Technical Article

Application of local upsetting technology in hydraulic support cylinder

During the design process of hydraulic support column cylinders, there may be situations where the cylinder port size is larger than the outer circle of the column. There are usually two solutions when encountering such design requirements: ① Adding materials to the welding cylinder mouth to increase the size; ② Weld a circular cylinder on the outer circumference of the cylinder to increase the size of the cylinder. Both schemes have their drawbacks: welding is the most effective method to increase size, but the hardness of the welding layer does not significantly improve after quenching and tempering treatment, which cannot meet the hardness requirements of the hydraulic support cylinder for mining. If the welding layer is too thick, it will cause deformation of the inner hole of the cylinder, which will have adverse effects on subsequent processing; Welding a circular cylinder outside the cylinder mouth can also pose quality risks due to quality defects in the welds between the cylinder and the circular cylinder. The development of local upsetting technology has effectively solved this problem. Local upsetting is the use of forging technology to increase the local area or diameter of the material. It can not only optimize the microstructure of metals, but also increase the local size of the base material, eliminate various quality problems caused by welding and surfacing, and improve product quality.

Application of local upsetting technology on outer cylinder

Forging is a forming process in which the height of the material decreases while the cross-section increases. Local upsetting heats up the material locally and uses forging to increase a portion of the cross-sectional area of the material. After local upsetting, the base metal and the cylinder head upsetting section are integrated, with the same mechanical properties and good quality of forgings. Design forging drawings based on part drawings → Design hot forging drawings → Design and process molds → Calculate cutting dimensions → Cutting → Heating → Forging → Cooling → Measurement.

Promotion of local upsetting technology on other components of oil cylinders

Considering that the application of local upsetting technology on the outer cylinder meets the mechanical performance requirements of the outer cylinder, it is recommended to promote the application of local upsetting technology on the piston rod of the oil cylinder.