PURPOSE: To prevent the turning of a slewing arm even when touched by an operating lever during the stoppage period on sloped path by converting the gain of electric signals for operating main valve according to detected amounts of revolving number of the rotator and also of discharge amount of a pump.
CONSTITUTION: The main valve 12, e.g., electromagnetic proportional valve, etc., to be operated by electric signals is connected to an operating lever through an amplifier 19. The discharge amount of a hydraulic pump 2 is detected by a detector 16, the revolving number of the hydraulic motor 1 is detected by a detector 15, and the electric signals of these are inputted an arithmetic unit 18. In the unit 18, both input signals are compared and calculated and the main valve 12 is controlled through the amplifier 12. When engine is stopped, signals from the detector 16 are zeroed, the displacement of the main valve 12 is regulated, and the turning of the slewing under its own weight can be prevented even by the inadvertent touching of the lever 21 during the stoppage on the sloped path.
| JP2001171985 | HYDRAULIC CIRCUIT OF WINCH |
| WO/2020/170540 | WORK MACHINE |
IMAI TOSHIYUKI
NAKAMURA KAZUTOSHI
OGAWA KEIJI
