low energy consumption of vehicles, and strive to transform research results in time.
Since 1996, more than 40 papers have been published in the Journal of mechanical engineering, automotive engineering and other international academic conferences, and the book "Introduction to automotive catalytic converter system" has been published.