Hitachi Construction Machinery Co., Ltd.

Genichiro Ishimaru

Koji Hyodo

Nobuhiro Suzuki

Yasuo Yamazaki

Koji Takano

Kazuo Chonan

Tetsuji Tanaka

Masaki Yoshikawa

Kazuo Ishida

Eiichi Sakai

Nobuyuki Hidaka

Tomoo Takahashi

There are provided: a first circuit for traveling HC, formed through a closed circuit connection of a variable displacement hydraulic pumpand a variable displacement hydraulic motor, that includes a motor control unitthat controls a displacement of the hydraulic motor; a second circuit for working HCthat drives a work hydraulic actuatorby pressure oil from a work hydraulic pump; and a maximum value control unit that controls a maximum displacement of the hydraulic motorin accordance with load pressure Pf in the second circuit HC. The maximum value control unit decreases the maximum displacement to a minimum limit qcorresponding to a maximum load pressure Pr in the second circuit when load pressure Pf in the second circuit exceeds a predetermined value Ps.

Travel control apparatus for working vehicle

A first motorand a second motorof variable displacement type are in parallel to each other connected to a hydraulic pumpin a closed circuit, through which the output torque from the first motoris transmitted to an output shaft. A clutch control unitcontrols a clutch deviceas: when the engine speed is N, which is the case where the accelerator pedal is fully depressed, the clutch is disengaged at the vehicle speed v. When the engine speed is N(&#x3c;N), which is the case where the accelerator pedal is half depressed, the clutch is disengaged at the vehicle speed v(&#x3c;v).

Clutch control device for hydraulically driven 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.

Gearshift controller for industrial vehicle

Growing community of inventors

Inashiki, Japan

Genichiro Ishimaru