Patent application number | Description | Published |
20130089399 | FORKLIFT ENGINE CONTROL DEVICE - An engine control device for a forklift that suppresses an increase in fuel consumption amount and noise by limiting an engine rotation speed when the forklift is driven without the need to increase the engine speed according to the accelerator operation even when the accelerator is depressed hard. Determining means in a controller determines whether all of the following conditions are satisfied: a neutral position of the traveling direction instructing means; a lift raising switch and first, second and third attachment switches are turned off. When all of the above conditions are satisfied, it is determined whether the forklift is driven in any of a plurality of states. An engine control means generates and outputs a control command to obtain the engine speed based on the accelerator pedal depression with the upper limit value of the engine speed set as an upper limit value of the engine speed. | 04-11-2013 |
20130218428 | ENGINE-OVERRUN-PREVENTING CONTROL DEVICE FOR WORK VEHICLE - In an engine-overrun-preventing control device, if an engine speed exceeds a maximum speed, a minimum value of an inching rate is set such that higher the actual engine speed results in a higher minimum value of an inching rate. The hydraulic pump displacement is adjusted to obtain a higher inching rate between the minimum value of the inching rate and an inching rate set based on a brake stroke. If the engine speed exceeds a commanded speed and a pressure time-rate-of-change at the pump intake exceeds a prescribed value, the minimum value of the inching rate is set such that the higher the pressure time-rate-of-change, the higher the minimum value of the inching rate. The pump displacement is adjusted to obtain a higher inching rate between the minimum value of the inching rate set based on the pressure time-rate-of-change and the inching rate set based on the brake stroke. | 08-22-2013 |
20150033718 | FORKLIFT AND INCHING CONTROL METHOD OF FORKLIFT - In order to provide a forklift capable of performing an inching control suitable for a specific work and a running operation of the forklift and an inching control method of the forklift, an inching ratio calculating unit calculates an inching ratio, a target engine speed calculating unit calculates a target engine speed, a modulation control unit sets a time constant of the inching ratio in response to a speed difference between the target engine speed and outputs a correction inching ratio having the time constant set thereto, a multiplication unit outputs a correction absorption torque obtained by multiplying the correction inching ratio by a target absorption torque, and a HST pump electromagnetic proportional control output current converting unit outputs a current instruction value to a pump capacity setting unit. | 02-05-2015 |
20150034424 | ENGINE-POWERED FORKLIFT TRUCK AND METHOD OF RELEASING LOAD HANDLING INTERLOCK THEREOF - An engine-powered forklift truck including a work device which is hydraulically driven by an oil hydraulic pump whose driving source is an engine, and including a load handling interlock mechanism which brings a work device operation into a locked state by turning a key switch off or turning a seat switch off, includes: a release control apparatus configured to, when the locked state exists, release the locked state on condition that the key switch is ON, the seat switch is ON, and the engine is rotated under a predetermined engine speed or more. | 02-05-2015 |
20150183625 | FORKLIFT AND CONTROL METHOD OF FORKLIFT - A forklift including a variable displacement HST pump driven by an engine, a hydraulic motor that forms a closed circuit with the HST pump therebetween and is driven by hydraulic oil discharged from the HST pump, and driving wheels driven by the hydraulic motor, wherein a control device calculates an inching rate corresponding to an operation amount of an inching pedal, and sets a lower limit of the inching rate to a value greater than 0, only in a state in which both of an accelerator pedal and the inching pedal are operated. | 07-02-2015 |
20150232312 | FORKLIFT AND CONTROL METHOD OF FORKLIFT - Provided is a forklift equipped with a variable displacement traveling hydraulic pump driven by an engine, a hydraulic motor that forms a closed circuit with the traveling hydraulic pump therebetween and is driven by hydraulic oil discharged from the traveling hydraulic pump, and driving wheels driven by the hydraulic motor. An accelerator opening is calculated by correcting an accelerator opening detected by an accelerator opening sensor, using a greater one of a first cut-off frequency calculated from the accelerator opening detected by the accelerator opening sensor, and a second cut-off frequency calculated from a corrected accelerator opening calculated at a timing before the first cut-off frequency is calculated. | 08-20-2015 |
20160082966 | WORK VEHICLE AND METHOD OF CONTROLLING WORK VEHICLE - A work vehicle includes a variable displacement hydraulic pump driven by an engine, a hydraulic motor forming a closed circuit with the pump and driven by hydraulic fluid discharged from the pump, wheels driven by the motor to allow the work vehicle to travel, a selector detecting an operating state of a switch switching the traveling of the work vehicle between forward and backward, and a controller. When the selector detects a reversal operation of the switch to reverse the traveling direction when the work vehicle travels, the controller sets relationship between the vehicle speed of the work vehicle and the upper limit of the rotational speed of the engine such that the upper limit increases as the absolute value of the vehicle speed approaches zero. The controller obtains an upper limit of the rotational speed from the relationship and a vehicle speed of the work vehicle. | 03-24-2016 |
20160084275 | WORK VEHICLE, AND CONTROL METHOD FOR WORK VEHICLE - A work vehicle including: a traveling hydraulic pump of a variable displacement type driven by engine; a hydraulic motor forming a closed circuit with the traveling hydraulic pump and driven by operating oil discharged from the traveling hydraulic pump; a drive wheel driven by the hydraulic motor; and a control device determining whether an operator of the work vehicle has an intention of decelerating the work vehicle, and when the operator has an intention of decelerating the work vehicle and when the work vehicle starts to increase its speed, the control device causes a capacity ratio obtained by dividing a capacity of the hydraulic motor by a capacity of the traveling hydraulic pump, to be equal to or larger than a value when the work vehicle starts to increase its speed, according to an increasing amount in the speed of the work vehicle. | 03-24-2016 |