CASE AND KEYBOARD INSTRUMENT

原文（中国語）

A case of a keyboard instrument includes a lower case formed from a resin material which is a first material and extended long in a left-right direction which is a first direction, plural reinforcement members (a first reinforcement member, a second reinforcement member) fixed to the lower case, made from a sheet of steel which is a second material whose linear expansion coefficient is smaller than a linear expansion coefficient of the first material, and disposed to be divided in the left-right direction, a front case formed in such a manner as to extend long in the first direction and fixed to each of the plural reinforcement members, and side cases (a left side case, a right side case) disposed adjacent to the front case and fixed to ends of the reinforcement members.