A plan view pattern control method for use in plate rolling called Mizushima Automatic Plan View Pattern Control System (MAS) or Dog Bone Rolling (DBR) was developed. In this method, slab is given a nonuniform thickness profile in the width direction to obtain nonuniform elongation. In order to make the plate more rectangular under various rolling conditions, the prediction of elongation is necessary. In this research, the influence of the width of the dog-bone (overly thick part at the slab width edge) on the fish-tail length (over-elongation at the slab end) is investigated. The fish-tail length increases as the dog-bone width increases and the dog-bone width ratio decreases. These phenomena are related to the following behavior of the restriction of excessive elongation at the dog-bone. As the dog-bone width increases and the dog-bone width ratio decreases, the working length of restricting stress increases. Hence restricting stress is released earlier and the rolling length of fish-tail formation increases. As a result, the fish-tail length increases. Therefore, in the prediction of the plan view pattern, not only the dog-bone thickness, but also the dog-bone width should be considered.
In this study, we propose the most suitable condition for blanking using a screw drive servo press. The conditions do not increase blanking vibration. Moreover, there is no wasted time during blanking. The screw drive servo press has a highly precise slide location system. This highly precise machine is realized by including a feedback control system of the slide position. However there is a problem that blanking vibration is increased by incorporating this system. When blanking speed is fast, this problem occurs. Thus, we studied the relationship between the control response and blanking vibration of the screw drive servo press to solve this problem. In this study, we carried out a simulation and an experiment. As a result of this study, we found the most suitable condition for low-speed blanking using the screw drive servo press to be a blanking time equal to the disturbance settling time of the feedback control system.
In this paper, we describe an experimental study on the development of a V-shape forming method for the
processing of carbon-fiber-reinforced thermoplastics (CFRTP), in which a right-angle die is used. The material investigated was polyamide 6 (PA6) matrix plain-weaved carbon-fiber composites. CFRTP sheets were heated to above the melting temperature of the matrix and then immediately transported into the forming die and formed under different conditions of die temperature. The relationship between the bending angle and die temperature, and the correlation between the bending angle and layer shift were investigated. The distortion of the formed sheet owing to the residual stress was discussed and found to be in good agreement with the experimental result.
Quenched and tempered (Q&T) steel sheets (JIS SK85) having an ultrahigh-hardness value of 55HRC [or an equivalent tensile strength (TS) value of about 1800 MPa] were pierced using a rounded tip edge punch and a sharp-edge die, and then subjected to a second press-shaving process that resulted in a press-shaved product with a substantially smooth and dimensionally precise cut edge.