Abstract: A diagnostic method of diagnosing a press for the presence of any abnormality that deteriorates a quality of a product manufactured by the press, wherein physical value (Fs, Fsi, Ff, Ffi, Fp, Fpi, Xsi, Xei, Xy, Xz, Vx, Gx, Gy, Gz, Temp A, Temp B, Va0, Vf0, Vd0, V, Aa, Ag, Az, Afi, Ps, Pmai, Psa, Paa, Pyai, Peai, Pzai) such as a load generated at a selected portion of the press during operation of the press is detected, and the press is diagnosed for any abnormality, on the basis of the detected physical value, and according to a predetermined reference.

Abstract: A diagnostic method of diagnosing a press for the presence of any abnormality that deteriorates a quality of a product manufactured by the press, wherein physical value (Fs, Fsi, Ff, Ffi, Fp, Fpi, Xsi, Xei, Xy, Xz, Vx, Gx, Gy, Gz, Temp A, Temp B, Va0, Vf0, Vd0, V, Aa, Ag, Az, Afi, Ps, Pmai, Psa, Paa, Pyai, Peai, Pzai) such as a load generated at a selected portion of the press during operation of the press is detected, and the press is diagnosed for any abnormality, on the basis of the detected physical value, and according to a predetermined reference.

Abstract: A cushioning apparatus for applying a blank-holding force to a pressure member to hold a blank on a press, through hydraulic cylinders on a cushion platen biased by a force generating device toward the pressure member, and cushion pins linked with the cylinders and supporting the pressure member, the blank-holding force being based on a biasing force generated by the force generating device, and controllable by a controller through a flow regulator provided in a discharge line for discharging the fluid from the cylinders, such that the controller controls the flow regulator to discharge the fluid from the cylinders during a pressing action on the blank by upper and lower dies, for thereby controlling the cylinder pressure according to a predetermined pattern of change in the pressure in relation to a downward movement of the upper die. The hydraulic cylinders may be classified into two or more groups connected to mutually independent discharge lines.

Abstract: A pressing load measuring device including a memory for storing a data map representative of a relationship between the output level of a strain sensor attached to a press frame and the actual pressing load value on the press, and a converter for converting the output of the strain sensor into the pressing load value on the basis of the sensor output and according to the stored relationship. Local pressing load values acting on local portions of a press slide through fluid-actuated cylinders are measured by a method wherein the actual local pressing load values at the local portions of the press slide are measured, and the pressure values of a fluid in the fluid-actuated cylinders independently of each other so that the measured actual local pressing load values at the local portions of the press slide substantially coincide with respective predetermined optimum values.

Abstract: An apparatus used for measuring a holding force expected to be applied to a pressure member of a press, before the lower and upper dies and the pressure member are installed on the press. The apparatus includes a measuring member to be placed on cushion pins of the press associated with a fluid-actuated cylinder via a cushion pad. A sensing element is disposed on the measuring member or a main slide carrying the upper die, such that the holding force produced by force applying means which includes the cylinder acts on the sensing element, when the measuring member is lowered with the sensing element by the main slide in its downward movement towards a bolster on which the lower due is fixed. A load detecting device is disposed on the sensing element for detecting the holding force acting on the latter. The apparatus also includes a device for recording the holding force as detected by the load detecting device.

Abstract: A hydraulic cushioning apparatus for a press having an upper and a lower die assembly (3, 9) for forming a sheet-like workpiece (6), including hydraulic cylinders (54) incorporated in one of the upper and lower die assemblies, and pressure pins (52) linked with the respective hydraulic cylinders. The pressure pins are reciprocable to apply a cushioning force (F) to the workpiece, in a pressing action of said die assemblies on the workpiece, so as to force the workpiece against the other die assembly. The apparatus is equipped with a hydraulic power supply device (72, 100, 117, 272) for delivering a pressurized fluid to the hydraulic cylinders (54). The power supply device is capable of changing an initial hydraulic pressure (P.sub.0) of the fluid to be applied to the hydraulic cylinders before the pressing action of said die assemblies.