Workpiece manufacturing apparatus

A workpiece manufacturing apparatus comprising:

• an upper die assembly and a lower die assembly, which are arranged on opposite sides of an unprocessed material, wherein the upper and lower die assemblies are moved relative to each other toward each other to be clamped and moved relative to each other away from each other to be opened;
• a punch, which is provided in the lower die assembly and punches out a workpiece from the unprocessed material in a clamped state of the die assemblies;
• an ejector, which is provided in the upper die assembly so as to be capable of approaching and moving away from the lower die assembly and to be located at a position corresponding to the punch;
• a spring, which is provided in the upper die assembly and urges the ejector toward the lower die assembly;
• and
• a locking device, which locks the ejector with respect to the upper die assembly at a position at which the punch punches out the workpiece from the unprocessed material and releases the ejector when the die assemblies are opened, wherein
• the locking device comprises:
• a slider, which is provided in the upper die assembly and is capable of sliding between a locking position, at which the ejector is locked, and a releasing position, at which the ejector is released,
• an actuator, which is provided in the upper die assembly and causes the slider to slide, and
• a control section, which controls the actuator,
• a roller being provided above the ejector, the roller being coupled to the ejector to be capable of moving integrally with the ejector,
• the roller being in contact with the slider by an urging force of the spring acting on the ejector,
• the slider slides in a horizontal direction between the locking position and the releasing position,
• the slider comprising:
• a releasing surface, which contacts the roller when the slider is in the releasing position,
• a locking surface, which is located at a higher level than the releasing surface, the roller contacting the locking surface when the slider is in the locking position, and
• a slope, which connects the releasing surface and the locking surface with each other,
• when the slider is in the locking position, the roller is pressed by the locking surface to compress the spring, thereby locking the ejector with respect to the upper die assembly, and
• when the slider is in the releasing position, the releasing surface is caused to contact the roller to weaken the urging force of the spring as compared with that during the compression, thereby releasing the ejector.