A computer-implemented method is provided for controlling a work tool coupled to a frame of a work vehicle and moveable relative thereto, wherein the work tool is configured in a first mode to apply an enclosing pressure on a load and in a second mode to release the enclosing pressure on the load. At least one work state of the work vehicle is determined. In association with the first mode, which may for example be user-selectable or otherwise determined in view of the work state, a configuration setting corresponding to the at least one work state of the work vehicle is automatically selected from data storage, and a control signal is generated for controlling an actuator associated with an amount of enclosing pressure applied by the work tool and upon the load, based at least in part on the selected configuration setting.

Disclosed are a fork leveling system and a method thereof, and a telescopic boom forklift. The fork leveling system includes an active leveling oil cylinder, a passive leveling oil cylinder and an electric control oil supplement valve, where a rodless cavity of the active leveling oil cylinder is communicated with a rodless cavity of the passive leveling oil cylinder, and a rod cavity of the active leveling oil cylinder is communicated with a rod cavity of the passive leveling oil cylinder; and an oil inlet of the electric control oil supplement valve is connected to an oil pump, and an oil outlet of the electric control oil supplement valve is connected to the rodless cavity of the active leveling oil cylinder and the rod cavity of the active leveling oil cylinder.

Disclosed are a fork leveling system and a method thereof, and a telescopic boom forklift. The fork leveling system includes an active leveling oil cylinder, a passive leveling oil cylinder and an electric control oil supplement valve, where a rodless cavity of the active leveling oil cylinder is communicated with a rodless cavity of the passive leveling oil cylinder, and a rod cavity of the active leveling oil cylinder is communicated with a rod cavity of the passive leveling oil cylinder; and an oil inlet of the electric control oil supplement valve is connected to an oil pump, and an oil outlet of the electric control oil supplement valve is connected to the rodless cavity of the active leveling oil cylinder and the rod cavity of the active leveling oil cylinder.

The present disclosure provides systems and methods for determining an efficient hydraulic pump speed of a hydraulic pump configured for use with a hydraulic system of a material handling vehicle having a fork assembly configured to perform a hydraulic function on a load on the fork assembly. In some configurations, the systems and methods may comprise measuring a height of the fork assembly using a height sensor. The systems and methods may further comprise measuring a temperature of hydraulic oil within the hydraulic system using a temperature sensor. The systems and methods may further comprise measuring a weight of the load using a weight sensor. The systems and methods may further comprise determining a hydraulic pump speed based on at least one of the height of the fork assembly, the temperature of the hydraulic oil, and the weight of the load.

The present disclosure provides systems and methods for determining an efficient hydraulic pump speed of a hydraulic pump configured for use with a hydraulic system of a material handling vehicle having a fork assembly configured to perform a hydraulic function on a load on the fork assembly. In some configurations, the systems and methods may comprise measuring a height of the fork assembly using a height sensor. The systems and methods may further comprise measuring a temperature of hydraulic oil within the hydraulic system using a temperature sensor. The systems and methods may further comprise measuring a weight of the load using a weight sensor. The systems and methods may further comprise determining a hydraulic pump speed based on at least one of the height of the fork assembly, the temperature of the hydraulic oil, and the weight of the load.

A hydraulic drive device for an industrial vehicle includes a variable displacement pump, a displacement control valve, a power steering cylinder, a power steering valve, a loading cylinder, a loading valve, a hydraulic oil passage, and a pilot line. The displacement control valve controls the variable displacement pump to increase displacement of the variable displacement pump when differential pressure between discharge pressure of hydraulic oil discharged from the variable displacement pump and pilot pressure generated in the pilot line is smaller than a predetermined set pressure. A spool of the loading valve is provided with a groove portion that forms a communication passage that makes communication between the hydraulic oil passage and the pilot line at a neutral position of the loading valve when the power steering valve is located in a neutral position.

A hydraulic drive device for an industrial vehicle includes a variable displacement pump, a displacement control valve, a power steering cylinder, a power steering valve, a loading cylinder, a loading valve, a hydraulic oil passage, and a pilot line. The displacement control valve controls the variable displacement pump to increase displacement of the variable displacement pump when differential pressure between discharge pressure of hydraulic oil discharged from the variable displacement pump and pilot pressure generated in the pilot line is smaller than a predetermined set pressure. A spool of the loading valve is provided with a groove portion that forms a communication passage that makes communication between the hydraulic oil passage and the pilot line at a neutral position of the loading valve when the power steering valve is located in a neutral position.

A system of controlling a lowering speed of a work lever of a forklift which includes, a hydraulic motor connected to the work lever through a hydraulic line to transmit a power to the work lever; an electronic solenoid valve for controlling the hydraulic motor connected to the work lever; a weight sensor provided at one side of the work lever, the weight sensor measuring a weight of a load placed on the work lever and transmitting the measured value to a controller; and a controller for controlling an RPM of the hydraulic motor and a current amount of the electronic solenoid valve based on the measured value transmitted from the weight sensor.

Forklift truck (1) mounted on a carrier vehicle and comprising a frame (16), forks (2), a lifting cylinder (4) for relatively moving the forks (2) and the frame (16) so as to allow, in a handling mode of operation, wherein the forks (2) are mounted so as to move freely upwards and downwards relative to the ground, the forks (2) to be lifted, and in a carrying mode of operation, wherein the forks (2) are in the high position and immobilised so that they do not move upwards and downwards relative to the ground, to allow the frame to be lifted (16), each chamber (7, 8) of the cylinder (4) being provided with a connecting fluid duct which connects the chamber (7; 8) to a hydraulic source. In the handling mode of operation, the forks (2) form an element which is used to actuate the lifting cylinder (4) in the direction in which the forks (2) are lowered, the fluid ducts of the chambers (7, 8) of the lifting cylinder (4) being connected to one other by a fluid connection provided with a closing member in the closed position at least in the carrying mode of operation when the frame (16) is being driven in the direction in which the frame (16) is lifted.

The present disclosure relates to a fork movement control device. A fork movement control device according to an exemplary embodiment of the present disclosure may control and simultaneously move two forks by manipulating a single lever.