Kubota Corporation

Toshiya Fukumoto

Shinnosuke Ishikawa

Eiji Nishi

Nobuyuki Okabe

Satoshi Machida

Shigekazu Hasegawa

Kentaro Nakamura

Masao Takagi

Akio Hattori

Tetsuya Nishida

Yuji Tomiyama

Katsuhiko Honda

Shohei Nakai

Norifumi Adachi

Akihisa Okano

Shouhei Nakai

A hydraulic system for a work vehicle is disclosed. A preferential flow-dividing valve supplies a fixed amount of oil discharged from a variable displacement pump preferentially to a preferential hydraulic oil section and a surplus oil flow from the pump to a non-preferential hydraulic oil section. A plurality of electromagnetic proportional control valves are provided in the non-preferential hydraulic oil section for controlling oil flows relative to a plurality of hydraulically operated devices provided in the non-preferential hydraulic oil section. A necessary flow rate calculating module calculates a necessary oil flow rate in each of the preferential hydraulic oil section and the non-preferential hydraulic oil section based on a preferential oil flow rate of the preferential flow-dividing valve supplied to the preferential hydraulic oil section and an amount of current distributed to each of the plurality of electromagnetic proportional control valves in the non-preferential hydraulic oil section.

Hydraulic system for a work vehicle

A display system for a work vehicle is disclosed including a display device () having an information display area (), a display control unit () for controlling the display device, and a display switching command device (A) which outputs a display switching command for switching a display in the display device. The display control unit () selects and sets, based on an output from the display switching command device (A), one or more of an operating time display mode for displaying an operating time of an engine, an instantaneous fuel consumption display mode for displaying an instantaneous fuel consumption, an average fuel consumption display mode for displaying an average fuel consumption, and an amount of used fuel display mode for displaying an amount of used fuel, as a display mode for the information display area ().

Display system for work vehicle having a display switching command device for switching a display in a display device

A fuel consumption amount evaluation system is disclosed. The system includes a rotational speed detecting section () for detecting an engine rotational speed of the engine-driven traveling vehicle as a measured rotational speed, an accelerator opening degree detecting section () for detecting an accelerator opening degree, a fuel injection amount calculating means () for calculating a fuel injection amount per predetermined unit from the accelerator opening degree and the measured rotational speed, and a mileage evaluating section () for effecting a mileage evaluation based on the fuel injection amount calculated by the fuel injection amount calculating means ().

Condition evaluation system for engine-driven traveling vehicle

An operation parameter display system for a working vehicle () fitted with a working implement () includes a parameter setting controller () setting a group of operation parameters appropriate for the working implement () and the working vehicle () for each state of an operation executed by the working vehicle () in response to an operation input from a manual operation input device (). A parameter recording controller () stores the group of operation parameters set by the parameter setting controller () in a memory () in response to the operation input from the operation input device (). A parameter display controller () displays the group of parameters stored in the memory () on a display device () in response to the operation input from the operation input device ().

Operation parameter display system for working vehicle fitted with working implement

A change-speed system for a utility vehicle includes a gear change-speed device operated for change speed in response to an operation of an actuator, a hydraulic clutch for selectively engaging/disengaging power transmission to the gear change-speed device, a current-controlled valve mechanism for feeding pressure oil to the hydraulic clutch and a hydraulic clutch controlling portion for controlling oil pressure in the hydraulic clutch by controlling a value of electric current to the valve mechanism. The hydraulic clutch controlling portion is operable to initiate a disengaging process of the hydraulic clutch based on initiation of the operation of the actuator and operable also to initiate an engaging process of the hydraulic clutch based on completion of the operation of the actuator. The engaging process of the hydraulic clutch includes a first engaging sub-process for rapidly raising the oil pressure to the hydraulic clutch for a predetermined period and a second engaging sub-process for gradually raising the oil pressure to the hydraulic clutch which has been temporarily dropped subsequent to the first sub-process. There is provided a manual setting device for adjusting the value of the electric current to the valve mechanism from the hydraulic clutch controlling portion in the second engaging sub-process.

Change-speed system for utility vehicle

A hydraulic change speed system for a working vehicle includes a gear type change speed device shiftable by an actuator, a hydraulic clutch connected to a power transmission line including the gear type change speed device, a valve unit for switching operative states of the hydraulic clutch, a controller for controlling the valve unit, and a timer for measuring a shifting time of the gear type change speed device. The valve unit is interlocked to the actuator to be controllable to pressurize the hydraulic clutch rapidly for a predetermined time from a start of engagement of the hydraulic clutch and to pressurize the hydraulic clutch gradually the predetermined time. The controller sets the predetermined time based on the shifting time measured.

Hydraulic change speed system for a working vehicle

A display control system for a working vehicle comprising a plurality of sensors arranged on a vehicle body, a display for displaying messages relating to various information, and a display controller operable in response to information from the sensors for selecting information to be displayed on the display. The display controller has an ordinary display mode for displaying, on the display during an operation, information necessary to the operation, an adjusting mode for displaying, on the display during a non-operating time, information for correcting signals from the sensors, and a diagnostic mode for displaying, on the display during a non-operating time, information for checking the signals from the sensors. The system includes a display mode selecting device for selecting one of the three display modes according to a state of the working vehicle.

Display control system for a working vehicle

A propelling transmission for an agricultural tractor includes a main change speed mechanism, an auxiliary change speed mechanism, and a high/low change speed mechanism for providing two, high and low, speeds with a smaller transmission ratio than a transmission ratio between speed stages of the main change speed mechanism. The main change speed mechanism, auxiliary change speed mechanism and high/low change speed mechanism are arranged in series. Speeds in a low-speed range for an operational run among speeds provided by the main change speed mechanism and auxiliary change speed mechanism are combined with the two speeds provided by the high/low change speed mechanism. The propelling transmission prevents the high/low change speed mechanism from being operated to the low speed in a high-speed range for a road run among the speeds provided by the main change speed mechanism and auxiliary change speed mechanism, whereby the high-speed range is combined only with the high speed provided by the high/low change speed mechanism.

Agricultural tractor

In carrying out a shifting operation in a working vehicle such as a tractor, an actual acceleration of the working vehicle is measured, and a feedback control of a control hydraulic pressure applied to a hydraulic clutch is performed to fix a jerk which is a differentiation of the measured acceleration with respect to time. Thereafter, a feedback control is performed to fix the acceleration. A theoretical running speed is derived from a rotating speed of the engine and a speed position detected. When an actual speed of the working vehicle becomes equal to the theoretical running speed, The control hydraulic pressure applied to the hydraulic clutch is increased to a maximum.

Clutch pressure control apparatus and method for a working vehicle

There is disclosed a plowing depth detecting system for a rotary plow adapted to detect an actual plowing depth on the basis of distance data with respect to the ground received from a distance sensor attached to the rotary plow which is vertically movably connected to a vehicle through a link mechanism. The distance sensor provides a microprocessor with distance data with respect to the ground rearwardly of the rotary plow. The microprocessor determines a value of actual plowing depth of the rotary plow on the basis of this distance data and a correction value according to a working condition of the rotary plow.

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Takarazuka, Japan

Toshiya Fukumoto