| 摘要 |
PROBLEM TO BE SOLVED: To provide an outer casing for a game machine, which conserves wood resources, saves a resources, can be recyclably used, can form a rib at an accurate position inside a resin board and can speedily produce the product of a high hollow ratio for weight saving by an original injection molding by reducing its weight while setting a product strength at a degree sufficiently immune to the total load to the casing in the case of keeping/carrying by using resin materials. SOLUTION: Each of surface boards 11-14 is composed of a resin board 20 composed of a pair of mutually confronted wall surface bodies 21 and 22 and a rib 23 connecting both the wall surface bodies 21 and 22. The rib 23 is located in a prescribed situation immune to the load from the upside to the resin board 20. Besides, this casing has a movable core 110, which is rectractable to/from a metal mold cavity in injection molding of the resin board 20 and by using a metal mold 100 capable of expanding/reducing cavity capacity by moving a cavity surface, with leaving of the movable core 110, the hollow ratio is increased by expanding the cavity capacity while forming the core of the rib 23 in the relevant portion. |
