Application example of energy recovery of accumulator Ⅲ

Using servo pumps or variable-speed pumps to directly control the motion of the differential hydraulic cylinder without throttling elements is one of the effective ways to achieve energy saving and reduce system heating in the field of hydraulic control technology. It is also a research hotspot at home and abroad. Develop an optimized loop principle to meet the requirements of the dynamic and static characteristics of the system while reducing energy consumption to a minimum. Based on this idea, a single variable pump combined with an accumulator and a bypass proportional valve is used for the characteristics of the movement in the injection molding machine. The loop principle of compound control of the differential cylinder movement not only simplifies the system, but also reduces the daily energy consumption of the clamping mechanism from 18KW/S to 11KW/S.
The circuit principle of using variable pump, proportional valve and accumulator to control the differential cylinder to drive the mold locking mechanism of the glue injection machine is shown in the figure.
The characteristic of the circuit is that when the piston rod of the hydraulic cylinder is extended, the hydraulic pump provides power, and at the same time the kinetic energy of the movement of the hydraulic cylinder is converted into pressure energy and stored in the high-pressure accumulator; when the piston rod is retracted, the accumulator provides energy to the system. In order to eliminate the energy consumed when the motor is under braking during the return stroke, a proportional throttle valve is connected in parallel between the hydraulic pump and the oil tank. In this way, when the piston rod is recovered, the hydraulic pump stops working and the proportional throttle valve controls the speed of the cylinder. . This circuit principle is not only suitable for variable speed pumps, but also for systems composed of traditional servo pumps. And only a hydraulic pump that works in one direction is needed. The glue injection machine has a long pressure-holding and constant-cooling cycle. The variable-speed pump composed of a servo motor and a quantitative pump is used as the power source to reduce the energy consumption of the motor during the cooling and pressure-holding cycles.