In the automobile industry, reduction of car weight is needed to deal with environmental issues. Recently, Carbon Fiber Reinforced Plastics (CFRP) is expected to be used for lightweight component parts. The application of CFRP will become possible to reduce car weights, because CFRP has higher specific strength and specific rigidity. However the cost of CFRP is so high that the use of CFRP does not increase. In addition, it is expected to use thermoplastics as a matrix of CFRP in consideration of recyclability. To mold Carbon Fiber Reinforced Thermoplastics (CFRTP), it is necessary to impregnate carbon fiber with thermoplastic resin by heating the materials. There are electromagnetic induction heating and direct resistance heating for heating method. The electromagnetic induction heating has a high production cost because of complicated equipment. On the other hand the direct resistance heating is performed with a simple piece of equipment and low consumed power. It is better to use direct resistance heating for low-cost CFRTP molding. We propose a method of CFRTP molding process using direct resistance heating of carbon fibers in n on crimp fabric (NCF). In this paper, the resistance heating characteristic of NCF and the influence of resistance heating upon mechanical properties of carbon fiber were discussed. The temperature distribution of 0° and 90° layer were sufficient and it took 70s to reach to 250°C on temperature history when heat is applied to the NCF [0°/90°] using direct resistance heating. From the results of tensile tests of single carbon fiber, tensile strength was not decreased by resistance heating at 300°C for 300s.

No abstract

A sun visor has been used only for the purpose of interrupting direct sunshine. Investigation, therefore, has not been made to be on the feeling of touch of the sun visor. In this study, the feeling of touch of sun visor installed in the present automobile was investigated. To clarify the relation between the sense of touch and the mechanical and physical quantity of the sun visor, prototype products of the sun visor of the same shape were made. Surface characteristics and cold feel characteristic of materials were measured by the KES system. In addition, we investigated the relation between the surface property and the sense of touch of various materials. The correlation between favorability and WC, RC, SMD was high on the sun visor prototype. As a result, it was clarified that materials whose surfaces were very smooth and soft were favorable. Those materials consist of leather and moquette. Conversely, the material sensed hard was not favorable. The relation between the mechanical and the physical properties of various materials, and the favorability was able to be approximated by the equation (1). Favorability = 2.482 + 0.02791LC + 0.293WC − 0.264RC + 0.0688MIU − 0.0966MMD + 0.0253SMD − 0.0288qmax (1)

In the automobile industry, it is required to reduce the weight of cars for better fuel consumption. Recently, Carbon Fiber Reinforced Thermoplastics (CFRTP) are expected to be used for lightweight component parts. However, the cost of CFRTP is so high that the use of CFRTP is barely applied in the automobile industry. In order to lower the cost of CFRTP, simple equipment and low consumed power are necessary. High-frequency direct resistance heating to CFRTP molding dies becomes possible to solve these issues. High-frequency direct resistance heating is a method that alternating current is directly applied to a metal, and metal surface is heated by skin effect. When opposite directions of an alternating current flow in a pair of metal sections which face each other with a small gap, the proximity effect also promotes the concentration of current density on proximal surfaces of the metal and heats the metal surface intensively by joule heat. By applying high-frequency direct resistance heating to CFRTP molding, cost reduction as well as simplification of the facilities can be expected. In this study, in order to apply high-frequency direct resistance heating to CFRTP molding die, the effects of the proximity effect on the mold are evaluated to clarify the heating characteristics and conditions of the proximity effect, and the applicability of CFRTP molding is discussed. The experimental result reveals that the proximal surfaces can be heated by proximity effect.

No abstract