A structure for connecting a metal lever and a metal link via a metal pin, said structure comprising: a metal lever having a circular connecting hole; a metal pin comprising a support shaft portion, a head portion and a connecting shaft portion; and a metal link having a coupling hole and being integrally connected to said metal pin, said coupling hole being fitted to said connecting shaft portion; wherein said support shaft portion is insertable through said connecting hole, and is pivotable and movable in an axial direction of said metal pin by a preset amount with respect to said connecting hole, said head portion is formed at one end portion of said support shaft portion and has a diameter larger than a diameter of said support shaft portion, said connecting shaft portion is formed at the other end portion of said support shaft portion and has a diameter smaller than said diameter of said support shaft portion, and said metal pin comprises an allowable portion (23a1) formed on at least one axial end portion of said support shaft portion of said metal pin, said allowable portion (23a1) is configured to increase an amount of swing of said metal lever on said metal pin in said axial direction of said metal pin, and said allowable portion (23a1) is formed so that only said one axial end portion of said support shaft portion of said metal pin has a diameter smaller than that of a center portion of said support shaft portion characterized in that only said one axial end portion has a curved surface shape in radial cross-section, and said structure further comprising a second allowable portion (21a1) formed as a chamfered portion or a rounded portion on the other axial end portion of said connecting hole of said metal lever, and said second allowable portion (21a1) being configured to increase said amount of swing of said metal lever on said metal pin in said axial direction of said metal pin. a metal lever having a circular connecting hole; a metal pin comprising a support shaft portion, a head portion and a connecting shaft portion; and a metal link having a coupling hole and being integrally connected to said metal pin, said coupling hole being fitted to said connecting shaft portion; wherein said support shaft portion is insertable through said connecting hole, and is pivotable and movable in an axial direction of said metal pin by a preset amount with respect to said connecting hole, said head portion is formed at one end portion of said support shaft portion and has a diameter larger than a diameter of said support shaft portion, said connecting shaft portion is formed at the other end portion of said support shaft portion and has a diameter smaller than said diameter of said support shaft portion, and said metal pin comprises an allowable portion (23a1) formed on at least one axial end portion of said support shaft portion of said metal pin, said allowable portion (23a1) is configured to increase an amount of swing of said metal lever on said metal pin in said axial direction of said metal pin, and said allowable portion (23a1) is formed so that only said one axial end portion of said support shaft portion of said metal pin has a diameter smaller than that of a center portion of said support shaft portion characterized in that only said one axial end portion has a curved surface shape in radial cross-section, and said structure further comprising a second allowable portion (21a1) formed as a chamfered portion or a rounded portion on the other axial end portion of said connecting hole of said metal lever, and said second allowable portion (21a1) being configured to increase said amount of swing of said metal lever on said metal pin in said axial direction of said metal pin.