Hitachi Construction Machinery Co., Ltd.

Kcm Corporation

Eiichi Sakai

Tetsuji Tanaka

Koji Hyodo

Masami Higaki

Hidenobu Tsukada

Hideo Nakayama

Nobuhiro Suzuki

Yasuo Yamazaki

Koji Takano

Genichiro Ishimaru

Hirofumi Ouchi

Tomoo Takahashi

An automatic transmission device for a wheel loader includes: a shift mechanism; a work detection device that detects that the wheel loader is performing an excavation work; and a shift control device that executes control so as to downshift a speed stage at the shift mechanism if the work detection device detects that the wheel loader is performing the excavation work.

Automatic transmission device for wheel loader and wheel loader

A speed change control system for industrial vehicle, includes: a speed ratio detecting unit that detects a speed ratio of speeds of an input shaft and of an output shaft of a torque converter; speed changer for operating based on the torque converter speed ratio that shifts up or down a speed stage of a transmission in response to the detected speed ratio; a braking detection unit that detects an operation of a braking device for traveling; and a downshift limit unit that permits a downshift to a 1st speed by the speed changer when a non-operation of the braking device is detected by the braking detection unit and limits a lowest speed stage upon downshift by the speed changer to a 2nd speed when an operation of the braking device is detected.

Speed change control system for industrial vehicle

A speed change control system for an industrial vehicle includes: a speed ratio detecting unit that detects a speed ratio of speeds of an input shaft and of an output shaft of a torque converter; a torque converter speed ratio-based speed changer that shifts up or shifts down a speed stage of a transmissionin response to the detected speed ratio; a vehicle speed detection unit that detects a speed of the vehicle; a mode selection unit that selects any one of an L-mode and an H-mode; and a speed change control unit that permits an upshift provided that the vehicle speed is equal to or higher than a first predetermined value when the L-mode is selected whereas permits the upshift provided that the vehicle speed is higher than another predetermined value which is larger that the predetermined value when the H-mode is selected.

A clutch control device includes: a plurality of hydraulic clutches built into a transmission; a clutch switching pattern storage device in which a plurality of clutch switching patterns, each defining engage/release changeover timing with which the plurality of hydraulic clutches are engaged/released are stored in correspondence to individual speed change patterns adopted by the transmission; a clutch switching pattern selection device that selects a clutch switching pattern stored in the clutch switching pattern storage device in correspondence to a speed change pattern for the transmission at a time of speed change; and a hydraulic control device that executes hydraulic control for the plurality of hydraulic clutches in correspondence to the clutch switching pattern selected by the clutch switching pattern selection device.

Clutch control device and clutch control method

A shift control device for a work vehicle that has a stepped automatic transmission includes: a control device that controls an engine rotation rate at the work vehicle and the stepped automatic transmission; a forward/reverse switchover member that outputs a forward/reverse switchover command for the work vehicle; and an operation quantity detection device that detects an accelerator pedal operation quantity in the work vehicle is operated. As the forward/reverse switchover command is output via the forward/reverse switchover member, the control device executes forward/reverse switchover control for the stepped automatic transmission and also controls the engine rotation rate so as to decrease the engine rotation rate gradually to a target lower limit value selected to ensure that a reverse rotation of a turbine runner at a torque converter in the work vehicle does not occur.

Shift control device for work vehicle

A gearshift controller for an industrial vehicle, includes: a speed ratio detection unit that detects a speed ratio of speeds of an input axis and of an output axis of a torque converter; a gearshift control unit that shifts up a speed stage when the detected speed ratio is equal to or more than a first predetermined value and shifts down the speed stage when the detected speed ratio is equal to or less than a second predetermined value, which is smaller than the first predetermined value; and an operation member with which a downshift to the first speed is instructed by operation thereof by an operator. When the downshift is instructed by the operation member, the gearshift control unit controls the speed stage to be kept at the first speed for a predetermined time period regardless of the speed ratio detected by the speed ratio detection unit.

Growing community of inventors

Ryugasaki, Japan

Eiichi Sakai