A pressing apparatus 1 includes a storage 27 that stores a plurality of actual data which are load data which was actually measured and which are configured of a first information and a second information, and a plurality of reference data which is a reference for the load data, an adjustor 23 that expands and contracts the first information of at least one of an actual data pattern which is based on the plurality of the actual data stored in the storage 27 and an reference data pattern based on the plurality of the reference data stored in the storage 27 to correspond with each other, and a determiner 24 that determines appropriateness of a load applied to the ram 9 in a pressing operation based on a similarity of the actual data pattern adjusted by the adjustor 23 and the reference data pattern adjusted by the adjustor 23.

An electric cylinder system includes: an electric cylinder including a rod and a strain detector; an output unit configured to output, on the basis of a reference load value in accordance with an output value of a strain detector for calibration obtained when the rod presses the strain detector for calibration and a measurement load value in accordance with an output value of the strain detector obtained when the rod presses the strain detector for calibration, a gain and an offset for causing the measurement load value to approach the reference load value; a storage unit configured to store the gain and the offset as a calibration parameter; and a calibration unit configured to calibrate a load value in accordance with an output value detected by the strain detector on the basis of the calibration parameter wherein the gain and the offset satisfy a preset relationship.

An electric cylinder system includes: a rod; a ball screw mechanism; a nut connected to the rod; a cylindrical body including a contact portion, the contact portion configured to be abutting the nut making the linear motion, the cylindrical body configured to support the ball screw mechanism in such a manner that the ball screw mechanism is displaceable in the axis direction of the ball screw; a strain detector fixed to the cylindrical body and configured to detect a value corresponding to a displacement of the ball screw mechanism; and a control section configured to make the ball screw mechanism be displaced by making the nut abut against the contact portion, and configured to detect an abnormality of the strain detector based on the value detected by the strain detector according to the displacement of the ball screw mechanism.

A curvature retaining device (1) includes two support points (25a) that can abut against one surface of a plate-shaped workpiece W, one or more pressing points (40a) that can abut against a position of the other surface of the plate-shaped workpiece (W) between the support points (25a), and forward/backward drive means (support unit (23) and pressing unit (33)) for moving at least either the support points (25a) or the pressing points (40a) forward to and backward from the other. Preferably, the two support points (25a) abut against the one surface of the plate-shaped workpiece (W) at a first distance (Ls), the two pressing points (40a) abut against the other surface of the plate-shaped workpiece (W) at second distance (Lp) shorter than the first distance (Ls), and a middle point of the first distance (Ls) and a middle point of the second distance (Lp) match with each other.

Disclosed herein are an electric press and a method for calibrating the electric press, which can implement a rapid calibration operation. An electric press (10) includes a ram location information storage unit (63) and a load control unit (64). The ram location information storage unit (63) stores ram location information, corresponding to actual load values and representing locations to which a ram is moved, in advance. The load control unit (64) applies an actual load, corresponding to at least one location which belongs to the locations represented by the ram location information and to which the ram is moved, to a compression target by moving the ram to the location. Accordingly, the load value output by the detection unit is calibrated based on the actual load value applied to the compression target.

Press-fitting work is evaluated by appropriately determining a load when sliding occurs. A load-drop determination unit determines whether or not a load value detected by a load detecting unit exceeds a load-drop determination value decided based on a moving average value and a dispersion average value stored in a storage unit. A data substitution unit substitutes the load value which is determined to exceed the load-drop determination value in the load-drop determination unit with a predetermined value.

Disclosed herein are an electric press and a method for calibrating the electric press, which can implement a rapid calibration operation. An electric press (10) includes a ram location information storage unit (63) and a load control unit (64). The ram location information storage unit (63) stores ram location information, corresponding to actual load values and representing locations to which a ram is moved, in advance. The load control unit (64) applies an actual load, corresponding to at least one location which belongs to the locations represented by the ram location information and to which the ram is moved, to a compression target by moving the ram to the location. Accordingly, the load value output by the detection unit is calibrated based on the actual load value applied to the compression target.

Disclosed is a double-motor double-station screw press, comprising two sets of screw pair mechanisms on both sides thereof, i.e., first and second screw pair mechanisms, where in the first screw pair mechanism, a first lead screw is driven by a resultant movement synthesized by first and second motors through a first differential gear train; in the second screw pair mechanism, a second lead screw is driven by a resultant movement synthesized by the first and second motors through a second differential gear train; a first slider and a second slider in the press work symmetrically; a transmission mode between the second motor and the second differential gear train is switched by controlling a steering switching apparatus, such that the second motor can assist the first motor during a single-cylinder pressing process to increase the output pressure, but also it is convenient to adjust a relative positions of two cylinders.

Press-fitting work is evaluated by appropriately determining a load when sliding occurs. A load-drop determination unit determines whether or not a load value detected by a load detecting unit exceeds a load-drop determination value decided based on a moving average value and a dispersion average value stored in a storage unit. A data substitution unit substitutes the load value which is determined to exceed the load-drop determination value in the load-drop determination unit with a predetermined value.

An electric cylinder system includes: a rod; a ball screw mechanism; a nut connected to the rod; a cylindrical body including a contact portion, the contact portion configured to be abutting the nut making the linear motion, the cylindrical body configured to support the ball screw mechanism in such a manner that the ball screw mechanism is displaceable in the axis direction of the ball screw; a strain detector fixed to the cylindrical body and configured to detect a value corresponding to a displacement of the ball screw mechanism; and a control section configured to make the ball screw mechanism be displaced by making the nut abut against the contact portion, and configured to detect an abnormality of the strain detector based on the value detected by the strain detector according to the displacement of the ball screw mechanism.