Provided is a press forming apparatus for a semi-solid metal material, including: a slide caused to make a reciprocating linear motion; a sub-slide mounted so as to be movable relatively to the slide; a fluid pressure mechanism interposed between the slide and the sub-slide, which is capable of moving the sub-slide relatively to the slide by fluid pressure; an upper die mounted to the sub-slide; and a lower die. The press forming apparatus is configured to press-form the material while applying predetermined pressure to the material for a predetermined period by bringing, along with descent action of the slide, the upper die into contact with the material fed into the lower die, then stopping the slide at a predetermined position, and moving the upper die mounted to the sub-slide relatively to the slide by the fluid pressure mechanism under a state in which the slide is stopped.

A hydraulic drive including at least one hydraulic cylinder that includes a piston chamber, an annulus, and a piston that separates the piston chamber from the annulus. The hydraulic drive also includes a first hydraulic pump hydraulically connected with the piston chamber, a second hydraulic pump hydraulically connected with the annulus, a third hydraulic pump, and a directional control valve that has a first switching position and a second switching position. The third hydraulic pump in the first switching position of the directional control valve is hydraulically connected with the piston chamber, and the third hydraulic pump in the second switching position of the directional control valve is not hydraulically connected with the piston chamber.

A machine press is provided in which at least one hermetically sealed hydraulic drive unit is switchable from a working mode, in which a base pressure above ambient pressure is continually exceeded, into a rest mode. To this end, in parallel with a pressure converter, to the high-pressure side of which a pressure store and a raising working chamber of a cylinder piston unit are connected, a bypass is provided, having a first blocking valve that is controllable by a control unit and, in its blocking position, blocks the through-flow direction from the high-pressure side of the pressure converter to the low-pressure side. Furthermore, the low-pressure side is connectable to a lowering working chamber via a second blocking valve controllable by the control unit. The pressure output of the hydraulic unit is connectable to the raising working chamber via a third blocking valve controllable by the control unit.

A hydraulic drive including at least one hydraulic cylinder that includes a piston chamber, an annulus and a piston that separates the piston chamber from the annulus. The hydraulic drive further includes a first hydraulic pump that has a pump intake and a pump outlet, a directional control valve that has a first and a second switching position, and a second hydraulic pump. The second hydraulic pump has a direction of delivery that is consistent with the direction of delivery of the first hydraulic pump at the pump outlet, wherein the second hydraulic pump in the first switching position of the directional control valve is hydraulically connected with the piston chamber and the second hydraulic pump in the second switching position of the directional control valve is not hydraulically connected with the piston chamber.

A hydraulic drive system for operating a hydraulic cylinder in first and second movement profiles. A hydraulic drive unit includes first and second hydraulic machines, each with first and second connections. In the first movement profile, a first cylinder chamber of the hydraulic cylinder is fluidly connected to a first fluid reservoir and a second cylinder chamber is fluidly connected to the second connection of the second hydraulic machine. In the second movement profile, the first connection of the first hydraulic machine is connected to the second connection of the second hydraulic machine.

The invention relates to a hydraulic drive device (11) with at least one press cylinder, in particular a press synchronous cylinder, for a hydraulic press, preferably a powder press (10), wherein the hydraulic drive device is configured to guide a cylinder piston of the press cylinder in a rapid movement at increased speed towards a pressed part and to press the pressed part in a pressing movement at low speed, wherein the drive device comprises a switching valve (17), a controllable pressing movement pump (15), in particular a speed-controllable pressing movement pump (15) for conveying fluid for the pressing movement and a control unit (28) for controlling the pressing movement pump (15), wherein the drive device is configured to perform the rapid movement when the switching valve (17) is open and to perform the pressing movement when the switching valve (17) is closed, wherein the control unit (28) is configured to control the pressing movement pump (15) in such a way that a conveyance rate of the pressing movement pump (15) is already increased before the closing of the switching valve (17).

A drive device for a bending press, in particular a press brake, with a press frame includes a stationary press beam and has a press beam which can be displaced relative to the press beam by a beam adjusting device formed by a closed hydraulic system including a hydraulic pump with a controllable drive motor, at least one control valve and at least one hydraulic linear actuator. The linear actuator includes a first piston arrangement with a first piston dividing a cylinder chamber into a first pressure chamber and a second pressure chamber and, in another cylinder chamber, a second piston arrangement with another piston and at least one other pressure chamber. The first piston arrangement and the second piston arrangement are coupled with one another.

A hydraulic drive including a first differential cylinder that includes a first and a second pressure chamber and a first piston that separates the first from the second pressure chamber and having two pumps delivering in opposite direction. The hydraulic drive further includes a second differential cylinder that includes a first and a second pressure chamber and a second piston that separates the first pressure chamber from the second pressure chamber, and a directional control valve that has a first and a second switching position. The pumps in the first switching position are respectively hydraulically connected via pressure chambers of the first differential cylinder that are different from each other and whereby the pumps in the second switching position are respectively connected via pressure chambers of the second differential cylinder that are different from each other.

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.

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.