Visit "World's First Crane"-Xugong's 2,600-Ton All-Ground Crane Lifting Heavy Worldwide

"No matter how complicated a 'big country's heavy army' is, it must start with building a 'screw".

Can you imagine XCA2600 such a "big guy", once because of a small threaded shaft and interrupted research and development.

In 2015, the first batch of products produced according to the design drawings broke repeatedly in the limit test. After dozens of failures and using all methods to analyze the fracture section, the R & D team found that the problem was on a threaded shaft of the load-bearing part.

At the critical moment, Meng Wei, the company's "000001" special technician, stepped forward. "The reason why the threaded shaft is easy to break is that the special-shaped thread on the shaft is not accurate enough, so the connection is not smooth enough, the force is uneven, and the processing technology needs to be improved."

Cutting tools, tools for grinding precision parts. Meng Wei pointed out that in order to improve the machining accuracy of special-shaped threads, one must start with cutting tools. However, the weight of threaded shaft parts is 139kg, and there is no suitable tool on the market to process.

Previously, Meng Wei's team used 18 non-standard tools to splice into new tools to process threaded shafts, but unfortunately they did not succeed. Meng Wei team repeated tests, has overturned more than 20 kinds of programs, and finally developed a set of precision to micron special tool.

"In the first batch, we only made 20 threaded shafts, and the success rate was still relatively low." Meng Wei said that after continuous optimization, the success rate increased a little bit and gradually adapted to the requirements of mass production.

The reporter learned in the interview that the production process of the XCA2600 has condensed the skills of many craftsmen.

Entering the welding workshop of Xuzhou Heavy Machinery Co., Ltd., the world's first laser hybrid welding special plane independently developed by my country is under intense operation. Its unique feature is that when the equipment is welded on the outside of the steel plate, the inside of the steel plate is also splashed with fire, welding on both sides of one operation. This overcomes the short board that ordinary arc welding can only weld the outside of the steel plate and the inside needs manual welding, and greatly improves the welding efficiency.

However, even with the help of the laser hybrid welding special machine, in the XCA2600 production process, in the face of complex super crane structural parts, there are still more than 50% of the welds need to be welded manually. Welder Zhang Huaihong told reporters that what is left for manual welding is often some special-shaped and hidden welds. "Taking the boom XCA2600 the largest cross-section as an example, it takes 9 highly skilled welding workers to work together for 15 days to complete the welding."

Welding work is very hard. In order to ensure that the weld is smooth and does not crack, the steel must be preheated to 100 degrees Celsius before each welding. Wearing a heat-insulating welding suit weighing more than 10 kilograms, lying on a steel plate at 100 degrees Celsius for 4 hours, and ensuring that the hands do not shake at all, the welding workers will be soaked every time they leave work.

The welding of XCA2600 boom is the ultimate embodiment of craftsman spirit. Zhang Huaihong said that the 2600-ton boom has a large welding capacity, and 80% of the positions require multi-layer and multi-pass welding. "When welding multiple layers and multiple passes, each layer must be polished and cleaned between layers before the next layer can be welded." Zhang Huaihong said.

"Welding is not only a technical work, but also a work of conscience. There is no room for carelessness. Every layer and weld must be welded according to the standard of high-quality products." Zhang Huaihong said that a small welding crack may cause serious accidents. It is the efforts of all welding craftsmen that create the excellent performance of the XCA2600.

The R & D and manufacturing of behemoths will get stuck on a thread; the design of each weld requires many times of communication and modification between the designer and the craftsman. Li Changqing sighed: "No matter how complicated the 'heavy weapon of a great power' is, we must start with building a 'screw."

The visit to XCA2600 is coming to an end, and the good news continues to come:

At the hoisting site in Wulat Houqi, Inner Mongolia, the efficient installation of a fan in 3 days won XCA2600 praise from customers: "The hoisting was completed quite beautifully, increasing the installation efficiency of super-large land fans by 30%."

In Xugong's super-large equipment commissioning site, two brand-new XCA2600 are ready to go. Since its listing at the end of last year, the XCA2600 has sold more than 10 units, and orders are still increasing.

On average, every two years, there is a crane product that refreshes the global lifting capacity; the product line spans 8 tons to 2600 tons, and the construction field covers municipal, chemical, wind power and other scenarios; all products below 300 tons are localized, and the localization rate of all product parts reaches 91% ...... As the world's largest crane manufacturer, XCMG is still striving forward and creating new achievements.

Source: People's Daily