| 摘要 |
<p>A ramp device comprises a first ramp portion (10), the base end of which is rotatably coupled to the vehicle body, and a second ramp portion (20) that is slidably and etendably coupled to the extension side of the first ramp portion (10). The first ramp portion (10) is configured so that the base end serves as the center of rotation, and is provided with an assist means for applying an assist force (Mf) in the direction of rotation towards the vehicle body. The assist force (Mf) is set so as to be greater than the lowering moment produced by the center of gravity (M1) of the entire ramp when horizontally extended with the second ramp portion (20) slid into and housed in the first ramp portion (10), and so as to be less than the lowering moment produced by the center of gravity (M2) of the entire ramp when the second ramp portion (20) is fully extended from first ramp portion (10). Sliding and extending the second ramp portion (20) in the extension direction of the first ramp portion (10) causes the center of gravity of the entire ramp to progressively change from the center of gravity (M1) to the center of gravity (M2) so that once the second ramp portion (20) extends beyond a set distance, the first ramp portion (10) rotates and the leading end of the ramp comes into contact with the ground.</p> |
