Welding technology and welding jigs and fixtures on the quality of the automobile production

　A, the current situation of the development of auto industry

China's economic growth has accelerated China's automobile manufacturing industry, engineering machinery industry, the development of the shipbuilding industry, according to the China association of automobile manufacturers, according to data released in China in 2007. Volume has more than 8.8 million vehicles, both rose as high as 22.02%, second only to the United States China become the second largest car consumer, expected car sales to 15 million vehicles in 2015. While special car production to develop in the direction of small batch, diversification. Auto mould, jig on the cost and manufacturing cycle brings great pressure to the production unit, therefore, flexible modular fixture has become an inevitable choice for manufacturing enterprises, this can reduce the matching cycle, reduce the production cost.

2002 years ago, the domestic mold enterprise mainly producing trucks and van mold, car mold in the production structure of mould level only; Welding jig enterprise's production capacity is limited to items within the production of welding fixture and parts assembly fixture. In 2003 ~ 2007, the domestic mold, mold enterprises gradually began to produce the whole car white body welding jig enterprises also have the chassis assembly from four doors, lateral confining to the master of the white body welding assembly line production capacity, and on the main technology is close to the international advanced level.

Some international advanced enterprises have higher levels of welding development ability, and formed by a handful of advanced welding technology platform for vehicle enterprises as the core, high degree of specialization of the pattern of small and medium-sized welding tooling companies for network. Abroad such as Japan's Toyota, Germany Volkswagen, Peugeot, each big auto companies such as general application of three-dimensional digital process planning and simulation software has a history of nearly ten years. Domestic for high yield, high degree of automation of the welding line process planning lack of unified digital information management, has not yet formed this kind of highly automated welding line planning ability.

　Second, the automobile welding jig

The optimization of welding jig design and manufacture accuracy is very important in the automobile manufacturing process of the link, the proper use of the flexible combination jig can save more money into fixture. Due to the high speed development of industry, China's mold, jig industry technology and management of ascension also entered the fast lane, and has set up a have the ability to challenge the fixture manufacturing in the developed countries. Five years ago, China import and export molds China welding production value amount to 5.8:1, in 2007, import and export ratio is 1.45:1, mold exports over 1.4 billion us dollars, it marked China's mold industry to scale into the international market time has come, and the three dimensional flexible combination welding jig has just entered the Chinese welding industry.

Japan's Toyota, Volkswagen and other international leading automotive manufacturers, has a special stamping, welding, assembly, painting process. Them together with the body design personnel in the r&d center of product manufacturability analysis. From the car body design to tooling manufacture all follow the principle of a unified, its integration degree is very high, very beneficial to the body's comprehensive quality, cost, cycle control. China's mold, welding industry mostly in their own way is, difficult to communicate between mold factory, welding fixture manufacturers, many problems have stuck to the auto makers production preparation period, of white body in the product quality and production cycle.

So, the welding jig industry is badly in need of an industry standard developed, flexible combination welding jig shows more and more important position in welding production!

The advantages of flexible combination welding jig application:

As special vehicles and special engineering vehicles to small batch production, diversification direction, in the development of new models and manufacture process, use of flexible, modular three-dimensional combination equipment replace traditional special tooling, can not only shorten the time required for the design, manufacture, and can be repeatedly used, cost savings, it is very economic and practical choice.

1, economy

Flexible combination fixture is a kind of universal fixture can free combination, can adapt to different workpiece shape, several sets of fixture system can replace a large number of the high cost of special tooling, after using the tooling, can save due to product changes into the specialized equipment and tooling cost and time. In many varieties, personalized car production, its economical efficiency is especially obvious.

Foreign data have shown that the cost of more than 9 sets of special welding jig (5 ~ 6 sets) in our country has more than a set of flexible fixture. At present, China's automobile manufacturing enterprises increase each year dozens of sets of special welding jig is very common, selects the flexible fixture economy is obvious.

2, flexible

Flexible tooling platform can be combined in three-dimensional space. Modular system in the installation, adjustment and clamping workpiece perfectly reflected its general function, on the welding of large workpieces, the more prominent characteristics. The other side of the flexibility in easy operation. On the bench and module, all with 12.5 mm and 25 mm as multiple dimensions can be found directly, coupled with a small amount of adjustment, can be convenient accurate positioning.

3, accuracy

All module processing precision is high, any two holes work platform tolerance within + / - 0.1 mm, can completely meet the needs of the welding process. Used in assembly or during the welding process, positioning, clamping device, connecting blocks of and support, to accurate positioning of workpiece, need welding workpiece can be stably fixed in each anchor point or location on the surface. If the geometry size of workpiece itself is not accurate, also can be detected quickly in the pretreating process will be eliminated.

4, repeatability

Using CAD and Pro/E design system, can be very easy to simulate assembly samples and precise assembly module size can guarantee accuracy.