50t truck crane box arm bending quality control

The structure of the company's 50t truck crane telescopic arm is shown in Figure 1. Its cross-sectional shape is 8-sided. The material is made of low-alloy high-strength steel WELDOX700, which is formed by bending into upper and lower arms and then welding. From the structure point of view, the lower arm body is 1 mm thicker than the upper arm body to meet the local stress requirements of the lower arm body. The length of the arm body is about 10m. The difficulty lies in how to ensure the angle and straightness in the longitudinal direction to achieve the height dimension and opening size required by the design.

First, the arm body forming process

According to the actual production situation of the company, the process arranges the following process control measures.

Cutting

The aspect ratio of the open frame of the truck crane is 11:1. After the underwater plasma cutting, the steel plate is bent due to the uneven release of internal stress. According to the actual production situation, the amount of side bend after the arm plate is cut is generally controlled to be 1 to 2 mm by reserving the process lacing. Taking into account the side bend after leveling, the actual expansion width of the arm body is 6mm larger than the theoretical one, that is, the margin of the edging process is adjusted to 3mm to reduce the workload of the subsequent planing process.

See the attachment for more details: