Leveling device null hull

摘要

PROBLEM TO BE SOLVED: To provide a device for levelling a high lift working vehicle, capable of eliminating the delay of the levelling of a working floor from the hoisting of a boom at starting the hoisting of the boom and holding the working floor in a balanced condition in the case of part of hydraulic fluid supply passage to a levelling cylinder being broken. ;SOLUTION: When the hoisting of a boom 14 is started in the condition that the boom 14 is not hoisted (the operation of a levelling cylinder 23 is stopped), an additional flow for restricting the delay of the operation of the levelling cylinder 23 from the hoisting of the boom 14 at starting the hoisting of the boom 14 is added to the levelling flow of hydraulic fluid required to support a working floor in a balanced condition. The hydraulic fluid of a corrected hydraulic fluid flow (a levelling flow plus an additional flow) obtained in this way is supplied to the levelling cylinder 23 by driving a balance control valve 55.;COPYRIGHT: (C)2001,JPO