Komatsu Corporation

Kabushiki Kaisha Komatsu Seisakusho

Hiroshi Itogawa

Hidekazu Nagase

Shigeru Yamamoto

Takuya Uemura

Toshikazu Okada

Taira Ozaki

Takashi Noda

Nobuhisa Kamikawa

Yuushi Oshikawa

Norihisa Matsumoto

Naomi Kobayashi

Koji Okazawa

Masami Hirayama

Noriaki Namiki

Kazuyuki Onohara

Yuya Takahashi

A work vehicle includes a vehicle body, a travel device, a driving source, and a cooling device. The travel device is provided below the vehicle body. The driving source is disposed in a front part of the vehicle body. The driving source generates driving power for the travel device. The cooling device is disposed on one side in the vehicle width direction of the vehicle body and rearward of the driving source.

Work vehicle

A tractor includes a vehicle body, an engine, a cooling device, a fan, and a first exterior member. The engine is disposed on the front side of the vehicle body. The cooling device is disposed behind the engine. The fan is arranged to produce cooling air for the cooling device. The first exterior member is disposed on the front side of the vehicle body and covers the engine, the cooling device, and the fan. A first discharge port is arranged to discharge the cooling air and is provided in a first side surface of the first exterior member. The front side surface is positioned on a first side in the vehicle left-right direction. The front surface of the first exterior member includes no opening.

Tractor

During dozing operation, the amount of earth (i.e., load factor) accumulated on the front face of a blade is automatically detected independently of the operator's perception and, based on the detection, the dozing operation is automatically shifted from digging to carrying. The load factor is calculated by obtaining a horizontal reaction force and a vertical reaction force exerted on the blade during digging and by calculating the ratio of the vertical reaction force to the horizontal reaction force. When the load factor reaches a specified value, the blade is automatically controlled to incline backward to hold the earth.

Dozing system for bulldozer

A hydraulic drive system for the pitch cylinders (4A, 4B) of a bulldozer blade apparatus can include (a) main hydraulic pumps (30A, 30B) and an assistant hydraulic pump (31) to make up the assistant hydraulic circuit, (b) variable displacement hydraulic pumps (21A, 21B), or (c) fixed displacement hydraulic pumps (30A, 30B) and a plurality of solenoid selector valves such that the pitch cylinders can be connected in series. The assistant hydraulic pump (31) is connectable to delivery lines of the main hydraulic pumps through an assistant solenoid selector valve (32) which is controlled by an external signal. The blade (10) can be formed so that a line (14) tangential to the lower edge of the curved panel of the blade is inclined rearwardly with respect to the front face (13) of the blade edge member (12). Earth-moving work can be performed by inclining the blade (10) rearwardly by an angle (.theta..sub.1) with respect to its posture in digging work, and earth-dumping work can be performed by inclining the blade (10) forwardly by an angle (.theta..sub.2) with respect to its posture in digging work. The coupling positions of the two pitch cylinders (4A, 4B) can be in asymmetrical relation to each other. Control signals can be provided by a blade lever (23), tilt/pitch changeover switch (24), and pitch speed changeover switch (25). The tilt/pitch changeover switch (24) and pitch speed changeover switch (25) can be replaced by pitch-dump selector switch (25A) and pitch-back selector switch (24A).

Blade apparatus and its control method in bulldozer

A geared steering device (30) selectively operates rightside and leftside driving mechanisms (2,3) of a crawler vehicle (1) for more efficient operation of the crawler vehicle. The geared steering device (30) comprises a power input drive element (33) for inputting a driving power from a prime mover (7), rightside and leftside steering brakes (38R, 38L), rightside and leftside direct-coupled clutches (36, 44), a turn clutch (46), three arrays of planet gear trains (40, 43 and 48), and power output shafts (32R, 32L) coupled to right and leftside steering brake hubs (34R, 34L). A control unit compares an actual steering ratio of a geared steering device (30) with a designated steering ratio, outputs control signals to respective solenoid valves for controlling the direct-coupled clutches, the turn clutch or a steering brake so as to cause the actual steering ratio to approximate the designated steering ratio. The control unit outputs an engagement signal to the one of the direct-coupled clutches (36 and 44) on the side opposite to a steering direction entered by the steering lever (57).

Geared steering device for crawler vehicle and control unit therefor

An operator cabin on construction equipment is provided with a supporting structure which improves the riding quality by absorbing and damping vibrations and large impacts transmitted to the operator cabin. The right and left side portions of a front portion of the operator cabin (1) are secured to a frame (3) of the body of the construction equipment through damper plate shock absorbers (10R, 10L) or rotatable mounts (30R, 30L), while the right and left side portions of a rear portion of the operator cabin (1) are secured to the frame (3) through spring biased hydraulic shock absorbers (20L, 20R). Each of the shock absorbers has a vibration damping function. In particular, the stroke of the spring biased hydraulic shock absorber is large enough to absorb a large impact energy. This makes it possible to absorb vibration of small amplitude. For a strong shock, the impact energy can be absorbed by oscillating the operator cabin (1) about a pivot axis through the front mounts, allowing damping of the vibration. Lateral oscillation can be minimized by a four-bar parallel linkage which includes upper and lower lateral bars (40a, 40b), one cabin side (1R), and a vertical bracket (4R) positioned adjacent to that cabin side (1R).

Supporting structure for an operator cabin on construction equipment

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Hirakata, Japan

Hiroshi Itogawa