Abstract: A mold-clamping device includes a fixed mold plate including a fixed mold; a movable mold plate including a movable mold; a hydraulic cylinder allowing the movable mold plate to approach or be separated from the fixed mold plate; a hydraulic pressure supply source supplying a hydraulic fluid to the hydraulic cylinder; and a control unit performing driving control on the hydraulic pressure supply source. The control unit includes a flow rate decrease control unit for deceleration for decreasing a flow rate of the hydraulic fluid according to a deceleration gradient set in advance when a movement of the movable mold plate is decelerated according to the deceleration gradient, and a flow rate increase control unit for controlling the flow rate of the hydraulic fluid to increase when the flow rate of the hydraulic fluid is decreased according to the deceleration gradient by the flow rate decrease control unit.

Abstract: The hydraulic source control device includes an operation input device capable of inputting operation conditions regarding the driving force of a fluid pressure control element, a servo motor including a motor section that drives a hydraulic pump and an amplifier that drives the motor section, and a controller that outputs a control command to the servo motor based on an input result to the operation input device. The controller obtains the fluid pressure of a working fluid based on the operation conditions regarding the input driving force, computes the output torque of the motor section based on the relationship between the fluid pressure and the output torque that are stored in advance, and outputs the computed output torque to the amplifier as a control command of the torque limitation value of the servo motor.

Abstract: A hydraulic supply device of an injection molding machine is provided with: a first main hydraulic power source including a first main hydraulic pump having a variable capacity and driven by a first constant rotational speed motor, and a first main discharge pipe through which working oil flows; an auxiliary hydraulic power source including an auxiliary hydraulic pump driven by a servo motor and operated at a specific capacity, an auxiliary discharge pipe through which the working oil flows, and a check valve that regulates the inflow of working oil to the auxiliary hydraulic pump; a hydraulic control unit that controls the first main hydraulic power source and the auxiliary hydraulic power source; a junction pipe at which the first main discharge pipe and the auxiliary discharge pipe join; and a switching unit that switches the supply/non-supply of working oil for a hydraulic actuator.

Abstract: A hydraulic oil storage device and an injection molding device are provided with a connection box that partitions a storage region of a sub-tank into a first region that includes a flow channel opening portion for a coupling tube and a second region other than the first region, in which the connection box is provided with an internal region communication portion that brings the first region and the second region into communication, and causes a pressure loss equal to the pressure loss of the coupling tube, or a pressure loss greater than that pressure loss, and a return tube is connected to the sub-tank so that the flow channel outlet faces the first region.

Abstract: A mold-clamping device includes a fixed mold plate including a fixed mold; a movable mold plate including a movable mold; a hydraulic cylinder allowing the movable mold plate to approach or be separated from the fixed mold plate; a hydraulic pressure supply source supplying a hydraulic fluid to the hydraulic cylinder; and a control unit performing driving control on the hydraulic pressure supply source. The control unit includes a flow rate decrease control unit for deceleration for decreasing a flow rate of the hydraulic fluid according to a deceleration gradient set in advance when a movement of the movable mold plate is decelerated according to the deceleration gradient, and a flow rate increase control unit for controlling the flow rate of the hydraulic fluid to increase when the flow rate of the hydraulic fluid is decreased according to the deceleration gradient by the flow rate decrease control unit.

Abstract: A hydraulic supply device of an injection molding machine is provided with: a first main hydraulic power source including a first main hydraulic pump having a variable capacity and driven by a first constant rotational speed motor, and a first main discharge pipe through which working oil flows; an auxiliary hydraulic power source including an auxiliary hydraulic pump driven by a servo motor and operated at a specific capacity, an auxiliary discharge pipe through which the working oil flows, and a check valve that regulates the inflow of working oil to the auxiliary hydraulic pump; a hydraulic control unit that controls the first main hydraulic power source and the auxiliary hydraulic power source; a junction pipe at which the first main discharge pipe and the auxiliary discharge pipe join; and a switching unit that switches the supply/non-supply of working oil for a hydraulic actuator.

Abstract: A method by which an operation characteristic of a proportional electromagnetic control valve can be automatically measured in a short period of time. For this purpose, in the operation characteristic measuring method of the present invention, when the proportional electromagnetic control valve to be measured is a proportional electromagnetic pressure control valve, at each step for measuring a pressure of a hydraulic circuit, the pressure is measured with a predetermined interval of time, the pressure is assumed to be stabilized at a point of time when a difference &Dgr;P between the measured pressure value and the previously measured pressure value becomes a predeterminied level or less, and the measured pressure value at this point of time is employed as a pressure corresponding to a load current at this step.