Komatsu Corporation

Kabushiki Kaisha Komatsu Seisakusho

Takashi Kuse

Eiji Yamaguchi

Masaaki Kuma

Shigeru Yamamoto

Naoki Ishizaki

Hikosaburo Hiraki

Toshikazu Okada

Hiroaki Takeshima

Chikara Nakao

Naoji Hamasaka

Masayuki Sato

Nobuaki Kawasaki

Masaru Nakamura

Akira Shibata

In a work vehicle, a control unit is configured to control a lock-up hydraulic pressure for controlling switching of a lock-up clutch. The control unit is configured to execute a lock-up slippage control for switching the lock-up clutch into a slippage state when the work vehicle starts moving. The control unit is configured to control the lock-up hydraulic pressure based on work instrument load information, pertaining to a load of a work instrument during execution of the lock-up slippage control.

Work vehicle and method of controlling the same

A lubricating oil supply control device controls a lubricating oil supply amount to a transmission in a construction machine including a torque converter with a lock-up clutch. The lubricating oil supply control device includes a clutch state determining section, a lubricating oil amount detecting section and a lock-up clutch controlling section. The clutch state determining section determines whether or not the lock-up clutch is being coupled. The lubricating oil amount detecting section detects whether or not the lubricating oil supply amount to the transmission is short of a preliminarily set supply amount. The lock-up clutch controlling section decouples the lock-up clutch when the lock-up clutch is being coupled and the lubricating oil supply amount is short of the preliminarily set supply amount.

Lubricating oil supply control device for construction machine

Provided is a device for performing speed change not leading to engine stall in a working vehicle such as a wheel loader while sustaining a required tractive force and reducing fuel consumption. When a speed ('forward', 'second speed') suitable for a work is selected by a speed change operator, control means makes a modulation clutch engaged in response to the vehicle speed drop and makes a lock-up state where a lock-up clutch is engaged transit to a lock-up and modulation clutch slip state where the lock-up clutch is engaged while the modulation clutch slips. Subsequently, the control means performs a clutch control for causing a transition to both clutch slip state where the lock-up clutch and the modulation clutch slip in response to the vehicle speed drop, hence causing the transition to a torque converter operation state where the modulation clutch is engaged and the lock-up clutch is released.

Speed change controller of working vehicle

A construction vehicle includes a control unit configured to shift gear after performing pre-shifting to couple a target speed-change gear that corresponds to a target speed with a target speed-change shaft in non-transmitting state of rotation of the input shaft when the gear shift is performed from a current speed to the target speed, in a state in which the current speed gear that corresponds to the current speed step and the current speed-change shaft that corresponds to the current speed gear are coupled. When the vehicle speed detected by the vehicle speed detecting section is zero, the control unit is configured to perform pre-shift auxiliary control prior to the pre-shifting control to input the rotation of the input shaft to the target speed-change shaft in a state in which the target speed-change shaft is not coupled to the plurality of speed-change gears.

Construction vehicle

A transmission is provided which has a very compact system configuration and is capable of exerting high energy efficiency over all speed regions from a low speed region to a high speed region, while providing improved operability free from a torque shortage. To this end, the transmission has an input shaft, an intermediate output shaft, a planetary gear mechanism, a first pump-motor, and a second pump-motor connected to the first pump-motor, the input shaft being coupled to a first element of the planetary gear mechanism, the second pump-motor being coupled to a second element of the planetary gear mechanism, the intermediate output shaft being coupled to a third element of the planetary gear mechanism, and the transmission further comprising a switching mechanism for selectively coupling the first pump-motor to either the input shaft or the intermediate output shaft.

Speed-changing device

A transmission is provided which has a very compact system configuration and is capable of exerting high energy efficiency over all speed regions from a low speed region to a high speed region, while providing improved operability free from a torque shortage. To this end, the transmission has an input shaft, an intermediate output shaft, a planetary gear mechanism, a first pump-motor, and a second pump-motorconnected to the first pump-motor, the input shaftbeing coupled to a first element (planetary carrier) of the planetary gear mechanism, the second pump-motorbeing coupled to a second element (sun gear) of the planetary gear mechanism, the intermediate output shaftbeing coupled to a third element (ring gear) of the planetary gear mechanism, and the transmission further comprising a switching mechanism (synchromesh mechanism) for selectively coupling the first pump-motorto either the input shaftor the intermediate output shaft

Control device and control method for transmission with clutch

Gear shot peening method

Epicycloidal gear type speed change gear system

A hydraulic vehicular transmission has a plurality of drive speed establishing devices (e.g. clutches) to be actuated for selecting a drive speed, and a pair of similar drive direction establishing devices to be actuated for selecting a drive direction. The drive establishing devices are all actuated and deactuated hydraulically by respective solenoid operated control valves via respective pilot operated valves. Since the solenoid valves are susceptible to malfunctioning, as in the event of trouble in the associated electrical circuitry, emergency control valves are interposed respectively between the solenoid valves and the pilot operated valves. Each emergency control valve is to be hand operated in the event of the malfunctioning of the associated solenoid valve for actuating or deactuating the associated speed or direction establishing device via the associated pilot operated valve. Additional features are incorporated for the greater utility of the transmission control system.

Growing community of inventors

Komatsu, Japan

Takashi Kuse