Hitachi Construction Machinery Co., Ltd.

Kcm Corporation

Kazuo Chonan

Koji Hyodo

Nobuhiro Suzuki

Masaki Yoshikawa

Yasuo Yamazaki

Koji Takano

Genichiro Ishimaru

Nobuyuki Hidaka

Kazuo Ishida

Atsushi Shimazu

Kentaro Itoga

Hiroki Nakazono

Tsuyoshi Takeyama

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 control apparatus for a working vehicle includes a travel circuit HCformed through a closed circuit connection of a variable displacement hydraulic pump driven by an engine and a variable displacement hydraulic motor, a work circuit HCthat includes a work hydraulic pump driven by the engine and a work hydraulic actuator that operates by pressure oil from the work hydraulic pump, a relief valve that relieves high pressure oil of the travel circuit HC, a rotation speed control unit that controls the engine rotation speed in correspondence to an accelerator pedal operation amount, a state detection unit that detects a vehicle state of high load travel and high load work, and a speed limitation unit that reduces an engine rotation speed upper limit when the vehicle state of high load travel and high load work is detected.

Control apparatus for working vehicle

There are provided: a pedal operation amount detection unitthat detects an operation amount s of the accelerator pedal; a speed ratio detection unitthat detects a speed ratio e of an input shaft and an output shaft of the torque converter; a load pressure detection unitthat detects a load pressure P of the hydraulic pump; a speed stage detection unitthat detects a low speed stage of a transmissioncapable of varying a speed stage between a low speed stage and a high speed stage; and a speed limiting unitthat limits a maximum speed of the engineto a lower speed upon satisfaction of following speed limitation conditions: at least a pedal operation amount s is equal to or greater than a predetermined value s, a speed ratio e is equal to or less than a predetermined value ea, a load pressure P is equal to or greater than a predetermined value Pa, and the low speed stage of the transmission has been detected.

Engine control device 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

Growing community of inventors

Moriya, Japan

Kazuo Chonan