The curb weight of electric trucks is more than 10% higher than that of conventional internal combustion engine trucks due to the motor and battery. For this reason, cargo box developed for small electric trucks is required weight reduction, and cargo door that can reduce weight and maintain strength are being developed. In this paper, we designed the lightweight cargo door, confirmed the stability of the door through structural analysis, and developed a cargo box door that was more than 25% lighter by applying composite materials such as Sheet Molding Compound(SMC) and Fiber Reinforced Plastic(FRP).

In this study, to reduce the weight of cross member assembly for small truck. In order to optimize the design of the cross member structure by changing the equation into the rivet coupling method, The size and the hole spacing of the large sheet plate, the rivet hole size of the large sheet plate, In the structural analysis, we looked at what was going to happen, and the tensile, shear The load test was carried out to investigate the damage caused by the maximum load acting on the rivet. Riveting work, but to improve productivity, we developed automated riveting device using robot To reduce the number of workers, reduce jig transfer and installation time, and reduce load factor. To produce the maximum output of the product.

The purpose of this study is to improve the durability by solving the crack problem of the steering gearbox bracket welded to the frame assembly. For the exact and effective analysis, we use charac- teristic(fishbone) diagram from the viewpoint of 4M1E. Through this analysis it was identified two kinds of problems, and develop improvement plan for it. Verification tests must be performed to confirm the improvement. So, the test method for steering gearbox bracket improvement was newly established by referring to similar case. As a result of the tests for verification, the stresses at crack point are decreased and the durability was improved about 2.6 times compared with product before improvement.