A cold forging machine comprises a fixed die 11 and a movable punch tool 13 reciprocable towards and away from the fixed die to act on a workpiece therein. The tool comprises a tubular punch 34 and extrusion pin 33 movable through the punch to form a bore in the workpiece. The die is provided with a tubular ejector 15 in which slides a carrier pin 16 to enter the bore of the formed workpiece to guide it during ejection. A fault detection system includes a switch 25,61 for detecting non-completion of the normal movement of the carrier pin 16 with respect to the ejector 15, and a further switch for detecting non-completion of normal movement of the extrusion pin 33 with respect to the punch 34.
A punch probing device including at least one punch and a cooperating punch feeler. The feeler is operable to detect both foreign matter on the punch and damage of said punch. The feeler is moved perpendicularly into and out of operative engagement with the punch by means of a linkage parallelogram. Controls for the punch and linkage are provided.
The invention concerns a process for checking the quality of formings executed by a machine for forming tube ends, according to which the forming machine is equipped with a force transducer (33) which is capable of measuring the reactive axial force exerted by the tube on the tool (9a) in a forming pass and, for each forming, in a preliminary learning phase, the maximum reactive axial force exerted by the tube on the tool (9a) is measured, the quality of the executed forming is verified in conventional manner and the value of the maximum reactive axial force obtained in a forming of a quality meeting the required conditions is recorded, then, in each forming pass, the maximum reactive axial force exerted by the tube on the tool (9a) is measured, the value of the said maximum axial force is compared with the recorded reference value and the forming is validated if the measured maximum axial force corresponds to the reference force with a predetermined tolerance.
A forging machine is disclosed which is provided with means to determine when an undersized or short blank is produced by the shear and to provide for the automatic rejection of such blank. Such short blanks can occur if the stock feed into the shear is insufficient. The illustrated embodiment includes a shear for progressively cutting blanks from the forward end of a piece of stock in which the shear is provided with a load cell in the stock gauge to determine when improper feeding has occurred. Such load cell includes a strain gauge and the signal produced by the strain gauge actuates an overstroke ejection which pushes the blank from the first working station through the transfer fingers so that it does not transfer to a subsequent work station. The overstroke is provided by a piston and cylinder actuator mounted on the ejector lever which operates in response to a signal that the blank in the work station is of improper size.
