I. Characteristics of Crawler Crane Chassis
A crawler crane, also known as a tracked hoist, is a crane that travels on tracks. These cranes boast significant lifting capacities and mobility, enabling heavy lifting while moving. Their robust lifting capabilities, albeit complex assembly/disassembly, make them suitable for large-scale factory operations within premises. The crawler cranes stand out from mobile cranes due to their higher lifting tonnage, greater lifting heights, extended ranges, smaller turning radii, and their ability to transport loads, demanding less from the ground. Consequently, they find extensive use in ports, petrochemical industries, and bridge construction.
A crawler crane comprises a power unit, a working mechanism, and components like the boom, turntable, and chassis. The boom, assembled from multiple sections, can alter its length by adjusting these sections. Its lower end is articulated at the front of the turntable, while the top utilizes a variable-angle wire rope pulley assembly for support. The turntable, mounted via a rotating support on the chassis, bears the entire weight of the crane. It houses the power unit, transmission system, winch, control mechanisms, counterweights, and cabin. The chassis comprises the travel mechanism and the traveling device: the former enables the crane to move forward and backward as well as turn left and right; the latter consists of the track frame, drive wheel, guiding wheel, counterweight wheel, sprocket wheel, and track wheel. The power unit rotates the drive wheel through a vertical axis, horizontal axis, and chain transmission, subsequently propelling the guiding and counterweight wheels, allowing the entire machine to travel along the track.
Most crawler crane chassis are predominantly welded using high-strength steel plates ranging from 10mm to 50mm in thickness. The manufacturing quality of welded components significantly impacts the product's quality, performance, and reliability.
P1 Crawler Crane
II. Crawler Crane Chassis Welding Client
Established in 1992, Zoomlion Heavy Industry Science and Technology Co., Ltd., primarily engages in the research and manufacturing of high-tech equipment such as engineering and agricultural machinery. Over two decades of innovative development have propelled Zoomlion into a global enterprise, leading with products covering 10 major categories, 56 product series, and over 600 varieties. Zoomlion successfully listed on both the Shenzhen and Hong Kong stock exchanges, becoming the first A+H share-listed company in the industry. Presently, the company actively pursues strategic transformation, aiming to become an integrated high-end equipment manufacturing enterprise encompassing engineering machinery, agricultural machinery, and financial services. Zoomlion has a presence in over 100 countries and regions, strategically positioning itself along the "Belt and Road" initiative. Its products are exported to high-end markets in the Middle East, South America, Africa, Southeast Asia, and Russia, as well as Europe, Australia, and the United States. The company has established subsidiaries in nearly 20 countries globally such as East Asia, Southeast Asia, and Europe, with industrial parks invested in Italy, Germany, Brazil, India, and Belarus. It's planning new factories in Turkey and Saudi Arabia, with over 50 permanent establishments established worldwide. With the UAE and Brazil at the center, it's gradually establishing a global logistics network and spare parts supply system.
Since its listing, Zoomlion consistently ranks at the forefront of comprehensive performance among listed companies in Shanghai and Shenzhen. Thanks to its outstanding corporate governance, it has received numerous "Golden Roundtable" awards for the best board of directors. In 2016, Zoomlion continued its transformative development, gaining international and domestic recognition for its achievements. It was listed by the Boston Consulting Group as one of the "Top 100 Global Challengers" in 2018 and ranked 129th in the "Top 500 Asian Brands" in the same year.
The party and state leaders highly commended Zoomlion's development achievements. National leaders such as Xi Jinping, Li Keqiang, Zhang Dejiang, Yu Zhengsheng, and Wang Qishan visited the company, acknowledging its accomplishments while expressing high expectations for its future development. Zoomlion will continue to advance its "transformation" and "internationalization," achieving steady and rapid growth within the evolving industry landscape, endeavoring to create a world-class enterprise in equipment manufacturing.
III. Challenges at the Crawler Crane Chassis Welding Site
The chassis crawler frame constitutes a closed box-type and belly plate hybrid structure welded together from top cover plates, belly plates, bottom plates, etc. The crawler frame and the frame connect via power pin axles, incorporating the walking mechanism, intended to withstand the machine's weight and operational loads. Hence, the crawler frame structure necessitates sufficient stiffness, strength, and precise structural dimensions. The primary structure of the crawler frame utilizes Q550 high-strength steel plates with thicknesses ranging from 30mm to 50mm. The customer stipulates the following welding requirements:
1）Reduced Splatter, and Increased Welding Efficiency: Minimize splatter during welding to enhance efficiency and decrease subsequent grinding processes.
2）Focused Arc Energy for Dimensional Compliance: Concentrate arc energy to prevent substantial part deformation, ensuring adherence to design specifications.
3）Controlled Heat Input for Q550 Material Sensitivity: Due to Q550 material's sensitivity to welding heat input, strict control is necessary to avoid compromising material properties and potential safety hazards.
4）Aesthetically Pleasing Weld Seam Formation: Achieve smooth, visually appealing weld seams without stress concentration, ensuring a depth not exceeding 2mm.
P2 Truck Frame
P3 Welding Workpiece
IV. Distinctive Features and Advantages of Megmeet's Artsen Plus 500P Welding Machine
In response to the customer's practical needs, the recommendation is the Megmeet Artsen Plus 500P welding machine utilizing a short-circuit direct current process. The Artsen Plus 500P welder is a fully digital high-frequency intelligent inverter welding machine capable of performing full-position direct current and pulse welding on materials such as carbon steel and stainless steel, among others. This welding machine boasts the following advantages to address customer concerns:
1）High-Speed Digital Control: Operates at an inverter frequency of 100KHz, enabling meticulous control over droplet transition states, ensuring stable welding with minimal splatter.
2）Built-in Expert Welding Database: Offers unified adjustments with parameters automatically linked to achieve optimal welding results.
3）Advanced Wire Feeding Mechanism: Utilizes high-performance digital motors, encoder feedback, four-wheel wire feeding, and precise feeding mechanisms, ensuring stable wire feeding for superior welding.
4）Robust Design for Reliability: Equipped with a lightning strike and surge protection measures to combat electromagnetic interference. Before leaving the factory, each welding machine undergoes rigorous reliability testing, ensuring stability and dependability.
5）Adjustable Start and Stop Arc Parameters: Guarantee smooth and full weld seams throughout the welding process.
P4 Short Arc Pulse
P5 Standard Pulse
P6 Weld Seam
V. Comparison of Crawler Crane Chassis Welding Results
Utilizing Megmeet Artsen PLUS 500P welding machine yielded satisfactory results for the customer. Minimized splatter significantly reduced subsequent grinding processes. The aesthetically pleasing weld seams showcased uniform and consistent surface formation, appearing bright white, achieving a qualification rate of 99.5%. Concentrated arc energy and low heat input, combined with appropriate welding procedures, led to minimal deformation, effortlessly meeting overall dimensional requirements.
VI. Application of Artsen Plus 500P Welding Machine
P7 Artsen Plus 500P Welding Machine Onsite Application
P8 Artsen Plus 500P Welding Machine Onsite Application
