Structure for side portion of vehicle body

A side structure of a vehicle body, comprising:

• a rail assembly extending in a front-and-rear direction of the vehicle body and defining an upper part of the side structure of the vehicle body;
• an arch assembly extending laterally of the vehicle body and having an end located on the rail assembly;
• a roof panel supported by the arch assembly;
• the rail assembly including:
• an outer portion extending in the front-and-rear direction of the vehicle body and located laterally outwardly of the vehicle body;
• an inner portion disposed closer to a lateral center of the vehicle body than the outer portion, the inner portion cooperating with the outer portion to define a closed cross-sectional structure extending in the front-and-rear direction of the vehicle body;
• an outer extension portion formed integrally with the outer portion and extending toward the lateral center of the vehicle body;
• and
• an inner extension portion formed integrally with the inner portion and extending toward the lateral center of the vehicle body, the inner extension portion having a lateral inner end located closer to the lateral center of vehicle body than a lateral inner end of the outer extension portion, the inner extension portion cooperating with the outer extension portion to define a closed cross-sectional structure;
• the arch assembly including:
• an upper member having a lateral outer end carried on the outer extension portion;
• and
• a lower member disposed below the upper member and having a lateral outer end carried on the inner extension portion, the lower member cooperating with the upper member to define a closed cross-sectional structure extending laterally of the vehicle body.