Steering wheel mounting structure thereof and boss structure thereof

A steering wheel comprising:

• a boss constructed and arranged to be fitted on a steering shaft, said steering shaft having a shaft serration composed of a plurality of teeth formed on an outer periphery thereof, said boss including a cylindrical portion with a boss serration on an inner periphery thereof corresponding to said shaft serration, and a yoke portion provided integrally with said cylindrical portion and having through holes formed near both ends thereof, at least one of said through holes being formed with an internal thread;
• a steering wheel body including a ring core bar, spoke core bars coupled to said ring core bar, sheaths covering said ring core bar and spoke core bars, and a pad formed integrally with said sheaths and located in a central upper portion of said ring core bar, part of said spoke core bars being connected to said boss;
• and
• a bolt having an external thread formed at least on an end thereof, said threaded end being constructed and arranged to be received by said through holes and engaged with the internal threads of the at least one through hole so as to fix the boss, to which said steering wheel body is connected, on said steering shaft, at least said spoke core bars being made of die-cast metal, and wherein said boss comprises a boss body composed of said cylindrical portion and said yoke portion, and a boss plate fixed to said boss body and having a larger area than said yoke portion, and an extreme edge of said boss plate is embedded in said spoke bars.