The Latest Development Trends of Construction Machinery Coating And Conveying Equipment

The latest development trends of construction machinery coating and conveying equipment

Abstract: This paper discusses the selection principles of conveying equipment for engineering machinery coating lines, and introduces bicycle trolleys, large-tonnage double-track bicycle trolleys, new wide push rod heavy-duty accumulation and release chains, accumulation and release chain hoist combinations, and heavy-duty skid conveyors. The application of new conveying equipment such as automatic rail-aligned push-pull transverse shift vehicles in engineering machinery coating lines looks forward to the development trend of engineering machinery painting and conveying equipment.

1 Introduction

From the perspective of workpieces, engineering machinery painting can be divided into structural parts painting, thin plate painting, and complete machine painting. Topcoating of components has gradually become a trend in engineering machinery painting. Therefore, the focus of engineering machinery painting is on parts. Painting. Engineering machinery parts have the characteristics of many varieties, complex specifications, heavy weight, and large size. The process usually includes shot blasting, cleaning, spraying, topcoat, drying and other processes. According to the process requirements of different enterprises, some production lines There are also processes such as cleaning, puttying and polishing online. Conveying is a key component of the coating line. It plays a decisive role in the utilization of the entire coating line and the improvement of coating efficiency. However, different coating objects, different coating processes, production scales, etc. have different specific requirements for coating transportation.

2 Principles for selecting conveying methods for engineering machinery coating lines

Conveying equipment is one of the key equipment in the construction machinery coating line. It directly affects many aspects such as workshop logistics and transportation, coating equipment selection, process investment, and production efficiency. Normally, the selection of transportation methods should follow the following main principles:

1) The selection of conveying equipment for the coating line should fully consider the logistics connection with the welding workshop and assembly workshop to reduce transfers between workshops. At present, there are two main methods. One is to use an accumulation and release chain system. The upper and lower workstations are extended to the corresponding positions in the welding workshop and assembly workshop respectively to reduce the cross-span transportation of workpieces. The second is to use a self-propelled hoist system, and the upper and lower parts are transferred using a ground trolley or skid system.

2) Reasonable selection according to the production program. For example, self-propelled hoists can only be produced according to a certain rhythm. When the production program is large, it is necessary to use a suspension conveyor for continuous production, or to use an accumulation chain to divide the painting system into several independent production units in parallel.

3) Reasonable selection according to the process flow of the coating line. The coating process of construction machinery of different companies is quite different. For example, some need to be inspected offline after shot blasting, and some workpieces need to be puttyed. You can make full use of the diverting and merging functions of the accumulation chain, such as using self-propelled hoists, and heavy-loaded workpieces for turnouts. The reliability of frequent use is relatively low and the failure rate is high.

4) Select the conveying method according to the process operation requirements. Suspension conveying and ground conveying are conducive to the bottom spraying operation of large workpieces; the lifting function of the hoist can meet the upper part of the workpiece; the self-propelled hoist cannot meet the needs of medium and high temperature baking operations. The heat is easily lost through the top opening, and affects the life of the slide line and the hoist. .

5) Meet the plant and investment scale restrictions. Aerial transportation has certain requirements for the height of the factory building, and the investment is usually much higher than that of ground transportation. If there are restrictions in this regard, it is more economical and reasonable to choose ground transportation, but the degree of automation and production efficiency will also differ from that of air transportation. There are certain differences.

3 The latest developments in conveying equipment for construction machinery coating lines

In recent years, with the development of my country's construction machinery industry, there have been major breakthroughs in the total product volume and tonnage. During the design process of the coating project, the design concept was also innovative, and higher requirements were put forward for the transportation of the structural parts coating line. On the basis of conventional self-propelled hoist conveying equipment and accumulation and release chain conveying equipment, the structural parts coating line There are some innovative applications emerging in conveyor equipment, which are briefly described below.

3.1 Bicycle aerial transfer machine

In order to solve the problem of difficulty in turning long workpieces such as large pump truck booms and crane booms, even if they can be turned, the scanning area is too large, which affects the layout of the production line, the large structural parts coating line uses a rectangular self-propelled hoist to transport the workpieces , both ends are moved by aerial translation trolleys to avoid turning or secondary landing of the workpiece and improve production efficiency. When the bicycle trolley reaches both ends, the aerial transfer machine automatically moves into position and automatically and accurately aligns with the fixed rail. After connecting to the bicycle trolley, it automatically ferries to another process route and automatically aligns with another fixed rail. Through the movement of the bicycle trolley, Aerial translation realizes the automatic operation of the entire production line conveying equipment. The air travel of bicycles can also avoid friction on curved rails and improve the reliability and life of the equipment. The monorail aerial translation trolley has been successfully used in many domestic production lines, and its maximum load capacity can meet the transportation needs of 16t workpieces.

3.2 Large-tonnage double-track bicycle trolley

The double-track bicycle trolley is mainly used to transport wide-body and ultra-long workpieces. It adopts four-point suspension lifting to improve the stability of wide-body workpiece transportation. This technology was first applied on the bus painting line. The products developed in China in the past few years include circular double-track and rectangular double-track, as well as three-track technology. However, the rectangular double-track conveying technology is technically more mature, reliable and widely used.

For large workpieces of engineering machinery, the ideal way is ground transportation. However, for workpieces that require shot blasting, there is no good solution to the protection problem of ground transportation equipment. Ground transportation usually can only be shot blasted. Workers The labor intensity is high and the working blind area at the bottom of the workpiece is large, which affects production efficiency. In order to solve the problem of automatic transportation of heavy-duty workpiece painting, China has learned from the double-track bicycle trolleys on the bus and truck frame painting lines and developed a heavy-duty double-rail bicycle trolley, which can meet the aerial transportation of workpieces with a maximum weight of 30 to 40 tons. The requirements for low-speed travel in the shot blasting section enable automatic transportation of heavy-duty workpieces in the coating line.

3.3 New wide push rod heavy-duty accumulation and release chain and spreader splitting mechanism

The application of wide push rod and wide lifting claw technology in the accumulation chain reduces the chain running resistance and noise, and improves the reliability and life of the conveyor operation. The new type of heavy-duty accumulation and discharge chain with wide push rod can transport workpieces up to 12t/hang. The workpieces are transported after hanging by the load-bearing trolley group of the accumulation chain and the multi-functional spreader group. An ingenious splitting mechanism is designed. Through the electric or pneumatic lever mechanism, the flexible splitting and combination between the two trolley groups of the accumulation and release chain is realized, and the effective combination of parts is realized. Each trolley unit can transport short workpieces independently after being split. The combination of two trolley units Long workpieces can then be transported. Our institute has successfully applied this method to the tower crane coating line, which is beneficial to the suspended transportation of workpieces with large differences in size and improves production efficiency.

3.4 Combined application of accumulation chain and hoist

This method makes full use of the diversion, merging and accumulation functions of the accumulation chain, and also uses the lifting function of the hoist to meet the lifting or swing requirements of some specific work stations, such as upper and lower work stations, immersion pre-treatment stations, scraper The putty station, grinding station, spray painting station, etc. can all lift the workpiece up and down according to the operating requirements, and the pre-processing station can swing the workpiece as needed. This method is to install a chain hoist under the accumulation trolley of the accumulation chain, and install a secondary spreader below the hoist. The hoist is powered by segmented power supply. This method is also used in the heavy-duty truck frame coating line, and adopts the technology of a single chain driving the beam trolley at the same time.

3.5 Application of heavy-duty skid conveyor

The skid conveyor is an advanced and complex material conveying equipment, and together with other types of conveying equipment, it is controlled by a programmable controller or computer to become a highly electromechanical integrated material storage and transportation system. The skid conveyor equipment is mainly used in automobile painting workshops. It has powerful functions and can adapt to changing process requirements, such as diversion and merging, vertical lifting, aerial stacking, etc. It is especially suitable for automatic spraying occasions and has accurate positioning.

The latest application in the construction machinery industry is mainly plane transportation. Application cases include: a company's transportation of large structural parts before they are painted on the line, workpiece transportation and transportation of forklift counterbalanced painting lines [6], and modified carriage body painting lines. Workpiece transfer, etc. Due to the particularity of the workpiece in engineering machinery painting, the skid system has not exerted its advantages, but the significance of its application is to change the original relatively backward logistics and production model, forcing the coating line to operate in a rhythmic manner, and the level of process equipment There has been a big improvement.

3.6 Automatic rail-aligned push-pull lateral shift vehicle

Painting lines with drawer-type layout or rectangular layout need to use transfer cars for ground transportation to transfer between multiple chambers. Since there are many specifications of large workpieces and the weight of the workpieces varies greatly, it is difficult to accurately align the rails. Manual inching is generally used. The rail alignment method requires a large investment in equipping each chamber with a ground traction chain, and many companies use manual push in and out of each chamber. Jiangsu Huayao Company independently developed an automatic rail-aligning push-pull lateral shift car. This product uses PLC control to enable the craft car track on the lateral shift car to automatically and accurately align with the ground track; it uses a multi-stage flexible push rod. mechanism, when the craft car track on the traversing car is not in a straight line with the ground track, it can automatically perform flexible compensation to achieve smooth operation; there is a pusher on the multi-stage flexible push rod mechanism, which has the functions of propulsion and The two major pull-back functions enable the cargo-carrying process vehicle to freely enter and exit each coating room, effectively reducing the labor intensity of workers and avoiding personal safety hazards.

4 Outlook

Domestic attention to the appearance quality of construction machinery products continues to increase. Construction machinery coating technology has developed rapidly in recent years. There are many solutions for the transportation of various coating lines, which need to be based on workpiece characteristics, process flow, operating methods, and logistics systems. Only through reasonable design and selection such as matching can the automation level of workshop transportation be improved and production efficiency improved. Construction machinery coating line conveying equipment still has potential for improvement in the following aspects:

1) Conveying equipment is further integrated with factory digitalization and informatization. At present, the most advanced construction machinery painting lines in China have connected the welding, painting, and assembly workshops into an organic system through conveying equipment. XCMG loaders use an 8,000m-long accumulation and release chain that runs through the entire process of structural parts, painting, assembly, and thin plate parts, and realizes functions such as classified storage of workpieces after painting and online calling of assembly units according to production instructions.

2) Flexible use and automatic transfer of multiple conveying methods to improve the level of automation. Engineering machinery coating production is usually divided into thin plate parts and structural parts coating units. The coating process includes mechanical shot blasting, chemical pretreatment, electrophoresis, spraying and other different processes. Each process has different requirements for conveying equipment. We can learn from automobiles. The application of some new equipment in the coating industry requires the rational selection of different conveying methods to achieve seamless connection between various functional segments.

3) Heavy-duty conveying equipment meets the conveying needs of large-tonnage workpieces of engineering machinery. The specifications of domestic large-scale construction machinery products continue to make breakthroughs, and it is difficult to meet complex painting requirements using conventional ground flat car transportation methods.