Komatsu Corporation

Taishi Oiwa

Shinji Kaneko

Yoshitaka Onodera

Jun Hashimoto

Yoshifumi Shitara

Hiroshi Yamamoto

Hideyuki Hiraiwa

Yoshio Yokouchi

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, when an accelerator opening detected by an accelerator opening sensor is reduced, the accelerator opening detected by the accelerator opening sensor and a target maximum absorption torque of the traveling hydraulic pump are given to a table on which a setting value calculated in advance depending on the accelerator opening, and the target maximum absorption torque of the traveling hydraulic pump or a vehicle speed of the forklift is described to calculate the setting value, and the accelerator opening detected by the accelerator opening sensor is corrected using the obtained setting value to calculate a corrected accelerator opening.

Forklift and control method of forklift

A work vehicle obtains determination information from information upon detecting inverting operation, the information upon detecting inverting operation indicating a traveling state of the work vehicle when an advancing direction detection device detects an inverting operation of an advancing direction switching device for inverting an advancing direction of the work vehicle while the work vehicle travels; decreases a first traveling instruction for allowing the work vehicle to travel in the advancing direction of the work vehicle upon the detection of the inverting operation, and increases a second traveling instruction for allowing the work vehicle to travel in the direction opposite to the advancing direction of the work vehicle upon the detection of the inverting operation, after detecting the inverting operation; and sets the first traveling instruction to 0 when speed information indicating a traveling state of the work vehicle becomes the determination information.

Work vehicle and control method for work vehicle

A forklift includes a hydraulic pump being a variable displacement pump driven by an engine, a hydraulic motor driven with fluid from the pump, a storage storing first and second groups, and a predetermined lift pressure setting value, the first group including output characteristics each representing relation between a rotational speed of the engine and a torque of the engine for each lift pressures, the second group including output characteristics each representing relation between the rotational speed and the torque for each pump pressures, and determining a greater one of first and second torques as a target torque of the engine, the first torque being calculated from one selected from the first group using the lift pressure setting value or an actual lift pressure and the rotational speed, the second torque being calculated from one selected from the second group using the pump pressure and the rotational speed.

Forklift and method for controlling forklift

A forklift includes a variable displacement hydraulic pump driven by an engine, a hydraulic motor that forms a closed circuit with the hydraulic pump therebetween and is driven by hydraulic oil discharged from the hydraulic pump, and driving wheels driven by the hydraulic motor. A control device of the forklift determines a rate of increase of an inching rate, based on at least one of an accelerator opening, a brake opening indicating an operation amount of a brake pedal, a change speed of the brake opening, and a vehicle speed detected by a vehicle speed sensor.

A work vehicle includes an accelerator operation amount generator receiving an actual accelerator operation amount of an accelerator operator to generate a control accelerator operation amount; an engine controller controlling the engine according to the control accelerator operation amount; and a storage storing a table in which an increasing speed for the control accelerator operation amount is set, wherein the accelerator operation amount generator obtains a difference between a converted accelerator operation amount of the accelerator operator converted from a rotating speed of the engine in a current control cycle and a control accelerator operation amount obtained in the last control cycle, determines an increasing speed of the control accelerator operation amount from the difference by referring to the table, and changes the control accelerator operation amount to an actual operation amount in the current control cycle with the determined increasing speed.

Work vehicle, and control method for work vehicle

A control device includes a target vehicle speed converter converting a first accelerator opening detected by an accelerator opening sensor into a target vehicle speed, an accelerator opening target value setting unit calculating a second accelerator opening by feedback control so that a deviation between the target vehicle speed and an actual vehicle speed becomes zero, an addition unit adding the first and second accelerator openings to obtain a third accelerator opening, a first maximum absorption torque calculator calculating a first maximum absorption torque of a traveling hydraulic pump based on the third accelerator opening, a second maximum absorption torque calculator calculating a second maximum absorption torque of the traveling hydraulic pump based on a rotational speed of the engine, and an HST pump electromagnetic proportional control output current converter converting a smaller one of the first and second maximum absorption torques into a target absorption torque.

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.

Work vehicle and method of controlling work vehicle

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.

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.

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Naka-gun, Japan

Taishi Oiwa