Kcm Corporation

Hitachi Construction Machinery Co., Ltd.

Keigo Kikuchi

Tetsuji Tanaka

Isamu Aoki

Koji Hyodo

Atsushi Shimazu

Takashi Takeyama

Masaki Yoshikawa

Yasuo Yamazaki

Katsutaka Hara

Shoroku Kawahara

Akira Shimohira

Keisuke Kobayashi

Masashi Yamashita

Nobuyuki Hidaka

Kentaro Oomae

Kohtaroh Uno

Provided is a work vehicle which is capable of appropriately setting the height of a work tool as a control threshold value for a ride control device or an automatic transmission control device, and which is excellent in operability, travel stability, and work efficiency. A value detected by an angle sensor () when a signal import switch () is operated by an operator is stored in a height position storage unit () of a main controller () as height position information about a bucket () for excavation work. In the height position storage unit (), the height position of the bucket () for hauling work and the height position of the bucket () for loading work are stored in advance as offset values from the height position information about the bucket () for excavation work. In this way, the ride control device or the automatic transmission control device can be appropriately controlled regardless of the preference or habit of the operator.

Work vehicle

To improve working efficiency in an eco mode when a power mode and the eco mode have been set in a wheel loader, the wheel loader is provided with a controller having an eco mode characteristic line, a power mode characteristic line, and a lifting operation characteristic line having a matching point C located between a matching point A between a working device operating engine torque characteristic line and the eco mode characteristic line and a matching point B between the working device operating engine torque characteristic line and the power mode characteristic line. The controller includes a control portion, which controls a HST pump in accordance with the lifting operation characteristic line when lifting operation of a lift arm is detected while the eco mode has been selected by a work mode selecting portion.

Wheel loader

A construction machine includes: a cover that covers an engine and a radiator; a radiator fan that is arranged at the rear of a vehicle body frame and discharges exhaust gas toward the rear of the vehicle body frame from the inner space of the cover; an injection device that injects a reducing agent into exhaust gas of the engine; a tank housing section that is arranged at one side of the vehicle body frame, includes an introduction section for introducing outside air, and houses a tank for storing the reducing agent injected by the injection device; and a connection section that is arranged in either the cover or the vehicle body frame and in the tank housing section, connects the inner space of the tank housing section and the inner space of the cover, and allows the outside air and the pipe to pass therethrough, the outside air having been introduced from the introduction section by the suction pressure of the radiator fan, the pipe supplying the reducing agent to the injection device.

Construction machine

An exhaust system of a work machine is equipped with a first exhaust system, a second exhaust system, and a third exhaust system. The first exhaust system and the third exhaust system are arranged to be in parallel with respective one ends directed in the same direction. In a plan view, the second exhaust system is arranged with the other end side directed in the same direction as the one end sides of the first exhaust system and the third exhaust system to be in parallel with the first exhaust system and the third exhaust system between the first exhaust system and the third exhaust system and, in a side view, is arranged above the first exhaust system and the third exhaust system.

Work machine

A work vehicle equipped with an HST traveling drive device, includes: an operation quantity detector that detects an operation quantity representing an extent to which an accelerator pedal is operated; a rotation rate detector that detects an actual rotation rate at a prime mover; a requested rotation rate calculation unit that calculates a requested rotation rate for the prime mover based upon the operation quantity detected by the operation quantity detector; and a prime mover control unit that controls the actual rotation rate based upon the requested rotation rate calculated by the requested rotation rate calculation unit. When the requested rotation rate is higher than a predetermined value, the requested rotation rate calculation unit calculates a rate of acceleration for the requested rotation rate based upon a difference between the requested and the actual rotation rate detected by the rotation rate detector and calculates the requested rotation rate based upon the calculated rate of acceleration.

An engine control device for work vehicle includes: a target rotation speed setting unit that sets a target rotation speed of an engine corresponding to an operation amount of an accelerator pedal; a rotation speed control unit that controls a rotation speed of the engine according to the target rotation speed; a travel driving unit that transmits rotation of the engine to wheels via a torque converter; a speed ratio detection unit that detects a speed ratio between an input shaft and an output shaft of the torque converter; and a target rotation speed correction unit that corrects the target rotation speed set by the target rotation speed setting unit so as to increase the target rotation speed based on the speed ratio when the operation amount of the accelerator pedal is smaller than a predetermined value and the speed ratio detected by the speed ratio detection unit is smaller than a predetermined value within a range which is equal to or greater than 0 and less than 1.

Engine control device for work vehicle

A clutch control device for a work vehicle includes a determination unit that determines as to whether or not a clutch cutoff condition has been established based upon whether or not the accelerator pedal is being operated, as determined by the accelerator pedal operation determination unit, the vehicle speed of the work vehicle detected by the vehicle speed detection unit and the braking force of the work vehicle detected by the braking force detection unit; and a clutch control unit that controls engagement/release of a clutch so as to release the clutch when the determination unit determines that the clutch cutoff condition has been established.

Clutch control device for work vehicle

A cooling fan control unit, in response to an operation performed at the rotation direction selector switch to select a reverse rotation setting while the cooling fan is rotating forward, lowers a relief pressure setting at the variable relief valve to a predetermined lower limit value over a predetermined length of time, and once the discharge pressure at the hydraulic pump detected by the pressure sensor is lowered to a predetermined switch-over pressure, executes control so as to switch the direction of flow of pressure oil to the hydraulic motor to the reverse direction by switching the direction switching valve and raises the relief pressure setting at the variable relief valve to a reverse rotation pressure setting, at which the hydraulic motor rotates in the reverse direction, over a predetermined length of time.

Cooling fan control device

To provide a travel control device for a working vehicle, including a speed change lever that is applicable even when a transmission in which speed stages are set to be larger by one stage is applied, the travel control device comprises a switching device () that switches speed changed by a transmission () either manually or automatically, a speed stage selecting device () that selects a speed stage out of a plurality of speed stages of the transmission (), and a first speed selecting device () that changes the speed stage manually down to a first speed separately from the speed stage selecting device (), regardless of a switching state of the switching device (), wherein the speed stage selecting device () selects the speed stages including a second speed or more but excluding the first speed, and a control device () is further provided, which controls the transmission () based on instructions sent from the switching device (), the speed stage selecting device (), and the first speed selecting device ().

Operation vehicle travel control device

A construction machine includes a condenserfor cooling refrigerant for an air conditioner; a fanfor cooling the condenserby using forward cooling air produced during normal-rotation drive; other cooled objects such as a radiatorand the like disposed under the lee of the forward cooling air with respect to the condenser; a refrigerant pressure detectorfor detecting the pressure of the refrigerant flowing in the condenser; and a controllerfor executing reverse-rotation stop processing for returning the fanto the normal-rotation drive when the pressure P of the air conditioner refrigerant detected by the refrigerant pressure detectorreaches a preset normal-rotation return pressure Pduring reverse-rotation drive of the fan. Thus, the lowering of the cooling effect of an air conditioner can be suppressed while reducing the burden of cleaning an engine room.

When a vehicle speed of a wheel loader () is determined to be not higher than a reference value (Yes) in step Sand a forward/reverse command switch () is determined to have been switchingly operated (Yes) in step S, the routine advances to step Swhere an increment &#x394;N of engine speed according to an engine load factor is determined. In step S, the increment &#x394;N of engine speed is then added to a target engine speed Na corresponding to a depression stroke of an accelerator pedal (), the thus-determined Na=Na+&#x394;N is set as a new target engine speed Na, and a target engine speed command iis sent to an engine controller ().

Growing community of inventors

Tsuchiura, Japan

Keigo Kikuchi