Die-casting machine asynchronous servo energy-saving control method and system

Abstract

The invention discloses a die-casting machine asynchronous servo energy-saving control method. The method includes a speed control method of an oil pump motor and an advanced acceleration method of the oil pump motor. In the speed control method of the oil pump motor, the rotating speed N of the oil pump motor is equal to N rate *PQW, wherein the N rate is the rated rotating speed of the oil pump motor. PQW is a self-adaptation motor speed given instruction of the oil pump motor, PQW is equal to PQ+ PQ auxiliary, and the PQ auxiliary is a motor fine tuning speed given instruction. PQ is a motor preliminary speed given instruction, PQ is equal to K*Q+(1-K)*P or PQ is equal to MAX {Q, P}, wherein Q is a flow coefficient of a die casting machine, Q is larger than or equal to 0 and smaller than or equal to 1. P is a pressure coefficient of the die casting machine, and P is larger than or equal to 0 and smaller than or equal to 1. K is a weight coefficient, and K is larger than or equal to 0 and smaller than or equal to 1. In the advanced acceleration method of the oil pump motor, the self-adaptation advanced time instruction delta t of the oil pump motor is equal to T average-T advance, and T advance is smaller than or equal to T average. The T advance is the set pre-advanced time of the die casting machine, and the T average is the average value of mechanical action time differences of all working stages of the production period of the die casting machine.

Description

technical field [0001] The invention belongs to the technical field of energy-saving control of die-casting machines, and in particular relates to an asynchronous servo energy-saving control method of a die-casting machine and a control system suitable for the control method. Background technique [0002] Aluminum alloy cold chamber die-casting machine processing equipment is a typical cyclical load type equipment, and its complete working cycle generally includes mold closing - feeding soup - injection - pressure relief (cooling) - mold opening - ejection - picking (energy storage )—Several processes such as spraying, each process uses the oil pump motor pump to output hydraulic oil to each oil cylinder to drive the transmission mechanism to complete a series of actions, and the pressure and flow required for each stage are different. For the hydraulic system, the matching of pressure and flow is different at each stage, while the power of the quantitative pump (generally q...

AI Technical Summary

Problems solved by technology

Theoretically, this transformation plan can meet the quick response requirements of the die-casting machine, but this transformation plan also has its own fatal shortcomings:

[0007] 1) For large-tonnage die-casting machines of 900 tons or more, since there is no other oil pump on the market to replace the double vane pump with large flow and high pressure characteristics, multiple servo oil pumps have to be installed on site to meet the pressure and flow requirements. Result in complicated installation and high cost!

[0008] 2) Due to the harsh production environment of the die-casting machine workshop (above 40°C in summer), the permanent magnet servo motor has the defect of demagnetization. After a long service life, the magnetic field will fade away, which greatly increases the failure rate of the equipment. Since the servo motor cannot be re-applied after demagnetization magnetic, you have to re-purchase a new servo motor

This greatly increases the maintenance cost of the enterprise's equipment, and the saved electricity is far from enough to purchase the equipment

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