Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kabushiki Kaisha

Ryoko Yamada

Noritaka Masumitsu

Shinichiro Otsuka

Kenji Katayama

Norihiko Suzuki

Masahiro Sakanushi

Shinichi Kikuchi

Hiroshi Oono

Yoshiaki Matsuzono

Hideki Uedahira

An exhaust purification system includes an LAF sensor provided in an exhaust pipe and generates a signal corresponding to an air-fuel ratio of exhaust gas. An upstream catalytic converter is downstream of the LAF sensor and has a catalyst to purify the exhaust gas. An O2 sensor is downstream of the upstream catalytic converter, and generates a signal corresponding to the air-fuel ratio of the exhaust gas. A GPF is downstream of a the O2 sensor and purifies the exhaust gas. An ECU controls an air-fuel mixture in an engine using output signal KACT of the LAF sensor and an output signal VOof the O2 sensor such that the air-fuel ratio of exhaust gas flowing into the GPF converges to a target value near the stoichiometric ratio. The GPF has a filter substrate and a downstream TWC supported by a partition of the filter substrate.

Exhaust purification system of internal combustion engine

Provided is a GPF capable of exhibiting better than conventional three-way purification function. A gasoline particulate filter (GPF) that is provided in an exhaust pipe of an engine and that performs purification by capturing particulate matter (PM) in exhaust gas is provided with a filter substrate in which a plurality of cells extending from an exhaust gas inflow-side end face to an outflow-side end face are defined by porous partition walls and in which openings at the inflow-side end face and openings at the outflow-side end face of the cells are alternately sealed; and a three-way catalyst (TWC) supported by the partition wall. The three-way catalyst is the GPF comprising a catalytic metal containing at least Rh, and a composite oxide having an oxygen storage capacity and containing Nd and Pr in a crystal structure.

Exhaust purification filter

An exhaust purification system includes an LAF sensor provided in an exhaust pipe and generates a signal corresponding to an air-fuel ratio of exhaust gas. An upstream catalytic converter is downstream of the LAF sensor and has a catalyst to purify the exhaust gas. An O2 sensor is downstream of the upstream catalytic converter, and generates a signal corresponding to the air-fuel ratio of the exhaust gas. A GPF is downstream of a the O2 sensor and purifies the exhaust gas. An ECU controls an air-fuel mixture in an engine using output signal KACT of the LAF sensor and an output signal VO2 of the O2 sensor such that the air-fuel ratio of exhaust gas flowing into the GPF converges to a target value near the stoichiometric ratio. The GPF has a filter substrate and a downstream TWC supported by a partition of the filter substrate.

An exhaust emission control system for an internal combustion engine is provided. The exhaust emission control system () includes a monolith catalyst (MC) that includes an oxygen storage agent and a noble metal-based three-way catalyst including Pd, Rh, and Pt disposed at an upstream location in the exhaust gas flow in the internal combustion engine (), and a perovskite-type double oxide having a three-way catalytic function disposed at a downstream location in the exhaust gas flow. The amount C1 of Pd carried is 0.97 g/L&#x2266;C1&#x2266;1.68 g/L, the amount C2 of Rh carried is 0.11 g/L&#x2266;C2&#x2266;0.2 g/L, the amount C3 of Pt carried is 0.06 g/L&#x2266;C3&#x2266;0.11 g/L, the amount C4 of the oxygen storage agent carried is 25 g/L&#x2266;C4&#x2266;75 g/L, and the amount C5 of the perovskite-type double oxide carried is 5 g/L&#x2266;C5&#x2266;15 g/L. It is thereby possible to provide an exhaust emission control system that can reduce the production cost by reducing the amount of noble metal-based three-way catalyst used and at the same time can maintain a high exhaust emission control rate.

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Wako, Japan

Ryoko Yamada