Energy-saving Research And Design In Hydraulic System Of Block Forming Machine

The hydraulic system of block forming machine powers forming action, and in the traditional design method of hydraulic system in block molding machine, it is usually that the velocity of piston is improved by increasing the flow of system to shorten the block molding cycle. High-speed movement of the piston will have a huge impact on the hydraulic cylinder, so the velocity of the piston in hydraulic cylinder must be restricted to some extent. But it is generally that flow control valve controls speed of hydraulic cylinder, which would cause the loss of flow and pressure loss. It can be seen that increasing flow of system simply to shorten the molding cycle, and to increase the velocity of the piston, could bring the great energy consumption of hydraulic system.To solve the problem of low efficiency and large energy loss in the hydraulic system, with the original hydraulic system of each mechanism in block forming machine studied, and the workings of the hydraulic loop analyzed, the reason that energy loss exist in each loop of hydraulic system is found. Analysis shows that the energy loss of the whole hydraulic system mainly exists in the molding process. After learning the domestic and overseas technology of saving energy in hydraulic system, combining with the characteristics of block forming machine’s hydraulic system, ultimately, the scheme with energy saving of hydraulic system is been determined, designing the schematic diagram of energy-saving hydraulic system.Pressure-limited variable pump and constant delivery pump are been chosen as the pumping source in the energy-saving hydraulic system, and grouping hydraulic actuator reasonably makes hydraulic system effectively use the flow from two hydraulic pump. Pressure-limited variable pump could meet the requirements high-pressure with low-flow, or low-pressure with large-flow. Cushioning technique for cylinder (Patent No.:201310290341.2) is been used in the hydraulic system, so improving the maximum speed of hydraulic cylinder piston is allowed. When move to the end of hydraulic cylinder, the piston in the cylinder can be smoothly stop in the action of buffer structure, reducing the impact that the piston put on the end of hydraulic cylinder, increasing speed of actuator, shortening the molding cycle. The load-sensing counterbalance valve (Patent No.:200610102007) is been used in die forming loop of Energy-saving hydraulic system. When the die down fast, the load-sensing counterbalance valve adjusts the return oil pressure automatically according to the magnitude of the load, ensuring die head be smoothly down. When the die molds, the load-sensing counterbalance valve changes the orifice size automatically, reducing pressure in cavity of discharge, thereby reducing the energy consumption of hydraulic system.The performance of the energy-saving hydraulic system is checked, counting pressure loss in hydraulic system, and the energy utilization rate reaches83%, which shows that the system is energy saving and high efficiency. Analysis on the modeling of hydraulic system and energy-saving hydraulic system with AMEsim software, power of hydraulic pump in energy-saving hydraulic system is lower than that in the original hydraulic system in the whole period. The relief valve in the energy-saving hydraulic system only plays the role of keeping safety, and the effect of energy conservation is obvious.Designing the energy-saving hydraulic system from an overall perspective, makes output flow from the hydraulic pump match load, and reduces the loss of overflow and the pressure loss of the system. Considering to reduce energy loss meanwhile to shorten the molding cycle, reduces energy consumption in production of single block, and the cost of block production.