Analysis And Transformation Of Energy-saving For Hydraulic System Forming Method Of Both Water Bulge And Cold Roll

Water bulge forming and cold roll forming are two forming methods in machining. In liquid (water, emulsified liquid or oil) as a power transmission medium, water bulge forming through the die makes the hollow or tubular blank expand from inside to outside stating in the absence of friction and is used widely in vacuum cup (stainless steel, copper, aluminum, iron and other materials), thermos, water bottles and other utensils. Cold roll forming is elastic, and plastic deformation that is bent by fluid pressure. But cold roll forming of hull profiles is a difficult plastic process. Two forming methods are based on the hydraulic drive system for mechanical power transmission equipment.Therefore, the research of energy-saving technologies of hydraulic systems regarding the two forming methods is of great significance.Firstly, this paper analyses the energy loss of hydraulic system, for example:the energy consumption of the power components, the energy consumption of the control unit, the energy consumption of actuator, the energy consumption of pipeline and common energy-saving technology. For example:improving the efficiency of hydraulic pumps and the efficiency of hydraulic valves, reducing the loss of hydraulic line pressure and system heat and leakage. The paper also descripts the energy-saving hydraulic circuit block layout called three-dimensional path connection rules.Secondly, this paper analyses hydraulic system diagram of the water bulge forming and the energy consumption of master cylinder movement circuit and conducts a simulation analysis of this circuit. The paper proposes energy efficiency program of master cylinder movement circuit, for example:pump control loop, pressure matching system,and analyses its advantages and disadvantages; the paper also proposes energy recycling loop, the accumulator and secondary regulation technology are used in the loop, analyses and compares them separately from improving the motor drive power. Then this paper obtains that the secondary regulation technology is an ideal energy saving solution other than full utilization of energy and recycling areas. Lastly, the paper introduces the principle of cold roll forming and hydraulic loop components and analyses energy-saving breakthrough used in the hydraulic circuit of cold roll forming called power matching. This paper proposes load-sensing technology used in the main bending circuit. Although it can make output pressure and flow of pump automatically adapt to the needs of the load, improve the efficiency of hydraulic system considerably, there are still many drawbacks. The paper also proposes a more efficient method of energy conservation called the use of electro-hydraulic proportional valve through controlling its input current to drive the spool displacement and gets the effect for controling the cylinder, but this method has more serious pressure losses. Finally, this paper uses electro-hydraulic valve and limited pressure variable pump, called pump control circuit through reducing pressrue loss and improving the efficiency of the circuit.