Pipe-bending technology in my country originated during the Bronze Age and has gradually evolved and developed. By the period spanning the Yin-Shang to the Spring and Autumn eras, the bronze smelting and casting industry was already highly advanced, producing various tools such as bronze knives, files, and saws. Archaeological finds and oracle bone inscriptions indicate that most bronze tools and implements produced during this period underwent cutting or grinding processes. my country's metallurgy and casting technology predated that of Western Europe by more than a millennium. Today, my country's machine tool manufacturing industry has reached maturity, particularly regarding conventional machine tools. Strictly speaking, machine tools serve as the vehicle for advanced manufacturing technology; the quality, rate of innovation, adaptability, and efficiency of mechanical products depend largely on them. Current demand in my country focuses primarily on mid-range CNC machine tools, machining centers, and specialized machine tools, with demand for other types being comparatively lower.

Driven by advancements in industrial technology, hydraulic transmission has become the fastest-growing technology in the field of mechanical equipment. Hydraulic pipe-bending machines—valued for their rational structure, ease of operation, safety, rapid loading/unloading capabilities, and versatility—are now widely used across various industries. Here, we examine the technology involved in retrofitting semi-automatic hydraulic pipe-bending machines.

The operating principle of the semi-automatic hydraulic pipe-bending machine is as follows: 1) Start the oil pump; 2) Press SB4; KA2 is energized, the mandrel advances, and the process completes upon contact with SO1; 3) Press SB5; KA3 is energized, clamping occurs, and the process completes upon contact with SO2; 4) Press SB6; KA4 is energized, the pressure die engages, and the process completes upon contact with SO3; 5) Press SB7; KA5 is energized, the bending arm advances, and the process completes upon contact with SO4; 6) Release SB7 (auto-reset), and all components return to their initial positions.

Although this hydraulic pipe-bending machine offers advantages such as high power transmission, precise control, and rapid response, it also suffers from the following drawbacks: 1) Low production efficiency due to an excessive number of operational steps; 2) High equipment wear and tear, resulting in a shortened service life; and 3) High labor requirements, leading to significant labor costs and higher overall product costs.Implementation of Automation

a) Modification Approach: Originally, the four actions of the pipe bending machine were not interlinked. To link them, we initially used proximity switches; however, this resulted in insufficient time intervals between actions, thereby compromising product quality. Subsequently, we incorporated time relays to introduce appropriate delays between the four actions, ensuring an orderly sequence and guaranteeing product quality.

b) Post-Modification Operating Principle: The schematic of the modified hydraulic pipe bending machine is shown in Figure 2. Its automatic operation sequence is as follows: Press the automatic run button (SB3) to initiate mandrel insertion; upon contact with limit switch XK5, mandrel insertion stops and clamping begins. After a 3-second delay, pipe clamping starts; upon contact with XK4, clamping stops and pressure application begins. After another 3-second delay, forward pushing and forward bending occur simultaneously. Once this stage is complete, the machine automatically resets: pressure is released, the clamp opens, reverse bending occurs, and the mandrel retracts, concluding the entire cycle.

c) Advantages of the Modification: The modified hydraulic pipe bending machine offers the following benefits: 1) Reduced operator actions, increased production efficiency, and a reduction in required personnel; 2) Reduced machine wear and extended service life; 3) Improved output and product quality.

Zhangjiagang Huameng Machinery Technology Co., Ltd. specializes in the manufacture of pipe bending machines, including CNC, hydraulic, and fully automatic models. Adhering to the business philosophy of "Customer First, Integrity-Based," we sincerely welcome new and existing customers to visit us; our entire team is dedicated to providing you with comprehensive service.