Komatsu Corporation

Takashi Katou

Hiroyuki Tomioka

Boku Itou

Kanji Namimatsu

Tetsuo Orita

Issei Hara

Hirofumi Kizawa

Shinji Tsujimura

Tadashi Iijima

Hiroshi Nakagami

Taira Ozaki

Hironori Yamamitsu

Masahiro Sawada

Yoshihisa Fujimoto

Tadashi Iljima

An exhaust treatment unit for a work vehicle includes a selective catalytic reduction apparatus, a connection pipe, an ejection apparatus attached to the connection pipe, a first pipe section that guides coolant to the ejection apparatus, a second pipe section that discharges coolant from the ejection apparatus, first and second retaining sections, and a coolant pump. The ejection apparatus ejects reducing agent into exhaust supplied to the selective catalytic reduction apparatus. The first and second retaining sections retain coolant and are connected to the first and second pipe sections above the ejection apparatus, respectively. The coolant pump is driven by an engine driving force and supplies the coolant to the ejection apparatus via the first pipe section. The first and second pipe sections extend upward from first and second connecting sections of the first and second pipe sections and the ejection apparatus toward the first and second retaining sections, respectively.

Exhaust treatment unit and work vehicle having exhaust treatment unit

A mixing device includes: an elbow pipe attached to an outlet pipe of a filter device, the elbow pipe changing a flow direction of an exhaust gas flowing from the filter device; a straight pipe connected to a downstream side of the elbow pipe, the straight pipe extending in a direction intersecting an axial line of the outlet pipe; an injector attached to the elbow pipe and injecting a reductant aqueous solution inside the elbow pipe toward the straight pipe; and a mixing pipe disposed in the elbow pipe to serve as a cover for the reductant aqueous solution, the mixing pipe being provided with openings on a circumferential wall thereof. A cutout is provided at a fixing portion of the mixing pipe with the elbow pipe at a position for allowing the exhaust gas entering through an inlet of the elbow pipe to flow toward the injection nozzle.

Reductant aqueous solution mixing device and exhaust aftertreatment device provided with the same

A mixing device includes: an elbow pipe attached to an outlet pipe of a filter device, the elbow pipe changing a flow direction of an exhaust gas flowing from the filter device; a straight pipe connected to a downstream side of the elbow pipe, the straight pipe extending in a direction intersecting an axial line of the outlet pipe; an injector attached to the elbow pipe and injecting a reductant aqueous solution inside the elbow pipe toward the straight pipe; and a mixing pipe disposed in the elbow pipe to serve as a cover for the reductant aqueous solution, the mixing pipe being provided with openings on a circumferential wall thereof. A plurality of large openings are provided on a circumferential wall of the mixing pipe near the injector and a plurality of small openings are provided on a circumferential wall of the mixing pipe near the straight pipe.

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.

A mixing device includes: an elbow pipe attached to an outlet pipe of a filter device; a straight pipe connected to a downstream side of the elbow pipe; and an injector attached to the elbow pipe and injecting a reductant aqueous solution into an inside of the elbow pipe toward the straight pipe. The elbow pipe is provided with an injector attachment to which the injector is attached with a bolt. An attachment face of the injector attachment is substantially flush with an end of an injection nozzle of the injector. The injector attachment is provided with a recess at which an end of the injection nozzle is exposed, the recess being enlarged toward the straight pipe. A heat-insulation layer located near an outer periphery of the recess is provided inside the injector attachment. An end of the bolt penetrates the injector from an outside to reach the heat-insulation layer.

Growing community of inventors

Oyama, Japan

Takashi Katou