| 摘要 |
PROBLEM TO BE SOLVED: To reduce the weight of a vehicle body frame while securing strength and rigidity thereof as the vehicle body frame.SOLUTION: The vehicle body frame structure of a motor cycle comprises: a head frame 1 having left and right frame parts 1c which extend rearward and downward while widening behind a head pipe 1a; left and right tank rails 2 that are joined with rear ends of the frame parts 1c and extended rearward and downward; and a body frame 3 which is joined with the rear ends of the left and right tank rails 2 and supports a swing arm. The head frame 1 has a hollow closed cross sectional structure ranging from a rear end of one frame part 1c through a joining part 1b to a rear end of the other frame part 1c, and at lower parts of the frame parts 1c is formed integrally an engine bracket part 9 having a closed cross sectional structure. Further, the tank rails 2 have a hollow closed cross sectional structure ranging from a front end to a rear end thereof, and lower parts of the tank rails 2 have a closed cross sectional structure in a region other than the front and rear ends of the tank rails 2, in which is formed integrally an engine bracket part 18 having a closed cross sectional structure. |
