Honda Giken Kogyo Kabushiki Kaisha

Honda Giken Kogyo Kabushiki Kabushiki Kaisha

Hiroshi Oono

Masahiro Sakanushi

Nobuaki Takaoka

Yoshiaki Matsuzono

Norihiko Suzuki

Toshikatsu Takanohashi

Shinichi Kikuchi

Ryoko Yamada

Hideki Uedahira

Hideki Uedahra

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.

Device for clarifying exhaust gas from internal combustion engine

The invention provides a catalyst deterioration detecting system that is capable of detecting the degree of deterioration of each catalyst in a catalyst converter which includes two or more catalysts in series. The catalyst deterioration detecting system of an internal-combustion engine according to the invention is provided with a upstream catalyst located on an upstream side of an exhaust system of the internal-combustion engine and a downstream catalyst located on a downstream side of the exhaust system. The device comprises an oxygen density detector which is disposed downstream of the downstream catalyst and a deterioration detector for detecting a deterioration degree of the upstream catalyst based on the output of the oxygen density detector. According to an aspect of the invention, the deterioration detector detects deterioration degree of the downstream catalyst based on the previously detected deterioration degree of the upstream catalyst.

Catalyst deterioration detecting system for an automobile

A proportional oxygen sensor, a three-way catalyst, a binary O sensor, a NOx purification device, and a binary O sensor are positioned in the named order in the exhaust system of an internal combustion engine. A correction coefficient KMON which is set in accordance with the degree of deterioration of a three-way catalyst, is used to correct the timer value tmMON used to measure the time extending from the time at which the output of the O sensor is changed when the air-fuel ratio is increased, until the time at which the output of the O sensor is changed. When the corrected timer value tmMON is smaller than a reference time TNOxREF, it is ascertained that deterioration of the NOx purification device has occurred.

Exhaust-gas purification device for internal combustion engine

In order to prevent degradation of an operational mode and a fuel consumption of an internal combustion engine at the time when raising the temperature of a catalyst poisoned NOx absorbent for removing the accumulated sulfur compounds, an exhaust purifying apparatus is provided in an exhaust pipe connected to an internal combustion engine The exhaust purifying apparatus comprises an air-fuel ratio controlling device for controlling the air-fuel ratio, and a fuel feeder for feeding fuel upstream of said nitrogen oxide absorbent; a temperature raising device for raising the temperature of the nitrogen oxide absorbent by feeding fuel by means of said fuel feeder, when the absorbing capability of the nitrogen oxide absorbent is catalyst poisoned by the accumulated sulfur compounds; and a restoring device for restoring the nitrogen oxide absorbing capability of said nitrogen oxide absorbent by controlling the air-fuel ratio so as to be made richer than the stoichiometric air-fuel ratio by said air-fuel ratio controlling device.

Exhaust purifying apparatus for internal combustion engine

A system for purifying exhaust gas of an internal combustion engine having a NOx reduction catalyst (NOx absorber) installed in the exhaust system of the engine which absorbs NOx in the exhaust gas generated by the engine in a lean environment where a lean fuel mixture is supplied and desorbs to reduce the absorbed NOx in a rich environment where a rich mixture is supplied. In the system, the rich fuel mixture is supplied for a period immediately before cutoff. With the arrangement, the NOx reduction catalyst desorbs the absorbed NOx and is regenerated to absorb NOx sufficiently. At the same time, the NOx reduction catalyst is regenerated from sulfur poisoning, thereby preventing the NOx purification efficiency from being degraded.

Growing community of inventors

Wako, Japan

Hiroshi Oono