Komatsu Corporation

Kanji Namimatsu

Takashi Katou

Tadashi Iijima

Hiroyuki Tomioka

Boku Itou

Tetsuo Orita

Issei Hara

Hirofumi Kizawa

Shinji Tsujimura

Hiroshi Nakagami

Taira Ozaki

Yasuyuki Onodera

Hironori Yamamitsu

Takumi Ito

Hiroshi Ohta

Kenji Matsubara

Shuki Akushichi

Tatsuya Iwazaki

Tomohiro Shimazu

Hatsuo Ando

Koichi Okaya

Masahiro Sawada

Tadashi Iljima

An exhaust gas treatment unit includes an exhaust gas treatment device, a bracket and a connecting pipe. The exhaust gas treatment device is mounted on a bracket. The connecting pipe is connected to the exhaust gas treatment device. The connecting pipe directs exhaust gas to the exhaust gas treatment device. The connecting pipe may include a supporting portion and a pipe portion, with the supporting portion supporting the bracket and the pipe portion being integrated with the supporting portion. Alternatively, the exhaust gas treatment unit may further include a supporting member having a supporting portion supporting the bracket and a pipe portion integrated with the supporting portion, with the pipe portion connected to the connecting pipe.

Exhaust gas treatment unit

An engine unit includes an engine, an exhaust gas treatment device and a connecting pipe. The engine has an exhaust gas port. The exhaust gas treatment device is arranged above the engine. The connecting pipe connects the exhaust gas port and the exhaust gas treatment device. The connecting pipe has an expandable-contractible bellows portion. The bellows portion has a linear form following the upward-downward direction. The lower end portion of the bellows portion is positioned lower than at least a part of the exhaust gas port.

Engine unit

An exhaust gas post-treatment unit includes a diesel particulate filtering device that treats engine exhaust gas, a selective catalyst reduction device that treats the engine exhaust gas, a connecting pipe, an injection device, a cooling water supply pipe and a cooling water return pipe. The connecting pipe connects the diesel particulate filtering device and the selective catalyst reduction device. The injection device is disposed on the connecting pipe and injects a reducing agent into the exhaust gas supplied to the selective catalyst reduction device. The a cooling water supply pipe guides cooling water to the injection device to cool the injection device. The cooling water return pipe discharges the cooling water from the injection device. At least one of the cooling water supply pipe and the cooling water return pipe has a convection section extending upward along the connecting pipe from a connecting portion with the injection device.

Exhaust gas post-treatment unit and construction vehicle carrying same

A reducing agent aqueous solution mixing device includes an exhaust pipe, an injector, an inner pipe and a tubular guide member. The exhaust pipe includes an elbow part having a curved portion, and a linear part disposed downstream of the elbow part. The injector is disposed outside of the curved portion, and injects a reducing agent aqueous solution into the elbow part towards the linear part. The inner pipe is disposed downstream of the injector within the exhaust pipe. The inner pipe has an inlet portion opening facing the injector and an outer peripheral surface spaced apart from the inner wall of the linear part. The inner pipe allows the exhaust gas to flow through the inside of the inner pipe and along the outer periphery of the inner pipe. The tubular guide member directs the reducing agent aqueous solution injected from the injector to the inner pipe.

Reducing agent aqueous solution mixing device and exhaust gas post-treatment device

A reducing agent aqueous solution mixing device includes an exhaust pipe, an injector, a mixing pipe, an inner pipe and a flow section. The exhaust pipe includes an elbow part and a linear part. The injector is disposed in the elbow part and injects a reducing agent aqueous solution. The mixing pipe receives the reducing agent aqueous solution injected from the injector, and includes an outlet portion formed spaced apart from an inner wall of the exhaust pipe, and a plurality of openings formed on the outer peripheral surface thereof. The inner pipe is disposed in the linear part and allows the exhaust gas to flow through the inside and the outer periphery thereof. The flow section is formed between the outlet portion of the mixing pipe and the inner wall of the exhaust pipe to direct the exhaust gas to the inner pipe.

A reducing agent aqueous solution mixing device includes an exhaust pipe, an injector, a mixing pipe and an inner pipe. The exhaust pipe includes an elbow part having a curved portion, and a linear part disposed downstream of the elbow part. The injector is disposed outside the curved portion and injects the reducing agent aqueous solution towards the linear part. The mixing pipe is disposed inside the elbow part to surround the reducing agent aqueous solution injected from the injector. The mixing pipe includes a plurality of openings on its outer peripheral surface. The inner pipe is disposed downstream of the mixing pipe and spaced apart from an outlet portion of the mixing pipe and from an inner wall of the linear part to allow the exhaust gas to flow through the inside of the inner pipe and along the outer periphery of the inner pipe.

An air cleaner includes a case in which an inner cylindrical filter and an outer cylindrical filter are housed, the case having a case body that defines an opening end surface closed by a cover member. The case includes an air inlet provided to an outer circumference of the case body for supplying outside air and an exhaust outlet provided to a bottom of the case body at a downstream side in an air-flowing direction for discharging the air supplied through the air inlet and filtered through the inner cylindrical filter and the outer cylindrical filter. A mass flow rate sensor is provided in the exhaust outlet to measure the flow rate of the air. A flow straightening grid is provided at the upstream side of the mass flow rate sensor to straighten the flow of the air.

Air cleaner, and engine control system

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 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.

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Oyama, Japan

Kanji Namimatsu