汽车缓速器（Automobile retarder）

汽车缓速器（Automobile retarder） 汽车缓速器(Automobile retarder) (1) the birth of retarder; In 1855, Mr. LeonFoucauit, a French physicist, discovered the phenomenon of eddy currents. In 1903, Mr. STECKEL, the French engineer, declared the world's first eddy current retarder patent. Since 1930s, some European manufacturers have paid more attention to the necessity of using commercial vehicles in mountainous and accident prone areas. But it was not until 1936 that JOURDAIN MONNERET of France produced the world's first eddy current retarder, according to another patented eddy current retarder, the French engineer RaoulSARAZIN. Because of the Second World War, the development and application of retarder were stopped. After the war, the French TELMA company officially purchased the Raoul SARAZIN eddy current retarder patent, and began to produce eddy current retarder in large quantities. And has launched a series of F retarder is installed on the transmission shaft of the A series retarder and installed in the gear box and the rear axle, the retarder not only through the security and reliability of the vehicle, or by reducing the automobile brake economy show reduced wear and maintenance costs of the shoe and the hub, so as to get accepted, acceptance and welcome the manufacturers and the users. And JOURDAIN MONNERET company for patent infringement by judicial decisions, in 1951 to stop production retarder. At the same time, other forms of automotive auxiliary braking devices, such as engine retarder and hydraulic retarder, have come out and developed and applied in Europe and america. As for commercial vehicles, with the increase of engine power, the reduction of engine speed, the acceleration of vehicle speed and the improvement of vehicle quality, the vehicle safety problem becomes very serious. The main brake car still friction brake, although the friction performance of brake shoe and the brake hub improved by shortening the distance between the progress of time, but for a long time or distance downhill and frequent braking, the braking durability has no obvious change. Many of the advanced electronic technology such as ABS anti lock braking system, electronic brake system EBS and drag the ASR control system used in the effective capacity range in braking system in the reliability is greatly improved, but the wear on the brakes and brake temperature is too high, but no help. (two) types and classification of automobile retarder The retarder can be divided into one retarder (retarder acting at the front of gearbox) and two stage retarder (retarder acting at the back of gearbox). A retarder engine retarder, including through adjusting the exhaust cam of the engine into the air compressor JACOBS retarder and directly through the exhaust valve on the exhaust gas in the closure of FOWA, OETIKER and SMITH retarder. A retarder braking power because of its small, difficult to reach the car brake regulations but only with the use of retarder and other; and because of the noise of the engine, the maintenance cost and the transmission shift when the clutch function in the process of retarder failure problem in end users especially the driver there are difficult to accept, so that its development is restricted. The two stage retarder has an electric eddy current retarder and a hydraulic retarder which are directly mounted on the gearbox. The function of the two stage retarder is independent of the clutch separation when the gearbox is shifting, and its reliability has been generally recognized by the manufacturers and users. Because of the flexibility of assembly, the eddy current retarder can not only be installed on the gearbox, but also can be mounted on the transmission shaft or back axle, that is, it can be installed in the automobile manufacturer and can be installed after the factory is out of the factory. Hydraulic retarder is usually a gearbox manufacturer with the box configuration of a retarder, so manufacturers in the choice of transmission, the end user has been chosen retarder. In form, hydraulic retarder can only be installed in the gearbox, the factory is almost impossible to install. Two. Regulations on automobile retarder The technology development and application of automobile industry are always ahead of the formulation and implementation of laws and regulations. The same is true of the development of automotive retarder. In 1930s, European car manufacturers and users first installed retarder for vehicles running in mountainous areas and in areas where accidents occurred frequently. But until July 17, 1954, the French Ministry of public works decided to assemble a retarder or an approved equivalent for a truck carrying more than 8t in mountainous and accident prone areas. This is the world's first government regulation on automotive retarder applications. In October 1954, the Motors Insurance Corporation for more than 20 seats (including 20 seats) of passenger cars and more than 8t (including 8t) trucks, as long as equipped with retarder, you can reduce the premium by 5%. In June 23, 1955, in view of the retarder's role in vehicle safety, France was allowed to assemble a retarder with an additional weight of no more than 500kg. In other words, a car rated 8t, in fact, the carrying capacity of up to 8.5t. This makes the car equipped with a retarder does not affect the rated load of the car because of its own weight. In this way, the safety of the automobile traffic and transportation is guaranteed in legislation, and the economic benefits of the automobile users with the retarder are ensured. In June 27, 1956, France made a detailed provision for the equivalent of the retarder involved in the July 1954 regulations. That is, whether the gearbox is in neutral or other gear, the retarder can ensure that the car runs steadily at a speed of 40km/h in the downhill of 8%. In order to ensure the implementation of the law, the French government has also made the test rules are as follows: in the case of full load, the vehicle on the flat road speed decreased from 40km/h to reduce the speed of 20km/h must be greater than 0.55 ~ 0.60 m/s2. This law not only puts forward the requirements in theory, but also has maneuverability in experiment. In June 11, 1957, France made a detailed definition of "mountainous and accident prone areas" in each district and province. In March 26, 1965, the French also equipped with retarder vehicles, allowing the rear shaft to add an additional load of no more than 400kg. In February 3, 1971, France relaxed measures for allowing additional load on vehicles equipped with retarder vehicles to all vehicles (trailers + semi trailers, trucks + trailers). In March 10, 1972, France required trucks carrying dangerous goods equal to and greater than 11T to be equipped with retarders. Other countries, such as Germany and Monaco, have also passed legislation to allow buses to be equipped with retarders. Germany introduced the detailed specifications of the brake system in 1955 and called the retarder "the third brake"". In February 1972, Switzerland detailed the deceleration performance of the retarder in the process of slowing down from 50km/h to 30km/h, and the retarder must achieve an average deceleration of at least 0.5m/s2. It is also stipulated that the shift operation shall not be carried out in this process to avoid vehicle instability due to clutch separation. Some countries such as Holland and Belgium, because the mountain is less, there is no clear government regulations, but because of the security and the enthusiasm of using retarder and vehicles registered in these countries can be in the free passage of other European countries, is also quite common retarder assembly. In 1971, the European Community formally used the 71/320/CEE code with the concept of brake durability. For trucks weighing more than 10t and passengers over 8 passengers, the downhill endurance test must be carried out. Let's illustrate these two types of tests in Figure 1: in Figure 1, downhill endurance tests, full load trucks on the 6% lower ramps, no braking devices, and trucks that can slope down at a steady rate of 30km/h. Full load passenger cars on the lower ramp of 7% shall not use brakes, and the passenger car will slope down at a steady rate of 30km/h. TELMA AC series retarder The European regulations specify the effect of the retarder, while the type of retarder is not required. In other words， No matter what kind of retarder is used, the vehicle can be used in the factory as long as it reaches the requirement of downhill endurance. In fact, the engine retarder has failed to meet the above test requirements. It can only be used in conjunction with an electric eddy current retarder or a hydraulic retarder. The law in 1974 after the improvement, and according to the company by 6 experts of the Committee in 2003 and 2004, submitted to the international standard ISO, and the formation of the draft ISO/TC/SC2. The 6 companies are: 1., three major car companies are Daimler-Benz, Chrysler, IVECO and MAN. 2., the three big retarder company is TELMA, VOITH, TURBO and ZF, thus we can see that these 6 companies represent the development level of the automobile retarder industry nowadays. EU Member States must comply with this law. But this is only a low limit. Some countries have adopted stricter state regulations for historical reasons and specific geographical conditions and road conditions. The regulations and conditions for the implementation of some countries are detailed in table 1. Three. Comparison and discussion of laws and regulations on retarders in China and foreign countries (I) Europe The formation of the European law has gone through more than 50 years of practice and is now undergoing a transition to international standards. But it should be noted that the car market has greatly exceeded the requirements of the requirements of the law. 1., even if the vehicle meets the requirements of this regulation, it will be able to decline 30km/h at the rate of 6km, and eventually the customer will not buy such a car. Because of this speed, the boss has no economic benefits. Therefore, the internal regulations of European auto manufacturers are based on the speed of 60km/h downhill 6km, so as to improve their competitiveness. 2., with the standardization of the automotive industry, the use of ISO-TS16949 audit vendors have been popular, no development capability of the retarder suppliers will be shut out. For example, in 1998, Spain had 12 retarder manufacturers, and now there are only 2. (two) China China's Ministry of transportation issued JT/T325 "passenger operation type and rating standard" in 1997, was revised in 2002, stipulated in the large - and medium high school level operation must be installed on the highway passenger car retarder, in 1999 China issued the national mandatory standards GB12676-1999 "automobile brake system structure, performance and test methods", it uses the ECE thirteenth regulations (ECER13) "on M, N, O motor vehicle brake braking system" Uniform provisions in type II and type II A test of braking performance, braking performance and test method of a vehicle retarder were specified. Although these Regulations are later than the foreign laws and regulations, they have played a positive role in the development of the retarder industry and the safety of the vehicles in china. Due to the provisions of the above criteria and further understanding of the role of the retarder, a sharp increase in China's automobile manufacturers and the yield of retarder retarder, in the market has also formed the industry disorderly competition retarder. Some do not have the ability to develop the production of retarder manufacturers blindly, has a negative impact on vehicle performance, quality and safety, so we must further develop relevant retarder product standards, design, production and testing specification of retarder, improve product quality and safety of the vehicle, the Ministry of construction for reference "road vehicles - cars and Trailer - continuous braking system test procedures" (ISO/WD12161Roadvehicle-Endurance braking systems ofmotor vehicle and fowed vehicles-Test procedures) in 2004 developed the industry standard "city bus braking performance requirements and test methods", and is planning of vehicle retarder industry standard. In addition, because our country has not for trucks and equipment retarder regulations, serious traffic accident accident occurred in December 4, 2005 and January 21, 2006 on the Beijing Badaling high-speed Beijing Zhuhai Expressway in Shaoguan on the passenger car crash is after the truck brake failure caused. Therefore, the regulations of the truck equipped with retarder are also urgent. At present, some bus manufacturers, retarder manufacturers and research units have made unremitting efforts to promote industry standards, but so far we have not seen the official text promulgated. The author suggests that relates to the ministries of road traffic safety, coordination of the retarder industry manufacturers and research institutions, the organization committee issued that can reflect the mitigation effect of the retarder as soon as possible, and has a test method of operational regulations.