The present invention relates to a servo hydraulic press for sheet metal forming. The press comprises a hydraulic cylinder, at least two servo motors and at least two pumps for supplying pressurized fluid to the hydraulic cylinder, where each servo motor drives at least one pump. The servo motors are operable at variable speed, and the first servo motor and first pump are operable in an opposite direction to the second servo motor and the second pump. With this arrangement, the servo hydraulic press may be operated at low speed without causing damage to the pumps or motors.

In a press forming device and a press forming method for press-forming a workpiece that includes a load control region to which a constant load is to be applied, the press forming device includes a die unit that includes an upper die and a lower die that sandwich the workpiece; a slider that holds the upper die; a bolster that holds the lower die; a pressing mechanism that presses the slider toward the bolster at a plurality of pressing points; and one or more support blocks arranged around the die unit, between the bolster and the slider. The support block is arranged farther outward than the pressing points, on a line that extends, in an arrangement direction of the pressing points, from a reference point on an end portion of the load control region.

In an apparatus and a method for controlling the primary drive of a hydraulically driven fine blanking press, the hydraulic circuit is simplified due to the elimination of hydraulic tubes, and the amount of hydraulic fluid is reduced, while increasing the number of strokes and achieving a simple design for the press.

A press brake includes a ram to which an upper or lower tool can be attached; a movable ram driver; and a controller that controls the ram driver, wherein the ram driver includes a rotation/linear motion converter composed of a screw fixed to the ram and moves upward and downward as the ram moves upward and downward, and a nut screw-coupled with the screw; a drive rotation body arranged rotatably about a rotation axis of the nut; a first motor arranged in a fixed state; a first power transmitter that transmits rotation of the first motor to the nut at high speed and with low torque; a second motor arranged in a fixed state; a second power transmitter that transmits rotation of the second motor to the drive rotation body at low speed and with high torque; and a clutch provided between the nut and the drive rotation body.

A motor control device, includes a pressure command unit calculating a pressure command for commanding pressure generated in a pressure control object, a pressure detection unit detecting the pressure generated in the pressure control object, a pressure control unit calculating a speed command for pressure control for the servo motor, based on the calculated pressure command and the detected pressure, and a servo control unit controlling speed of the servo motor, based on the calculated speed command. The pressure control unit performs an integral operation. When a direction of increasing pressure in the integral operation is defined as a positive direction in the integral operation, and a direction of decreasing the pressure is defined as a negative direction, a median between an upper limit in the positive direction and a lower limit in the negative direction in the integral operation is larger than zero.

This disclosure relates to methods and apparatuses for punching workpieces. A punching tool is configured to move during a punching stroke along a stroke axis towards a workpiece to be punched. The punching tool is configured to move away from the punched workpiece during a return stroke. The punching tool includes first and second components configured to be coupled hydraulically for concurrent movement along the stroke axis. The punching tool includes a punching drive for moving the first component along the stroke axis. The punching apparatus is configured to move the second component relative to the first component at a first transmission ratio during the punching stroke. The punching apparatus is configured to move the second component relative to the first component at a second transmission ratio in response to a reaction force of the workpiece exceeding a threshold value of the punching drive during the punching stroke.

The present invention relates to an electro-hydrostatic system (1) with a hydraulic machine (11) which is driven by an electric motor (10) and has a variable volume and/or rotational speed for providing a volumetric flow rate of a hydraulic fluid, a differential cylinder (20) with a piston surface and with an annular surface, and at least one equalization container (30, 37), wherein the drive system (1) has a closed hydraulic circuit and during operation has an overpressure relative to the environment by means of the hydraulic machine (11) and/or a pretensioning source (15, 37), and the drive system (1) provides a movement of the cylinder in a first direction by means of a volumetric flow rate of the hydraulic machine (11) and a volumetric flow rate from the equalization container (30, 37), and provides a movement in a second direction by means of a volumetric flow rate of the hydraulic machine (11) and a volumetric flow rate into the equalization container (30, 37), and a power operating mode and a speed operating mode are provided with the differential cylinder (20).

A hydraulic drive including a differential cylinder that has a first pressure chamber and a second pressure chamber and a differential piston, a first hydraulic pump that includes a pump intake and a pump outlet, a directional control valve having a first switching position and a second switching position, a high pressure tank, and an additional hydraulic cylinder that includes an additional pressure chamber hydraulically connected with the pump intake and with the high pressure tank and an additional piston limiting the additional pressure chamber, the differential piston being movably coupled with the additional piston, wherein in the first switching position of the directional control valve the first pressure chamber is hydraulically connected with the second pressure chamber, and in the second switching position of the directional control valve the second pressure chamber is not hydraulically connected with the first pressure chamber.

An actuator device includes two drive units for an actuator output element. The first drive unit has a first piston chamber and a first piston displaceable therein and also first hydraulic means for displacing the piston. The second drive unit has a second piston chamber and a second piston displaceable therein and also second hydraulic or pneumatic means for displacing the piston. The second piston is joined to the actuator output element for conjoint movement therewith and can be coupled to the first piston for thrust, so that the second piston is displaceable in an outward direction by the first piston. The first drive unit is configured for a larger thrust force than the second drive unit, while the second drive unit is designed for a greater stroke speed than the first drive unit.

A high-speed hydraulic forging press is disclosed. The high-speed hydraulic forging press includes a forging hammer, a movable beam, a main hydraulic cylinder, a single-rod elevation hydraulic cylinder, a plurality of main hydraulic pumps, a high-pressure energy accumulator, an intermediate-pressure energy accumulator, an oil tank, a programmable logic controller and a valve-regulation system. During a rolling process, when a rolling resistance applied to the forging hammer increases to cause pressure in the main hydraulic cylinder to reach a predetermined value, the programmable logic controller controls the valve-regulation system so that the high-pressure energy accumulator stops supplying the hydraulic oil to the main hydraulic cylinder, and that the hydraulic oil in the main hydraulic cylinder is supplied by at least one of the plurality of main hydraulic pumps. The high-speed hydraulic forging press exhibits remarkable advantages including a reasonable resource allocation, a simple structure, low equipment investment, and high energy utilization.