A punch press includes a die, a punch, a support that supports the punch, a shifting member, and a rotating mechanism. The shifting member includes an opposing surface that opposes the punch. The shifting member is movable toward and away from the die together with the support and the punch and rotatable about an axis extending in a direction in which the shifting member moves toward and away from the die. The shifting member includes a recess in the opposing surface. The rotating mechanism rotates the shifting member about the axis to shift the shifting member between an abutment position where the basal end surface of the punch is abut against the opposing surface and a retraction position where the basal end surface of the punch is retracted into the recess.

A punch press includes a die, a punch, a support that supports the punch, a shifting member, and a rotating mechanism. The shifting member includes an opposing surface that opposes the punch. The shifting member is movable toward and away from the die together with the support and the punch and rotatable about an axis extending in a direction in which the shifting member moves toward and away from the die. The shifting member includes a recess in the opposing surface. The rotating mechanism rotates the shifting member about the axis to shift the shifting member between an abutment position where the basal end surface of the punch is abut against the opposing surface and a retraction position where the basal end surface of the punch is retracted into the recess.

A punching device includes a body, a drive unit connected to an upper part of the body, and a cam block that moves in a horizontal direction in the interior of the body under a driving action of the drive unit. A second rotating roller, which is connected to a rod, is inserted in a second cam groove of the cam block. The second cam groove includes first and second groove portions inclined at predetermined angles with respect to the direction of movement of the cam block, such that when the rod descends downwardly toward a workpiece, a second rotating roller moves from the second groove portion to the first groove portion having a smaller angle of inclination, whereby the driving force transmitted to the rod is boosted in power.

A punching device includes a body, a drive unit connected to an upper part of the body, and a cam block that moves in a horizontal direction in the interior of the body under a driving action of the drive unit. A second rotating roller, which is connected to a rod, is inserted in a second cam groove of the cam block. The second cam groove includes first and second groove portions inclined at predetermined angles with respect to the direction of movement of the cam block, such that when the rod descends downwardly toward a workpiece, a second rotating roller moves from the second groove portion to the first groove portion having a smaller angle of inclination, whereby the driving force transmitted to the rod is boosted in power.

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.

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 a method and an apparatus for reducing the cutting impact in a hydraulically-driven precision blanking press, the force necessary to reduce the cutting impact as a counterforce is generated directly in the pressure chamber of the drive piston such that the counterforce acts directly on the cutting punch and so that the design of the press can be simplified, costs can be reduced, no additional external hydraulic-mechanical means for reducing the cutting impact are needed, and so that the loads on the press and the die can be reduced.

In a method and an apparatus for reducing the cutting impact in a hydraulically-driven precision blanking press, the force necessary to reduce the cutting impact as a counterforce is generated directly in the pressure chamber of the drive piston such that the counterforce acts directly on the cutting punch and so that the design of the press can be simplified, costs can be reduced, no additional external hydraulic-mechanical means for reducing the cutting impact are needed, and so that the loads on the press and the die can be reduced.

An exchangeable plate is suspended on a top plate and held in a lower end position without force by a hydraulic clamps. In an upper end position, it is connected with force fit to, and re-detached from, the top plate as a function of a stripping operation of a scrap web from a V-ring pressure plate. The exchangeable plate is transferred from the lower into the upper end position by movement of a ram, and transferred from the upper into the lower end position by gravity. A sensing distance, adapted to the brake path of the drive system, is provided between the top plate and the exchangeable plate. A sensing device in the V-ring pressure plate outputs a signal to the computer for stopping the drive system and deactivating the hydraulic system. A. sensor detects premature movement of a pressure plate in the exchangeable plate.

An exchangeable plate is suspended on a top plate and held in a lower end position without force by a hydraulic clamps. In an upper end position, it is connected with force fit to, and re-detached from, the top plate as a function of a stripping operation of a scrap web from a V-ring pressure plate. The exchangeable plate is transferred from the lower into the upper end position by movement of a ram, and transferred from the upper into the lower end position by gravity. A sensing distance, adapted to the brake path of the drive system, is provided between the top plate and the exchangeable plate. A sensing device in the V-ring pressure plate outputs a signal to the computer for stopping the drive system and deactivating the hydraulic system. A. sensor detects premature movement of a pressure plate in the exchangeable plate.