Control device for hydraulic drive winch
AssigneeKolbelco Construction Machinery Co., Ltd.
InventorsYoshio Nishimoto, Takahiro Kobayashi, Taisuke Tsunoo, Etsujiro Imanishi, Satoshi Yonezawa
Life of this patent
Estimating the term…
Abstract
A winding-down side pilot port of a control valve is of a 2-port construction comprising a normal winding-down side port having a large pressure receiving area and a free fall side port having a small pressure receiving area, wherein in the free fall operation carried out by setting a motor to a small capacity, a pilot pressure of a winding-down side remote control valve is supplied to the free fall side port through a mode switching valve. Thereby, a stroke of the control valve can be suppressed so that a speed of a motor does not exceed an allowable speed.
Claims12
A control device for a hydraulic drive winch, comprising:
- a winch drum;
- a variable capacity type hydraulic motor for driving said winch drum;
- a hydraulic pump as a hydraulic source for said hydraulic motor;
- a control valve for controlling a supply and a discharge of pressure oil to said hydraulic motor;
- winding-up operating means for operating said control valve to a winding-up side;
- winding-down operating means for operating said control valve to a winding-down side;
- motor capacity control means for controlling a capacity of said hydraulic motor;
- free fall instruction means for outputting free fall instructions, wherein said motor capacity control means is actuated by free fall instructions from said free fall instruction means to set said hydraulic motor to a small capacity, in which state, said winding-down operating means is operated to thereby rotate said winch drum at high speeds to effect free fall operation;
- and
- control valve control means, an opening degree of said control valve relative to an operating amount of said winding-down operating means being controlled to be smaller than that of normal winding-down operation where no free fall instructions is present, wherein in said free fall operation, a flow rate supplied to said hydraulic motor is not more than an allowable flow rate of said hydraulic motor.
A control device for a hydraulic drive winch, comprising:
- a winch drum;
- a variable capacity type hydraulic motor for driving said winch drum;
- a hydraulic pump as a hydraulic source for said hydraulic motor;
- a control valve for controlling a supply and a discharge of pressure oil to said hydraulic motor;
- winding-up operating means for operating said control valve to a winding-up side;
- winding-down operating means for operating said control valve to a winding-down side;
- motor capacity control means for controlling a capacity of said hydraulic motor, said motor capacity control means increasing a motor capacity according to an engine speed for driving said hydraulic pump on a high engine speed side to thereby control the speed of said hydraulic motor to not more than an allowable speed of said hydraulic motor at the time of free fall operation;
- and
- free fall instruction means for outputting free fall instructions, wherein said motor capacity control means is actuated by free fall instructions from said free fall instruction means to set said hydraulic motor to a small capacity, in which state, said winding-down operating means is operated to thereby rotate said winch drum at high speeds to effect free fall operation.
A control device for a hydraulic drive winch, comprising:
- a winch drum;
- a variable capacity type hydraulic motor for driving said winch drum;
- a hydraulic pump as a hydraulic source for said hydraulic motor;
- a control valve for controlling a supply and a discharge of pressure oil to said hydraulic motor;
- winding-up operating means for operating said control valve to a winding-up side;
- winding-down operating means for operating said control valve to a winding-down side;
- motor capacity control means for controlling a capacity of said hydraulic motor;
- free fall instruction means for outputting free fall instructions;
- and
- free fall control means, said free fall control means changing the capacity of said hydraulic motor from a large capacity to a small capacity in proportional to an operating amount of said winding-down operating means.
Dependencies are inferred from the claim text.