On March 24, 2017, the brake business of the us fulmen group held a technical exchange day activity together with Zhejiang asia-pacific Mechanical& Electronic Co.,Ltd.Ms. Shen liangyu, vice President and general manager of fumen brake business Asia Pacific, and the director of shizhengtang of Asia Pacific electromechanical co., ltd. delivered speeches respectively. The two sides held in-depth exchanges and discussions on the current progress of cooperation and follow-up cooperation planning.
On the day of the event, the company presented a series of projects that have been successfully marketed and developed specifically for China, and gave presentations on innovations in friction materials and global trends.At the same time, from xinhui door brake business in Asia Pacific, engineering director leedham zhou friction material are introduced in the Chinese market of present three features: Creep Groan (start) noise, Stiction Corrosion (disc adhesion), MPU (metal scales).Based on these features, the company is working with local brake system suppliers and vehicle manufacturers to provide better solutions for Chinese customers on the brake system.
Generally speaking, there are mainly three points:Inevitable start noise of automatic car (Greep Groan)Because China spans a wide range of longitude and latitude, friction materials in the Chinese market presents unique characteristics.First, Greep Groan (start noise), a feature that is evident in almost all automatic vehicles, as soon as the coupling point of the brake pedal is released.In theory, it is impossible to eliminate, only to narrow the pedal range, or to reduce the probability of production, or to reduce the degree of interference.In the early stage of the development of the friction disc and brake system, the primary concern of the selection of friction disc is its physical characteristics, chemical characteristics and braking efficiency.However, Chinese consumers pay special attention to noise. Usually, when selling new cars, 4S stores deliberately show the characteristics of low noise for consumers. Therefore, to solve the problem of starting noise, suppliers need to invest more energy and resources.
Greep Groan (start noise) is mainly reflected in the adhesion and coupling of brake disc and friction disc, but does not exclude all parts on the chassis (such as sheep Angle, suspension, chassis, etc.) and even the entire body design is related to it.In terms of the phenomenon, the starting noise is the typical low-frequency noise, which comes from the whole braking system, or the vibration of the whole chassis suspension.From the perspective of platform validation, considering the convenience, repeatability and correlation with the vehicle results, the experimental method of half bridge/whole bridge is preferred.If only by the sheep horn experiment, the results of the starting noise will not be amplified by the system, and the actual results of the vehicle test will not be obtained.Mathematically, the international mainstream brake suppliers will transfer the selected start noise signal into energy when calculating Greep Groan (start noise), and then analyze the impact of start noise from the energy.
At present, it has the ability to reproduce the vehicle starting noise on the platform and the corresponding experimental procedures.For example, the materials of FER 4511 B/E and j200-10 are excellent in starting noise and have accumulated a good reputation in the market.
Disc adhesion in high temperature and high humidity area (Stiction Corrosion)
The second major characteristic of friction materials in Chinese market is disc adhesion.Lin hanzhou pointed out that the main factors affecting the plate adhesion are the friction plate formulation and porosity, brake plate plating and type, experimental procedures, brake clamp size, and environmental conditions.
In the areas with high temperature, high humidity and strong ph variation, such as the east coast of China and the south, the friction plate adhesion is relatively serious, and the friction material is also vulnerable to corrosion.Therefore, environmental and brake disc factors should be taken into account as much as possible during the development process.To cope with rust adhesion, the formulation of friction tablets and the role of porosity prominent.The product of wimen FER 4297 b-3 has a very good performance in rust adhesion. In the process of development, the most demanding environment and areas are selected for testing, so as to better understand the test procedures and standards.
Generation of metal fish scales between friction disc and brake disc (MPU)
A third feature is the generation of metal fish scales (MPU) between the friction disc and the brake disc.To a large extent, the formation of such metal fish scales is caused by uneven pressure transfer from brake to friction plate, insufficient mixing of brake disc and friction material, and inconsistent heat accumulation caused by different rotation speeds of the outer diameter/inner diameter of brake disc.Lin said that the upper limit of ferrite and carbides can reduce the probability of MPU occurrence correspondingly. If the brake disc has a lot of debris spalling on the surface during the processing, MPU will be adversely affected.
With the high localization of the automobile industry and the rise of the local automobile manufacturers, the company will make use of the global quality resources and cooperate with the German headquarters research and development team to develop friction materials that are highly suitable for the Chinese market.By studying the local environment and combining with customer needs, local design is carried out to develop the local testing capacity, so as to provide customers with cost-effective products.