Round tube crimping machine,also known as round‑tube end‑swaging machine,realizes various end‑forming effects through cold plastic deformation by replacing different mould sets.It is widely used for guardrail pipes,greenhouse frames,furniture tubular parts and mechanical connecting pipes.The achievable finished shapes mainly include diameter‑reduced cylindrical ends,tapered conical ends,stepped variable‑diameter ends,closed sealed ends,flanged bosses,and special custom‑profiled ends,while processing quality is restricted by tube wall thickness,material ductility and mould precision.
Cylindrical equal‑wall‑thickness reducing end is the most common finished shape.The machine compresses the round‑tube end to a smaller uniform diameter,so that one pipe section can be directly inserted into another matching pipe for lap assembly.This shape is heavily adopted for guardrail and greenhouse pipe connection,eliminating complex welding positioning procedures.It requires stable pressure‑holding function of hydraulic system to prevent tube wall wrinkling.
Tapered conical end is another mainstream forming result.The tube end is gradually shrunk into smooth cone shape,which is convenient for pipe insertion and guiding assembly.Conical transition can be designed with different taper angles according to customer drawing requirements.It is suitable for inserting‑type connection of thin‑medium‑wall carbon‑steel round tubes.Excessive taper angle will cause tube‑end cracking risk during crimping.
Stepped variable‑diameter end forms multi‑stage diameter change on single tube end.One section remains original pipe diameter,and adjacent section is crimped to two or more different diameters.This stepped structure is used for positioning and limit connection of mechanical tubular components.Corresponding multi‑stage cavity moulds are required,and wall‑thickness shall not exceed machine forming capacity.
Tube‑end closing and sealing forming can also be completed.According to mould cavity,it can produce hemispherical round‑closed end,flat‑closed end or arc‑transition semi‑closed end.This process is widely applied for end sealing of guardrail stand‑pipes and fence support tubes,avoiding sharp‑cut open‑pipe end faces.Full sealing effect depends on reasonable wall‑thickness matching;too‑thin wall will lead to wrinkling,while over‑thick wall may bring incomplete closure.
Flanged boss and local upsetting shapes are available for bolt assembly.Through radial compression,local tube‑wall material accumulates outward to form raised boss,which provides higher strength for hole‑tapping and bolt connection.Besides standard shapes,custom‑made special moulds can realize partial flat‑squeezed ends,simple oval transition and other non‑standard profiles for special‑purpose tubular parts.
Nevertheless,technical limitations should be noted.This machine mainly completes local end forming,and cannot process full‑pipe complex bending.Too‑large deformation ratio will trigger tube‑end crack defects.High‑hardness alloy round tubes have poor cold‑forming performance and may need auxiliary heating.Before batch production,sample crimping test with real round‑tube workpieces is strongly recommended to check surface integrity and assembly fitness.
In short,round tube crimping machine can produce cylindrical reduced ends,tapered conical ends,stepped variable‑diameter ends,sealed closed ends,flanged bosses and other custom special‑profiled ends by changing moulds,serving pipe‑insertion assembly,end sealing and mechanical connection requirements for guardrail,greenhouse and hardware industries.
References
APA 7th
Wang,H.,&Zhang,Y.(2023).Research on cold crimping forming process and shape adaptability of thin‑walled round steel tubes.*Journal of Physics:Conference Series*,2578(1),012061.
MLA 9th
Wang,Hao,and Yu Zhang.“Research on Cold Crimping Forming Process and Shape Adaptability of Thin‑walled Round Steel Tubes.”*Journal of Physics:Conference Series*,vol.2578,no.1,2023,p.012061,
GB/T 7714‑2015
WANG H,ZHANG Y.Research on cold crimping forming process and shape adaptability of thin‑walled round steel tubes[C]//Journal of Physics:Conference Series.IOP Publishing,2023,2578(1):012061.
