| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the acceleration performance at the time of start by allowing a wide speed reduction clutch to slip, and thereafter performing the changeover to the clutch on the side of small speed reduction until a supercharger attains its rotational frequency at which it functions at the time of wide speed reduction in setting the level of acceleration. SOLUTION: When a forward mode is selected by a frontward-rearward changeover valve V2 for performing acceleration at the time of start, pressure oil of forward 2-speed clutch FC2 is released, before the changeover from a forward 2-speed clutch FC2 of wide speed reduction and low speed to a forward 1-speed clutch FC1 of small reduction speed and high speed, to generate a slip state to reduce the number of rotations of a propeller. In this case, while the number of rotations is low the hydraulic clutch is made to slip for connecting the clutch FC2 immediately, thereby making short the time when the maximum engine speed is obtained. Accordingly, it is possible for a supercharger to increase the engine speed to the effective speed in a short time.</p> |
