Press machine

A press machine comprising:

• a support frame;
• a ram supported by the support frame so as to be movable up and down, the ram including a plurality of punches protruding from the ram downward;
• three or more ram driving cams, configured to push down the ram toward a bottom dead center, the three or more ram driving cams including:
• at least two lifting and lowering cams configured to apply both a pushing down force and a pushing up force to the ram, and
• at least one lowering cam configured to apply only the pushing down force to the ram;
• a shaft that is rotatably supported by the support frame and that integrally rotates with the ram driving cams;
• a plurality of working stages arranged in an axial direction of the shaft below the ram and including a plurality of does corresponding to the plurality of punches, the plurality of punches of the ram being arranged in the axial direction of the shaft;
• and
• a workpiece production mechanism provided in a working stage of the plurality of working stages at an end in an aligning direction of the plurality of working stages and configured to punch a blank from a sheet metal and to form the blanks into a cylindrical workpiece, the workpiece production mechanism including:
• a first punch having a cylindrical shape, fixed to the ram, and configured to punch the blank from the sheet metal;
• a second punch fitted inside the first punch and configured to form the blank into a cylindrical workpiece, and
• an auxiliary cam provided integrally rotatable with the shaft and configured to lift and lower the second punch at a timing different from a lifting and lowering operation of the ram,
• wherein:
• the support frame includes a pair of rotation support portions fitted to both end portions of the shaft between which all of the ram driving cams are disposed, and rotatably supporting the both end portions;
• a support groove is provided in a shaft support portion that is fixed to the support frame, having shape opened downward, and rotatably supporting an intermediate portion of the shaft disposed between the ram driving cams;
• two of the ram driving cams are disposed on both sides of the workpiece production mechanism;
• and
• the cylindrical workpiece is formed using the punches and the dies by drawing or ironing in the plurality of working stages on a downstream side of the workpiece production mechanism in a workpiece conveyance direction.