As the most important stressed part of the equipment, the welding quality of the excavator boom is directly related to the overall quality and performance of the excavator. The core of the boom welding process of excavator is to control the welding stress and minimize the displacement and residual stress at the weld, so as to make the boom welding quality of small excavator more reliable. After welding, the excavator boom also needs to carry out a series of processing, such as boring the inner hole, milling the end face, processing the assembly hole of the bucket rod and oil cylinder, and the processing of these parts has high requirements for accuracy. Once there is a problem in welding, it is likely that other components cannot be installed, resulting in product scrapping and direct economic losses. Therefore, the welding process of excavator boom is very important. However, welding deformation and welding cracks are easy to occur in the welding process of excavator boom. This article will explain the control method of boom welding deformation for reference only.
1. Specify reasonable welding process
The welding process is directly related to the welding quality of excavator boom. Only by supporting the standardized process flow, the quality of products can be guaranteed. Welding process parameters are the optimization data obtained from many experiments, including the selection of welding method, welding sequence, welding direction, starting position and ending position. The welding process is not invariable, but needs to change with the material, plate thickness, welding position and the actual situation of welding gap. The selection of welding current should be as small as possible to reduce heat input and fast welding speed. When the plate thickness is thick, the welding current should be appropriately increased, but the upper limit current must be strictly controlled to reduce the imbalance of internal stress distribution at the weld and reduce the occurrence of deformation.
2. Welding equipment conforming to actual conditions shall be adopted
The welding process of excavator boom is complex and difficult to operate. During welding, the direction of the material needs to be adjusted at all times to avoid the occurrence of welding dead corners. At the same time, attention should be paid to prevent the displacement of the object to be welded during the welding process. Therefore, the main equipment for excavator boom welding includes lap welding platform, welding positioner, welding fixture, etc. The lap welding platform, also known as tack welding, is mainly used to weld the plate into a frame structure, so as to improve its ability to resist welding deformation and effectively weld all parts accurately. Because the quality and shape of the excavator boom are relatively large, the welding positioner is not convenient to change the direction during welding, and it is easy to have dead corners. The welding positioner can make the boom of small excavator switch freely according to human needs during welding, so as to facilitate welding and optimize the welding state. During welding, the boom components not only need accurate positioning, but also need enough clamping force to bear the gravity and welding stress of the components.
