Unique PQ (pressure and flow) decoupling control scheme and multi-stage PID control technology, faster molding and more precise; stand-alone power range of 7.5kW-55kW, for the die casting machine with a system displacement of 320L / min above, due to the limit of oil pump displacement and response speed, the control program of multi-pump confluence can be used.
3. Features of hydraulic servo control scheme
1) Energy saving: the system pressure, flow double closed loop, the hydraulic system supplies the oil in accordance with the actual needs of flow and pressure, which has overcomed the high energy consumption generated by the high pressure overflow of ordinary quantitative pump system, it has decreased the motor rotational speed in the pressure, cooling and other low flow working stages, pump motor actual energy consumption has been reduced by 50% -80%.
2) Fast response, high production efficiency: fast response, pressure and flow rise time as fast as milliseconds, which have improves the response speed of hydraulic system, and reduced the action conversion time, speeded up the running of whole beat; When the hydraulic system of die-casting machine is running automatically, the system pressure will drop instantaneously once the valve opens. MH500 servo can quickly replenish the oil within 30ms and restore the pressure to the set value.
3) Stable and precise pressure: strong servo adjustment ability, pressure closed-loop control mode makes the system pressure very stable, pressure fluctuations less than ± 1kg, which have improved the molding quality of metal products; In accordance with arbitrary pressure, flow curve set by the computer, it has created the conditions for the development of various metal products molding process.
4) Low noise, weak vibration: the servo is driven under the vector control, so the servo motor runs very smoothly, under normal circumstances, the motor noise almost cannot be heard, there is only a small vibration in running, that is the so-called moisturizing silence.
5) Speed increasing and large flow: adopt constant power control technology, the constant power of motor with rated speed of 1500RPM is improved to 2000RPM, which has improved the opening and closing speed of die-casting machine; Under the premise of ensuring the same flow, choose the pump with a small displacement, motor and drive with a lower class power to reduce the system costs.
4. Servo die casting machine features
1) Single mode has a higher energy saving rate: the complete elimination of high pressure throttling, energy saving than traditional die-casting machine 40% -70%.
2) Fast response speed of servo system: 0-100% pressure changes up to 30ms, improve production efficiency of 5% -12%. Take Yizumi DM500 model as an example, the production of a product, the original cycle of 34s, the cycle time is improved to 31s after being put into servo system.
3) Reduce the hydraulic oil temperature: reduce more than 30% cooling water amount, in some occasions even without water cooling, improve the lifetime of hydraulic components and reduce the amount of maintenance.
4) improve the working environment: reduce operating noise, in the non-working state, the servo motor is in the stop state, no noise, the general full load running time is very short, which has reduced the overall noise.
5. Transformation application of die casting machine
In the composition of the cost of die-casting machine production, electricity fee accounts for a considerable proportion, the power consumption of traditional die-casting machine oil pump motor accounts for 50% -80% of the entire equipment power consumption. The energy saving transformation of die-casting machine servo has greatly reduced the energy consumption of oil pump motor and realized the high energy-saving rate of die-casting machine. At the same time, it has great effect on the improvement of machine precision, production efficiency and qualified rate. Ordinary die-casting machine servo transformation will become the leading direction of domestic die-casting machine energy-saving transformation, only the first half, INVT transformed die-casting machine reaches more than 200 units in East China.
After the energy saving transformation of die-casting machine servo, the system pressure, flow double closed loop, hydraulic system will supply the oil in accordance with the actual needs of flow and pressure, which has overcomed the high energy consumption generated by the high pressure overflow of ordinary quantitative pump system.
After the energy saving transformation of die-casting machine, when the servo system controls the oil pump, because the servo can quickly respond to the given control signal, and can flexiblely switch between speed control and torque control to achieve motion control or die control, So the working cycle can also be shortened, the quality of die-casting products have also been improved; reasonable fuel supply control has reduced the load and power loss of cooling system.
Figure 1: Motor and pump before the transformation of die-casting machine
Figure 2: Servo motor and gear pump after the transformation of die-casting machine
Figure 3: the transformation application of MH500 hydraulic servo in Yizumi die-casting machine
Figure 4: The transformation application of MH500 hydraulic servo in the force casting machine
Figure 5: The transformation application of MH500 hydraulic servo in double pump
In recent years, with the increasingly high demand of customer for the die-casting machine efficiency, stability, low energy consumption, maintainability and other aspects and a substantial decline of the mature application and price of servo motor. The drive part of die-casting machine also evolves from the application technology of quantitative pump into a servo technology.
MH500 servo energy-saving technology is another major breakthrough of hydraulic drive technology in the field of die-casting machine. Under the premise of meeting the demand of cost, performance, and stability, MH500 electro-hydraulic servo system has perfectly solved to the user concerned about the cost, efficiency, oil temperature and other issues, representing the development direction of die-casting machine