| 摘要 |
PURPOSE:To improve the operation performance by arbitrarily carrying out the deceleration operation of a decelerating means, connected to a control lever for controlling the engine revolution, through the operation of a manual switch, and automatically releasing the deceleration state by the operation of a working-machine operating lever. CONSTITUTION:When a manually operating switch 20 installed onto the knob 19a of a working-machine operating lever 19 is turned-ON, in order to suspend a work from the full revolution state of an engine 1, a solenoid valve 13 is excited through a controller 21, and switching from the cut-off position 132 to the communication position 131 is performed. Then, the hydraulic pressure in a main conduit 14 flows into the pressure chamber 41 of a decelerating cylinder 4, and a control lever 3 is operated from the full throttle position C' to the decelerating position B' by the cylinder 4, and the engine 1 is put into deceleration state. Then, when the operating lever 19 is set at the working position from this state, a pilot pressure is supplied into a working-machine operating valve from a pilot control valve 16, and when a pressure switch 18 senses said pilot pressure, the deceleration state is automatically released through a controller 21. |
