| 摘要 |
<p>A head pipe (7) includes a pipe portion (7a) and a bracket portion (7b) which is contiguously formed on a rear portion of the pipe portion (7a) in a state where front end portions of the main frames (8) and a front end portion of the down frame (9) are jointed to the bracket portion (7b). A widthwise center line CL of the main frames (8) in the vertical direction is directed toward an intermediate portion of the pipe portion (7a) in the vertical direction, and an upper surface extension line LA and a lower surface extension line LB which are on the extension in the frontward direction of an upper surface and a lower surface of the main frames (8) pass between an upper end and a lower end of the pipe portion (7a), and the down frame (9) is inclined so as to be directed toward the intermediate portion of the pipe portion (7a) in the vertical direction.</p> |
