Experimental validation of a reconfigurable guillotine shear and bending press machine

The reconfigurable guillotine shear and bending press machine is a dual-functional machine that combines cutting and bending processes in sheet metal processing, minimising the time required for set-up and operating seamlessly. The objective of this study is to carry out the performance evaluation of the cutting and bending operations of the developed machine using physical experimentations with aluminium 7075 sheet metal. The cutting and bending processes were conducted successively using the developed machine under pre-designed operating conditions. The thickness of the aluminium sheet metal was 0.5 mm, while the velocity of the guillotine was kept constant at 0.015 mm/sec. A constant cutting force of 25.6 kN and a constant bending radius of 2 mm as well as varying bending angles (30-90 & DEG;) and bending forces (5-15 kN) were employed to investigate the total time taken for the bending and cutting operations as well as the effect of the bending angles and bending forces on the springback phenomenon. The lowest bending angle (30 & DEG;) has the highest springback factor of 1.43 under a bending force of 5 kN, while the highest bending angle (90 & DEG;) has the lowest springback factor of 1.11 under an optimum bending force of 10 kN. The percentage difference in the time saved using the developed machine ranges from a minimum value of 58.66% to a maximum value of 60.22%. The results show that there is a direct relationship between the average time taken and the bending angles for the bending operation. Conversely, for the cutting operation, a direct relationship was observed between the average time taken and the cut angles. The results obtained also indicate that higher bending angles reduce the springback phenomenon but with an increase in the time taken for the bending operation and vice-versa. The results from the physical experimentation provide insight into the effectiveness of the machine in meeting its service and functional requirements.