Steering system development trend

Since the reform and opening up, China's automobile industry has developed rapidly. As one of the key components of the automobile steering system has also been developed accordingly, basically has formed a professional, serialized production situation. Data shows that steering gear factories in many foreign countries have developed into professional factories of mass production, with an annual output of more than one million units, monopolizing the production of steering gear and selling points all over the world.

The usage dynamics of steering devices in modern automobiles

With the rapid development of the automobile industry, the structure of the steering device has changed greatly. The structure of the car steering gear is many, from the general degree of use, the main steering gear type has 4 kinds: there are worm Shaw type (WP type), worm roller type (WR type), circulating ball type (BS type), rack and pinion type (RP type). These four types of steering gear have been widely used in automobiles.

It is understood that in the world, the automobile cycle ball steering gear account for about 45%, rack and pinion steering gear account for about 40%, worm roller steering gear account for about 10%, other types of steering gear account for 5%. The circular ball steering gear has been developing steadily. In Western Europe, the rack-and-pinion type steering gear has a great development. Japanese car steering gear is characterized by cycle ball steering account for more and more proportion, Japanese equipment of different types of engines of various types of cars, using different types of steering gear, the use of cycle ball steering gear in buses, has been from the 60's 62.5%, the development of 100% of the present (worm roller steering gear in the bus has been eliminated). Large and small trucks mostly use circular ball steering gear, but rack and pinion steering gear has also been developed. The circulatory ball type steering gear accounted for 65% of the minivans, and the rack and pinion type accounted for 35%.

Based on the above analysis of the use of the steering gear, the following conclusions can be drawn:

· Circulating ball steering gear and rack and pinion steering gear have become the two main steering gear in today's world; And worm gear #0; Worm steering gear and worm steering gear are being phased out or retained a smaller position.

· There are different views on the development of steering gear on small buses. The United States and Japan focus on the development of circular ball steering gear, and the ratio has reached or exceeded 90%; Western Europe focuses on the development of rack and pinion steering gear, the ratio of more than 50%, France has reached 95%.

· Due to the advantages of the rack and pinion steering gear, its application in small vehicles (including small buses, minivans or passenger and cargo vehicles) has been developed rapidly; And the large vehicle with circular ball steering as the main structure.

Characteristics of circulating ball steering gear

· Circulating ball steering gear is characterized by high efficiency, easy handling and a smooth handling force characteristic curve.

· Convenient layout. Especially suitable for large and medium vehicles and power steering system; Easy to transmit driver control signals; High reverse efficiency, good return, and the action of the hydraulic booster device cooperate well.

· It can realize the characteristics of variable speed ratio and meet the requirements of light control. The middle position steering force is small and often used, requiring sensitive steering, so it is hoped that the speed ratio near the middle position is small to improve sensitivity. The large Angle steering position has high steering resistance, but it is used less times. Therefore, it is hoped that the speed ratio of the large Angle position should be larger to reduce the steering force. Because the circulating ball steering gear can realize the speed change ratio, it is used more and more widely.

· Steering force is transmitted through rolling contact of a large number of steel balls, with high strength and good wear resistance. And the steering gear can be designed to have equal strength structure, which is one of the reasons for its wide application.

· Variable speed ratio structure has high stiffness, especially suitable for the improvement of high-speed vehicle speed. High speed vehicles need better steering stability at high speed and must ensure that the steering gear has high stiffness.

· Adjustable clearance. Rack fan pair wear can be readjustedclearance, so that it has a suitable steering gear transmission clearance, so as to improve the life of the steering gear, is also one of the advantages of this steering gear.

China's steering gear production, in addition to the early production of the Jiefang brand automobile worm roller steering gear, Dongfeng Automobile worm Shaw steering gear, most of the other models are using the circular ball structure, and have a certain production experience. Jiefang, Dongfeng are also in the active development of circular ball steering gear, and has been widely used in the second generation of vehicles. It can be seen that China's steering gear is also developing to mass production of circular ball steering gear.

Steering gear production is specialized

Circulatory ball steering gear has realized specialized production in foreign countries. At the same time, professional factories are mainly used for testing and research, which greatly improves the output and quality of products. In Japan "Seiko" (NSK) company's circular ball steering gear with low cost, good quality, large output, gradually occupied the Japanese market, and sold its products to the world. Germany ZF company is also known as a large - scale steering gear factory. It began to produce ZF-type steering gear in 1948, with an annual output of more than 2 million units of various steering gear. There are also some large steering gear manufacturers, such as Delphi SAGINAW; British BURMAN Company are more famous professional manufacturers, have a large output and sales. Specialized production has become a trend, only by taking this road, can we make products of high quality, large output, low cost and competitive in the market.

Power steering is the direction of development

The application of power steering system is increasingly extensive, not only in heavy vehicles must be equipped, in the limousine application is also more, in the medium car application is also gradually promoted. The main point is to reduce driver fatigue, improve the maneuverability and stability; The secondary point is to reduce the accident caused by the sudden burst of the front tire in high-speed driving. Although it brings high cost and complex structure and other problems, but because of its obvious advantages, it has been rapidly developed.

There are three types of power steering: integral, semi-detached and combined valve power steering. The three forms have their own characteristics and develop rapidly. The integral type is mostly used for vehicles with front axle load of 3 ~ 8t, and the combined valve type is mostly used for front axle load of 5#0; 18t automobile, semi-split type is mainly used for the front axle load above 6t to super heavy vehicles.

From the development trend, the foreign integral steering gear develops fast, and the integral steering gear transfer valve structure is the direction of development.