In the manufacturing process of radiator hoses, the pulling deformation of the internal surface is a key process step that directly affects the sealing, durability, and overall performance of the product. This process involves the comprehensive application of materials science, mechanical processing, and precision control technology. Its core lies in forming a uniform and smooth surface structure on the inner wall of the rubber hose through plastic deformation, while ensuring dimensional accuracy and mechanical strength. The following analysis will be conducted from several dimensions, including process flow, deformation mechanism, and quality control.

1、 Process flow of drawing deformation

The drawing deformation of radiator hoses is usually divided into three stages: pretreatment, drawing forming, and post-treatment. In the pre-processing stage, rubber or synthetic materials are mixed and extruded to form pipe blanks, during which there are microscopic irregularities and residual stresses on the inner surface. When entering the drawing stage, the tube blank is heated to 80-120 ℃ (depending on the material), and axial tension is applied through a drawing machine with precision molds to reduce the diameter of the tube by 10% -30%.

2、 Microscopic deformation mechanism and material behavior

During the drawing process, the inner surface of the rubber hose undergoes complex stress states: axial tensile stress, radial compressive stress, and circumferential shear stress form a three-dimensional stress field. Polymer chains undergo orientation rearrangement under stress. Studies have shown that when the deformation rate is controlled between 0.5-1.2m/s, the internal crystallinity of nitrile rubber can be increased by 15%, significantly enhancing its creep resistance. However, excessive pulling speed (such as exceeding 2m/s) can cause the "shark skin" effect, resulting in periodic cracks on the surface. Through SEM observation, it was found that the optimized process can form a dense "scale like" structure on the inner wall of the hose.

With the increasing demand for cooling systems in new energy vehicles, precise control of the inner surface of radiator hoses has become a focus of technological competition. It may develop towards intelligent drawing systems, integrating quality prediction and adaptive adjustment functions, which is of great significance for achieving micrometer level morphology control.