Hitachi, Ltd.

Miho Saito

Hisashi Takahashi

Katsuhiko Yuura

Shoichi Kubo

Yuichi Mashita

Toshio Ogawa

Akira Kato

Osamu Kuroda

Hiroshi Miyadera

Takahiro Tachi

Noriko Watanabe

On a computer, components forming a development subject are arranged on a scenario editor by using basic component parts, and the component data are set. And a procedure call sequence is defined by specifying procedures of defined components in order of call. The call sequence data is generated in the computer as scenario data. Then, the defined group of scenarios are selected and reflected on the model editor. A whole requirement is created. At that time, a procedure name to be called subsequently on the connection line between components is acquired from the defined procedure sequence data, and a program for effecting animation is generated. Finally, by executing the generated animation program, the procedure call sequence is displayed in an animation form and the requirement is created. By interactive operation alone of the screen using the scenario editor and the model editor, therefore, the requirement of the development subject from the customer can be easily acquired and the whole requirement can be created.

Method for inputting and acquiring requirement

An apparatus is provided for purifying an exhaust gas discharged from an internal combustion engine, which comprises a first exhaust gas passage including a nitrogen oxide removing catalyst and a three way catalyst, a second exhaust gas passage including the three way catalyst, a gas flow regulator for selectively directing the exhaust gas to the first and second exhaust gas passages, and a control unit which directs the exhaust gas to the first exhaust gas passage (thereby passing exhaust gas first through the nitrogen oxide removing catalyst and thereafter through the three way catalyst) when the temperature of the nitrogen oxide removing catalyst is within a hydrocarbon adsorbing range of temperature thereof while the engine is warming up, and to the second exhaust gas passage (thereby passing the exhaust gas only through the three way catalyst) when the temperature of the nitrogen oxide removing catalyst exceeds the hydrocarbon adsorbing range of temperature thereof.

Exhaust gas purifying apparatus and method for internal combustion engine

Growing community of inventors

Sagamihara, Japan

Miho Saito