| 摘要 |
PURPOSE:To make improvements in starting characteristics and economical efficiency by negative-feedback-controlling the displacement volume of an input side hydraulic pump/motor so as to keep the extent of effective differential pressure in a hydrostatic transmission system to the setting pressure conformed to an accelerator angle. CONSTITUTION:When an accelerator 11 is operated at time of starting, a throttle is interlocked with it and varied into a step form. In this case, displacement volume of an input side hydraulic pump/motor 1 gets varying by means of negative-feedback control without waiting an up of engine speed so as to have effective differential pressure kept in the setting value conformed to the accelerator operated variable. With this constitution, when an output side hydraulic pump/motor 2 gets rotating, the displacement volume of the input side hydraulic pump/motor 1 is further increased in order to compensate a drop in the displacement volume due to the swallowing of pressure fluid. This action occurs in a linkage manner, and the displacement volume of the input side hydraulic pump/motor 1 is increased in a moment the accelerator 11 is operated, and when the effective differential pressure is stabilized and maintained, the effective differential pressure is proportioned to acceleration of a car body, thus stable and effective tractive force is securable. |
