Komatsu Corporation

Yasuyuki Onodera

Toshihiko Nishiyama

Fumihide Sato

Yoshiki Kanzaki

Takumi Ito

Takahisa Iino

Kanji Namimatsu

Kozo Okuda

Shuki Akushichi

Shouhei Nagasaka

Kunihiko Komiyama

Jin Yogita

Hideo Oguri

Kenji Mihara

Kiichirou Kouno

Tatsuya Iwazaki

Minato Tomuro

Koichi Okaya

Hatsuo Ando

Ken Itou

A work vehicle includes a vehicle body, a guiding pipe, a first heating section, and a second heating section. The vehicle body has a partition wall that partitions a space in an inner section into a first region and a second region. The guiding pipe is configured to guide a reducing agent. The guiding pipe has a first pipe section and a second pipe section. The first pipe section is positioned inside the first region. The second pipe section is positioned in the second region. The first heating section heats the first pipe section. The second heating section heats the second pipe section and adjusts the temperature independently from the first heating section.

Work vehicle

An engine () has an exhaust manifold () provided with a communicating portion (B) of a bypass line () from an air-supply side and a branch portion (A) to an EGR line (). When an exhaust gas outlet () is provided in an intermediary of the exhaust manifold () in a longitudinal direction along an engine cylinder line, the communicating portion (B) of the bypass line () and the branch portion (A) of the EGR line () that are provided on the exhaust manifold () are provided on both sides in the longitudinal direction sandwiching the exhaust gas outlet () and spaced apart from each other so that a part of the exhaust gas is pushed by an air supply fed from the bypass line () is pushed to enter the EGR line ().

Supercharged engine with EGR device

An intake controller installed in a diesel engine, wherein the control part of a valve controller fully opens a bypass valve in a bypass passage when it determines that the operating state of the diesel engine is suddenly decelerated from a middle and high speed and middle and high load range. Accordingly, the control part can feed an intake air from the outlet passage side of a compressor to the inlet passage side of an exhaust turbine, and can rapidly lower the rotational speed of an exhaust turbine supercharger () which tends to be rotated at a high speed by inertia. As a result, since the operating state not enter a surging area while an operating point is moving, surging can be securely avoided.

Intake controller of internal combustion engine

In an open/close control deviceinstalled in a diesel engine, when a rotational speed N of the diesel engineis equal to or higher than an intermediate rotational speed and a fuel injection amount is equal to or less than an idling injection amount Fi, a control portionof a valve opening and closing controlling meansdetermines that the diesel engine is in such a state that engine brake is to be actuated, and controls to close both a bypass valveand an EGR valve. Accordingly, since there is no fear that exhaust gas returns from an inlet line side of an exhaust turbineto an outlet line side of a compressor, the engine brake can be effectively actuated during running at high speeds and running on a downward slope.

Open/close controller of intake and exhaust communication circuit

Cylinder heads (toare respectively provided with fuel injectors (to). Each of the fuel injectors () is connected to each of joints (to) in a common rail () extending linearly through fuel injection pipes (to). In this example, it can be achieved to allow all the fuel injection pipes (to) to have the same length by crossing the injection pipes (and) to connect. With this configuration, it is possible to reduce the irregularities in the amount of fuel injection and to enhance the engine performance.

Piping structure of fuel injection pipes for engine

A bypass conduit () connects an outlet passage of a compressor () of an exhaust gas turbocharger () and an inlet passage of an exhaust turbine (), and a bypass valve () is provided therein. When the operating condition of a diesel engine () is found to be in a low-speed and high-load region, the bypass valve () is controlled by means of a valve controller to adjust the bypass conduit () so as to open it. Then, the charge air partly flows into an exhaust conduit () to increase the rotational speed of the exhaust turbine () and hence the charge air flow rate raises the output of the diesel engine (). Additionally, as the charge air flow rate is increased, the operating condition of a compressor () is prevented from approaching the surging range.

Internal combustion engine provided with intake bypass control device

A control method of an EGR system of an engine capable of effectively performing an EGR control at a time of rapid acceleration. For this purpose, an intake air flow rate of the engine is obtained, and from a target EGR valve opening degree and a difference in pressure in front of and behind the EGR valve, a virtual EGR gas flow rate is arithmetically operated. A virtual EGR rate is obtained from the intake air flow rate, the fuel flow rate and the virtual EGR gas flow rate, and a difference from or a ratio to a target EGR rate obtained from the engine speed and the fuel flow rate is obtained. A command EGR valve opening degree is obtained from an EGR valve opening degree correction coefficient obtained from the difference or the ratio, and the target EGR valve opening degree, whereby the EGR vale is driven.

Control method of EGR system of engine

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 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.

Growing community of inventors

Oyama, Japan

Yasuyuki Onodera