Concrete Machine Change:shifted from extensive, imitative, and quantitative to technological innovation, quality and efficiency

1、 The development of the construction machinery industry has shifted from extensive, imitative, and quantitative to technological innovation, quality and efficiency, and aesthetic and environmental protection. The technological development goal of the construction machinery industry during the 12th Five Year Plan period is to prioritize technology and focus on the comprehensive implementation of low-carbon, green, efficient, energy-saving, and information-based projects. The development goals of energy conservation, consumption reduction, and emission reduction are achieved through optimizing product structure and lightweight design, as well as reducing exhaust emissions; On the other hand, traditional manufacturing processes should be transformed to increase specialized production scale, and energy-saving, environmentally friendly, and low-carbon process equipment should be adopted in the production process for product manufacturing. And the painting process is precisely the energy consuming and environmentally friendly key link in the manufacturing process. Therefore, it is imperative to apply energy-saving, environmentally friendly, and low-carbon coating technology in industries of this scale such as construction machinery. This is also necessary for the construction of a "resource-saving" and "environmentally friendly" society in China.

2、 Characteristics of Coating for Construction Machinery

In recent years, construction machinery enterprises have continuously increased investment in technological transformation, improved production capacity, and continuously updated and improved manufacturing processes, mainly manifested in the improvement of manufacturing quality and surface coating level. From the perspective of the development of painting technology alone, the outdoor spraying process for street vendors has been eliminated, and the level of painting technology continues to improve. Painting equipment is becoming more advanced, automated, and efficient. Some parts have been painted using advanced painting processes and equipment in the automotive industry, with more complete processes, more beautiful and weather resistant coatings, more reliable anti-corrosion coatings, and more environmentally friendly coatings and equipment. However, as a large-scale industry, construction machinery is different from other industries such as automobiles, home appliances, furniture, etc. It has its own characteristics and needs to be carefully studied

1. The types of products and workpieces are complex, and the sizes of workpieces vary. The length of components ranges from a few hundred millimeters to 10-20 meters, and the weight ranges from a few kilograms to 20-30 tons; The whole machine ranges from a few meters to fifty or sixty meters, and the weight ranges from a few tons to two or three hundred tons; The thickness of the board ranges from one or two millimeters to one or two hundred millimeters.

2. The structure is complex, the workpiece has multiple internal cavities, and the single piece operation time is long.

3. The workpiece has multiple machining surfaces and holes, and the shielding is complex.

4. The supply of sheet metal is poor, mostly using hot-rolled plates and profiles, with severe surface corrosion and uneven pits.

5. The painting process for components and the entire machine is complex and involves multiple procedures. Parts that are processed or assembled after primer coating and then subjected to intermediate coating or surface coating; During the assembly and testing of the entire machine, there may be contamination, and even welding damage during the assembly process. The entire machine needs to be re polished and then coated with a surface coating; The whole machine or components need to be colored multiple times.

All of these pose challenges to the selection of coating process equipment and the application of energy-saving, environmentally friendly, and low-carbon coating technologies.

3、 Application of energy-saving, environmentally friendly, and low-carbon coating technology for painting process equipment

1. Pre shot blasting processing equipment

(1) The production scale of major host or structural component manufacturers now cannot be compared to before the 11th Five Year Plan Large and efficient. For example, the starting scale of excavator factories is over 10000 units/year, and several factories have a capacity of 20000 to 30000 units/year; Loader factory The production capacity of the First Army Group has reached 30000 units per year, and some factories have already reached over 40000 units per year; Forklift factories have a production capacity of over 10000 units per year, with some factories exceeding 60000 units per year; The production capacity of cranes is mostly over 10000 units/year, and some factories have exceeded 20000 units/year; The production capacity of cement mixer trucks is mostly over 3000 units per year, and some factories are already planning a production capacity of 30000 units per year.

Such batches and types require detailed classification of workpieces, especially by cross-sectional size. The cross-sectional size of workpieces in continuous shot blasting chambers affects the arrangement, number, and size of the blasting heads, thereby affecting the dust removal air volume. These two parts of power consumption account for more than 70% of the power consumption of shot blasting equipment.

As for excavators, they have a capacity of over 10000 units per year Two structural component coating lines need to be built, traditionally designed as two universal lines, now designed as: one line for shot blasting and painting on the upper and lower platforms, and one line for shot blasting, cleaning, phosphating, and powder spraying on the boom, boom, and bucket. Only the energy consumption of shot blasting equipment can save 200Kw.

(2) The shot blasting machine adopts a direct connection method to reduce power transmission loss and increase maintenance space.

(3) The use of belt conveyors for pellet recycling reduces equipment failures and saves energy.

Especially for long workpieces such as crane booms, tower crane booms, balance arms, and crawler cranes, the shot blasting equipment and cleaning and spraying equipment are very long. Spiral conveying is often used, requiring 6-8 levels, high power consumption, high failure rate, deep pits, and increased investment. If belt conveying is used instead, it will be more energy-efficient, simple, and practical.

(4) The dust collector must adopt two-stage dust removal: cyclone+filter element. The filter element adopts imported filter paper, automatic pulse back blowing, and the discharge pipe is equipped with detection holes for easy detection. The filter element is maintained and replaced according to requirements to ensure standard discharge.

(5) For suspended through shot blasting equipment, the sealing material and structural type at the top opening need to be continuously improved. Some joint venture companies' sealing structures are worth learning from to effectively reduce the risk of personal injury caused by leaked shot and reduce environmental pollution in the workshop. The usual practice now is to use composite color plates to create a barrier wall from the separator platform downwards, which can greatly reduce the splashing of flying pills and has a good effect.

(6) The recommended protective material is rolled Mn13, which is impact resistant. The impact of the thrown pellets actually makes it more wear-resistant, significantly improves its service life, and is easy to install and maintain. Welding connection is sufficient.