Komatsu Corporation

Kabushiki Kaisha Komatsu Seisakusho

Fumihide Sato

Yasuyuki Onodera

Yoshiki Kanzaki

Toshihiko Nishiyama

Takahisa Iino

Taku Murakami

Kiyoharu Nakao

Kunihiko Komiyama

Haruo Hashimoto

Toyoichi Ono

Ichio Ichikawa

Kenji Mihara

Koji Iijima

Hiroshi Ohkawa

In an internal combustion engine having an exhaust gas recirculation circuit, the efficiency of a turbocharger is raised in a wide engine rotational speed area and, even when a pressure in an intake circuit is higher than that in an exhaust circuit, an exhaust gas can be circulated. For this purpose, an openable intake throttle valve ( ) is provided on the more upstream side than an exhaust gas circulation position of the intake circuit ( ), or a narrow portion ( ) is formed on the exhaust gas circulation position of the intake circuit and an intake bypass circuit ( ) for bypassing the narrow portion is provided. Further, an intake and exhaust bypass circuit ( ) for connecting the intake circuit to the exhaust circuit ( ) is provided. Then, the opening degree of the intake throttle valve or intake bypass circuit and the opening degree of the intake and exhaust bypass circuit are adjusted so as to set the pressure at the exhaust gas circulation position of the intake circuit to be lower than that in an exhaust manifold ( ).

Exhaust gas recirculation control apparatus for internal combustion engine

A life estimation device which numerically measures the damage to a machine such as an engine accurately to estimate, the life of the machine accurately without requiring skill. A load map (B) of the two-dimensional distribution of the operation parameters of an engine is made. In accordance with the weighted integration time &agr;i&middot;ki at each level (Bi) of the load map (B), the actual damage &dgr;&equals;&Sgr;&agr;i&middot;ki to the engine for a certain lapse of time &tgr; is calculated. By operating the engine beforehand, a correspondence relation L between the magnitude of the damage &dgr; and the life H is predetermined. The life H corresponding to the calculated actual damage &dgr; is determined in accordance with the predetermined correspondence relation L and the H is outputted as the estimated life of the engine.

Life estimation device for engine and machine having heat source

A Roots blower driven by a direct-current motor provided to a recirculation duct for connecting an exhaust duct and an intake duct to extract a part of exhaust gas of a diesel engine to recirculate to an intake side. Accordingly, even when a differential pressure between an exhaust side and the intake side, or even when a pressure on the intake side is higher than the exhaust side fluctuates, the exhaust gas flowing to the recirculation duct can be forcibly pumped by the Roots blower while appropriately controlling flow rate thereof, so that an optimum recirculation amount of exhaust gas in accordance with operation condition of the diesel engine can be recirculated to the intake side.

Exhaust gas recirculation device and control method thereof

An apparatus and method for predicting a lubricating oil replacement time for an engine by precisely predicting a total acid value and/or an amount of soot in a lubricating oil and by displaying an accurate time which will elapse before a required lubricating oil replacement. Accurate prediction of lubricating oil replacement prevents engine seizing and other damage and avoids wasteful replacement of otherwise useful lubricating oil.

Apparatus and method for predicting replacement timing of engine

Sea water cooling apparatus for marine diesel engine

A fuel injection timing control apparatus is disclosed, which comprises a fuel injection timing control mechanism including an input and an output shaft respectively with a first and a fourth gear, at least one of these gears being a helical gear, and an axially movable shaft with a second and a third gear respectively in mesh with the first and fourth gears, a piston-cylinder assembly with a piston rod coupled to the axially movable shaft, and a piston-cylinder assembly control mechanism having detector means for detecting the phases of the first and fourth gears. The phase relation between the first and fourth gears is varied with displacement of the second and third gears caused through control of the piston-cylinder assembly according to the difference between a reference phase angle and a detected phase angle.

Apparatus for controlling fuel injection timing

A fuel injection system for an internal combustion engine employing a rotary valve for delivering fuel to fuel injectors in which fuel injection timing is precisely controlled to an optimum range by automatically controlling the rotary valve in response to the number of revolutions of the engine. The system includes a high pressure accumulator connected to a fuel pump and a low pressure accumulator connected to a tank through a variable restrictor valve. The rotary valve functions to selectively connect each injector to the high and low pressure accumulators as it rotates whereby metered amount of fuel can be fed into a plunger chamber of each injector when a piston chamber of the injector is connected to the low pressure accumulator and the fuel can be injected through nozzle orifices when the piston chamber is connected to the high pressure accumulator.

Growing community of inventors

Oyama, Japan

Fumihide Sato