Hitachi Construction Machinery Co., Ltd.

Hitachi Chemical Company, Ltd.

Makoto Sugaya

Tsukasa Toyooka

Tsutomu Udagawa

Akira Nakayama

Takeshi Takahashi

Takayuki Shimodaira

Eiji Egawa

Kazuo Takiguchi

Kensuke Satou

Tsuyoshi Nakamura

Hideaki Kawata

Shigeyuki Sakurai

Kensuke Sato

Hideki Akita

Hidekazu Tokushima

Makoto Motozu

Osamu Gokita

Daisuke Fukae

Makoto Matsushita

Takaharu Nishimura

Shougo Kimura

Kazuyoshi Yamada

Osamu Mawatari

Ryuji Takada

Yuuji Nagashima

Seiichiro Takeshita

Osamu Watanabe

Hideo Sorata

Akiko Satou

Naohiro Ishikawa

A sliding bearing assembly for joints of construction equipment can be provided, in which production cost is reduced by decreasing the used amount of Cu and sulfides having high fixability to a matrix are dispersed. The sliding bearing assembly for joints of construction equipment, includes at least a shaft and a bush made of an iron-based sintered material which functions as a sliding bearing, in which the bush has the overall composition of, by mass %, 0.1 to 10% of Cu, 0.2 to 1.2% of C, 0.03 to 0.9% of Mn, 0.36 to 1.68% of S, and the balance of Fe and inevitable impurities, a metal structure has pores dispersed in a matrix mainly including a martensite structure and sulfide particles precipitated and dispersed, and the sulfide particles are dispersed at 1 to 7 volume % in the matrix.

Sliding bearing assembly

An arm of a hydraulic excavator is formed as a box-shaped structural body surrounded by left and right side plates, an upper plate, a lower plate, and a thick rear plate. An upper end of the thick rear plate is protruded upward from an outer surface of the upper plate. Upper ends of a pair of arm cylinder brackets joined to an outer surface of the thick rear plate are arranged higher than the outer surface of the rear thick upper plate and lower than the upper end of the thick rear plate. As a result, in each of the arm cylinder brackets, a joint area with the thick rear plate can be ensured large, and joint strength can be improved.

Arm for construction machine with upper ends of rear plate protruding upward

An arm of a hydraulic excavator is formed as a box-shaped structural body surrounded by left and right side plates, an upper plate joined to each of the upper end sides of each side plate, a lower plate joined to each of the lower end sides of each side plate, and a thick rear plate joined to each of the rear end sides of each side plate and the upper plate. The side plates are formed by joining a rear thick side plate and a front thin side plate. The upper plate is formed by joining two members, that is, a rear thick upper plate and a front thin upper plate, and the lower plate is formed by joining two members, that is, a rear thick lower plate and a front thin lower plate.

Arm for construction machine

In an arm for a construction machine formed as a box-shaped structural body by left and right side plates, an upper plate, a lower plate, and a rear plate, a left rear thick side plate constituting the left side plate, a right rear thick side plate constituting the right side plate, a rear thick upper plate constituting the upper plate, and a rear thick lower plate constituting the lower plate are formed by using a soft steel material having a large plate thickness. A left front thin side plate constituting the left side plate, a right front thin side plate constituting the right side plate, a front thin upper plate constituting the upper plate, and a front thin lower plate constituting the lower plate are formed by using a high tensile steel material having a small plate thickness. As a result, the weight of the entire arm can be reduced.

A travel control device for a work vehicle includes: a hydraulic pump; a plurality of hydraulic motors connected to the hydraulic pump in parallel through a closed-circuit connection, that drive different wheels with pressure oil delivered from the hydraulic pump; a slip detection device that detects a slip occurring at each of the wheels; and a flow control device that reduces, upon detection of a slip occurring at any of the wheels by the slip detection device, a quantity of pressure oil supplied to a hydraulic motor for driving the wheel at which the slip has been detected, among the plurality of hydraulic motors.

Travel control device for work vehicle and work vehicle

A travel drive system for a work vehicle includes: an HST drive device comprising a hydraulic pump driven by a prime mover and a hydraulic motor connected to the hydraulic pump by a closed circuit; an electric motor driven by using electric power generated by drive of the prime mover; a first drive wheel driven by the HST drive device; a second drive wheel driven by the electric motor; a vehicle speed detector that detects a vehicle speed; and a control unit that distributes output of the prime mover to the HST drive device and to the electric motor such that, as the vehicle speed detected by the vehicle speed detector increases, a proportion of a first power distributed to the HST drive device decreases and a proportion of a second power distributed to the electric motor increases.

Travel drive system for work vehicle, work vehicle, and travel drive method

A hydro-static transmission travel system for a working machine enables the working machine to travel over a range from low speed to high speed with a simplified circuit arrangement. By referring to a machine traveling speed (vehicle speed) based on a detected signal from a rotation sensor, a controller computes respective target tilting amounts of hydraulic motorsand controls the tilting amount for the hydraulic motors and a clutch. Depending on whether the traveling speed exceeds a setting speed as a reference boundary, the controller selectively switches over a drive mode between low-speed four-wheel drive, in which travel unitsare both driven, and high-speed two-wheel drive, in which the front-wheel side hydraulic motoris controlled to zero displacement and only the rear-wheel side travel unitis driven.

HST travel system for working machine

One of the mode lampsandof the mode indicatorcorresponding to the current steering mode is turned on yellow and the other mode lamps are turned on green or turned off, thereby indicating whether front wheelsand rear wheelsare at neutral. A controllerdoes not operate a mode changing valveeven with an instruction outputted from a mode change switchwhen the front and rear wheels are not at neutral, and operates, in response to an instruction outputted from the mode change switch, the mode changing valveto establish a steering mode corresponding to the instruction when the front and rear wheels are at neutral. Also, the mode indicatoris controlled to always indicate, as the current steering mode, one corresponding to the steering mode actually established by the mode changing valve. With those features, in a working vehicle in which the mode of steering front and rear wheels can be changed over between two-wheel steering and four-wheel steering, a steering system having superior operability and high reliability can be provided.

Steering system for working truck

A construction machine of the present invention is provided, in a compartment formed by a cover, with an engine, a centrifugal fan, and a heat exchanger for exchanging heat between cooling air blown by the centrifugal fan and a specified medium, wherein the centrifugal fan and the heat exchanger are arranged further upstream than the engine with respect to flow of cooling air, so that cooling air sucked in by the centrifugal fan is led to the engine after passing through the heat exchanger.

Construction machine

Growing community of inventors

Narita, Japan

Makoto Sugaya