Patent ID: 8163223

Claim:
A control method for an injection molding machine, comprising: controlling at least two operational processes in a molding cycle by variably controlling a number of revolutions of a drive motor in a hydraulic pump which is capable of setting a first fixed discharge flow rate Qo for enabling the hydraulic pump to function as a small-capacity hydraulic pump, and a second fixed discharge flow rate Qs for enabling the hydraulic pump to function as a large-capacity hydraulic pump having a capacity larger than the small-capacity hydraulic pump, setting the hydraulic pump to one of the first and second fixed discharge flow rates Qo, Qs corresponding, respectively, to each of the at least two operational processes based upon one or more predetermined conditions of the injection molding machine determined in advance by an operator, and switching the hydraulic pump to one of the first and second fixed discharge flow rates Qo, Qs corresponding, respectively, to each of the at least two operational processes while concurrently, each of the operational processes are controlled by variably controlling the number of revolutions of the drive motor, wherein the step of setting the first and second fixed discharge rates Qo, Qs is performed by changing an operation mode of the hydraulic pump, and further comprising: changing the operation mode of the hydraulic pump by changing an angle Rs at which a swash plate of the hydraulic pump is positioned from one to another of a plurality of fixed positions.