| 摘要 |
<p>A device for setting the speed of, in particular, an excavator engine which is to operate at a speed adapted to the type of work to be done and is automatically shifted to resting speed when no work is done. In this manner, fuel consumption and the disturbing effect of unnecessarily high noise levels are reduced. The setting device comprises simple electronic control units and actuates the fuel-controlling means (7) of the engine in that a d.c. servo motor (1) connected to said fuel-controlling means is supplied with a referene value signal corresponding to the desired engine speed. By manual activation of a push-button (16) on the control lever, the device provides the possibility of manually stepping the engine speed upwards or downwards to at least three different levels (w1, w2, w3). The device also comprises a resting speed unit (3) ("idling unit") having a preset high (z1) and preset low (z2) resting speed. If the manual control means of the machine are not activated for a given short period of time, the unit (3) provides a high (z1) resting speed, and if no manual control means is activated for a further period of time, it provides a low (z2) resting speed. On activation of any manual control means, the engine resumes the actual working speed.</p> |
