Die Casting machine servo energy saving principles

1.Die Casting machine hydraulic system principle overview.
The fully hydraulic die casting machine is a periodic working equipment of typical, in one comlpete cycle of operation(process) can be divided into clamping ,soup, and shoot, core pulling, mold, thimble, cooling, pressrue stages, each stage is through the oil pump hydraulic oil to the oil cylinder driving mechanism to drive complete a series of actions, the pressure and flow is different in different period. For the hydraulic system, each stage the pressure,flow matching are different, however the power of pump motor is based on the operation process of maximum load configuration and die casting machine, but a working cycle only high pressure mode locking and injection phase of the work load is large, the other stage is generally small, almost zero in the load cooling process. For the oil pump motor, the process of loading condition is changeable, in the pump hydraulic system, oil pump motor provide a constant flow at a constant speed, working pressure and flow rate required by size on pressure proportional valve and flow proportional valve to regulate, by adjusting the pressure or flow proportional valve opening to control pressure or flow. Redundant hydraulic oil through the relief valve return, this process is called high pressure closure, the energy loss about 70%.

2.Description of Die Casting machine pump system
The original casting hydraulic system with quantitative pump system of asynchronous motor, the motor drives the pump suction from the tank and pressure output, the control valve to control the oil pressure, flow and direction, to ensure that the working mechanism to a certain force(or torque)and certain speed according to the required direction. In order to achieve the process of die casting  machine. The traditional quantitative pump die casting machines are in the need to change the load flow and pressure, quantitative pump speed is not adjustable, with a valve, the excess oil through the overflow valve into the fuel tank, a large amout of energy in the form of loss pressure difference in valve.
Variation of hydraulic system load automatically adjust the output load, the excess energy can only be in the valve plate, oil leakage, oil temperature rise of consume, this process has the following drawbacks:
Wear all kinds of valves.
Cause the temperature up.
Motor noise too large.
And the mechanical life shortening phenomennon.

Servo control system benefits
a).Energy saving rate high: Complete elimination high pressure throttle, quantitative pump energy saving 30%-60%, than the variable pump energy saving 10%-30%.
b).Quick response:0-100%L, reduction of speed change up to 30ms time ≤ 0.1 seconds, 0-100% pressure change time ≤ 0.1 second, improve production efficiency.
c).Precise control: because the speed feedback and the pump servo motor itself pressure sensor and actuator forms two closed loop control, thus greatly improve the accuracy.
d).High overload capability: servo torque overload ratio ≥ 200%.
e).State transition flexible: speed, torque control flexible switch, smoothing.
f).Reduce hydraulic oil temperature: ruduce the amount of cooling water more than 30%, some even without water.
g).Prolong the service life of the equipment: reduce the opening, locking impact, prolong the hydraulic oil pump, mechanical and service life of die.
h).Noise: noise reduction, reduction of environmental pollution.